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The fossil Acrididae fromthe Oligocene of Izarra (Alava, Spain). The antiquity of gregarious behavior (Orthoptera, Caelifera)
THE FOSSIL ACRIDIDAE FROM THE OLIGOCENE OF IZARRA (ALAVA, SPAIN). THE ANTIQUITY OF GREGARIOUS BEHAVIOR (ORTHOPTERA, CAELIFERA)
ANTONIO ARILLO & VICENTE M. ORTUI~IO ARILLO A. & ORTUI~O V.M. 1997. The fossil Acrididae from the Oligocene of Izarra (Alava, Spain). The antiquity of gregarious behavior (Orthoptera, Caelifera). [Les Acrididae fossiles de l'Oligoc~ne d'Izarra (Alava, Espagne). L'anciennet~ du comportement gr~gaire (Orthoptera, Caelifera)]. GEOBIOS, 30, 2 : 231-234. Villeurbanne, le 17.05.1997. Manuscrit d~pos~ le 30.10.1995; accept~ d~finitivement le 30.01.1996. ABSTRACT - In this paper fossil Acrididae from Izarra (Alava, Spain) are studied, The site is dated as Oligocene and this is the oldest record of this family found in Spain. In this site Acrididae represent around 20 % of all the fossil insects. Commonly, in Tertiary sites, Caelifera occur as isolated specimens. The large percentage in Izarra could represent the oldest evidence of gregarious behavior between locusts. KEYWORDS: PALAEOENTOMOLOGY,CAELIFERA,ACRIDIDAE,OLIGOCENE, SPAIN, GREGARIOUS BEHAVIOR. RI~SUMI~ - Sont ~tudi~s ici les Acridedae fossiles d'Izarra (Alava, Espagne). Le gisement est dat5 de l'OligocSne ce qui fournit le plus ancien t~moignage pour cette famille en Espagne. Les Acricidae y repr~sentent environ 20% des insectes fossilis~s. Habituellement, dans les gisements tertiaires, les Caelifera sont repr~sent~s seulement par les exemplaires isol~s. Un pourcentage tel que celui d'Izarra pourrait ~tre la plus ancienne manifestation comme d'un comportement gr~gaire chez les orthopt~res. MOTS-CL]~S: PALI~AOENTOMOLOGIE, CAELIFERA, ACRIDADAE, OLIGOCI~NE, ESPAGNE, COMPORTEMENT GRI~GAIRE.
INTRODUCTION The Izarra fossil site is located in the province of Alava, about 2.5 km from this town. It was discovered in 1977 as a result of the construction of the motorway A-68 between Zaragoza and Bilbao. Its s t r a t i g r a p h y was brevely described by Fern~ndezMarrSn et al. (1979). Tertiary continental sediments, very rich in fossil insects, are dated as Oligocene. They are found overlying Cretaceous marine sediments. Fossil insects appear in lacustrine limestone nodules (with plant remains, crustaceans, snail shells and fishes) and its study has begun only recently (Arillo 1994; Nel & Arillo 1995; Nel et al. 1995). The fossiliferous nodules appear in a clay matrix. Acrididae are known as fossils only since Eocene, a l t h o u g h its origin probably occurs in the Cretaceous (Zeuner 1941; Sharov 1971; Jarzembowski & Ross 1993). Acrididae is a very common family today, being often the dominating group of insects in tropical
s a v a n n a h regions (Joyce 1978). However t h e y commonly appear as isolated specimens in all known fossil deposits, probably due to their living behavior in connection to open (and often arid) spaces far from the common insects fossiliferous sites, mainly lacustrine or amber deposits. Some extant Acrididae have gregarious behavior making mass migrations. In some species like the desert locust (Schistocerca gregaria) swarms m a y consist of 50 x 10 ~ individuals per k m 2 and m a y cover 1000 km 2 or more, eating 100.000 tons of fresh vegetation daily (Joyce, op.cit.). This species is polymorphic existing as two extreme types: the gregarious and the solitarious phases with morphological differences between both. Swarming is highly adaptative for species t h a t practice it and represents an i m p o r t a n t advantage when environmental conditions are adverse. This could have been important in the evolution of the group. So there are authors who t h i n k t h a t this mode of life is p r i m a r y for all Acrididae (Zakharov 1946) against the opinion of others who
232 "~ " " :~:~i
FIGURE 1 - a. A c r i d i d a e sp 1 JLB-005. b . A c r i d i d a e sp. 2 J F P - 0 0 4 . Scale b a r 5
!!.--
i
b
think t h a t this behavior is a modern adaptation (Bei-Bienko & Mischenko 1951 apud Sharov op.cit.). The low percentage of Acrididae in all known fossil insects deposits makes Sharov (op.cit.) t h i n k t h a t gregarious mode of life is a recent developm e n t in the evolution of Caelifera.
