Tertiary ostracods of Gebel Withr, southwestern Sinai, Egypt: pal˦ontology, biostratigraphy and pal˦obiogeography

Journal

of African

Earth Snences.

Vol. 31, No. 2, pp 285-315, 2000 o 2000 Elsewer Soence Ltd All rights reserved. Printed I” Great Brttam 069%X362/00 $- see front matter

Pergamon PII:SO899-5382(00)00091-9

Tertiary

ostracods of Gebel Withr, southwestern palaeontology, biostratigraphy and palaeobiogeography A.

Geology

Department,

Faculty

of Science,

Sinai, Egypt:

SHAHIN* Mansoura

University,

35516

Mansoura,

Egypt

ABSTRACT-The exposed Early Eocene-Early Miocene interval in the study area yields considerable amounts of ostracods. A detailed investigation of the ostracod content has led to the recognition of 79 species and subspecies, five of which are reported as new species. They are Semic ytherura bassiounii, Semic ytherura gammudii, Pterygocythere withrensis, Paracosta reymenti and Cativella bulgi. An attempt to reconstruct a local ostracod biozonation has led to the recognition of six biostratigraphical zones. These biozones are arranged from the youngest to the oldest as follows: Leguminocythereis bopaensis-Leguminocythereis bicostata Assemblage Zone; Reticulina saitoi-Trachyleberis nodosus Assemblage Zone; Asymmetricythere yousefi-Cytherellapiacabucuensis Assemblage Zone; LeguminocythereisafricanaBuntonia faresi Assenblage Zone; and Grinioneis haidingeri-Pokornyella deformis minor Assemblage Zone. The pakeobathymetric estimates for these assemblages reveals a great deal from the inner neritic to the upper bathyal environments. The cosmopolitan distribution of the recorded species proved to be useful for pakeobiogeographic reconstruction. This reveals that there was a direct connection throughout the Tethyan realm and a connection between the Tethyan North Africa and West Africa via the Trans-Saharan Seaway, at least until the end of the Palseocene, through which the migration of benthic organisms had occurred. 0 2000 Elsevier Science Limited. All rights reserved. RESUME-L’intervalle Eocene inferieur-Miocene inferieur expose dans la region etudiee, fournit une quantite considerable d’ostracodes. L’etude detaillee du contenu en ostracodes a permis d’identrfier 79 especes et sous-especes. Cinq d’entre elles sont de nouvelles especes; ce sont : Semic ytherura bassiounii, Semic ytherura gammudii, Pterygoc ythere withrensis, Paracosta reymenti et Cativella bulgi. Une tentative de reconstruction d’une biozonation locale des ostracodes a permis d’etablir six zones biostratigraphiques qui sont, de la plus jeune a la plus vieille, les zones A: Leguminocythereis bopaensi-Leguminocythereis bicostata; Trachyleberis nodosus; Asymmetricythere yousefi-Cytherella piacabucuensis; c ythereis africana-Buntonia faresi; et Grinioneis haidingeri-Pokorn yella L’interpretation paleobathymetrique de ces assemblages indique une d’environnements, depuis le ndritique inferieur jusqu’au bathial superieur. cosmopolite des especes enregistrees s’est averee tres utile pour les paleobiogeographiques. Ces dernieres indiquent qu’il existait une connexion du realm thethysien ainsi qu’une connexion entre I’Afrique du Nord thethysienne de I’Ouest vra des voies maritimes trans-sahariennes au moins jusqu’l la grace auxquelles la migration des organismes benthiques a pu se produire. Science Limited. All rights reserved. (Received

86198:

revised

version

received

17/6/00:

accepted

Reticulina saitoiLeguminodeformis minor. grande variete La distribution reconstructions directe au travers et I’Afrique fin du Paleocene Q 2000 Elsevier

18/6/00)

l [email protected]

Journal

of African

Earth Sciences

285

A. SHAHIN INTRODUCTION The measured sections in the Gebel Withr area are located just to the north of the entrance of Wadi Feiran, southwestern Sinai, about 60 km to the south of Abu Zeneima. The studied exposure in this area represents a marine interval from the Early Eocene to the Early Miocene. The investigated samples were obtained from the Early Eocene to Early Miocene interval in three neighbouring sections within the study area (Fig. 1). These sections are carefully measured and sampled at intervals ranging from 0.5 m, especially in the shaley facies and soft marls, to 3.0 m in the hard calcareous bands. About 120 samples were collected from this succession for the stratigraphical and fauna1 investigation. Most of these samples, except for the nummulitic and reefal facies, yielded foraminifera, while 25 samples yielded considerable amounts of ostracods (Figs 2 and 3). The studied Tertiary succession includes various types of facies that had led to subdividing it into six formal lithostratigraphical units. Their age determination is based mainly on their planktonic foraminiferal content (Shahin, 1998). They are arranged from base to top as follows: i) Thebes Formation (Early Eocene): only 62 m representing its upper part. It is composed mainly of limestone with chert bands and nodules. iii Samalut Formation (Middle Eocene): 89 m of argillaceous limestone and shale intercalations at the base followed by nummulitic limestone at the top. iX9 Mokattam Formation (Middle Eocene): about 11.5 m of recrystallised nummulitic limestone. iv) Tanka Formation (Late Eocene): 7 m of calcareous shale and shale intercalation. v) Tayiba Formation (Oligocene): 18 m of yellowish, brownish shale and coquinoid limestone at the top. vii Nukhul Formation (Early Miocene): only 29 m representing its lower part is measured and consists mainly of yellowish, sandy and shaley limestone with algal limestone. This Palaeogene-Neogene exposure overlies the Late Cretaceous-Early Tertiary interval that appears eastwards due to the faulting of the area (Fig. 1). Until now, there is no publication on the whole Tertiary ostracods in the study area, or even in Sinai, but there are many published works on the Eocene ostracods in other Egyptian areas. These areas include the Mokattam and Heluan area (Bassiouni, 1969c, 1969d, 1971), the Nile Valley area (Cronin and Khalifa, 1979; Khalifa and Cronin, 1979; Boukhary et al., 1982a, 1982b), the Fayoum area (Bassiouni et al., 1984; Boukhary et a/., 1993), the Shabrawet area (Shamah and Helal, 1993) and the Red Sea Coast (Aref, 1995). On the other hand,

286 Journal

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few publications on the Oligocene and Miocene ostracods of Egypt have appeared. Therefore, this interval needs more attention to delineate the ostracod content. Most of the Egyptian Tertiary ostracod assemblages are compared with those recorded in the Eocene of Jordan (Bassiouni, 1969a, 1969b, 1970) and Israel (Honigstein et a/., 1991). They are also correlatable with those recorded in the Tertiary sediments of Libya (Salahi, 1966; ElWaer, 1988, 1991, 1992; Gammudi and Keen, 1993; Gammudi, 1996), Tunisia (Said, 1978; Donze et a/., 1982) and Algeria (Grekoff, 1969) to reconstruct the palaeobiogeography of the recorded ostracods. In part, the scope of the present study is to shed some light on the ostracod content, with their biostratigraphy, and to complete the palseobathymetric picture of the studied interval by means of the recorded ostracods. All of the studied material is deposited in the Geology Department, Faculty of Science, Mansoura University, Egypt under the catalogue number SSW.

SYSTEMATIC

PALAONTOLOGY

The close examination of the studied succession proved to be rich in ostracods in some intervals, which had led to the establishment of 79 species and subspecies. They belong to 37 genera and 14 families of the suborders of Platycoprna and Podocopina. Out of them, five are reported as new species. The abbreviations L, H, W in the description of these new species refer to length, height and width. They were identified at the species and subspecies levels and classified according to Benson et a/. (1961) and Hartmann and Puri (1974). The later established genera were classified as proposed by their authors. All the encountered species are SEM photographed and illustrated in four plates, where they are arranged in taxonomic order. Their vertical distributions are given in Figs 2 and 3, where only the samples with ostracods are listed. The recorded species are briefly discussed and arranged alphabetically within the genera and species. Subclass: Ostracoda Latreille, 1806 Order: Podocopida Mueller, 1894 Suborder: Platycopina Sars, 1866 Family: Cytherellidae Sars, 1866 Genus: Cytherella Jones, 1849 Cytberella cf. compressa (Muenster ) (Fig. 4.1) 1830 Cythere compressa Muenster, p. 64 1968 Cytherella compressa (Muenster) - Haskins, p. 252, pl. 1, figs 1-8 1984 Cytherella aff. C. compressa (Muenster) Swain, p. 333, pl. 2, figs 3-4.

Tertiary

Nukhul

Formation

Tayiba

Formation

Tanka

Formation

Mokattam

ostracods

of Gebel

Withr,

Sinai,

4

Egypt

SINAI

n

Formation

Samalut

southwestern

Formation

Thebes

Formation

(upper part)

Thebes

Formation

(lower

part)

Abu Zeneima

Esna Shale Sudr Chalk

28’

f Studied sections

km Figure

7. Location

and

geological

map

of the study

area,

southwestern

Sinai,

Egypt.

Journal

of African

Earth Sciences

287

A. SHAHIN

h~f 0

Limestone Nummulitic

-

LEI -

Shale -.

B

Sandy and arillaceou s limestone

Figure 2. Lithoand blostratigraphy of the Early-Middle Eocene with the vertical distribution of the recorded ostracods in the Gebel Withr area where only the samples with ostracods are fisted. Planktonic foramtniferal blostratigraphy (Shahin, 1998): 1’ Acarrnrna pentacamerata Zone; 2: Acarinrna bullbrookr Zone; 3: Globrgerrnatheka kuglerr/Turborotalra cerroazulensrs pomerolr Zone; 4: Truncorotalordes rohn Zone; 5: Globtgerrnatheka semrrnvoluta Zone; 6: Globrgerma gortanrr/Turborotalra centralrs Zone; 7: Globorotalra oprma oprma Zone; 8: Globrgerrna crperoensrs crperoensrs Zone 5.1.: Barren lnterzone; 9: Globrgerrnordes prrmordrus Zone. Ostracod biostratfgraphy: 7: Legumrnocytherers bopaensisLegumrnocytherers brcostata Assemblage Zone; 2; Retrculrna saltor-Trachyleberrs nodosus Assemblage Zone, 3: Asymmetrrcythere yousefi-Cytherella ptacabucuensrs Assemblage Zone, 4; Legumrnocytherers afrrcana-Catrvella bulge Zone; 6: Grrnroners hardingerr-Pokornyella deformrs manor Zone.

Figure 3. ostracods

Lithoin the

288

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Journal

and study

biostratigraphy area where

Earth Snences

of only

the Middle the samples

Eocene-Early with ostracods

Miocene with the vertical are listed. For b!ozonation,

distribution see the

of caption

the recorded of F/g, 2.

Tertiary

ostracods

of Gebel

Withr,

southwestern

Sinai,

Egypt

mcarla

..................................

l

............... ...............

..................................

...............

.................................. .................................. ..................................

...............

culiba

mokattamensis heluanenslj

Cythenzlla piacabucuensis Bimtoni .4 am~ogonensi~ Cytherella cf harmonensis Pterypythemis withrensis SbudaneUa &in m’angularis Tmchyleb& teiskotensis Acanthccythereir salahii &mtonia tbrtunata

..................................

t. ev

&hizxythere g+raten& Bythocypti mjx&ensii Grim’oneis haidbgeri Aurila soummamensis cln’novaia carinata bkom~lla defbnnh minor Occultacythereis indtincta Semicytherura basbuni: Semic,ytherura gammuciii

Journal

of African

Earth Sciences

289

A. SHAHIN Material: 8 carapaces Occurrence: This species is known from the Bartonian of England (Haskins, 1968; Keen, 1978) and Spain (Swain, 1984). In the present study, it occurs in the Middle and Late Eocene. Cytherek dixoniJones and Sherborn (Fig. 4.2) 1887 Cytherella dixoniJones and Sherborn, n. ser. 3, vol. 4, p. 485; 1989, p. 47, pl. 1, fig. 24 1968 Cytherella dixoni Jones and Sherborn - Haskins, p. 252, pl. 1, figs 9-l 6 1978 Cytherella dixoni Jones and Sherbron - Keen, pl. 1, figs 7-9 Material: 13 carapaces Remarks: The sexual dimorphism is distinct. The male carapace is centrally swollen, whereas the female one is posteriorly swollen. Occurrence: It is known from the Middle Eocene of England ( Jones and Sherborn, 1887; Haskins, 1968; Keen, 1978). In the present study, it occurs in the Middle and Late Eocene. Cythere/la cf. harmoniensis van den Bold (Fig. 4.3) 1960 Cytherella harmoniensis van den Bold, p. 150, pl. 1, fig. 2 a-d 1979 Cytherella harmoniensis van den Bold Neufville, p.138, pl. 1, fig. 2 a-d Material: 7 carapaces Remarks: The male carapace is subovate in lateral view and smooth to weakly punctate, whereas the female one is punctate. Occurrence: This species was originally described from the Late Eocene of Trinidad (van den Bold, 1960) and then reported in the Early Eocene of Brazil (Neufville, 1979). In the present study, it occurs In the Late Eocene.

