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Late Devonian phoebodont (Pisces: Chondrichthyes) from the Confusion Range; Utah
LATE DEVONIAN PHOEBODONT (PISCES : CHONDRICHTHYES) FROM THE CONFUSION RANGE, UTAH I! ~28
SUSAN T U R N E R & WALTER Y O U N G Q U I S T TURNER S. & YOUNGQUIST W. 1995 - Late Devonian phoebodont (Pisces Chondrichthyes) from the Confusion Range, Utah. [Phoebodonte (pisces : chondrichthyes) du Ddvonien supdrieur de Confusion Range, Utah]. GEOBIOS, M.S. 19 : 389-392. ABSTRACT A small sample of phoebodontiform teeth confirms a Late Devonian (presumed late Frasnian rhenana conodont zone) sitein the Confusion Range of Utah, western U.S.A. KEY-WORDS :DEVONIAN, FRASNIAN, UNITED STATES, CHONDRICHTHYES, PHOEBODONTIDAE.
R~,SUM~, Un petit lot de dents de phoebodontiforme de Confusion Range de 12Jtah, U.S.A. occidentale confirme un Ctge d~vonien supdrieur (Frasnien sup~rieur, rhenana zone). MOTS-CLI~S : DI~VONIEN, FRASNIEN, I~TATS-UNIS,CHONDRICHTHYES,PHOEBODONTIDAE.
INTRODUCTION Devonian vertebrates have long been known from Lower to Middle? Devonian Water Canyon Fm. (late Lochkovian-Emsian or younger) of Utah, USA (e.g., Ilyes & Elliott 1993). Miller (1981) reported the oldest shark from U t a h which w a s a cladodont tooth of Carboniferous (late Mississippian) which he called "Cladodus" (actually a S y m m o r i u m sp.) from the Chesterian Great Blue Limestone Fm. This paper records the first Late Devonian fish and the first Devonian shark remains from the State from a restricted outcrop on the north east flank of the Confusion Range most probably from the late Frasnian. In 1950 one of us (WY, then of the University of Idaho) with his s u m m e r research assistant J e r r y Haegele visited the Confusion Range at the request of Phillips Petroleum to investigate cephalopods from an Upper Devonian locality in desert country discovered by field geologists E d w a r d Zeller and J a c k Mann, which WY identified as Manticoceras sp. Youngquist collected for conodonts and in the residue found instead several
small shark teeth which were transmitted to Dr Bobb Schaeffer of the American Museum of Natural History (AMNH), New York. In 1983 the senior author visited AMNH and discovered the specimens which were named Phoebodus? sp. Subsequent study and renewed field work to locate the original site has been in operation since 1993. The junior author has visited the Range on two occasions but as yet no new material has been located. The possibility that the shark teeth came from a small lens which has subsequently been eroded cannot be ruled out. New collecting of a contemporaneous site in Nevada (by WY in 1994) now under s t u d y should help to confirm the stratigraphic horizon of the original specimens.
GEOLOGY The t e e t h came from a restricted outcrop on the northeast flank of the Confusion Range most probably from the late Frasnian '(rhenana Zone) at the base of the Pilot Shale, (section in Sandberg et al. 1988, fig. 13). In an attempt to rediscover the original site and to explore the setting Youngquist has re-collected in the Confusion Range
390
2
3 4
s
9
Figure 1 - SEM p h o t o m i c r o g r a p h s of t e e t h of U t a h Late Devonian phoebodont, P h o e b o d u s b i f u r c a t u s G~N'PH~ & IVANOV. 1, A M N H 371.1, lingual view ; 2, A M N H 371.1, lateral view ; 3, A M N H 371.2, apical view ; 4, A M N H 371.2~ lingual view ; 5, A M N H 372.1, lingual view ; 6, A M N H 372.1, l a t e r a l view ; 7, A M N H 372.1, labial view ; 8, A M N H 372.2, lingual view ; 9, A M N H 372.1, labial view. Microphotographie S E M de dents de Phoebodon.te.~ du D(~vott.ien sup&ieur de l'Utah, P h o e b o d u s b i f u r c a t u s GINTHER (~ IVANOV. 1, A M N H 37l. l, rue linguale ; 2, A M N t I 37l. l, rue latdrale ; 3, A M N H 371.2, rue apicale : 4, A ~ I N H 371.2, rue linguale ; 5, A M N H 372,1, vtte linguale ; 6, A M N H 372.1, vue lat&ale ; 7, ~ F I N H 372.1, utte labiale ; 8, A M N H 372.2, vtte lingttale : 9, A M N H 372.1, uue labiale.