MATERIAL A lot of Oligocene Acrididae was identified from Izarra site, representing about 20% of all the fossil insects found in this locality. Most of them are represented as three-dimensional carapaces or as isolated and f r a g m e n t a r y fore wings, but there are also some hind wings, metafemora and abdomen. There are also an almost complete specimen here studied. Most of specimens belong to the N a t u r a l Sciences Museum of A]ava (Museo de Ciencias Naturales de Alava, MCNA), but there are some material belonging to private collectors in Vitoria (Alava), Mr. J.L. Bueso (JLB), Mr. J. Fernandez de Pinedo (JFP) and Mr. J. Sanz (JS).
SYSTEMATICS Order ORTHOPTERAOlivier, 1789 Suborder CAELIFERAAnder, 1939 Family ACRIDIDAELatreille, 1825 It is very possible t h a t all Neogene Acrididae belong to extant genera and even to living species (Sharov op.cit.) although several authors have described some new genera, but t h e y probably are s y n o n y m w i t h Recent g e n e r a (Zeuner 1941, 1942a, 1942bi 1944; Zhang 1989; Zhang et al. 1994) Acrididae 1, Gen. et sp. indet. All specimens are incomplete so we have selected some of them (the best preserved): MCNA-3752; MCNA-5177; MCNA-5474; MCNA-5475; JLB-005 and JS-277. The most complete specimen is JLB005 (Fig. 1): it is a laterally preserved fossil and it has a good body preservation. The length is around 42.5 mm. The head is rounded, with one eye preserved and basal parts of both antennae. The pronotum u n f o r t u n a t e l y is poorly preserved.
233 . ° .
FIGURE 2 - a. Acrididae sp. 1 MCNA-5177. b. Acrididae sp. 1 MCNA-3475. c. Acrididae sp. 1 MCNA-3752. d. Acrididae sp. 1 JS277. e. Acrididae sp. 2 MCNA3974. Scale b a r 5 m m .
°
•
°
-
.
.
.
.
.
.
-
.
,,,
~'-.-.~,(~,,'~ .
The fore-wing was about 32.5 mm long and 6.5 mm wide. The venation is preserved only in its distal part. Part of the legs I and II are preserved. Also the m e t a f e m u r is about 16.5 mm long (not reaching the end of the abdomen). The specimen MCNA-5475 has a shorter metafemur (about 14.5 mm long) but also part of the metatibia is preserved. Other fossils are isolated fore-wings with a length similar to that of JLB-005. The most important cha-
,
.
)
/','JJbgllV
J II
.
Jlt
.
/
.
.
.
.
.
.
--
racter is the absence of discoidal cell. Radial sector (Rs) has at least four secondary branches and the intercalar vein (I) is absent in the medial area. Although specimens are poorly preserved to provide a generic determination, the wing venation is very similar to the s u b f a m i l y C y r t a c a n t h a cridinae, mainly to some genera without discoidal cell as Anacridium Uv~ov, 1923 or Nomadacris UVA~OV, 1923 (Dirsch 1965).
234 Acrididae 2, Gen. et sp. indet. The s p e c i m e n J F P - 0 0 4 (Fig. lb) h a s only preserved p a r t of t h e fore-wing a n d a small p a r t of the a b d o m e n , b u t the v e n a t i o n is well preserved. I t clearly belongs to a different species s m a l l e r t h a n Acrididae 1. T h e m o s t i m p o r t a n t c h a r a c t e r is the p r e s e n c e of a discoidal cell. Radial sector (Rs) h a s four s e c o n d a r y b r a n c h e s a n d vein (I) is absent. T h e r e are n o t e n o u g h c h a r a c t e r s for a s u b f a m i l y
attribution.