Cytherella cf. londinensis Jones (Fig. 4.4 and 4.5) 1857 Cytherella londinensis Jones, p. 55, pl. 5, figs 20-22 1978 Cytherella londinensis Jones - Keen, pl. 1, figs l-3 1984 Cytherella cf. londinensis Jones - Swain, p. 334, pl. 1, figs 2-3 Remarks: The ma!e carapace is posteroventrally swollen, while in the female one the swelling lies more posteriorly. The female carapace is similar to that of C, compressa (van Muenster) but differs in having a slightly different outline. Occurrence: This species was recorded in the Middle Eocene of England (Jones, 1857) and Spain (Swain, 1984) and then reported in the Early Eocene of England (Haskins, 1968; Keen, 1978). In the present study, it occurs in the Middle and Late Eocene. Cytherellamuensteri(Roemerj (Fig. 4.6 and 4.7) 1838 CytherinamueneteriRoemer, p. 516, pl. 6, fig. 13 1978 Cytherina mueneteriRoemer - Keen, pl. 1, fig. 6 Material: 12 entlre carapaces and 2 valves Remarks: The male carapace, in the dorsal view, is swollen centrally and the female one is swollen posteriorly. Occurrence: This species is known from the Middle Eocene of England (Keij, 1957; Haskins, 1968; Keen, 1978). In the present study, it occurs in the Middle and Late Eocene. Cytherellapiacabucuensis Neufville (Fig. 4.8 and 4.9) 1979 Cytherellapiacabucuensis Neufville, p. 137, pl. 1, fig. 3 a-d 1990 Cytherellapiacabucuensis Neufville - Bassiouni and Luger, p. 777, pl. 1, figs 7-l 2

Figure 4. (11 Cytherella cf. compressa lvan Munster), lateral view of left valve, x 100, Samalut Formation. 121 Cytherella dlxonr Jones and Sherborn, lateral view of left valve, x 100, Samalut Formation. (3) Cytherella cf. harmoniensls van den Bold, lateral view of right valve, x 75, the upper half of Samalut Formation (4-5) Cytherella cf. londmesls Jones, lateral views of left valves, x 75, x 100, Samalut Formatton. (6-7) Cytherella muensten (Roemer), lateral view of left valve and dorsal view of carapace, x 75, x 75 respectively, Tanka Formation. (8-9) Cytherella placabucuensls Neufville, lateral view of left valve and dorsal wew, x 75, x 75 respectively, Tanka Formation. (101 lsohabrocythere telskotensls Apostolescu, lateral view of left valve, x 75 Tanka Formation. (1 1) Bafrdla cespendensls van den Bold, lateral view of left valve, x50, Tayiba Formatton. (12) Balrdla dollcha van den Bold, lateral view of right valve, x 50, Nukhul Formation. ll314) Balrdla hlwanneensls Howe and Lea, lateral views of right valves, x 50, x 75, Samalut Formation. (151 Balrdla llaroensls Reyment and Reyment, lateral view of right valve, x35, Nukhul Format/on. (16- 17) Balrdoppllata gIlbert Keij, lateral views of right valves, x50, 50, Samalut Formation. (18) Bythocypns tnpollensls Gammudl and Keen, lateral view of right valve, x50, Taylba Formation. (19) Paracypns communes van den Bold, lateral view of left valve, x 75, Tanka Formation. (201 Paracyprrs Jones1 Bonnema, lateral view of right valve, x 100, Tanka Formation. (211 Paracypns nlgenensls Reyment, lateral view of rtgh t valve, x50, Samalut Formation. 1221 Novocypr~s eocenana Ducasse, lateral view of right valve, x50, Samalut Formation. (23-241 Dlsopontocypns schwejen van den Bold, lateral views of right valves, x 100, Tayiba Formation. (2526) Pontocyprella recurva Esker, lateral vtew of right valve and carapace dorsal view, x 50, Samalut Formation. (2 7-281 Cytheropteron boukharyr Khalifa and Cronm, lateral view of right valve and carapace dorsal wew, x 100, Samalut Formation. 1291 Cytheropteron cf. Heteropunctata Guernet and Bassioum, lateral view of right valve, x 150, Thebes Formation. 130) Semlcytherura gammudll n. sp., lateral view of left calve of the holotype, x 100, Nukhul Formation. (31-321 Semicytherura basslounll n. sp. 2, lateral view of left valve of the holotype and carapace dorsal view, x 100, Nukhul Formation. (33-34) Digmocythere lsmalll Basslouni, lateral view of right valve and carapace dorsal view, x 75, Samalut Formation. (35) Pterygocythere cf. P. alata (Bosquetl, carapace dorsal view, x 100, Samalut FormatIon.

290 Journal

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Tertiary

ostracods

of Gebel Withr,

south

western

Sinai,

Egypt

Journal

of Afr/can

Earth Snences

29 1

A. SHAHIN 1991 Cytherellapiacabucuensis Neufville - Honigstein et a/., p. 98, pl. 1, fig. 3 Material: 11 carapaces Remarks: El-Sogher (1996) described his new species Cytherella bassiouni (p. 290, pi. 1, figs 9-l 3, 1617) from the Danian of Libya. This new species is very similar to C. piacabucuensis Neufville except for the orientation of the dorsal depression, which is horizontal in the former one and vertical in the latter one. They could be synonymous. Occurrence: This species was originally described from the Early Palaeocene of Brazil (Neufville, 1979) and then reported in the Middle Palaeocene-Early Eocene of southern Egypt (Bassiouni and Luger, 1990) and Middle Eocene of the Jordan Valley (Honigstein et a/., 1991). The similar species of El-Sogher (1996) was described from the Maastrichtian-Danian of Libya. In the present study, it occurs in the Middle and Late Eocene. Genus: lsohabrocythere Apostolescu, 1961 lsohabrocythere teiskotensis Apostolescu (Fig. 4. IO) 1961 lsohabrocythere teiskotensis Apostolescu, p. 794, pl. 1, figs 15-l 7; pl. 15, figs 297-298 1983 lsohabrocythere teiskotensis Apostolescu Foster et a/., p. 113, pl. 3, figs 1 l-l 3; pl. 8, figs 1-2 1990 lsohabrocythere teiskotensis Apostolescu Bassiouni and Luger, p. 794, pl. 6, figs l-2,4-5,7-8 1996 lsohabrocythere teiskotensis Apostolescu - ElSogher, p. 294, pl. 3, figs 5-9 Material: 3 carapaces Occurrence: This species was originally described from the Late Palseocene of Mali and Ivory Coast (Apostolescu, 1961) and then reported in the Palaeocene of Libya (Barsotti, 1963; Salahi, 1966; ElSogher, 1996). It is also known from the Palaaocene of Nigeria (Reyment and Reyment, 1980; Foster et a/., 1983) and southern Egypt (Bassiouni and Luger, 1990). In the present study, it occurs in the Late Eocene and Late Oligocene. Suborder: Podocopina Sars, 1866 Superfamily: Bairdiacea Sars, 1888 Family: Bairdiidae Sars, 1888 Genus: Bairdia McCoy, 1844 Bairo’ia cespendensis van den Bold (Fig. 4.11) 1946 Bairdia cespendensis van den Bold, p. 73, pl. 4, fig. 8 1979 Bairdia cespendensis van den Bold - Neufville, p. 138, pl. 2, fig.1 a-d 1984 Bairdia cespendensis van den Bold - Steineck et a/., fig. 7, G and I Material: 5 carapaces Remarks: This species is characterised by its highly convex dorsal margin. The male carapace is more

292 Journal

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elongate and the greater width lies just anterior to the centre. Occurrence: This species was first described from the Late Cretaceous of Cuba (van den Bold, 1946) and subsequently from the Eocene, Oligocene and Early Miocene of Trinidad (van den Bold, 1950, 1960). It is also known from the Early Eocene of Brazil (Neufville, 1979) and the Middle Eocene of Barbados in the Caribbean area (Steineck et a/., 1984). In the present study, it occurs ranging from the Middle Eocene to Early Miocene. Bairdia dolicha van den Bold (Fig. 4.12) 1957 Bairdia dolicha van den Bold, p. 5, pl. 2, fig. 2a, b 1979 Bairdia dolicha van den Bold - Neufville, p. 139, pl. 1, fig. 4a, b Material: 5 carapaces Occurrence: This species was originally recorded in the Palaeocene and Middle Eocene of Trinidad (van den Bold, 1957,196O). It is also known from the Early Eocene of Brazil (Neufville, 1979). In the present study, it occurs in the latest Eocene and Early Miocene. Bairdia hiwanneensis Howe and Lea (Fig. 4.13 and 4.14) 1936 Bairdia hiwanneensis Howe and Lea ( in Howe and Law, 19361, p. 27, pl. 2, fig. 9; pl. 3, fig. 1 1979 Bairdia hiwanneensis Howe and Lea - Neufville, p. 140, pl. 2, fig. 4 a, b Material: 5 carapaces Occurrence: This species was first described from the Oligocene of Louisiana (Howe and Law, 1936). It is also known from the Oligo-Miocene of Trinidad (van den Bold, 1957) and the Danian of Brazil (Neufville, 1979). In the present study, it occurs in the Middle Eocene and Early Miocene. Bairdia ilaroensis Reyment and Reyment (Fig. 4.15) 1959 Bairdia ilaroensis Reyment and Reyment, p. 61, pl. 1, figs l-7; text figs 1 a, b, 3 a-m, 5a-h 1981 Bairdia ilaroensis Reyment and Reyment Reyment, p. 56, pl. 9, figs 6-7 1990 Bairdia ilaroensis Reyment and Reyment Bassiouni and Luger, p. 780, pl. 1, fig. 15 1996 Bairdia sp. aff. llaroensis Reyment and Reyment - El-Sogher, p. 295, pl. 4, figs 1-5 Material: 4 carapaces Occurrence: This species was originally described from the Palasocene of Nigeria (Reyment and Reyment, 1959) and subsequently by Foster eta/. (I 983). It is also known from the Maastrichtian of Nigeria (Reyment, 19811, the Maastrichtian-Early Eocene of Egypt (Bassiouni and Luger, 1990; Aref, 1995) and the Danian of Libya (El-Sogher, 1996). In the present study, it occurs in the latest Eocene and Early Miocene.

Tertiary

ostracods

of Gebel

Genus: Bairdoppilata Coryell, Sample and Jennings, 1935 Bairdoppilatagliberti Keij (Fig. 4.16 and 4.17) 1957 Bairdoppilata gliberti Keij, p. 53, pl. 1, figs 1821 1984 Bairdoppilata cf. glibettiKeij - Swain, p. 335, pl. 1, figs 9-l 0 1984 Bairdia glibetti (Keij) - Bassiouni et al., p. 182, pl. 2, fig. 10 1985 Bairdoppilata cf. gliberti Keij - Monostori, p. 33, pl. 1 1, figs 1-9 Material: 4 carapaces Occurrence: This species is known in the Middle Eocene of England (Keen, 19781, Spain (Swain, 1984) and Egypt (Bassiouni et al., 1984). It was also recorded in the Hungarian Eocene (Monostori, 1985). In the present study, it occurs in the Middle and Late Eocene. Family: Bythocyprididae Maddocks, 1969 Genus: Bythocypris Brady, 1880 BythocyPrs tripoL&sis Gammudi and Keen (Fig. 4.18) 1993 Bythocypris tripoliensis Gammudi and Keen, p. 126, pl. 1, figs 4-6 1996 Bythocypris tripoliensis Gammudi and Keen, p. 397, pl. 1, figs 8-9 Material: 3 carapaces Occurrence: It was originally described from the Miocene of Libya (Gammudi and Keen, 1993; Gammudi, 1996). In the present study, it occurs in the Late Oligocene. Superfamily: Cypridacea Baird, 1845 Family: Paracyprididae Sars, 1923 Genus: Paracypris Sars, 1866 Paracypris conmunis van den Bold (Fig. 4.19) 1946 Paracypris communis van den Bold, p. 66, pl. 2, fig. 11 1957 Paracypris communis van den Bold - van den Bold, p. 5, pl. 2, fig. 12 a, b Material: 3 carapaces Occurrence: This species was first recorded in the Palaeocene and Early Eocene of Guatemala and Honduras (van den Bold, 1946) and subsequently in the Palasocene of Trinidad (van den Bold, 1957). In this study, it occurs in the Late Eocene. Paracypris jonesi Bonnema (Fig. 4.20) 1941 ParacyprisjonesiBonnema, p. 115, pl. 3, figs. 24-28 1968 Paracypris jonesiBonnema - Esker, pl. 1, fig. 13 1986 Paracypris cf. jonesiBonnema - Carbonnel, p. 103, pl. 3, fig. 6 1990 Paracypris jonesi Bonnema - Bassiouni and

Withr,

south western

Sinai,

Egypt

Luger, p. 783, pl. 2, figs 9 and 11 Material: 3 carapaces Occurrence: This species was originally described from the Late Cretaceous of Holland (Bonnema, 1941). It is also known in the Danian of Tunisia (Esker, 19681, in the Late Palaeocene of Senegal (Carbonnel, 1986) and the Middle Palseocene-Early Eocene of southern Egypt (Bassiouni and Luger, 1990). In the present study, it occurs in the Late Eocene and Early Miocene. Parac ypris nigeriensis Reyment (Fig. 4.2 I) 1960 Paracypris nigeriensis Reyment, p. 66, pl. 4, fig. 2a, b 1981 Paracypris nigeriensis Reyment - Reyment, pl. 1, fig. 6 1990 Paracypris? nigeriensis Reyment - Bassiouni and Luger, p. 783, pl. 2, figs 13-l 8 1995 Paracypris? nigeriensis Reyment - Honigstein and Rosenfeld, p. 53, pl. 1, fig. 6 Material: 10 carapaces Occurrence: This species was originally recorded in the Maastrichtian-Palaeocene of Nigeria (Reyment, 1960) and subsequently by Reyment (I 981) and Ficarrelli (1976). It is also known in the Palseocene of Israel (Honigstein and Rosenfeld, 1995) and the Early Eocene of southern Egypt (Bassiouni and Luger,1 990). In this study, it occurs in the Middle and Late Eocene. Family: Cyprididae Baird, 1854 Genus: Novocypris Ducasse, 1967 Novocypriseocenana Ducasse (Fig. 4.22) 1967 Novocypris eocenana Ducasse, p. 34, pl. 1, figs 17-18 1984 Novocypris eocenana Ducasse - Bassiouni et al., p. 182, pl. 1, fig. 2 Material: 6 carapaces and 3 valves Remarks: This species is distinguished from N. whitecliffensis (Haskins) in having a less convex dorsal margin. Occurrence: It was first described from the Eocene of North Aquitain, France (Ducasse, 1967). It is also found in the Middle Eocene of Egypt (Bassiouni et al., 1984). In the present study, it occurs in the MiddleLate Eocene and Early Miocene. Subfamily: Disopontocypridinae Mandelstam, 1958 Genus: Disopontocypris Mandelstam, 1958 DisopontocypdsschweJien’van den Bold (Fig. 4.23 and 4.24) 1966 Disopontocypris schwejerivan den Bold, p. 159, pl. 4, fig. 3a, b 1974 Disopontocypris schwejeri van den Bold Coutelle and Yassini, p. 87, pl. 1, figs 2 and 8 1996 Disopontocypris schwejeri van den Bold Gammudi, p. 397, pl. 1, fig. 10