391 Figure 2 - S k e t c h e s of basal view of t e e t h of U t a h Late Dev o n i a n phoebodonte Phoebod u s b i f u r c a t u s GINTHER IVANOV. 1, A M N H 371.1 ; 2, A M N H 372.2 (Scale b a r = 0.2 m m ; both a p p r o x i m a t e l y to scale). Dessins en vue basale de dents de P h o e b o d u s bifur. c a t u s GINTHER • IYANOV, du Dgvonien supgrieur de l'Utah. 1, A M N H 371.1 ; 2, A M N H 372.2 (E,chelle = 0,2 ram).
(CON on Sandberg et al. 1988, map 12). At a site in the lower m e m b e r of the Pilot Shale of Nevada (Manticoceras Zone ; section in Sandberg et al. fig. 11) occurs a thin siliceous band about 120 mm thick rich in Palmatolepis sp. (presumably P. semichatovae) associated with fish remains in the top 15 m m preserved in vivianite (see also Hilpman 1956), which are now under investigation. SYSTEMATIC
PALEONTOLOGY
Class C H O N D R I C H T H Y E S Huxley, 1880 Family P H O E B O D O N T I D A E Williams, 1985 P H O E B O D U S B I F U R C A T U S GINTER • IVANOV, 1992 : Figs 1, 2. M a t e r i a l - Five teeth, one a broken cusp : Youngquist & Haegele coll. 1950 AMNH 371- 372. L o c a l i t y - Approximately 114 37' W 39 28' N, 8 k m north of Skunk Springs, north east flank of western Confusion Range, U t a h
Stratigraphy - basal m e m b e r Pilot Shale, rhenana Conodont Zone, upper Frasnian, Upper Devonian. M e a s u r e m e n t s - Largest tooth is l m m across the (AMNH 372a) others 0.5mm or less.
Description
- Crown of three to five cusps. Each cusp has a rhombic cross-section towards the tip; more rounded proximally on the lingual side. Labial lip prominent. Dorso-Lingual round-elongate raised torus with 2-3 prominent foramina at the lingual basasl rim. Base shape strongly bifurcated or horshoe shaped (Fig. 2). Basal concavity rounded with few 2-3 prominent foramina housed in elongate pits. Only one specimen shows wellpreserved cusps and these are widely separated and all have a distinct lateral carina (Figs. 1.3,4)
; this tooth (372a) has an elongated ovoid base which is not bifurcated. The specimen with widely-spaced cusps (Figs. 1.3,4) can only tentatively be referred to P. bifurcatus because of its damaged base. R e m a r k s - Phoebodus bifurcatus was described from the Frasnian of Poland and Russian platform and is known also from Lesni Lom Quarry in the Czech Republic (Ginter in Hladil et al. 1991, pl. 8.1) but is not previously known from the U.S.A. The U t a h specimens can be compared especially with the so-called juvenile tooth from Timan (Ginter & Ivanov 1992, fig. 4A) from certain gigas (now rhenana) conodont zone. Clearly the smaller (juvenile/early ontogentic teeth) are more strongly birfurcated which might reflect a difference in the juvenile diet of these sharks. The phoebodont occurs with palmatolepid conodonts and Manticoceras. We postulate that either conodont animals or more likely cephalopods made up the diet of these sharks with grasping teeth in a comparable manner to the modern Frilled shark Chlamydoselachus which eats squids and has an extremely similar tooth pattern. S i g n i f i c a n c e - Phoebodont sharks were first decribed from the USA by St John & Worthen (1875) and under the name "Diplodus" by Eastman (1899) from late Middle (now presumed early Frasnian of Illinois and Iowa) (see discussion in Turner in press) and Upper Devonian. Phoebodus species are now known to be widespread in the mid to late Devonian of central and eastern Europe, South-east asia and Australia (e.g. Ginter & Ivanov 1992, this volume). This is the farthest west in continental North America that a phoebodont has been recorded. The record of a phoebodont shark in relatively deep water shales confirms the spread of the massive IId transgression of Johnson & Murphy
392 (1984), Johnson & Sandberg (1988), and Sandb e r g et al. (1988) into t h e w e s t e r n U.S.A. The e u s t a t i c rise w h i c h b r o u g h t p o s t u l a t e d connections w i t h M i d c o n t i n e n t U S A ( S a n d b e r g et al. 1988, fig. 12) w o u l d h a v e allowed t h e rapid disp e r s a l of p h o e b o d o n t s h a r k s . The s u b s e q u e n t eust a t i c fall in t h e l a t e s t F r a s n i a n / e a r l y F a m e n n i a n r e s u l t e d in t h e m o s t s e v e r e Palaeozoic extinction recorded ( J o h n s o n & S a n d b e r g 1985) a n d certainly no definite L o w e r F a m e n n i a n p h o e b o d o n t s are k n o w n from t h e U.S.A. a l t h o u g h p r e s u m e d L a z a r u s species a p p e a r in the L a t e F a m e n n i a n (e.g., E a s t m a n 1899, Gross 1973). A c k n o w l e d g e m e n t s - We heartily thank Edward Zeller (now Space Technology Center, University of Kansas), Michal Ginter (Faculty Geology, Warsaw), Gary Webster (Washington State University) for information and discussion, and Kathy Wolfram and John Maisey (AMNH) for loan of specimens in their care. Dora Aitken carried out SEM work at the Queensland Museum under the auspices of Australian Research Coucil grant n ° A39132723. This is a contribution to IGCP 328. Palaeozoic Microvertebrates.