PALAEOBIOLOGY It is highly probable that such a percentage of fossil Acrididae in t h e paleolake could be due to the p r e s e n c e of a m i g r a t o r y s w a r m . S u r e l y t h e surface of the lake w a s a t r a p for t h e s w a r m as it occurs t o d a y b e c a u s e locusts h a v e a poor capacity to fly a n d t h e m o v e m e n t of the s w a r m is m a i n l y due to t h e w i n d ( E v a n s 1984). I n this case I z a r r a could r e p r e s e n t the oldest k n o w n evidence of g r e g a r i o u s b e h a v i o r b e t w e e n locusts. Acknowledgements - We wish to express our gratitude to Dr. Andr6 Nel and to Dr. Wieslaw Krzeminski for their suggestions in the first version of the manuscript. Also we express our aknowledgement to the people of the Natural Sciences Museum of Alava, and to Mr. Jos~ Luis Bueso, Mr. Joseba Fernandez de Pinedo and Mr. Javier Sanz for the loan of their material. This work was made with the support of the Natural Sciences Museum of Alava.
REFERENCES ARmLO A. 1994 - Nota sobre una larva de Odonato del Oligoceno de Izarra (A]ava) en la colecci6n del Museo Geominero (Odonata, Anisoptera, Libellulidae). Bolet[n Geol6gico y Minero, 105, (4): 325-328. DIRSCH V.M. 1965 - The African Genera of Acridoidea. Cambridge University Press, 579 p. EVANS H.E. 1984 - Insect Biology. Addison-Wesley Publishing Company, 436 p. FERNANDEZ-MARRON T., OLIVE A., DEL OLMO P. & PORTERO J.M. 1979 - La flora terciaria del yaeimiento de Izarra (Alava) y sus implicaciones cronoestratigr~ficas. Boletin GeolSgico y Minero, 90: 6-12.
JARZEMBOWSKI E. • Ross A. 1993 - Arthropoda (Hexapoda: Insecta). In BENTONM.J. (ed.), The Fossil Record 2. Chapmann & Hall. London: 263-426. JOYCE R.J.V. 1978 - Schistocerca gregaria. In KRANTZJ., SCHMUTTERERH. & KOCHW. (eds), Diseases, Pest and Weeds in Tropical Crops. John Wiley & Sons. 666 p. NEL A. & ARILLOA. 1995 - R6vision de Mastotermes haidingeri (HEER, 1849). Description de deux nouveaux Mastotermes de l'Oligoc~ne de France et d'Espagne (Isoptera, Mastotermitidae). Bulletin de la Soci~tg entomologique de France, 100, (1): 67-74. NEL A., ARILLOA. & OmwuI~OV.M. (in press).- D~couverte du premier de l'Oligoc~ne d'Espagne. Bulletin de la
Socigtg entomologique de France. SHAROVA.G. 1971 - Phylogeny of the Orthopteroidea. Israel Program for Scientific Translations, 251 p. (Translated from: Sharov 1968 - Filogeniya ortopteroidnykh nasekomykh, in Russian). ZAKHAROVL.Z. 1976 - The genesis of the Instinct in Gregarious Locusts. Uchenye Zapiski Saratovskogo Gosudarstvennogo Universiteta, 16, (1): 168-173 [in Russian]. ZEUNER F.E. 1941 - The fossil Acrididae (Orth.Salt.). Part 1. Cantatopinae. Annals of Magazine of Natural History, 11, (8): 510-522. ZEUNER F.E. 1942a - The fossil Acrididae (Orth.Salt.) Part II. Oedipodinae. Annals of Magazine of Natural History, 11, (9): 128-134. ZEUNER F.E. 1942b - The fossil Acrididae (Orth.Salt.) Part III. Acridinae. Annals of Magazine of Natural History, 11, (9): 304-314. ZEUNER F.E. 1944 - The fossil Acrididae (Orth. Salt.) Part IV. Acrididae incertae sedis and Addendum to Catantopinae. Annals of Magazine of Natural History, 12, (2): 359-383. ZHAN~J. 1989 - Fossil insects from Shawang, Shadong, China. Shadong Science and Technology Publishing House, 459 p [In Chinese with abstract in English]. ZANG~J., SUN B. & ZHANGX. 1994 - Miocene insects and spiders from Shanwang, Shandong. Science Press, 298 p. [In Chinese with abstract in English]. A. ARILLO & V.M. ORTUNO Dpto. Biologia Animal I (Entomologia) Facultad de Ciencias Biol6gicas Universidad Complutense E-28040 Madrid