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A. SHAHIN Material: 4 carapaces Occurrence: This species was origrnally reported from the Neogene of Gabon (van den Bold, 1966). It was also found in the Burdigalian of Algeria (Coutelle and Yassini, 1974) and the Miocene of Libya (Gammudr and Keen, 1993; Gammudi, 1996). In the present study, it occurs in the latest Eocene and Late Oligocene. Family: Pontocyprididae Mueller, 1894 Genus: Pontocyprella Lyubimova, 1955 Pontocyprellarecurva Esker (Fig. 4.25 and 4.26) 1968 Pontocyprella recurva Esker, p. 323, pl. 1, figs 6-7 1982 Pontocyprella recurva Esker - Donze et al., p. 281, pl. 2, figs 1-2 1990 Pontocyprella recurva Esker - Bassiounr and Luger, p. 785, pl. 3, fig. 1 Material: 32 entire carapaces and 3 valves Remarks: This species differs from that of Bassiounl and Luger (I 990) in having a less convex ventral margin and a less pointed posterior end. Occurrence: It was reported from the MaastrichtianEarly Palaaocene of Tunisia (Esker, 1968; Donze et al., 1982). It was also found in the Mlddle and Late Palaaocene of southern Egypt (Bassiouni and Luger, 1990) and the Bartonian of Spain (Swain, 1984). In the present study, it occurs in the Early and Middle Eocene. Superfamily: Cytheracea Baird, 1850 Family: Cytheruridae Mueller, 1894 Genus: Cytheropteron Sars, 1866 Cytheropteron boukharyi Khalifa and Cronin (Fig. 4.27 and 4.28) 1979 Cytheropteron boukharyi Khalifa and Cronin, p. 1 13, pl. 2, figs 17-21 199 1 Cytheropteron boukharyi Khalifa and Cronln Honigstein eta/., p. 102, pl. 2, fig. 3 Material: 33 carapaces Occurrence: This species was originally described from the Middle Eocene of Egypt (Khallfa and Cronin, 1979) and Jordan Valley (Honigsteln et al., 1991). In this study, it occurs ranging from to Late Eocene. Cytheropteron heteropunctata Guernet and Bassiouni (Fig. 4.29) 1993 Cytheropteron heteropunctata Guernet and Basslouni, p. 208, pl. 5, figs 5-7 Material: 8 carapaces Remarks: This species is similar to C. liogluma Munsey illustrated by van den Bold (1957, pl. 4, fig. 5) from the Palaaocene of Trinidad but differs In having a less convex dorsal margin and a less pointed posterior end.

294 Journal

of African

Earth Sciences

Occurrence: It was originally recorded in the Middle Eocene of the Fayoum district, Egypt (Boukhary et al., 1993) and consequently in the Early and Late Eocene of the study area. Genus: Semicytherura Wagner, 1957 Semicytheruragammudiin. sp. (Fig. 4.30) 1996 Semicytherura sp. Gammudi, p. 402, pl. 3, fig. 3 Derivation of Name: It was derived from Amar Gammudi who first recognised a similar species in the Libyan Miocene sediments. Diagnosis: It is a coarse, reticulate species of the genus Semicytherura with a short caudal process. The longitudinal walls are hidden within the reticulation. Material: 3 entire carapaces and some fragments Holotype: Figured specimen, SSWI Dimensions: L 0.49 mm, H 0.23 mm, W 0.23 mm Type locality and horizon: Early Miocene Nukhul Formation In Gebel Wlthr, southwestern Sinai, Egypt Description: The test is subrectangular in a lateral view. The dorsal and ventral margins are slightly concave to straight. The maximum height at the anterior is one third of the carpace. The anterior margin is rounded. The posterior margin IS pointed with a short caudal process. The surface is reticulate with longitudinal faint nb-like marks. The posterior alar prolongation is pronounced. Occurrence: It is found in the Early Miocene Nukhul Formation. The similar forms of Gammudi (1996) are also found in the Miocene of Libya. Semicytherura bassiounin. sp. (Fig. 4.31 and 4.32) Derivation of name: It was named in honor of Prof. M.A. Basslouni, Aln Shams University, the Egyptian pioneer of Ostracoda. Diagnosis: A fine reticulate species with longitudinal walls of reticulation forming faint ribs and sulcus in the centrodorsal area Material: 6 entire carapaces Holotype: Figured carapace, SSW2 Dimensions: L 0.44 mm, H 0.22 mm, W 0.22 mm Type locality and horizon: Early Miocene Nukhul Formation, Gebel Withr, southwestern Sinai, Egypt Description: The carapace is subrectangular in the lateral view. The maximum height at the anterior is one third of the carapace. The anterior margin is broadly rounded. The posterior margin is pointed with a short caudal process. The right valve is slightly larger than the left valve. The dorsal margin is concave in the middle. The ventral margin is slightly convex. The eye tubercle is Indistinct. The surface is finely reticulate with longitudinal ribs that seem to be stronger than the reticulation. The distinct centrodorsal sulcus extends vertically from the centre to the

Tertiary

ostracods

of Gebel

Withr,

dorsal margin. The ventral rib extends ventrolaterally towards the posterior to form a prominent posterior alar prolongation. Remarks: This species is differentiated from the Semicytherura sp. in haiving finer reticulation and more distinct longitudinal ribs. Occurrence: It occurs in the Early Miocene Nukhul Formation. Family: Brachycytheridae Puri, 1954 Subfamily: Brachycytherinae Puri, 1954 Genus: Digmocythere Mandelstam, 1958 Digmocythere ismaii!i Bassiouni (Fig. 4.33 and 4.34) 197 1 Brach ycythere (Digmocythere) ismaili Bassiouni, p. 170, pl. 7, figs 5-6 199 1 Brachycythere (Digmocythere) ismaili Bassiouni - Honigstein et a/., p. 104, pl. 2, fig. 6 1993 Brachycythere?ismai/i Bassiouni - Boukhary eta/., p. 202, pl. 4, fig. 1 Material: 41 carapaces Remarks: The male carapace is longer and thinner than the female one, which is stubby and rounded. Occurrence: This species was originally described from the Middle and Late Eocene of Egypt (Bassiouni, 1971) and subsequently from the Middle Eocene of the Jordan Valley (Honigstein et a/., 1991) and the Fayoum area, Egypt (Bassiouni et a/., 1984; Boukhary et a/., 19931, as well as the Shabrawet area, Egypt (Shamah and Helal, 1993). In the present study, it occurs ranging from the Early to Late Eocene. Subfamily: Pterygocytherinae Puri, 1957 Genus: Pterygocythere Hill, 1954 Rerygocythere cf. alata (Bosquet) (Fig. 4.35) 1847 Cypridina alata Bosquet 1961 Pterygocythere alata (Bosquet) - Benson et a/., p. 267, fig. 190 no. 3 Material: 5 carapaces Remarks: This species is similar to the original one but differs in having less prominent alae that are situated closer to the centre and in having a less pointed posterior end. Occurrence: It was reported in the Maastrichtian (Benson et a/., 1961) and in the Middle and Late Eocene of the present study. Prerygocythere withrensis n. sp. (Fig. 5.1 and 5.2) Derivation of name: It is named after Gebel Withr, southwestern Sinai, the type locality of this new species. Diagnosis: Carapace with a strong pointed ventrolateral alae and a prominent dorsal spine Material: 8 carapaces Holotype: figured specimens, SSW3 Dimensions: L 0.45 mm, H 0.22 mm, W 0.26 mm

south western

Sinai,

Egypt

Type locality and horizon: Late Eocene Tanka Formation, Gebel Withr, southwestern Sinai, Egypt Description: The carapace is ovoid to elliptical. The anterior margin is symmetrically rounded. The posterior margin is narrowly rounded with two small denticles in the posteroventral portion. The dorsal margin is nearly straight. The ventral margin is curved. The surface is smooth. The wing-like protrusion extends as a ridge from the weak eye spot, near the anteroventral area, to the posterior one third as a wing partially overlaps the posteroventral margin. The dorsal view is nearly arrow-shaped. Remarks: This species is similar to P. jonesi (Mehes) described by Monstori (I 985, p. 73, pl. 8, figs 6-9) from the Hungarian Eocene, but differs in lacking the anterior and posterior marginal denticulation and in the shape of the ventrolateral alae. It is also similar to Pterygocythereis sp. of Honigstein et a/. (I 991, pl. 2, figs I-21, but differs in having a more convex dorsal margin, a less convex ventral margin and lacking a faint reticulation. Alatacythere AUR described by Grekoff (1969) from the Algerian Late Coniacian seems to be morphologically identical to this species, but differs in the stratigraphical position. Occurrence: It occurs in this study in the Middle and Late Eocene. Family: Leguminocythereididae Howe, 1961 Genus: Leguminocythereis Howe, 1936 L eguminocythereis africana Bassiouni (Fig. 5.3) 1969 Leguminocythereis africana Bassiouni, p. 223, pl. 21,figs4and6 1979 Leguminocythereis africana Bassiouni - Cronin and Khalifa, p. 404, pl. 1, fig. 25 1984 Leguminocythereis africana Bassiouni Bassiouni et a/., p. 186, pl. 1, fig. 6 Material: 7 carapaces Occurrence: This species was originally described from the Late Eocene of Egypt (Bassiouni, 1969d) and subsequently by Cronin and Khalifa (I 979). It was also known in the Middle Eocene of Egypt (Bassiouni et a/., 1984). In the present study, it occurs in the Late Eocene. Leguminocythereis bicostata Haskins (Fig. 5.4 and 5.5) 1970 Leguminocythereis bicostata Haskins, p. 823, pl. 10, figs 184-185 1978 Leguminocythereis bicostata Haskins - Keen, pl. 9, figs 4 and 6 Material: 7 carapaces Occurrence: This species was first recorded in the Early Eocene of England (Haskins, 1970; Keen, 1978). In the present study, it occurs in the Early and Middle Eocene.

Journal

of African

Earth Sciences

295

A. SHAHIN Lqpm~ocythetWIsbopaen~ (Apostolescu) (Fig. 5.65.9) 1961 Anticytherekz bopaensis bopaensis Apostolescu, p. 815, pl. 10, figs 197-205 1969 Anticythereis cf. bopaensis Apostolescu Grekoff, p, 246, pl. 3, fig. 48 1983 Leguminocythereis bopaensis Apostolescu - Foster et a/., p. 1 15, pl. 4, figs 9-14; pl. 4, figs l-2 Material: 52 entire carapaces and 11 valves Occurrence: This species was originally described from the Late Palaaocene of Benin and the Ivory Coast (Apostolescu, 1961). It was also known in the Late Palaeocene of Libya (Barsotti, 1963; Reyment and Reyment, 1980) and Nigeria (Reyment, 1963; Foster et a/., 1983). It was also reported from the Early Eocene of Algeria (Grekoff, 1969). In the present study, it occurs ranging from the Early to Late Eocene. Leguminocythereis cance//osa Haskins (Fig. 5.10) 1970 Leguminocythereis cancellosa Haskins, p. 21, pl. 3, figs l-6 Material: 6 carapaces Occurrence: This species was recorded in the European Tertiary deposits (Haskins, 1970) and in the Middle Eocene of the study area. Leguminocythereiis exigua (Apostolescul (Fig. 5.11) 1961 Anticythereis exigua Apostolescu, p. 815, pl. 10, figs 194- 196 1969 Anticythereis ex. gr. exigua Apostolescu Grekoff, p. 246, pl. 3, fig. 46 1982 Leguminocythereis? Aff. exigua (Apostolescu) - Donze ef a/., p. 296, pl. 12, figs 4-5 Material: 6 entire carapaces and 1 valve Occurrence: This species was originally described from the Late Palaeocene of the Ivory Coast (Apostolescu,

1961). Eocene et

a/.,

Middle

It was also known in the Palaeocene to Early of Algeria (Grekoff, 1969) and Tunisia (Donze 1982). In the present study, it occurs in the Eocene.

Leguminocythereis lokossaensis Apostolescu (Fig. 5.13and 5.14) 196 1 Leguminocythereis lokossaensis Apostolescu, p. 823, pl. 10, figs 184-l 86 1966 Leguminocythereis lokossaensis Apostolescu - Salahi, p. 16, pl. 4, figs 15-l 7 1986 Leguminocythereis lokossaensis Apostolescu - Carbonnel, p. 87, pl. 3, figs 1-3 1990 Leguminocythereis lokossaensis Apostolescu - Bassiouni and Luger, p-792, pl. 5, figs 3-8 Material: 6 carapaces Occurrence: This species was originally recorded in the Late Palaaocene and Early Eocene of Togo (Apostolescu, 1961). It was also known from the Late Palaeocene of Senegal (Carbonnel, 19861, the Early Eocene of Libya (Barsotti, 1963; Salahi, 1966) and the Late Palaaocene to Early Eocene of southern Egypt (Bassiouni and Luger, 1990). In the present study, this species occurs in the Middle Eocene. Leguminocythereis oertli Keij (Fig. 5.12) 1958 Leuminocythereis oert/iKeij, p. 70, pl. 1, figs l-3 1978 Leuminocythereis oertliKeij - Keen, pl. 9, figs 2 and 5 Material: 7 carapaces Occurrence: This species was originally described from the Lutetian of France (Keij, 1957) and subsequently from the Middle Eocene of England (Haskins, 1970; Keen, 1978). In the present study, it occurs in the Late Eocene.