REFERENCES EASTMAN C.R. 1899 - Descriptions of new species of Diplodus teeth from the Devonian of northeastern Illinois. Journal Geology, 7 : 489-493. GINTER M. & IVANOVA. 1992 - Devonian phoebodont shark teeth. Acta Palaeontologica Polonica, 40 : 6981. GINTER M & IVANOVA. 1995 - Middle/Late Devonian phoebodont-based ichthyolith zonation. VIIIth E/LV Symposium, Paris 4-8 Sept. In H. LELII~VRE, S. WENZ, A. BLIECK & R. CLOUTIER (eds.) : Premiers Vertebras et Vertebras inf~rieurs. Geobios, M.S. 19: 351-355. GROSS W. 1973 - Kleinschuppen, Flossenstacheln und Z~hne yon Fischen aus europ~iischen und nordamerikanischen Bonebeds des Devons. Palaeontographica Abteilung A, 142 : 51-155. HILPMAN P.L. 1956 - Geology of the Easy Ridge Area, White Pine County, Nevada. Master's Thesis, Uni-
versity of Kansas, Lawrence, Kansas : 72 p. (unpublished). HLADIL J., KREJCI Z., KALVODAJ., GINTER M., GALLE A. & BEROUSEKP. 1991 - Carbonate ramp environment of Kellwasser time-interval (Lesni Lom, Moravia, Czechoslovakia). Bulletin de la Socidt~ belge de Gdologie, 100 : 57-119. ILYES R.R. & ELLIOTT D.I~ 1993 - The significance of Lower Devonian vertebrate-bearing deposits of western North America. In S. TURNER (ed.) : IGCP328 : SDS The Gross Symposium, Scientific Sessions, GNttingen 4-6 Aug. 1993, Abstracts, University of Lille. JOHNSON J.G., KLAPPER G. & SANDBERG C.A. 1985 Devonian eustatic fluctuations in Euramerica. Bulletin of the geological Society of America, 96 : 567587. JOHNSON J.G. & SANDBERGC.A. 1988 - Devonian eustatic events in the western United States and their biostratigraphic responses. Devonian of the World.
Canadian Society of Petroleum Geologists, Memoirs 14, (3) : 171-178. JOHNSON J.G. & MURPHYM.A. 1984 - Time-rock model for Siluro-Devonian continental shelf, western United States. Geological Society of American Bulletin 95 : 1349-1359. MILLER W.E. 1981 - Cladodont shark teeth from Utah. Journal. of Paleontology, 55 : 894-895. ST JOHN O. & WORTHEN A.H. 1875 - Descriptions of fossil fishes. Geological Survey of Illinois 6, part 2 Palaeontology, 1 : 245-488. SANDBERG C.A., POOLE F.G. & JOHNSON J.G. 1988 Upper Devonian of western United States. Devonian of the World. Canadian Society of Petroleum Geologists, Memoirs, 14, (1) : 183-20. TURNER S. (in press) - "Dittodus" species of Eastman 1899 and Hussakof and Bryant 1918 (Mid to Late Devonian). In W. WIMBLEDON, S. TURNER & A. BLIECK (eds) : IGCP 328 : SDS, The Walter Gross Symposium. Modern Geology.