ANTONIO ARILLO & VICENTE M. ORTUI~IO ARILLO A. & ORTUI~O V.M. 1997. The fossil Acrididae from the Oligocene of Izarra (Alava, Spain). The antiquity of gregarious behavior (Orthoptera, Caelifera). [Les Acrididae fossiles de l'Oligoc~ne d'Izarra (Alava, Espagne). L'anciennet~ du comportement gr~gaire (Orthoptera, Caelifera)]. GEOBIOS, 30, 2 : 231-234. Villeurbanne, le 17.05.1997. Manuscrit d~pos~ le 30.10.1995; accept~ d~finitivement le 30.01.1996. ABSTRACT - In this paper fossil Acrididae from Izarra (Alava, Spain) are studied, The site is dated as Oligocene and this is the oldest record of this family found in Spain. In this site Acrididae represent around 20 % of all the fossil insects. Commonly, in Tertiary sites, Caelifera occur as isolated specimens. The large percentage in Izarra could represent the oldest evidence of gregarious behavior between locusts. KEYWORDS: PALAEOENTOMOLOGY,CAELIFERA,ACRIDIDAE,OLIGOCENE, SPAIN, GREGARIOUS BEHAVIOR. RI~SUMI~ - Sont ~tudi~s ici les Acridedae fossiles d'Izarra (Alava, Espagne). Le gisement est dat5 de l'OligocSne ce qui fournit le plus ancien t~moignage pour cette famille en Espagne. Les Acricidae y repr~sentent environ 20% des insectes fossilis~s. Habituellement, dans les gisements tertiaires, les Caelifera sont repr~sent~s seulement par les exemplaires isol~s. Un pourcentage tel que celui d'Izarra pourrait ~tre la plus ancienne manifestation comme d'un comportement gr~gaire chez les orthopt~res. MOTS-CL]~S: PALI~AOENTOMOLOGIE, CAELIFERA, ACRIDADAE, OLIGOCI~NE, ESPAGNE, COMPORTEMENT GRI~GAIRE.
INTRODUCTION The Izarra fossil site is located in the province of Alava, about 2.5 km from this town. It was discovered in 1977 as a result of the construction of the motorway A-68 between Zaragoza and Bilbao. Its s t r a t i g r a p h y was brevely described by Fern~ndezMarrSn et al. (1979). Tertiary continental sediments, very rich in fossil insects, are dated as Oligocene. They are found overlying Cretaceous marine sediments. Fossil insects appear in lacustrine limestone nodules (with plant remains, crustaceans, snail shells and fishes) and its study has begun only recently (Arillo 1994; Nel & Arillo 1995; Nel et al. 1995). The fossiliferous nodules appear in a clay matrix. Acrididae are known as fossils only since Eocene, a l t h o u g h its origin probably occurs in the Cretaceous (Zeuner 1941; Sharov 1971; Jarzembowski & Ross 1993). Acrididae is a very common family today, being often the dominating group of insects in tropical
s a v a n n a h regions (Joyce 1978). However t h e y commonly appear as isolated specimens in all known fossil deposits, probably due to their living behavior in connection to open (and often arid) spaces far from the common insects fossiliferous sites, mainly lacustrine or amber deposits. Some extant Acrididae have gregarious behavior making mass migrations. In some species like the desert locust (Schistocerca gregaria) swarms m a y consist of 50 x 10 ~ individuals per k m 2 and m a y cover 1000 km 2 or more, eating 100.000 tons of fresh vegetation daily (Joyce, op.cit.). This species is polymorphic existing as two extreme types: the gregarious and the solitarious phases with morphological differences between both. Swarming is highly adaptative for species t h a t practice it and represents an i m p o r t a n t advantage when environmental conditions are adverse. This could have been important in the evolution of the group. So there are authors who t h i n k t h a t this mode of life is p r i m a r y for all Acrididae (Zakharov 1946) against the opinion of others who
232 "~ " " :~:~i
FIGURE 1 - a. A c r i d i d a e sp 1 JLB-005. b . A c r i d i d a e sp. 2 J F P - 0 0 4 . Scale b a r 5
!!.--
i
b
think t h a t this behavior is a modern adaptation (Bei-Bienko & Mischenko 1951 apud Sharov op.cit.). The low percentage of Acrididae in all known fossil insects deposits makes Sharov (op.cit.) t h i n k t h a t gregarious mode of life is a recent developm e n t in the evolution of Caelifera.