Figure 5. 11-21 Pterygocytherers wrthrensis n. sp., lateral view of left valve of the holotype and carapace dorsal vrew, x 100, Tanka Formation. 13) Legumrnocythereis afncana Bassrouni, lateral view of nght valve, x 75, Tankka Formation. (45) Leguminocythereis bicostata Haskins, lateral view of left valve and carapace dorsal view, x 75, Samalut Formatron. 1691 Legumrnocythereis bopaensis IApostolescuJ; 6 and 7 dorsal view of female and male carapaces, x 100, x 75, respectively; 8 and 9 lateral views of the same left valve, x 75, x 70, respectively, Samalut Formation. /IO/ Leguminocytherers cancellosa Haskins, lateral veiw of left valve, x 75, Samalut Formation. (1 1) Legumrnocythereis exrgua IApostolescuJ, lateral view of left valve, x 75, Samalut Formation. (12-13) Legumrnocytherers lokossaensrs Apostolescu, lateral view of right valve and dorsal view of female carapace, x 75, Samalut Formation. (141 Leguminocytherers oertlr Kerj, lateral view of left valve, x 100, Tanka Formation. (15) Nucleollna tatteulrensls (Apostolescul, lateral vrew of left valve, x 75, Tanka Formation. 116) Aurila soummamensis Coutelle andYassmi, lateral view of left valve, x 75, Nukhul Formation. (I 7) Pokornyella deformrs minor (MoyesJ, lateral view of right valve, x 75, Nukhul Formation. /I81 Loxoconcha cf. L. alata Athersuch, lateral view of left valve, x 100, Samalut Formation. (19-2 1) Loxoconcha blanckenhornr Bassiouni and Luger, lateral views of right, left and right valves, respectively, x 100, Tanka Formation. (22) Loxoconcha mataensrs Khalifa and Cronin, lateral view of left valve, X 100, Samalut Formation. (231 Loxoconcha ex. gr. ovulata (Costa), lateral vrew of left valve, x 100, Tanka Formation. 124-25) Loxoconcha pseudopunctatella Cronin and Khalrfa, lateral views of male and female right valves, x 100, Samalut Formation. (26-271 Loxoconcha punctatella Reuss, lateral views of male and femalright valves, x 75, Samalut Formation. (28) Loxoconcha saharaensis Bassiouni and Luger, lateral vrew of right valve, x 150, Tanka Formation. (29) Schrzocythere gujaratensls Guha, lateral view of left valve, x 100, Tanka Formation. 1301 Acanthocytherers prolecta Bassiounr, lateral view of left valve, X 75, Samalut formation. 1311 Acanthocytherers salahrr Bassrount, lateral view of left valve, x 75, Tanka Formation.

296 Journal

of African

Earth Saences

Tertiary

ostracods

of Gebel

Withr,

southwestern

Sinai,

Egypt

Journal

of Ahcan

Earth Snences

297

A. SHAHIN Genus: Nucleolina Apostolescu and Deroo, 1966 Nuc/eo/ina tatteuliensis (Apostolescu 1 (Fig. 5.15) 1961 Ambocythere? tatteuliensis Apostolescu, p. 814, pl. 9, figs 175-l 79; pl. 15, fig. 300 1983 Buntonia tatteuliensis (Apostolescu) - Foster et al., p. 132, pl. 7, figs 4-5 1990 Nucleolina tatteuliensis (Apostolescu) Bassiouni and Luger, p. 793, pi. 5, figs 9-l 1 1996 Buntonia tatteulrensis (Apostolescu) - El-Sogher, p. 307, pl. 13, figs 5-8 Material: 3 entire carapaces and some fragments Remarks: Both Reyment (I 981) and Foster et al. (1983) noticed the existence of two forms of ornamentation in this species. However, Bassiouni and Luger (1990) referred to the existence of only one form bearing long faint nblets on the surface. In the present material, the recorded form has sinuous longitudinal ribs and pitted rntercostal areas very similar to those figured by Foster et al. (I 983, pt. 5, figs 3, 5 and 9) and matches well with the nbbed variants of Reyment (1981). This species is distinguished from Soudanella laciniosa laciniosa Apostolescu by its sinuous longitudinal ribs and pitted intercostal areas. Occurrence: It was ongrnally described from the Late Palaaocene of Mali (Apostolescu, 1961). It was also known in the PalEocene of Nigeria (Reyment, 1981; Foster et al., 19831, Libya (Barsottr, 1963; El-Sogher, 1996) and the Late Palaaocene(?) or basal Eocene of southern Egypt (Bassiounr and Luger, 1990). In the present study, it occurs in the Late Eocene. Genus: Aurila Pokorny, 1955 AunTa soummamensis Coutelle and Yassini (Fig. 5.16) 1974 Aurila soummamensis Coutelle and Yassrni, p. 93, pl. 1, figs 1 O-l 1, 13-l 4 and 17; pl. 3, fig. 11 1979 Aurila soummamensis Coutelle and Yassrni Bassiouni, p. 123, pl. 20, figs 12-l 5 1993 Aurila soummamensis Coutelle and Yassini Gammudi and Keen, p. 131, pl. 3, figs 1-3 Material: 3 carapaces Occurrence: This species was ortgrnally recorded In the Early Miocene of Algeria (Coutelle and Yassrnr, 1974). It was also known from the Early Miocene of Turkey (Bassiouni, 1979; Gokcen, 1984) and Libya (Gammudi and Keen, 1993). In this study, It occurs also in the Early Miocene. Genus: Pokornyella Oertli, 1956 Pokornyela deformis minor (Moyes) (Fig. 5.17) 1965 Pokornyella deformis minor Moyes, p. 99, pl. 13, figs 1-4 1979 Hemicythere deformis minor Moyes Bassiounr, p. 112, pl. 19, figs 18-21

298 Journal

of African

Earth Soences

1993 Hemicythere deformis minor Moyes - Gammudi and Keen, p. 132, pl. 3, figs 7-9 Material: 3 carapaces Remarks: This species is similar to P. tumescens Ducasse described by Monstori (I 985, pl. 9, figs 1320; pl. 10, figs I-6) from the Hungarian Eocene, especially In the general outline, the concave posterodorsal margin and the protruded posterior end. However, the species herein has a course reticulation that may be considered an ecological character. Occurrence: It was originally described from the Early Miocene of the Aquitarn Basin, France (Moyes, 1965). It was also known from the Early Miocene of Turkey (Bassrouni, 1979) and Libya (Gammudi and Keen, 1993). In the present study, it occurs in the Early Miocene. Family: Loxoconchidae Sars, 1925 Genus: Loxoconcha Sars, 1866 Loxoconcha cf. alata Athersuch (Fig. 5.18) 1996 Loxoconcha cf. Alata Athersuch - Gamudi, p. 405, pl. 4, fig. 4 Material: 13 carapaces Diagnosis: The carapace is ovate. The anterior margin is rounded. The posterior margin is narrowly rounded. The dorsal margin is slightly convex. The ventral margin is more convex due to the ventrolateral alae. The surface IS reticulate. Remarks: This species IS similar to the original one but differs in havrng more tapering antenor and posterior margins and a concentric reticulation. It is also diferentiated from L.gr. L. alata Athersuch described from the Libyan Middle Miocene (Gammudi, 1996) by having a less convex dorsal margin and a more concentric reticulation. Occurrence: It was reported in the Early to Middle Miocene of Libya (Gammudi, 1996). In this study, it occurs ranging from Early to Late Eocene. Loxoconcha blanckenhorniBassiouni and Luger (Fig. 5.19-5.21) 1990 Loxoconcha blanckenhorni Bassiouni and Luger, p.808,pl. 10,flgs10-11,13-14 Material: 14 carapaces Remarks: The male carapace is longer and thinner than the female one. Occurrence: It was found in the Early Eocene of southern Egypt (Bassiouni and Luger, 1990). In this study, it occurs ranging from the Early to Late Eocene. Loxoconcha mataensis Khalifa and Cronin (Fig. 5.22) 1979 Loxoconcha mataensis Khalifa and Cronrn, p. 179, pl. 1, figs 21-22 Material: 9 carapaces Remarks: The more plump ventrolateral area of this

Tertiary

ostracods

of Gebel

Withr,

species, than the original one, may be due to sexual drmorphism variations. Occurrence: It was reported In the Middle Eocene of Upper Egypt (Khalifa and Cronrn, 1979). It also occurs in the Middle Eocene In this study. Loxoconcha ex. gr. ovulata (Costa) (Fig. 5.23) 1853 Cytherina ovulata Costa, p. 177, fig. 7 1984 L oxoconcha gr. ovulata (Costa) - Bonaduce and Russo, p. 434, pl. 5, fig. 9 1996 Loxoconcha gr. ovulata (Costa) - Gammudr, p. 405, pl. 4, fig. 3 Material: 5 carapaces Remarks: This species is characterised by a concentrrc surface retrculation that is coarser in the ventrolateral alae. Occurrence: It was reported in the Late Miocene of central-western Sardinia (Bonaduce and Russo, 1984) and the Early to Middle Miocene of Libya (Gammudi and Keen, 1993; Gammudi, 1996). In the present study, It occurs ranging from the Late Eocene to Early Miocene. Loxoconcha pseudopunctami’a Cronin and Khalifa (Fig. 5.24 and 5.25) 1979 Loxoconcha pseudopunctatella Cronin and Khalifa, p. 408, pl. 2, figs 22-24 1984 Loxoconcha pseudopunctatella Cronrn and Khalifa - Bassiounr et a/., p. 186, pl. 2, figs 1 l-l 2 Material: 31 carapaces Occurrence: This species was ongrnally described from the Late Eocene of Gebel El-Merier, Nile Valley, Egypt (Cronin and Khalifa, 1979). It was also reported in the Middle Eocene of the Mokattam area, Egypt (Bassrouni et a/., 1984). In the study area, it occurs In the Early and Middle Eocene. Loxoconchapunctatella (Reuss) (Fig. 5.26 and 5.27) 1850 Cypridinapunctatella Reuss, p. 65, pl. 9, fig. 15 1955 Loxoconchapunctatella (Reuss) - Keij et a/., p. 132, pl. 20, figs 7-8 1996 Loxoconchapunctatella (Reuss) - Gammudi, p. 404, pl. 3, fig. 4 Material: 7 carapaces Occurrence: This species was recorded in the Ostrean Tertiary (Reuss, 1850). It was also reported in the Miocene of Libya (El-Waer, 1991; Gammudi, 1996) and France (Keij et a/., 1955). In the present study, it occurs in the Middle and Late Eocene. Loxoconcha saharaensis Bassiouni and Luger (Fig. 5.28) 1990 Loxoconcha saharaensis Bassrouni and Luger, p. 809, pl. 10, figs 12, 15-l 8

south western

Sinai,

Egypt

Material: 11 carapaces Remarks: L. sp. 1 of Salahr (1966) seems to be the same as this species and is considered here as synonymous. The male carapace IS longer and thinner than the female one. Occurrence: It was first recorded in the Late Palseocene of southern Egypt (Bassiounr and Luger, 1990). In the present study, It occurs in the Middle and Late Eocene. The similar species of Salahi (1966) was known in the Early(?) Palaeocene of Libya. Genus: Schizocythere Schizocytheregujaratensis Guha (Fig. 5.29) 1968 Schizocythere gujaratensis Guha, p. 84, pl. 1, figsll-14, 16and20 1981 Schizocythere gujaratensis Guha - Siddiqui, p. 235, pl. 18.2, figs 5-l 2 1996 Schizocythere gujaratensis Guha - Bassiouni and Luger, p. 58, pl. 21, fig. 14 Material: 3 carapaces Occurrence: This species was described from the Middle Eocene of Kuch, India (Guha, 19681, and Pakistan (Srddrqui, 1981). It was also recorded in Somalia (Bassiouni and Luger, 1996). In the present study, it occurs in the Late Eocene. Family: Trachyleberidrdae Sylvester-Bradly, 1948 Subfamily: Trachylebendrnae Sylvester-Bradly, 1948 Genus: Acanthocythereis Howe, 1963 Acanthocythereis projecta Bassiouni (Fig. 5.30) 1969c Acanthocythereisprojecta Bassrouni, p. 391, pl. 25, figs 5-6 1993 Acanthocythereis projecta Bassrouni Boukhary et al., p. 198, pl. 1, figs 7-8 Material: 3 carapaces Remarks: This species IS similar to A. reticulospinosa (van den Bold) and A. hystrix (Reuss) and A. spinosa (Lrenrnklaus) but differs in having prominent eye tubercles, coarse reticulatron and protruded marginal spines. Occurrence: It was recorded in the Middle Eocene of Egypt (Bassrouni, 1969c; Boukhary et a/., 1993), and in the present study, it occurs in the Middle Eocene. Acanthocythereis salahii Bassiouni (Fig. 5.3 I) 1969c Acanthocythereis sa/ahiiBassiouni, p. 389, pl. 25, figs 1-2 1981 Acanthocythereis salahii Bassiounr - Mechm&he, p. 48, pl. 2, figs 5-l 0 1993 Acanthocythereis salahii Bassrouni - Boukhary et a/., p. 198, pl. 1, figs 5-6 Material: 4 carapaces Occurrence: This species was recorded in the Late Eocene of Egypt (Bassiouni, 1969c) and the Middle Eocene of Egypt (Boukhary et a/., 1993). In this study, it occurs In the Middle and Late Eocene.

Jownal

of African

Earth Soences

299

A. SHAHIN Genus: Carinovala Srssrngh, 1973 Carinovala carinata (Moyes) (Fig. 6.1) 1965 Ruggleria carinata Moyes, p. 91, pl. 11, figs IO-12 1988 Carinovala carinata (Moyes) - El-Waer, p. 51, pl. 1, fig. 12; pl. 2, figs I-2 1996 Carinovala carinata (Moyes) ~ Gammudr, p. 407, pl. 4, fig. 11 Material: 3 carapaces Occurrence: This species was ongrnally reported In the Late Miocene of the Aqurtarn Basin, France (Moyes, 1965). It was also recorded In the Late Miocene of northwest Lrbya (El-Waer, 1988) and the Middle Miocene of Libya (Gammudr and Keen, 1993; Gammudr, 1996). In the present study, It occurs In the Early Miocene. Genus: Catwella Corryel and Fields, 1973 Cativellabulgin. sp. (Fig. 6.2 and 6.3) Derivation of name: The name IS derived from the swellrng and plumping of the carapace. Diagnosis: A smooth, plump large-srzed ovoid species of Cativella with three longrtudrnal ribs. Material: 10 carapaces Holotype: Figured specimens, SSW4 Dimensions: L 0.50 mm, H 0.29 mm, W 0.30 mm Type locality and horizon: Late Eocene, Tanka Formation of Gebel Wrthr, southwestern Srnar, Egypt Description: The carapace IS large, plump and ovoid to subquadrate laterally, and ellrptrcal and plump In the dorsal view. The dorsal margin IS nearly straight, inclined downward to the posterior end. The ventral margin convex. The anterior margin IS strongly rnclrned towards the rear and broadly rounded. The posterior margin IS narrowly rounded. The maxrmum herght IS in the first third of the anterior portion. The maxrmum wrdth IS In the central line. The surface IS smooth with three longrtudrnal ribs and faint crossrng riblets In between. The median ridge IS nearly diagonal. The ventral ridge parallels the ventral margin and turned

upward postenoriy. The dorsal ridge runs parallel to the dorsal margin. The eye tubercle is faintly promrnent. Remarks: Thts species IS differentiated from Cativella qurnensis Bassrounr by having a plump large-sized but shorter ovoid carapace, a less pointed posterior end and a convex ventral margin. Cativella ducassae (Bassrounr et al.) differs from this species in having a longer and thinner carapace, more tapering posterior end and In being hexagonal with parallel sides In the dorsal view. Occurrence: It IS found in the Late Eocene Tanka Formatron. Cativella ducassae (Bassiouni et al.) (Fig. 6.4-6.6) 1984 Costa ducassae Bassrouni et al., p. 182, pl. 1, figs 12aab Material: 16 carapaces Remarks: This species IS very similar to Cythereis deltaensis Reyment In the general outline but differs In having a hexagonal dorsal view and less denticulate anterior and posterior margins. Bajacythere bajaensis n. sp. described by Carreno and Cronrn (1993) from the Middle Eocene of Mexico IS very similar to this species but differs In having small, deep pits in a pollshed surface and more dentrculate anterior and posterior margins. The recorded species is also differentiated from Cythereis humboldtl (Bassrounr, 1969c, pl. 27, figs 5-6) In the absence of the depression In the anterior part of the median ridge and the lacking of the transverse nblets between the longitudinal ribs. Occurrence: It was ongrnally recorded In the Middle Eocene of the Fayoum area, Egypt (Bassiouni et a/., 1984). The previous srmrlar forms were also descrrbed from the Middle Eocene. In this study, it occurs in the Late Eocene. Cativella qurnensis Bassiuouni (Fig. 6.7 and 6.8) 1969b Cativella qurnensis Bassiounr, p. 398, pl. 27, figs 8a-c