S. TURNER Queensland Museum P.O. Box 3300 S. Brisbane, Qd 4101, Australia W. YOUNGQUIST P.O. Box 5501 Eugene, Oregon 97405, U.S.A.
SUSAN T U R N E R & WALTER Y O U N G Q U I S T TURNER S. & YOUNGQUIST W. 1995 - Late Devonian phoebodont (Pisces Chondrichthyes) from the Confusion Range, Utah. [Phoebodonte (pisces : chondrichthyes) du Ddvonien supdrieur de Confusion Range, Utah]. GEOBIOS, M.S. 19 : 389-392. ABSTRACT A small sample of phoebodontiform teeth confirms a Late Devonian (presumed late Frasnian rhenana conodont zone) sitein the Confusion Range of Utah, western U.S.A. KEY-WORDS :DEVONIAN, FRASNIAN, UNITED STATES, CHONDRICHTHYES, PHOEBODONTIDAE.
R~,SUM~, Un petit lot de dents de phoebodontiforme de Confusion Range de 12Jtah, U.S.A. occidentale confirme un Ctge d~vonien supdrieur (Frasnien sup~rieur, rhenana zone). MOTS-CLI~S : DI~VONIEN, FRASNIEN, I~TATS-UNIS,CHONDRICHTHYES,PHOEBODONTIDAE.
INTRODUCTION Devonian vertebrates have long been known from Lower to Middle? Devonian Water Canyon Fm. (late Lochkovian-Emsian or younger) of Utah, USA (e.g., Ilyes & Elliott 1993). Miller (1981) reported the oldest shark from U t a h which w a s a cladodont tooth of Carboniferous (late Mississippian) which he called "Cladodus" (actually a S y m m o r i u m sp.) from the Chesterian Great Blue Limestone Fm. This paper records the first Late Devonian fish and the first Devonian shark remains from the State from a restricted outcrop on the north east flank of the Confusion Range most probably from the late Frasnian. In 1950 one of us (WY, then of the University of Idaho) with his s u m m e r research assistant J e r r y Haegele visited the Confusion Range at the request of Phillips Petroleum to investigate cephalopods from an Upper Devonian locality in desert country discovered by field geologists E d w a r d Zeller and J a c k Mann, which WY identified as Manticoceras sp. Youngquist collected for conodonts and in the residue found instead several
small shark teeth which were transmitted to Dr Bobb Schaeffer of the American Museum of Natural History (AMNH), New York. In 1983 the senior author visited AMNH and discovered the specimens which were named Phoebodus? sp. Subsequent study and renewed field work to locate the original site has been in operation since 1993. The junior author has visited the Range on two occasions but as yet no new material has been located. The possibility that the shark teeth came from a small lens which has subsequently been eroded cannot be ruled out. New collecting of a contemporaneous site in Nevada (by WY in 1994) now under s t u d y should help to confirm the stratigraphic horizon of the original specimens.
GEOLOGY The t e e t h came from a restricted outcrop on the northeast flank of the Confusion Range most probably from the late Frasnian '(rhenana Zone) at the base of the Pilot Shale, (section in Sandberg et al. 1988, fig. 13). In an attempt to rediscover the original site and to explore the setting Youngquist has re-collected in the Confusion Range
390
2
3 4
s
9
Figure 1 - SEM p h o t o m i c r o g r a p h s of t e e t h of U t a h Late Devonian phoebodont, P h o e b o d u s b i f u r c a t u s G~N'PH~ & IVANOV. 1, A M N H 371.1, lingual view ; 2, A M N H 371.1, lateral view ; 3, A M N H 371.2, apical view ; 4, A M N H 371.2~ lingual view ; 5, A M N H 372.1, lingual view ; 6, A M N H 372.1, l a t e r a l view ; 7, A M N H 372.1, labial view ; 8, A M N H 372.2, lingual view ; 9, A M N H 372.1, labial view. Microphotographie S E M de dents de Phoebodon.te.~ du D(~vott.ien sup&ieur de l'Utah, P h o e b o d u s b i f u r c a t u s GINTHER (~ IVANOV. 1, A M N H 37l. l, rue linguale ; 2, A M N t I 37l. l, rue latdrale ; 3, A M N H 371.2, rue apicale : 4, A ~ I N H 371.2, rue linguale ; 5, A M N H 372,1, vtte linguale ; 6, A M N H 372.1, vue lat&ale ; 7, ~ F I N H 372.1, utte labiale ; 8, A M N H 372.2, vtte lingttale : 9, A M N H 372.1, uue labiale.