MATERIAL A lot of Oligocene Acrididae was identified from Izarra site, representing about 20% of all the fossil insects found in this locality. Most of them are represented as three-dimensional carapaces or as isolated and f r a g m e n t a r y fore wings, but there are also some hind wings, metafemora and abdomen. There are also an almost complete specimen here studied. Most of specimens belong to the N a t u r a l Sciences Museum of A]ava (Museo de Ciencias Naturales de Alava, MCNA), but there are some material belonging to private collectors in Vitoria (Alava), Mr. J.L. Bueso (JLB), Mr. J. Fernandez de Pinedo (JFP) and Mr. J. Sanz (JS).
SYSTEMATICS Order ORTHOPTERAOlivier, 1789 Suborder CAELIFERAAnder, 1939 Family ACRIDIDAELatreille, 1825 It is very possible t h a t all Neogene Acrididae belong to extant genera and even to living species (Sharov op.cit.) although several authors have described some new genera, but t h e y probably are s y n o n y m w i t h Recent g e n e r a (Zeuner 1941, 1942a, 1942bi 1944; Zhang 1989; Zhang et al. 1994) Acrididae 1, Gen. et sp. indet. All specimens are incomplete so we have selected some of them (the best preserved): MCNA-3752; MCNA-5177; MCNA-5474; MCNA-5475; JLB-005 and JS-277. The most complete specimen is JLB005 (Fig. 1): it is a laterally preserved fossil and it has a good body preservation. The length is around 42.5 mm. The head is rounded, with one eye preserved and basal parts of both antennae. The pronotum u n f o r t u n a t e l y is poorly preserved.
233 . ° .
FIGURE 2 - a. Acrididae sp. 1 MCNA-5177. b. Acrididae sp. 1 MCNA-3475. c. Acrididae sp. 1 MCNA-3752. d. Acrididae sp. 1 JS277. e. Acrididae sp. 2 MCNA3974. Scale b a r 5 m m .
°
•
°
-
.
.
.
.
.
.
-
.
,,,
~'-.-.~,(~,,'~ .
The fore-wing was about 32.5 mm long and 6.5 mm wide. The venation is preserved only in its distal part. Part of the legs I and II are preserved. Also the m e t a f e m u r is about 16.5 mm long (not reaching the end of the abdomen). The specimen MCNA-5475 has a shorter metafemur (about 14.5 mm long) but also part of the metatibia is preserved. Other fossils are isolated fore-wings with a length similar to that of JLB-005. The most important cha-
,
.
)
/','JJbgllV
J II
.
Jlt
.
/
.
.
.
.
.
.
--
racter is the absence of discoidal cell. Radial sector (Rs) has at least four secondary branches and the intercalar vein (I) is absent in the medial area. Although specimens are poorly preserved to provide a generic determination, the wing venation is very similar to the s u b f a m i l y C y r t a c a n t h a cridinae, mainly to some genera without discoidal cell as Anacridium Uv~ov, 1923 or Nomadacris UVA~OV, 1923 (Dirsch 1965).
234 Acrididae 2, Gen. et sp. indet. The s p e c i m e n J F P - 0 0 4 (Fig. lb) h a s only preserved p a r t of t h e fore-wing a n d a small p a r t of the a b d o m e n , b u t the v e n a t i o n is well preserved. I t clearly belongs to a different species s m a l l e r t h a n Acrididae 1. T h e m o s t i m p o r t a n t c h a r a c t e r is the p r e s e n c e of a discoidal cell. Radial sector (Rs) h a s four s e c o n d a r y b r a n c h e s a n d vein (I) is absent. T h e r e are n o t e n o u g h c h a r a c t e r s for a s u b f a m i l y
attribution.