Figure 6. (11 Carlnovala carlnata (Moves), lateral vrew of left valve, x 75, Nukhul Formatron (2-31 Catwella bulge n.sp. lateral vrew of left valve of the holotype and carapace dorsal vrew, x 75, Tanka Formatron (4-61 Catwella ducassae Bassrouni et al , lateral vrews of left and right valves and carapace dorsal vrew, x 75, Tanka Formatron (7-8) Catwella qurnensls (BassrounrJ, lateral vrew of left valve and carapace dorsal vrew, x 75, Tanka Format/on. /9- 101 Costa praetncostata Bassrouni, lateral vrew of left valve and carapace dorsal vrew, x 75, Samalut Formation. (7 l-131 Gnnlonels haldlngen (Reussl, lateral vrew of left valve and dorsal vrews of the same carapace, x 75, x 70, respectively, Tay:ba Formation. (74) Gnnlonels rnoos~ (Bassrounr), lateral vrew of left valve, x 75, Samalut Formatron. (15) Grlnotnels paljenborchlanus (Kerjl, lateral vrew of left valve, x 75, Samalut Formatron 116- 17) Gerocythere celata Al Furarh, lateral vrew of rtght valve and carapace dorsal view, x 100, Samalut Formatron (18-191 Occultocytherels IndIstIncta Srddrqur, lateral vrew of left valve and carapace dorsal vrew, x 100, Nukhul Formatron. (201 Paracosta bensonl (Damotte and Donze), lateral vrew of right valve, x 100, Samalut Formation (21-22) Paracosta mokattamensls (Bassrounr), lateral vrew of left valve and carapace dorsal vrew, x 75, Samalut Formatron. 123-241 Paracosta parakefensls Bassrounr and Luger, lateral vrews of female right valve and male left one, x 75, Samalut Formatron 125-271 Paracosta pervlnqulerl (Donze and Said), vrews of lateral malevalve, carapace dorsal and female left valve, x 75, Tanka Formatron. (28-301 Paracosta reymentl, lateral view of male left valve, x 75, carapace dorsal view, x50 and lateral vrew of female rrght valve, x50, Samalut Formatron.

300 Journal

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Tertiary

ostracods

of Gebel

Withr,

southwestern

Sinal,

Egypt

Journal

of African

Earth Snences

30 1

A. SHAHIN 1979 Costa qurnensis Bassiouni - Cronin and Khalifa, p. 405, pl. 1, figs 20-21. 1984 Cativella qurnensis Bassrounr - Bassiouni et a/., p. 183, pl. 1, fig. 1 la, b. Material: 4 carapaces Occurrence: It was first recorded in the Middle Eocene of Egypt (Bassiouni, 1969b; Cronin and Khalrfa, 1979; Bassiouni et a/., 1984). In this study, it occurs in the Late Eocene. Genus: Costa Neviani, 1928 Costapraetricostata Bassiouni (Fig. 6.9 and 6.10) 1969c Costapraetricostata Bassiouni, p. 405, pl. 25, figs 7-9 1979 Costa praetricostata Bassiouni - Cronrn and Khalifa, p. 402, pl. 1, fig. 24 1993 Costapraetricostata Bassiouni - Boukhary et a/., p. 199, pl. 1, figs 1-3, 5-6 Material: 28 carapaces Occurrence: This species was recorded in the Middle Eocene of Egypt in Bassiouni (I 969c), Cronin and Khalifa (1979), Boukhary eta/. (I 993) and this study. Genus: Grinioneis Liebau, 1975 Grinioneishaitingeri(Reuss1 (Fig. 6.1 1-6.13) 1850 Cypridina haidingeriieuss, p. 68, pt. 10, fig. 13 1965 Hermanites haidingeri (Reuss) ~ Moyes, p. 84, pl. 10, fig. 12 1996 Hermanites haidingeri (Reuss) - Gammudi, p. 408, pl. 5, figs 4-5 Material: 5 carapaces Occurrence: This species was originally described from the Late Miocene of the Vienna Basin (Reuss, 1850). It was also found in the Miocene of France (Moyes, 1965) and the Aquitanian of Libya (Gammudr and Keen, 1993; Gammudr, 1996). In the present study, it occurs in the Early Miocene. GrinioneismoosifBassiouni) (Fig. 6.14) 1969d Limburgina moosiBassiounr, p. 21 1, pl. 18, figs 1-3 1993 Grinioneis moosi (Bassiouni) - Boukhary et al., p. 200, pl. 1, fig. 9 Material: 3 carapaces Remarks: Hemanites wahaensis n. sp. described by El-Sogher (I 996) from the Maastrichtian-Danran of Libya is very similar to this species but differs in having the curved ventral ridge and the more pointed posterior margin. Also this species is similar to Hermanites n. sp. 1 Salahi (I 966), but the latter has a larger and more entire reticulation carapace with some drfferences in the general posterior outline. Occurrence: This species was recorded in the Middle Eocene of Egypt in Bassiouni (1969d), Boukhary et al. (1993) and this study.

302 Journal

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Grinioneispaijenborchianus (Keij) (Fig. 6.15) 1957 Hermanitespaijenborchiana Keij, p. 110, pl. 17, figsll-14;pl.21,figslO-11 1971 Hermanitespaijenborchiana Keij - Blondeau, p. 55, pl. 5, fig. 15 1979 Hermanites cf. paijenborchianus Keij - Cronin and Khalifa, p. 403, pl. 1, fig. 16 Material: 4 carapaces Occurrence: It was first recorded in the Early to Middle Eocene of Belgium (Keij, 1957) and subsequently reported from the Eocene of France (Ducasse, 1969; Blondeau, 1971). It was also known in the Early Miocene of India (Khosla, 1978). It occurs in the Middle Eocene of Egypt in Cronin and Khalifa (I 979) and this study. Genus: Gyrocythere Siddiqui, 197 1 Gyrocthere celata Al Furaih (Fig. 6.16 and 6.17) 1983 Gyrocythere celata Al Furaih, p. 3, pl. 3, figs 1-2 Material: 3 carapaces Remarks: This species is similar to G. mitigata Siddiqur (1971) described from the Middle Eocene of Pakistan but differs In having celate reticulation and less developed dorsal and ventrolateral ridges. Occurrence: It was recorded in the Early Eocene of Saudi Arabia (Al Furaih, 1983). In this study, it occurs tn the Middle Eocene. Genus: Occultocythereis Howe, 1951 Occultocythereis indistincta Siddiqui (Fig. 6.18 and 6.19) 197 1 Occultocythereis indistincta Siddiqui, p. 53, pl. 27, figs 13-I 5; pl. 28, figs 1-4 1996 Occultocythereis indistincta Siddiqui - Bassiouni and Luger, p. 30, pl. 17, fig. 23 Material: 3 carapaces Occurrence: This species was recorded in the Middle Eocene of Pakistan (Siddiqui, 1971) and Somalia (Bassiouni and Luger, 1996). In the present study, it occurs In the Early Miocene. Genus: Paracosta Siddiqui, 1971 Paracosta bensoni(Damotte and Donze) (Fig. 6.20) 1982 Palaaocosta bensoniDamotte and Donze (Donze et a/., 19821, p. 285, pl. 4, figs 4-8 1990 Reymenticosta bensoni(Damotte and Donze) Bassrouni and Luger, p. 839, pl. 21, figs 7-9 1996 Paracosta bensoni (Damotte and Donze) - ElSogher, p. 321, pl. 26, figs 1 O-l 3; pl. 27, figs I-14; pl. 29, figs l-4 Material: 6 carapaces Remarks: This species is similar, in the general outline, to the juvenile forms of Aegyptiana anguloreticulata illustrated by Bassiounr and Luger (I 990, pl. 15, figs 12, 15) but differs in having an anterodorsal depression.

Tertiary

ostracods

of Gebel

Occurrence: It was origrnally reported from the Late Palaaocene of Tunisia (Donze et a/., 1982). It was also known in the Maastnchtran and Danian of Libya (El-Waer, 1992; El-Sogher, 1996) and the Late Palzocene of southern Egypt (Bassiouni and Luger, 1990). In the present study, it occurs in the Middle Eocene. Paracosta mokattamensis (Bassiouni) (Fig. 6.21 and 6.22) 1969c Costa mokattamensis Bassiouni, p. 399, pl. 27, figs 3-4 1982 PalBocosta aff. mokattamensis (Bassiouni) Donze et a/., p. 286, pl. 5, figs 1-5 Material: 14 entire carapaces and 3 valves Remarks: Costa berggreniof Khalifa and Cronln (1979) seems to be very similar to thus species in the outline and reticulation and may be considered as synonymous. The male carapace is longer and thinner than the female one. Occurrence: This species was first recorded in the Middle Eocene of Egypt (Bassiounl, 1969c). It was also known In the Late Palaeocene of Tunisia (Donze et a/., 1982). In this study, It occurs In the Middle and Late Eocene. Paracostaparakefensis Bassiouni and Luger (Fig. 6.23 and 6.24) 1990 Paracosta parakefensis Bassiouni and Luger, p. 834, pl. 19, figs 10, 13-23 Material: 5 carapaces Occurrence: This species was recorded in the Late Palseocene of southern Egypt (Bassiouni and Luger, 1990) and the Early and Middle Eocene in this study. Paracosta pervinquiri (Donze and Said) (Fig. 6.256.27) 1982 Pal;eocostapervinquiriDonze and Said, p. 280, pl. 3, figs 4-10 1990 Paracosta pervinquiri (Donze and Said) Bassiouni and Luger, p. 834, pl. 20, figs 7-10 1996 Paracosta pervinquiri (Donze and Said) - ElSogher, p. 323, p. 30, figs 1-5 Material: 7 carapaces Occurrence: This species was recorded in the Maastrichtian-Early Palaaocene of Tunisia (Donze et a/., 1982) and Libya (El-Sogher, 1996). It was also reported In the Middle Maastrichtian of southern Egypt (Basslounr and Luger, 1990). In this study, It occurs in the Middle and Late Eocene. Paracostareymentin. sp. (Fig. 6.28-6.30) Derivation of name: After Prof. Reyment, Uppsala University, Sweden, who IS the first to have figured similar specimens from the Nigerian Palaeocene. Diagnosed: Sub-rectangular carapace of Trachyleberidinae with coarse reticulation over the whole

Withr,

south

western

Sinai,

Egypt

surface and very faint longitudinal ridges that hardly outreach the strong reticulation. Material: 9 carapaces Holotype: Figured carapaces, SSW5 Dimensions: L 0.45 mm, H 0.29 mm, W 0.28 mm Type locality and horizon: Mtddle Eocene, Samalut Formation In Gebel Withr, southwestern Sinai Description: The carapace IS sub-rectangular and large in size. The maximum height at the anterior is one fourth of the carapace. The dorsal margin is nearly straight. The ventral margin is gently curved. The anterior margin is broadly rounded. The posterior margin IS narrowly rounded. The ornamentation of the coarse retrculatlon becomes coarser in the central part with no distinct longitudinal ridges, due to their absorption in the coarse, strong reticulation. Remarks: Thus species IS similar to both Paracosta warriensis (Reyment) and P, kefensis (Benson) in the general outline and ornamentation but differs in the apparent absence of longitudinal ribs and in having coarser vertically standing reticulation. Occurrence: This species occurs in the Middle and Late Eocene. The aforementioned species were recorded in the Palaeocene. Genus: Reticulina Bassiouni, 1969 Reticuiina heluanensis Bassiouni (Fig. 7.1) 1969c Carinocythereis (Reticulina) heluanensis Bassiounl, p. 392, pl. 26, figs 5-l 0 1979 Anticythereis? cf. heluanensis (Basslouni) Cronin and Khallfa, p. 405, pl. 2, fig. 13 1995 Reticulina heluanensis (Bassiouni) - Aref, p. 124, pl. 1, frg. 8 Material: 7 entire carapaces and 2 valves Occurrence: This species was recorded from the Late Eocene of Egypt (Basslouni, 1969~; Cronin and Khalifa, 1979) and the Early Eocene of Egypt (Aref, 1995). In the present study, it occurs in Middle and Late Eocene. Reticulinaproteros Bassiouni (Fig. 7.2) 1969b Carinocythereis (Reticulina) scitula proteros Bassiouni, p. 11, pl. 1, fig. 8; pl. 2, figs 6-8 1982 Reticulinaproteros Bassiouni - Donze et al., p. 287, pl. 5, frgs 7-8 1990 Reticulina proteros Bassiouni - Bassiouni and Luger, p. 836, pl. 20, figs 16-21 1995 Reticulina proteros Bassiounl Honlgstein and Rosenfeld, p. 60, pl. 3, figs 5-6 Material: 7 carapaces Occurrence: This species was originally described from the Early Eocene of Jordan (Bassiouni, 1969b). It was also reported in the Early Palaaocene-Early Eocene of Tunrsla (Said, 1978; Donze et a/., 1982) and Israel (Honlgsteln et a/, 1991; Honlgstein and

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A. SHAHIN Rosenfeld, 1995). In Egypt, It occurs in the Late Palzeocene (Basslounl and Luger, 19901, the Early Eocene (Aref, 1995) and the Late Eocene of the present study. Reticulina saitoi(Khalifa and Cronin) (Fig. 7.3) 1979 Anticythereis saitoi Khallfa and Cronln, p. 177, pt. 2, figs IO-I 2 1993 Reticulina cf. saitoi (Khallfa and Cronln) Boukharyeta/., p. 198, pl. 1, fig. 10 Material: 13 carapaces Occurrence: This species occurred in the Middle Eocene of Egypt (Khalifa and Cronln, 1979; Boukhary et a/., 1993). In this study, It occurs ranging from the Early to Late Eocene. Reticulina scitula Bassiouni (Fig. 7.4) 1969c Carinocythereis (Reticullnal scitula Basslounr, p. 396, pl. 26, figs l-4 Material: 5 carapaces Occurrence: It was recorded in the Early and Middle Eocene of Egypt and Jordan (Basslounl, 1969c) and occurs In this study In the Middle Eocene. Genus: Schizoptocythere Slddlqul and Al Furalh, 1981 Schizoptocythere taurus Siddiqui and Al Furaih (Fig. 7.5 and 7.6) 1981 Schizoptocythere taurus Slddlqui and Al Furaih, p. 884, pl. 125, figs 4, 6 Material: 3 carapaces Remarks: The Egyptian Early Eocene Pterygocythere austraegyptiaca Bassiounl and Luger (I 990) IS similar to this species but differs In havtng a more protruding eye tubercle and anterodorsal spines. Pterygocythere compressa described from the Campanlan of Texas seems to be related to this species. Occurrence: It was first recorded in the Early Eocene of Pakistan by Slddiqul and Al Furath (1981). In this study, It occurs In the Late Eocene.