391 Figure 2 - S k e t c h e s of basal view of t e e t h of U t a h Late Dev o n i a n phoebodonte Phoebod u s b i f u r c a t u s GINTHER IVANOV. 1, A M N H 371.1 ; 2, A M N H 372.2 (Scale b a r = 0.2 m m ; both a p p r o x i m a t e l y to scale). Dessins en vue basale de dents de P h o e b o d u s bifur. c a t u s GINTHER • IYANOV, du Dgvonien supgrieur de l'Utah. 1, A M N H 371.1 ; 2, A M N H 372.2 (E,chelle = 0,2 ram).
(CON on Sandberg et al. 1988, map 12). At a site in the lower m e m b e r of the Pilot Shale of Nevada (Manticoceras Zone ; section in Sandberg et al. fig. 11) occurs a thin siliceous band about 120 mm thick rich in Palmatolepis sp. (presumably P. semichatovae) associated with fish remains in the top 15 m m preserved in vivianite (see also Hilpman 1956), which are now under investigation. SYSTEMATIC
PALEONTOLOGY
Class C H O N D R I C H T H Y E S Huxley, 1880 Family P H O E B O D O N T I D A E Williams, 1985 P H O E B O D U S B I F U R C A T U S GINTER • IVANOV, 1992 : Figs 1, 2. M a t e r i a l - Five teeth, one a broken cusp : Youngquist & Haegele coll. 1950 AMNH 371- 372. L o c a l i t y - Approximately 114 37' W 39 28' N, 8 k m north of Skunk Springs, north east flank of western Confusion Range, U t a h
Stratigraphy - basal m e m b e r Pilot Shale, rhenana Conodont Zone, upper Frasnian, Upper Devonian. M e a s u r e m e n t s - Largest tooth is l m m across the (AMNH 372a) others 0.5mm or less.
Description
- Crown of three to five cusps. Each cusp has a rhombic cross-section towards the tip; more rounded proximally on the lingual side. Labial lip prominent. Dorso-Lingual round-elongate raised torus with 2-3 prominent foramina at the lingual basasl rim. Base shape strongly bifurcated or horshoe shaped (Fig. 2). Basal concavity rounded with few 2-3 prominent foramina housed in elongate pits. Only one specimen shows wellpreserved cusps and these are widely separated and all have a distinct lateral carina (Figs. 1.3,4)
; this tooth (372a) has an elongated ovoid base which is not bifurcated. The specimen with widely-spaced cusps (Figs. 1.3,4) can only tentatively be referred to P. bifurcatus because of its damaged base. R e m a r k s - Phoebodus bifurcatus was described from the Frasnian of Poland and Russian platform and is known also from Lesni Lom Quarry in the Czech Republic (Ginter in Hladil et al. 1991, pl. 8.1) but is not previously known from the U.S.A. The U t a h specimens can be compared especially with the so-called juvenile tooth from Timan (Ginter & Ivanov 1992, fig. 4A) from certain gigas (now rhenana) conodont zone. Clearly the smaller (juvenile/early ontogentic teeth) are more strongly birfurcated which might reflect a difference in the juvenile diet of these sharks. The phoebodont occurs with palmatolepid conodonts and Manticoceras. We postulate that either conodont animals or more likely cephalopods made up the diet of these sharks with grasping teeth in a comparable manner to the modern Frilled shark Chlamydoselachus which eats squids and has an extremely similar tooth pattern. S i g n i f i c a n c e - Phoebodont sharks were first decribed from the USA by St John & Worthen (1875) and under the name "Diplodus" by Eastman (1899) from late Middle (now presumed early Frasnian of Illinois and Iowa) (see discussion in Turner in press) and Upper Devonian. Phoebodus species are now known to be widespread in the mid to late Devonian of central and eastern Europe, South-east asia and Australia (e.g. Ginter & Ivanov 1992, this volume). This is the farthest west in continental North America that a phoebodont has been recorded. The record of a phoebodont shark in relatively deep water shales confirms the spread of the massive IId transgression of Johnson & Murphy
392 (1984), Johnson & Sandberg (1988), and Sandb e r g et al. (1988) into t h e w e s t e r n U.S.A. The e u s t a t i c rise w h i c h b r o u g h t p o s t u l a t e d connections w i t h M i d c o n t i n e n t U S A ( S a n d b e r g et al. 1988, fig. 12) w o u l d h a v e allowed t h e rapid disp e r s a l of p h o e b o d o n t s h a r k s . The s u b s e q u e n t eust a t i c fall in t h e l a t e s t F r a s n i a n / e a r l y F a m e n n i a n r e s u l t e d in t h e m o s t s e v e r e Palaeozoic extinction recorded ( J o h n s o n & S a n d b e r g 1985) a n d certainly no definite L o w e r F a m e n n i a n p h o e b o d o n t s are k n o w n from t h e U.S.A. a l t h o u g h p r e s u m e d L a z a r u s species a p p e a r in the L a t e F a m e n n i a n (e.g., E a s t m a n 1899, Gross 1973). A c k n o w l e d g e m e n t s - We heartily thank Edward Zeller (now Space Technology Center, University of Kansas), Michal Ginter (Faculty Geology, Warsaw), Gary Webster (Washington State University) for information and discussion, and Kathy Wolfram and John Maisey (AMNH) for loan of specimens in their care. Dora Aitken carried out SEM work at the Queensland Museum under the auspices of Australian Research Coucil grant n ° A39132723. This is a contribution to IGCP 328. Palaeozoic Microvertebrates.