PALAEOBIOLOGY It is highly probable that such a percentage of fossil Acrididae in t h e paleolake could be due to the p r e s e n c e of a m i g r a t o r y s w a r m . S u r e l y t h e surface of the lake w a s a t r a p for t h e s w a r m as it occurs t o d a y b e c a u s e locusts h a v e a poor capacity to fly a n d t h e m o v e m e n t of the s w a r m is m a i n l y due to t h e w i n d ( E v a n s 1984). I n this case I z a r r a could r e p r e s e n t the oldest k n o w n evidence of g r e g a r i o u s b e h a v i o r b e t w e e n locusts. Acknowledgements - We wish to express our gratitude to Dr. Andr6 Nel and to Dr. Wieslaw Krzeminski for their suggestions in the first version of the manuscript. Also we express our aknowledgement to the people of the Natural Sciences Museum of Alava, and to Mr. Jos~ Luis Bueso, Mr. Joseba Fernandez de Pinedo and Mr. Javier Sanz for the loan of their material. This work was made with the support of the Natural Sciences Museum of Alava.
REFERENCES ARmLO A. 1994 - Nota sobre una larva de Odonato del Oligoceno de Izarra (A]ava) en la colecci6n del Museo Geominero (Odonata, Anisoptera, Libellulidae). Bolet[n Geol6gico y Minero, 105, (4): 325-328. DIRSCH V.M. 1965 - The African Genera of Acridoidea. Cambridge University Press, 579 p. EVANS H.E. 1984 - Insect Biology. Addison-Wesley Publishing Company, 436 p. FERNANDEZ-MARRON T., OLIVE A., DEL OLMO P. & PORTERO J.M. 1979 - La flora terciaria del yaeimiento de Izarra (Alava) y sus implicaciones cronoestratigr~ficas. Boletin GeolSgico y Minero, 90: 6-12.
JARZEMBOWSKI E. • Ross A. 1993 - Arthropoda (Hexapoda: Insecta). In BENTONM.J. (ed.), The Fossil Record 2. Chapmann & Hall. London: 263-426. JOYCE R.J.V. 1978 - Schistocerca gregaria. In KRANTZJ., SCHMUTTERERH. & KOCHW. (eds), Diseases, Pest and Weeds in Tropical Crops. John Wiley & Sons. 666 p. NEL A. & ARILLOA. 1995 - R6vision de Mastotermes haidingeri (HEER, 1849). Description de deux nouveaux Mastotermes de l'Oligoc~ne de France et d'Espagne (Isoptera, Mastotermitidae). Bulletin de la Soci~tg entomologique de France, 100, (1): 67-74. NEL A., ARILLOA. & OmwuI~OV.M. (in press).- D~couverte du premier de l'Oligoc~ne d'Espagne. Bulletin de la
Socigtg entomologique de France. SHAROVA.G. 1971 - Phylogeny of the Orthopteroidea. Israel Program for Scientific Translations, 251 p. (Translated from: Sharov 1968 - Filogeniya ortopteroidnykh nasekomykh, in Russian). ZAKHAROVL.Z. 1976 - The genesis of the Instinct in Gregarious Locusts. Uchenye Zapiski Saratovskogo Gosudarstvennogo Universiteta, 16, (1): 168-173 [in Russian]. ZEUNER F.E. 1941 - The fossil Acrididae (Orth.Salt.). Part 1. Cantatopinae. Annals of Magazine of Natural History, 11, (8): 510-522. ZEUNER F.E. 1942a - The fossil Acrididae (Orth.Salt.) Part II. Oedipodinae. Annals of Magazine of Natural History, 11, (9): 128-134. ZEUNER F.E. 1942b - The fossil Acrididae (Orth.Salt.) Part III. Acridinae. Annals of Magazine of Natural History, 11, (9): 304-314. ZEUNER F.E. 1944 - The fossil Acrididae (Orth. Salt.) Part IV. Acrididae incertae sedis and Addendum to Catantopinae. Annals of Magazine of Natural History, 12, (2): 359-383. ZHAN~J. 1989 - Fossil insects from Shawang, Shadong, China. Shadong Science and Technology Publishing House, 459 p [In Chinese with abstract in English]. ZANG~J., SUN B. & ZHANGX. 1994 - Miocene insects and spiders from Shanwang, Shandong. Science Press, 298 p. [In Chinese with abstract in English]. A. ARILLO & V.M. ORTUNO Dpto. Biologia Animal I (Entomologia) Facultad de Ciencias Biol6gicas Universidad Complutense E-28040 Madrid