Genus: Trach yleberis Brady, 1898 Trachyleberis nodosus Bassiouni (Fig. 7.7) 1969c Trachyleberis nodosus Bassiouni, p. 385, pl. 24, figs I-3 1979 Trachyleberis nodosus Bassiouni - Cronin and Khallfa, p. 401, pl. 2, figs 9-l 0 1993 Trachyleberis nodosus Basslouni Boukhary et al., p. 196, pl. 1, figs 1-4 Material: 7 carapaces Occurrence: This species was recorded in the Middle Eocene of Egypt In Basslouni (I 969c), Cronin and Khallfa (19791, Basslounl et al. (I 984), Boukhary et al. (1993) and the present study. Trach yleberis teiskotensis (Apostolescu) (Fig. 7.8 and 7.9) 1961 Actinocythereis teiskotensis Apostolescu, p. 814, pl. 13, figs 253-256 198 1 Trach yleberis teiskotensis (Apostolescu) Reyment, p. 61, pl. 7, figs 1 O-l 4 1983 Trachyleberis teiskotensis (Apostolescu) Fosteretal.,~. 131,pl. 5,flgs7-16;pl.9,fig. 11;pl. 1 1, figs 556 Materiai: 26 carapaces Occurrence: This species was originally described from the Palazocene of Mali, Ivory Coast and Benin (Apostolescu, 1961). It was subsequently recorded from the Pal;eocene of Libya and the Saharan province (Reyment, 1980; Reyment and Reyment, 19801, Nigeria (Reyment, 1963, 1981; Foster et a/., 1983). In the present study, It occurs in the Middle and Late Eocene. Subfamily: Buntonlnae Apostolescu, 1961 Genus: Asymmetncythere Basslounl, 1971 As ymmetricythere yousefi Bassiouni (Fig. 7.10 and 7.11) 197 1 Asymmetncythere yousefi Bassiounl, p. 180, pl. 8, figs I-5 1979 Asymmetricythere yousefi Basslounl - Cronin and Khallfa, p. 406, pl. 1, figs 1-6

Figure 7. (1) Retlcullna heluanensls Bassloum, lateral vjew of right valve, x 75, Samalut Format/on. (2) Retlcultna proteros Bass,oun,, lateral view of left valve, x 75, Tanka Format/on. 13) Retlcullna salto1 IKhalifa and Cronlnl, lateral view of right valve, x 75, Samalut Format/on. 14) Retlcullna scltula Basslounl, lateral view of right valve, x 100, Samalut Formation 1% 6) Schlroptocythere taurus Siddlqu, and Al Furaih, lateral view of right valve and carapace dorsal view, x 100, Tanka Format/on. (71 Trachylebens nodosus Basslounl, lateral vfew of left valve, x 75, Samalut Format/on. (B-91 Trachyleberls telskotensls (Apostolescul, lateral vfew of right valve and dorsal wew, Tanka Formation. (lo171 Asymmetrqthere yousefl Bass,oum, lateral view of left valve and carapace dorsal wews, x 100, Samalut Formation. 1721 Buntonla attltogonensls Apostolescu, lateral view of left valve, x 75, Tanka Format/on (13-141 Buntonla fares1 Bassloum, lateral view of male right valve, x 75, Tanka Format/on. 1751 Buntonla fortunata Apostolescu, lateral views of right and left valves, x 100, Tanka Formation. (16-171 Protobuntonla nakkadll Bassloun,, lateral v,ews of female and male valves, x 100, Tanka Formation. (78- 191 Rugglena (Keyella) glabella Bassfounl, lateral view of left valve and carapace dorsal vrew, x50, Samalut Formation. (20-23) Soudanella laclnlosa trlangulata Apostolescu, two lateral views of right valves and two dorsal views of the same carapace, x 75, Tanka Formation (24-25) Xestolebens chamela van den Bold, lateral view of left valve and dorsal view, x 100, Tanka Formatron (26-271 Xestolebens kenawyl Khaljfa and Cronln, carapace dorsal view and lateral view of right valve, x 75, Samalut Formation 1281 Xestoleberis maurayae van den Bold, lateral view of right valve and dorsal wew, x 100, Samalut Format/on. 129-301 Xestoleberls tunlslensls Esker, lateral view of left valve and carapace dorsal view, x 100, Samalut Format/on

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A. SHAHIN 1993 Asymmetricythere yousefi Bassiouni Boukhary et al., p. 204, pl. 3, fig. 13 1996 Asymmetricythere yousefi Bassiounl Bassiouni and Luger, p. 38, pl. 11, figs 1-6 Material: 4 carapaces Occurrence: This species was first described from the Late Eocene of Egypt (Bassiounl, 1971) and later by Cronin and Khalifa (1979). It was also known from the Middle Eocene of Egypt (Bassiouni et a/., 1984; Boukhary et a/., 1993) and Somalia (Bassiouni and Luger, 1996). In this study, It occurs in the Middle and Late Eocene. Genus: Buntonia Howe, 1935 Buntonia attitogonensis Apostolescu (Fig. 7.12) 1961 Buntonia attitogonensis Apostolescu, p. 799, pl. 3, figs 46-49 1963 Buntonia attitogonensis Apostolescu - Reyment, p. 200, pl. 17, fig. 8 1983 Buntonia (Buntonia) attitogonensis Apostolescu - Foster et a/., p. 119, pl. 6, figs 2, 5, 15-l 6 Material: 6 carapaces Occurrence: This species was origlnally recorded in the Early Eocene of Togo (Apostolescu, 1961). It was also known in the Eocene of southwestern Nigeria and Libya (Reyment, 1963) and the Late Palaeocene of Nigeria (Foster et a/., 1983). In this study, it occurs in the Late Eocene. Buntonia faresiBassiouni (Fig. 7.13) 1971 Buntonia faresiBassiouni, p. 173, pl. 8, figs 7-8 1993 Buntonia faresi Bassiouni - Boukhary et al., p. 206, pl. 3, fig. 12 Material: 5 carapaces Occurrence: This species was recorded In the Middle Eocene of Egypt (Bassiouni, 1971; Boukhary et al., 1993) and the Late Eocene of the present study. Buntonia fortunata Apostolescu (Fig. 7.14 and 7.15) 1961 Buntonia fortunata Apostolescu, p. 801, pl. 3, figs 61-67 1983 Buntonia (Buntonial fortunata Apostolescu Foster et a/., p. 120, pl. 3, fig. 10; pl. 7, figs 8-9 1996 Buntonia fortunata Apostolescu - El-Sogher, p. 305, pl. 13, figs 9-l 6; pl. 14, figs l-l 0 Material: 4 carapaces Occurrence: It was originally reported from the Danian of Benin (Apostolescu, 1961) and later from the PalEocene of Nigeria (Reyment, 1963; Foster et a/., 1983). It was also recorded in the Late Cretaceous and Early Palaeocene of Libya WSogher, 1996). In this study, it occurs in the Late Eocene. Genus: Protobuntonia Grekoff, RotobuntonianakkadiiBassiouni

306 Journalof

Ahcan

Earth Sciences

1954 (Fig. 7.16

and 7.17)

1970 Protobuntonia nakkadiiBassiouni, p. 23, pl. 2, figs 1-3 1982 Protobuntonia nakkadii Bassiouni - Donze et a/., p. 295, pl. 12, fig. 1; pl. 14, fig. 6 1990 Protobuntonia nakkadii Bassiouni - Bassiouni and Luger, p. 845, pl. 23, figs 23-24 Material: 10 carapaces Occurrence: This species was originally described from the Middle Paleocene of Jordan (Bassiouni, 1970). It was also known In the Palaeocene and Early Eocene of Tunisia (Said, 1978; Donze et al., 1982). In Egypt, It occurs in the Late Palaeocene (Khalifa et a/., 1984), the Middle Maastrichtian and Middle Palaeocene (Bassiouni and Luger, 1990) and the Late Eocene of the present study. Genus: Ruggieria Keij, 1957 Subgenus: Keqella Ruggieri, 1967 Ruggieria (KeJella) glabella Bassiouni (Fig. 7.18 and 7.19) 1971 Ruggieria (Ke(iella) glabella Bassiouni, p. 182, pl. 9, figs 1-6 1984 Ruggieria (KeJella) glabella Bassiouni - Bassiouni et al., p. 185, pl. 2, figs 4a, b Material: 3 carapaces Occurrence: This species was recorded in the Middle Eocene of Egypt (Bassiouni,l971; Bassiouni et al., 1984). In this study, it is found in the Middle and Late Eocene. Genus: Soudanella Apostolescu, 1961 Soudanella laciniosa triangulata Apostolescu (Fig. 7.20-7.23) 1961 Soudanella laciniosa triangulata Apostolescu, p. 810, pl. 7, figs 130-I 35 1968 Soudanella laciniosa triangulata Apostolescu Grekoff, p. 17, pl. 3, fig. 44 1970 Soudanella laciniosa triangulata Apostolescu Basslounl, pl. 3, figs 1 1 a-c 1982 Soudanella laciniosa triangulata Apostolescu Donze et al., p. 295, pl. 12, figs 2-3 1990 Soudanella laciniosa triangulata Apostolescu Basslounl and Luger, p. 847, pl. 24, fig. 18 Material: 19 carapaces Occurrence: It was first recorded in the Early Paleocene of Senegal (Apostolescu, 1961 ).lt was also reported from various ages and localities such as the Maastrichtian-Early Paleocene of Algeria (Grekoff, 19691, the Late PalEocene-Early Eocene of Tunisia (Donze et a/., 19821, the Early Eocene of Jordan (Bassiouni, 1970), the Late Paleocene of southern Egypt (Basslouni and Luger, 1990) and the Early Eocene of the Egyptian Red Sea area (Aref, 1995). In the present study, it occurs in the Middle and Late Eocene.

Tertiary ostracods of Gebel Withr, south western Sinai, Egypt Family: Xestoleberididae Sars, 1928 Genus: Xestoleberis Sam, 1866 Xestoleberis charnela van den Bold (Fig. 7.24

BIOSTRATIGRAPHY AND PALAOBATHYMETRY and

7.25)

1960 Xestoleberis chamela van den Bold, p. 182, pl. 6, figs IOa, b

1979 Xestoleberis charnela van den Bold - Neufville, p. 159,

pl. 7, figs 6a, b

1984 Xestoleberis chamela van den Bold - Steineck, fig. 6L

Material: 35 carapaces Occurrence: This species

was first recorded in the Eocene-Oligocene of Trinidad (van den Bold, 1960). It was also known from the Eocene of Brazil (Neufville, 1979) and the Eocene-Oligocene of Barbados (Steineck et a/., 1984). In the present study, it occurs in the Middle and Late Eocene. Xesto/eberis and 7.27)

Khalifa and Cronin (Fig. 7.26

kenawyi

1979 Xestoleberis kenawyiKhalifa

and Cronin,

p. 116,

pl. 1, figs 7-8

1991 Xestoleberis kenawyi Khalifa and Cronin et a/., p. 100, pl. 1, figs 7-8 Material: 45 carapaces Occurrence: This species was recorded in the Middle Honigstein

Eocene of Upper Egypt (Khalifa and Cronin, 1979) and Israel (Honigstein et a/., 1991). In this study, it occurs ranging from the Middle Eocene to Early Miocene. Xestoleberis murrayae van den Bold (Fig. 7.28) 1957 Xestoleberis maurraye van den Bold, p. 12, pl. 1, figs 6a, b Material: 23 carapaces Remarks: This species is distinguished from Xestoleberis truncata Alexander in having a lower anterior end and a sinuate ventral margin. Occurrence: It was recorded in the Palasocene of Trinidad (van den Bold, 1957) and the Middle Eocene of this study. Xestoleberis figs 13-I

4; pl. 4, fig. 2

1982 Xestoleberis p. 282,

Esker (Fig. 7.29 and 7.30) tunisiensis Esker, p. 332, pl. 2,

tunisiensis

1968 Xestoleberis

tunisiensis Esker - Donze

et al.,

pl. 2, fig. 9

1990 Xestoleberis tunisiensis Esker - Bassiouni

and p. 847, pl. 25, figs 1-7 Material: 33 carapaces Occurrence: This species was recorded from the Maastrichtian to Early Paleeocene of Tunisia (Esker, 1968; Said, 1978; Donze et a/., 1982) and the Palseocene to Early Eocene of Egypt (Bassiouni and Luger, 1990). In the present study, it occurs in the Early to Late Eocene.