REFERENCES EASTMAN C.R. 1899 - Descriptions of new species of Diplodus teeth from the Devonian of northeastern Illinois. Journal Geology, 7 : 489-493. GINTER M. & IVANOVA. 1992 - Devonian phoebodont shark teeth. Acta Palaeontologica Polonica, 40 : 6981. GINTER M & IVANOVA. 1995 - Middle/Late Devonian phoebodont-based ichthyolith zonation. VIIIth E/LV Symposium, Paris 4-8 Sept. In H. LELII~VRE, S. WENZ, A. BLIECK & R. CLOUTIER (eds.) : Premiers Vertebras et Vertebras inf~rieurs. Geobios, M.S. 19: 351-355. GROSS W. 1973 - Kleinschuppen, Flossenstacheln und Z~hne yon Fischen aus europ~iischen und nordamerikanischen Bonebeds des Devons. Palaeontographica Abteilung A, 142 : 51-155. HILPMAN P.L. 1956 - Geology of the Easy Ridge Area, White Pine County, Nevada. Master's Thesis, Uni-
versity of Kansas, Lawrence, Kansas : 72 p. (unpublished). HLADIL J., KREJCI Z., KALVODAJ., GINTER M., GALLE A. & BEROUSEKP. 1991 - Carbonate ramp environment of Kellwasser time-interval (Lesni Lom, Moravia, Czechoslovakia). Bulletin de la Socidt~ belge de Gdologie, 100 : 57-119. ILYES R.R. & ELLIOTT D.I~ 1993 - The significance of Lower Devonian vertebrate-bearing deposits of western North America. In S. TURNER (ed.) : IGCP328 : SDS The Gross Symposium, Scientific Sessions, GNttingen 4-6 Aug. 1993, Abstracts, University of Lille. JOHNSON J.G., KLAPPER G. & SANDBERG C.A. 1985 Devonian eustatic fluctuations in Euramerica. Bulletin of the geological Society of America, 96 : 567587. JOHNSON J.G. & SANDBERGC.A. 1988 - Devonian eustatic events in the western United States and their biostratigraphic responses. Devonian of the World.
Canadian Society of Petroleum Geologists, Memoirs 14, (3) : 171-178. JOHNSON J.G. & MURPHYM.A. 1984 - Time-rock model for Siluro-Devonian continental shelf, western United States. Geological Society of American Bulletin 95 : 1349-1359. MILLER W.E. 1981 - Cladodont shark teeth from Utah. Journal. of Paleontology, 55 : 894-895. ST JOHN O. & WORTHEN A.H. 1875 - Descriptions of fossil fishes. Geological Survey of Illinois 6, part 2 Palaeontology, 1 : 245-488. SANDBERG C.A., POOLE F.G. & JOHNSON J.G. 1988 Upper Devonian of western United States. Devonian of the World. Canadian Society of Petroleum Geologists, Memoirs, 14, (1) : 183-20. TURNER S. (in press) - "Dittodus" species of Eastman 1899 and Hussakof and Bryant 1918 (Mid to Late Devonian). In W. WIMBLEDON, S. TURNER & A. BLIECK (eds) : IGCP 328 : SDS, The Walter Gross Symposium. Modern Geology.
S. TURNER Queensland Museum P.O. Box 3300 S. Brisbane, Qd 4101, Australia W. YOUNGQUIST P.O. Box 5501 Eugene, Oregon 97405, U.S.A.