Luger,

As a sound stratigraphical position, it is possible to establish at least a local biostratigraphical zonal scheme based on ostracod content. Because of the discontinuous nature of the producing samples, any biostratigraphical and pakeoenvironmental predictions by using ostracod populations should be regarded as tentative. The proposed ostracod biozones should be correlated with the planktonic foraminiferal zonation of the same interval to justify the age assessment. In the definition of these zones, some characteristic associations are recorded and the remainder can be seen in Figs 2 and 3. A statistical attempt (Table 1) to use the triangle diagram of Dingle (1981) for reconstructing a simple palaeobathymetric picture for each ostracod assemblage is carried out. This diagram seems to be suitable for neritic and bathyal environments. In this diagram, the heads of the triangle diagram is referred as Cytheracea, CypridaceaBairdiacea and Cytherellidae. The marine water depths are shown in the seven fields of the diagram where fields 1-3 refer to a depth < 100 m, 4a refers to a 100-200 m depth, 4b to a depth of about 200 m, 5a to a 200-300 m depth, 5b to a 300-500 m depth and 6-7 refer to a > 500 m depth (Fig. 8). The vertical distribution of the recorded ostracods proved to be more suitable to subdividing the studied sequence into five biostratigraphical units with rare ostracod intervals in between. These ostracod assemblages (Figs 2 and 3) are arranged from the older to the younger and briefly discussed below. Leguminocythereis bopaensis-Leguminocythereis bicostata Assemblage Zone (I I This zone is defined as the interval with the nominate taxa ranging from the base of the studied exposure to the first appearance of Reticulina saitoi (Khalifa and Cronin). It is nearly equivalent to the Early Eocene foraminiferal biozones of Acarininapentacacamerata Zone and the lower two thirds of Middle Eocene A. bullbrooki Zone. The upper part of this zone is very poor in ostracods. Besides the nominate species, it includes Cytheropteron boukharyiKhalifa and Cronin, Costa praetricostata Bassiouni, Digmocythere ismaili Bassiouni, Loxoconchapseudopunctatella Cronin and Khalifa and others (Fig. 2). Most of the recorded ostracod species in this zone belong to the Cytheracea that dominates the other groups (83- 100%; Table 1) and refers to the inner and middle neritic (O-100 m depth). Also the assemblage plots on the triangle diagram is found in field I, which means a marine water depth of < 100 m (Fig. 8). This result matches well with that deduced previously from the foraminiferal content (Shahin, 1998).

Journalof

African

Earth Sciences

307

A. SHAHIN Table

1. Percentage

Sample No. Section

Zone No.

of the ostracod

groups

Ostr. No.

Cytheracea

113

Cytherellidae

No.

%

No.

%

No.

49

40

82

5

IO

4

a

5

27

19

70

8

30

-

-

Reticulina saitoiTrach yleberis nodosus Assemblage Zone (2) This zone is defined as the interval from the first occurrence of Reticulina saitoi (Khalifa and Cronin) to the last appearance of Trachylebens nodosus Bassiouni. It is equivalent to the foraminiferal biozones of the upper one third of the Acarinina bullbrooki Zone and Globigerinatheka kugleri/rurborotalia cerroazulensis pomerolizone that belong to the Middle Eocene. Most of the ostracods found in the preceding zone extend within this zone to associate with the nominate taxa. Others which first appeared within this zone are Loxoconchapunctatella (Reuss), L. mataensis Khalifa and Cronin, Paracosta bensoni(Damotte and Donze), t? mokattamensis (Bassiouni), P. reymenti, Leguminocy-thereis lokossaensis Apostolescu, Reticulina proteros Bassiouni, Bairdia hiwanneensis Howe and Lea, Paracypris nigeriensis Reyment, Grinioneis paijenborchianus (Keij) and others (Fig. 2).

of African

Cypridacea + Bairdiacea

reconstruction

1

%

1

109

308 Journal

used in the palreobathymetric

Earth Sciences

It is clear that Cytheracea, including the genera Paracosta, Leguminocythereis, Loxoconcha and Cytheropteron, dominate the other groups (5096%; Table 1). They are a diagnostic assemblage for inner and middle neritic environments (O-1 00 m depth). Also, the assemblage plots on triangle diagram lies in field 1 referring to a marine water depth of < 100 m (Fig. 2). This result conforms to the neritic conditions deduced from the foraminiferal content. Asymmetrkythere youse fi-CythetMa piaca-bucuensk Assemblage Zone (3) This zone is defined as the interval from the last local occurrence of Tracylebereis nodosus Bassiouni to the first appearance of Leguminocythereis africana Bassiuouni. In this zone, the ostracods, as well as planktonic foraminifera as a whole, were impoverished, while the nummulitic facies were

Tertiary

ostracods

of Gebel

dominant. This interval is equivalent to the foraminiferal Truncorotaloides rohrizone of the latest Middle Eocene (Fig. 1). Although ostracods rarely occurred, cytheraceans dominate the other groups (48-75%; Table 1). This scarcity of ostracods (Fig. 31, associated with larger, dominant benthic foraminifera (Nummulites and Operculina) and rare planktonic ones, refers to an inner to middle neritic environment. However, as stated by Shahin (19981, the shaley facies at the top of the Samalut Formation, including flourishing planktonic foraminifera and deeper benthic foraminifera with very little ostracods, was deposited in an outer neritic to upper bathyal environment (- 100-300 m depth). Leguminoc ythereis africana-Buntonia faresi Assemblage Zone (4) It is defined as the interval from the first to the last appearance of the nominate taxa. It is equivalent to the foraminiferal Globigerinatheka semiinvoluta and Globigerina gortanr2Turborotalia centralis Zones of the Late Eocene. This zone is rich in ostracods, as well as planktonic and benthic foraminifera. Besides the nominate taxa, the associated ostracods include many species of the genera Cytheropteron, Costa, Paracosta, Cytherella, Buntonia, Protobuntonia, Leguminocythereis, Soudanella and Paracypris (Fig. 3). The cytheraceans dominate the other groups (57-95%), whereas the Cytherellidae constitutes 5-37%. (Table I) The association of these genera characterises the inner to outer neritic environments. The relatively deeper marine ostracod genera, including Leguminocythereis and others associated with costate buliminid and uvigerinid foraminifers of upper bathyal environments, increase upwards in this zone. This may be due to the progressive deepening of the sea through this zone. The assemblage plots on the triangle diagram lies on the Cytheracea-Cytherellidae line and to the right of field 1. It can be concluded that this empty space in the diagram may refer to outer neritic to upper bathyal belonging to field 5a (200-300 m depth; Fig. 81. The overlying Late Oligocene-Early Miocene interval that is equivalent to the planktonic foraminiferal Globorotalia opima opima, Globigerina ciperoensis ciperoensis Zones and the Barren Interzone of Shahin (1998) yielded very rare ostracods. These ostracodes are progressively reduced in abundance and diversity (Fig. 3). The foraminiferal content, including miogypsinids, agglutinated benthic foraminifera and rare cibicidids associated with algae, suggest a shallowing of the sea to a depth of no more than 30 m.

Withr,

southwestern

Sinai,

Egypt

Grinioneis haidingeri-Pokorn yella deformis minor Assemblage Zone (5) This zone is defined as the interval from the first occurrence of the nominate taxa and extends upwards till the top of the measured succession. It is equivalent to the foraminiferal Globigerinoidesprimordius Zone of Early Miocene. About 27 ostracod specimens were raised from this zone. Besides the nominate taxa, this assemblage includes Aurila soummamensis (Coutelle and Yassini), Disopontocypnsschwegerivan den Bold, Semic ytherura gammudii, Semic ytherura bassiounii, Carinovala carinata (Moyes), Bythocypris tripoliensis Gammudi and Keen, Bairdia ilaroensis Reyment and Reyment and others (Fig. 3). It seems that the low diversity and abundance of ostracods characterises this zone. On the other hand, the flourishing planktonic foraminifera, associated with costate buliminid and uvigerinid foraminifers, indicate a deeper marine environment that may reach outer neritic or even upper bathyal conditions (100-300 m depth). The scarcity of ostracods and benthic foraminifera may reflect an oxygen deficiency at the sea bottom of the outer neritic zone.

Many Palseogene ostracod genera and species have a relatively long stratigraphical range. Because of their generally narrow ecological adaptation and wide geographical distribution, they are very useful for regional palaeobiogeographical reconstruction. Concerning this point, the recorded species are valuable in palaeogeography as shown in Table 2. Obviously, there is no controversy over the existence of inland seas across the Sahara during the Cretaceous that continued till the end of the Palaeocene. This Saharan seaway was a southward extension of the Tethys and a northward extinction from the Gulf of Guinea. Most geologists agree that there was an inland connection between the South Atlantic and the Tethys through Libya, Algeria, Mali and Nigeria through which some organisms migrated. The biostratigraphical and palasogeographical evidence suggests that the acme of this Trans-Saharan Seaway transgression was attained in the Late Palaeocene (Reyment, 1980). This connection was postulated through many valuable ostracod researches in Mali (Apostolescu, 19611, North Africa, Nigeria and Mali (Reyment, 1980; Reyment and Reyment, 1980; Foster et al. 1983). Some similarities are expected between the Egyptian assemblages and that of north Tethyan west European regions such as England, France, Belgium and Spain, as well as that of the Caribbean region. Accordingly, this fauna1 similarity will prove that Egyptian ostracods, like those of the study area, reveal

Journal

of African

Earth Sciences

309

A. SHAHIN

0

Zone

1

*

Zone

2

+

Zone

3

0

Zone

4

A Zone

5

Cypridacea + Balrdlacea

Cytherellidae

Figure 8. Triangle diagram for pala?obathymetric reconstruction (modified after Dingle, 7981) where the points are Cytheracea, Cyprldacea f Baidiacea and Cytherellidae. The assemblage helds used to depict the pakodepth are as follows: 1-3: depth < 100 m; 4a: 100-200 m depth; 46: -200 m depth; 5a: 200-300 m depth; 5b: 300-500 m depth; 6 and 7: >500 m depth.

some affinity to those of north Tethyan west European, as well as the Caribbean regions, and add an idea about the palaeogeographical distribution of the recorded ostracods. During the Palzogene, north Africa was considered the southern shore of the Tethys. Most of the ostracod species occurring in many localities in north African countries, as well as the western and eastern extremities of the present Mediterranean Sea, characterise the southern Tethyan Province. There is a great similarity between the Tertiary as-semblages recorded in Tunisia (Said, 1978; Donze et al., 19821, Libya (Barsotti, 1963; Salahi, 1966; El-Waer, 1988, 1991, 1992; ElSogher, 1996) and Egypt. Of this assemblage, those species that these countries have in common are lsohabrocythere teiskotensis Apostolescu, Paracosta bensoni (Damotte and Donze), P. pervinquieri (Donze and Said), Leguminocythereis bopaensis (Apostolescu), L. exigua (Apostolescu), Soudanella laciniosa triangulata Apostolescu, Protobuntonia nakkadii Bassiouni and others (Table 2). Further to the east, some species that Jordan and Egypt have in corn-mon (Bassiouni, 1969c, 1971) are Protobuntonia nakkadii Bassiouni, Reticulina proteros Bassiouni, Reticulina scituta

3 10 Journal

of African

Earth Sciences

Bassiouni, Soudanella laciniosa triangulata Apostolescu and others. It also seems that at least five species, described from the Palaso-cene and Eocene of Israel (Honigstein et a/., 1991; Honigstein and Rosenfeld, 19951, are identical with the recorded Sinai species. Among these species there are Cytherella piacabucuensis, Paracypris nigeriensis, Digmocythere ismaili, Reticulina proteros and Xestoleberis kenawyi. The recorded Gyrocythere celata Al Furaih, Occultocythereis indistincta Siddiqui and Schizoptocythere taurus Siddiqui and Al Furaih, in the study area of Egypt, were previously recorded in Saudi Arabia (Al Furaih, 1983) and Pakistan (Siddiqui, 197 1; Siddiqui and Al Furaih, 1981). This ostracod similarity demonstrates a direct connection between these Tethyan areas during that time (Fig. 9). Moreover, Bassiouni and Luger (1996) stated that there are eight species in common between Egypt, Libya and Somalia. Among their assemblages, few species are recorded in the study area. They are Bairdia ilaroensis Reyment and Reyment, Asymmetricythere yousefi Bassiouni, Occuftocythereis indistincta Siddiqui and Xestoleberis tunesiensis Esker. In spite of the scarcity of the published works on the Tertiary ostracods of eastern Africa, this similarity refers to a direct

Tertiary

Table 2. Palaeogeographic

ostracods

distribution

of Gebel

and stratigraphical

Withr,

southwestern

Sinai,

range of the important

Egypt recorded

ostracods

SoudaneNa lacin fnangulata Apostolescu Batrdfa hwaneens6 Howe andLea

Cyfherella

sfolebens

harmomens

van den Bold

cha

e and Yasslnl A: Algeria; B: Benm; Be: Belgwm; Br: Brazil; E: Egypt; L: Libya; M: Mali; N: Nigeria; P: Pakistan; S: Senegal;

En: England; F: France; I: Ivory Coast; In: Sa: Saudi Arabia; T: Tunwa; Tr: Trinidad;

connection between the southern Tethyan Province, including Somalia and the free migration of the benthic fauna. In addition, there is some similarity between the Egyptian, as well as north African assemblages, and that reported from Brazil (Neufville, 19791, Trinidad and Banama (van den Bold, 1950, 1957, 1960, 1967). From the recorded species, these areas have in common: Cytherella harmoniensis van den Bold; C. piacabucuensis Neufville; Bairdia dolicha van den Bold: B. hiwanneenssis Howe and Lea; Soudanella laciniosa triangulata Apostolescu, Xestoleberis chamela van den Bold; X. murrayae van den Bold and others (Table 2). This common occurrence supports the direct connection between north Africa, Brazil and the Caribbean region. The typical western European Tethyan genera, such as Leguminocythereis bicostata Haskins and L. oertlii Keij, together with Cytherella dixoni Jones and Sherborn, C. londinensis Jones, C. muensteri (Roemer) and C. compressa (van Muenster), that were reported from the Eocene of England (Haskins, 1968, 1970; Keen, 19781, Belgium (Keij, 19571, France (Ducasse, 1967, 1969) and Spain (Swain, 1984), are common in Egypt. Moreover, Aurila

India; Lo:

J: Jordan Louisiana;

and Israel; K: Turkey.

soummamensis Coutelle and Yassini and Pokornyella deformis minor (Moyes) occurred in the Lower Miocene sediments of Egypt as shown in the present study. They are also recoded in the Lower Miocene of Libya (Gammudi and Keen, 19931, Algeria (Coutelle and Yassini, 1974) and Turkey (Bassiouni, 1979; Gokcen, 1984). On the other hand, Grinioneis haidingeri (Reuss), G. paijenborchianus and Carinovala carinata (Moyes) were among the Miocene assemblages that were recorded in the Aquitanian of Libya (Gammudi and Keen, 1993; Gammudi, 1996). They were also recorded in the Lutetian (Ducasse, 1969; Blondeau, 197 1) and Miocene (Moyes, 1965) of France, the Lutetian of Belgium (Keij, 19571, the Early Miocene of India (Khosla, 1978) and the Early Miocene of the present study. This fauna1 similarity suggests a fauna1 exchange between the south Tethyan north African and the north Tethyan west European, as well as the east European regions, during the PalBogene and Early Neogene. This connection seems to be a reality during that time due to the progressive closure of the Tethys Ocean that caused its shallowing and permitted free ostracod exchange. This aforementioned, regional palseobiogeographical

Journal

of African

Earth Sciences

3 11

A. SHAHIN

w u

Migration

Figure 9. Palaaobiogeographrc distnbutron and migratron routes of the recorded Palzeogene ostracods. 6: Libya; 7: Tunwa; 8: Algeria, 9: Somalta; 10: Spain; Saudi Arabia; 4: Jordan and Israel; 5: Egypt; 17: Malt; 18: Ivory Coast, 19: Senegal; 20: 13: England; 14: Turkey; 15: Nigeria; 16: Benin; Louisiana.

distnbutron of the Palaeogene ostracods supports the dominant shelf environment containing the south Tethyan fauna in those various areas. Accordingly, the areas, stretching from the Middle or even Far East through north Africa to the Caribbean region, are considered portions of the Tethyan realm that is considered a distributional way for nerrtic ostracods during the Palaeogene (Fig. 9). The common occurrence of Palseogene ostracods in Egypt, as well as north Africa, and western Africa supports the view of Barsotti (1963) on possible migration routes within west Africa and the adjacent epicontinental seas. He believed that the west African ostracods migrated northwards with a reverse direction from the Tethys to the Nigerian coastal basin. There is general agreement that the marine connection across the Sahara was broken towards the end of the Palasocene. Therefore, the fauna1 migration had

3 12 Journal

of A fncan Earth Soences

mutes 1. India; 2: Pakrstan; 3: 1 1: France; 12: Belgium; Brazil; 2 1: Trtntdad; 22:

occurred during the Paleocene and earlier, and most migrated Palaaocene ostracods possessed relatively long chronostratrgraphrcal ranges in north Africa and other southern Tethyan realms and survived at least to the Late Eocene. The recorded ostracods, Including lsohabrocythere teiskotensis Apostolescu, and Nucleolina tatteuliensis (Apostolescu), are of great similarity to the Malran association (Apostolescu, 1961) and the Nigerian one (Reyment, 1981; Foster et al., 1983). They are restricted to the epineritic environment of the Afrotethyan-type of Bassiouni and Luger (I 990). This supports the presence of a Saharan epeiric sea, during the time of migration, connecting directly wrth the Tethys by a shallow narrow strait through which the exchange of shallow water ostracods had occurred between the Tethys and northwestern Nigeria (Fig. 9b). For example, during that time the northward migration route for Bairdia

Tertiary

ostracods

of Gebel

Withr,

ilaroensis (Reyment and Reyment) and Trachyleberis teiskotensis (Apostolescu) from northwestern Nigeria to North Africa through the Trans-Saharan Seaway was established by Reyment and Reyment (I 980). Several species from the Middle Pakeocene of southwestern Nigeria are already recorded in the Egyptian Palaeocene-Early Eocene association (Bassiuoni and Luger, 1990) and it is suggested here that some of them had occurred and extended to Late Eocene. These species include Bairdia ilaroensis (Reyment and Reyment), Paracypris nigeriensis Reyment, and Soudanella laciniosa triangulata Apostolescu, in addition to the most common Leguminocythereis bopaensis (Apostolescu). They commonly occur in southwestern Nigeria (and do not occur in northwestern Nigeria), the northwest African coast and the north African Tethyan Province. These relatively deeper neritic ostracods of southwestern Nigerian (of Midway-type), belonging to the Guinean Fauna1 Province (Foster et a/. 19831, could not live and migrate through the shallow Trans-Saharan Seaway. The alternative northward migration route was via the deeper northwestern African coast and then through the western Tethys. Bassiouni and Luger (1990) have already stated this idea. The common occurrence of Leguminocythereis lokossaensis Apostolescu in Senegal (Carbonnel, 19861, Libya (Barsotti, 1963) and Egypt. Also, the occurrence of Reticulina proteros Bassiouni in Senegal (Carbonnel, 1986), Tunisia (Donze et al. 19821, and Egypt (as stated in the present study and elsewhere) and Jordan (Bassiouni, 1969a). In addition, the disappearance of these forms in the Trans-Saharan Province support this alternative route of migration via the northwestern African coast. Moreover, Bertels (1969) noted the occurrence in Argentina of Soudanella and Leguminocythereis, which are already recorded here. She considered this occurrence to be closely related to west African forms, indicating a direct connection between these areas. From the aforementioned discussion, it is evident that the Egyptian ostracods have a strong affinity to that of north Africa, western Africa, the Carib-bean and South American regions, the western European Tethyan Province and the Middle East. These provinces were close to each other or even contiguous and connected by epicontinental seas, in which the exchange and mixing up of the fauna could have occurred. Editorial handling - T. Weissbrod

REFERENCES Al

Furaih, A.A.F., 1983. Paleocene Ostracode from the Umm Er Radhuma Arabia. Paleontological Contributions, 107, 6p.

and Lower Formation Umversity

Eocene of Saud1 Kansas

southwestern

Sinai,

Egypt

Apostolescu, V., 1961. Contribution B 1’6tude palbontologique (Ostracodes) et stratigraphique des bassins cr&ace et Tertiares de I’Afrique occidentale. Revue lnstitut FranCais P&role 16 (7-8), 779-867. Aref, M., 1995. Early Eocene Ostracoda from the Thebes Formation along the Red Sea Coast, Egypt. Egyptian Journal Geology 39 (l), 113-131. Barsotti, G., 1963. Paleocene ostracods of Libya (Sirte Basin) and their wide African distribution. Revue lnstitut FranCais PBtrole 18 (11). 1520-1535. Bassiounl, M.A.B., 1969a. Einige Buntonia and Soudanella Arten (Ostracoden, Crustacea) aus dem Eoztin von Jordanien. Paltiontologische Zeitschrift 43 (3-4). 205214. Bassiounl, M.A.B., 1969b. Etnige Costa und Carinocythereis (Reticulinal-Arten aus dem Paleozln und Eozln von Jordanien (Ostracoda). Neues Jahrbuch Geologische, Palsontologische Abhandlungen 134 (1 ), 1 - 16. Bassiouni, M.A.B., 1969~. Ostracoden aus dem Eoztin von Agypten. 1-Trachylebertdinae. Geologisches Jahrbuch 87, 383-426. Bassiounl, M.A.B., 19694. Ostracoden aus dem Eozln von ligypten. 2-Die unterfamilien Hemicytherinae, Thaerocytherinae und Campylocythennae. Geologisches Jahrbuch 88, 203-234. Basslounl, M.A.B., 1970. Ostracoda (Mauritsininae und Trachyleberidlnae) und lhre bedeutung fijr die biostratlgraphle des Maastricht und des Altertertilr von Jordanien. Belhefte Jahrbuch, 106, 5-52. Basslounl, M.A.B., 1971. Ostracoden aus dem Eoztin von Ijgypten. 3-Die unterfamilien Brachycythennae und Buntoninae. Geologisches Jahrbuch 89, 169-l 92. Basslouni, M.A.B., 1979. Brackish und marine Ostracoden (Cytherideinae, Hemicytherinae, Trachyleberidinae) aus dem Oligozln und Neogen der Tijrkei. Geologisches Jahrbuch 131, 3-l 95. Basslouni, M.A.B., Boukhary, M., Shamah, K., Blondeau, A., 1984. Middle Eocene ostracodes from Fayoum, Egypt. GBologie MBdlterranben XI (2). 181-l 92. Bassluoni, M.A.B., Luger, P., 1990. Maastrichtain to Early Eocene Ostracoda from southern Egypt: paleontology, paleoecology, paleogeography and biostratigraphy. Berliner Geowissenschaftlischen Abhandlungen (A), 120 (21, 755-928. Bassiouni, M.A.B., Luger, P., 1996. Middle Eocene Ostracoda from Northen Somalia. Courier Forschungsinstittit Senckenberg, 192, l-l 39. Benson, R.H., Berdan, W.A., van den Bold, W., Hanai, T., Hessland, I., Howe, H.V., Kesllng, R.V., Levinson, S.A., Reyment, R.A., Moore, R.C., Scott, H.W., Shaver, R.H., Sohn, I.G., Stover, L.F., Swain, F.M., Sylvester-Bradley, P.C., Wamwright, J., 1961. Arthropoda 3, Crustacea, Ostracoda. In: Moore, R.C. (Ed.), Treatise on invertebrate Paleontology, Part 0. Geological Society America, University of Kansas Press, 442~. Bertels, A., 1969. Estratgraffia del llmlte Cretacico-Tertiario en Patagonia septentrional. Revista Association Geologica Argentina 24, 41-54. Blondeau, J.G., 1971. Contrrbution B I’btude des ostracodes eochnes des basins de Campbon et de Saffre (LoireAtlantlque). Ph.D. th&se, Universitb Nantes, 157~. Bonaduce, G., Russo, A., 1984. The Miocene Ostracodes of Sardinia, Bollettino Societa Paleontologlca ltalianna 32 (2), 421-437. 1941. Ostracoden aus der Kreide des Bonnema, J.H., Untergrundes der nordijstlichen Niederlande. Natuurhistonsch Maandblad 29, 9-l 2; 30, l-6, 35~. Boukhary, M., Guernet, C., Mansour, H., 1982. Ostracodes du Tertaire infeneur de I’Egypt. Cahiers Micropalt+ontologle 1, 13-20.

Journal

of African

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Grekoff, N., 1969. Sur la valeur stratrgraphique et les relations paleogeographiques de quelques ostracodes du C&ace, du Paleocene et I’eocene inferieur d’Algerre onentale. Proceedings 3rd African Micropaleontologrcal Colloquium, Cairo, pp. 222-248. Guha, D.K., 1968. Ostracoda from Mrddle Eocene of Kuch, Gujarat State, Western India. 011 Natural Gas Commission, Bulletrn 5 (l), 83-92. Hartmann, G., Puri, H.S., 1974. Summary of neontological and paleontologrcal classification of Ostracoda. Mitteilungen Hamburg Zoologische Museum lnstitijt 70, 7-73. Haskins, C.W., 1968. Tertiary Ostracoda from the Isle of Wight and Barton, Hampshire, England, Part 1. Review Micropalaeontology 10, 250-260. Haskrns, C.W., 1970. Tertiary Ostracoda from the Isle of Wrght and Barton, Hampshire, England, Part V. Review Micropalaeontology 13, 13-29. Honrgstern, A., Rosenfeld, A., 1995. Paleocene ostracods from southern Israel. Revue Mrcropaleontologre 38 (11, 49-62. Honigstein, A., Rosenfeld, A., Benjamrni, C., 1991. Ostracods and foramtnrfera from the Early-Middle Eocene of Qeren Sartaba, Jordan Valley. Journal Micropalaeontology 10 (1 ), 95- 107. Howe, H.V., Law, J., 1936. Louisiana Vicksburg Oligocene Ostracoda. Louisiana Geological Surey Bulletin 7, l-30. Jones, T.R., 1857. A monograph of the Tertiary Entomostracea of England. Palaeontographical Society London, pp. 1-68. Jones, T.R., Sherborn, C.D., 1887. Further notes on the Tertrary Entomostracea of England, with special reference to those from the London Clay. Geologrcal Magazine 4 (9910), 385-392; 450-460. Keen, M., 1978. The Tertiary Paleogene. In: Bate, R.H., Robinson, E. (Eds.), A Stratrgraphical Index of British Ostracoda. Srel House Press, Lrverpool, pp. 385-450. Kerj, A.J., 1957. Eocene and Oligocene Ostracoda of Belgrum. Memorre lnstrtut Royale Scrence Naturelles Belgrque 136, I-210. Kerj, A.J., Kaasschieter, J.P.H., Drooger, W.C., 1955. The microfauna of the Aqurtanian - Burdrgalran of Verhandelingen Konrnklrjke southwest France. Nederlandse Akademie Wetenschappen Afdelrng Natuurkunde 1, lOl136. Khalrfa, H., Cronrn, T.M., 1979. Ostracodes de I’Eocene moyen de El-Sherkh Fadl, Est de Benr Mazar, HauteEgypte. Review Micropalaeontolgy 22 (31, 172-l 85. Khalifa, H., El-Younsy, A.R., El-Boukhary, M.A., 1984. The Cretaceous/Paleocene boundary as defined by Ostracodes at the North Western approach of Kharga Oasts, Western Desert. Bulletm Faculty Science, Assrut University 13 (11, 159-173. Khosla, S.C., 1978. Lower Miocene Ostracoda from Jamnagar and Porpander districts, Gujrat, India. Mrcropalaeontology 24 (31, 251-296. Monoston, M., 1985. Eocene ostracods from the Dorog Basin (Northern Transdanubra, Hungary). Akademija Kradd, Budapest, 214~. Moyes, J., 1965. Les ostracodes du Miocene Aquitanien. Essar Paleoecolgre, Stratrgraphrque, Paleogeographre, Drourllard edit., Bordeaux, 339p. Neufvrlle, E.M.H., 1979. Upper Cretaceous-Paleogene marine Ostracods from the Sergrpe-Alapoas Basin, northeastern Brazil. Bulletin Geologrcal Institute, Uppsala Unrversrty, N.S. 8, 135-172. Reyment, R.A., 1960. Studies Cretaceous and Lower Tertiary and Maastrichtran Ostracoda. Geology 10, 286~.

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