Articles

Print Email

The oldest record of gnathostome fossils from Greece: Chondrichthyes from the Lopingian of Hydra Island

Thodoris Argyriou, Carlo Romano, Jorge D. Carrillo-Briceño, Morgane Brosse, and Richard Hofmann

Plain Language Abstract

Until now, no jawed vertebrate (fishes and tetrapods) fossils were known from Paleozoic deposits in Greece. Recent fieldwork on Hydra Island, Western Aegean Sea, brought to light some 255 million year old shark remains. Tooth anatomy suggests that the Hydriot shark fed on hard, likely shelled prey, and shows anatomical similarities with other iconic Paleozoic and Mesozoic bottom feeding sharks. However, fine anatomical differences, like tooth ornamentation, do not allow us to include the Hydriot shark in any previously known species. The Hydriot shark material is not only the first known occurrence of jawed vertebrates in Greece, but also corresponds to one of the few occurrences of such animals in the late Paleozoic sediments of the Paleotethyan Ocean.

Resumen en Español

El registro más antiguo de gnatóstomos fósiles de Grecia: Condrictios del Lopingiense de la isla de Hidra

Los yacimientos del Pérmico de la isla de Hidra, Grecia, se conocen desde hace más de un siglo y albergan algunas de las asociaciones de invertebrados más estudiadas y más diversas del antiguo Océano Paleotetis. Sin embargo, hasta ahora, no se habían encontrado fósiles paleozoicos de vertebrados con mandíbula en Grecia. Los trabajos de campo recientes en la isla de Hidra sacaron a la luz raros restos de peces cartilaginosos, incluyendo un diente perteneciente a un tiburón desconocido del orden Hybodontiformes, así como un dentículo dérmico no identificable de un tiburón Euselachii. A pesar de las similitudes con los icónicos Euselachii durófagos del Paleozoico y Mesozoico, el diente de Hidra probablemente corresponde a una nueva especie, pero provisionalmente se hace uso de la nomenclatura abierta hasta que se disponga de más ejemplares. Los nuevos fósiles de condrictios de la isla de Hidra corresponden a uno de los pocos registros del Lopingiense (Permico tardío) conocidos para el Paleotetis. Además, constituyen el registro más antiguo de fósiles de vertebrados con mandíbula de Grecia, y son más de 50 millones de años más antiguos que los registros más antiguos hasta ahora en este país.

Palabras clave: Pérmico tardío; Paleotetis; peces fósiles; Hybodontiformes; Isla de Hidra; Grecia

Traducción: Enrique Peñalver (Sociedad Española de Paleontología) 

Résumé en Français

La plus ancienne occurrence de fossiles de gnathostomes en Grèce : des fossiles de Chondrichthyes du Lopingien de l'île d'Hydra

Les dépôts permiens de l'île d'Hydra, Grèce, sont connus depuis plus d'un siècle et incluent certains des assemblages d'invertébrés les mieux étudiés et les plus divers de l'ancien océan Paléotéthys. Cependant, aucun fossile paléozoïque de vertébrés à mâchoires n'avait été signalé en Grèce jusqu'à maintenant. Un travail de terrain sur l'île d'Hydra a récemment permis de mettre à jour de rares restes de poissons cartilagineux, incluant une dent qui appartient à un requin hybodontiforme inconnu, ainsi qu'un denticule cutané non identifiable d'un requin eusélacien. Malgré des similarités avec les eusélaciens durophages emblématiques du Paléozoïque et du Mésozoïque, la dent de l'île d'Hydra correspond probablement à une nouvelle espèce, mais elle est laissée pour l'instant en nomenclature ouverte en attendant que plus de matériel soit disponible. Les nouveaux fossiles de l'île d'Hydra correspondent à une des rares occurrences lopingiennes (Permien récent) connues dans la Paléotéthys. De plus, ils constituent la plus ancienne occurrence de fossiles de vertébrés à mâchoires en Grèce, étant antérieurs aux occurrences plus récentes de plus de 50 millions d'années.

Mots-clés : Permien récent ; Paléotéthys ; poissons fossiles ; Hybodontiformes ; île d'Hydra ; Grèce

Translator: Antoine Souron

Deutsche Zusammenfassung

Der älteste Nachweis fossiler Gnathostomen aus Griechenland: Chondrichthyes aus dem Lopingium von Hydra

Die permischen Ablagerungen auf Hydra, Griechenland, sind seit über einem Jahrhundert bekannt. Sie beherbergen eine der am besten untersuchten und vielfältigsten Invertebraten-Assemblage der Paläotethys. Über kiefertragende Wirbeltiere aus Griechenland wurde bis jetzt jedoch noch nicht berichtet. Jüngste Ausgrabungen auf Hydra brachten Überreste von Knorpelfischen zu Tage, inklusive eines Zahnes von einem unbekannten hybodontiformen Hai, ebenso wie ein nicht identifizierbarer Dermaldentikel eines Euselachiers. Trotz Ähnlichkeiten mit den ikonischen paläozoischen und mesozoischen durophagen Euselachiern, gehört der Zahn von Hydra eher zu einer neuen Art. Er wurde jedoch provisorisch in der offenen Nomenklatur belassen bis mehr Material zur Verfügung steht. Die neuen Chondrichthyer-Fossilien von Hydra stimmen mit einem der wenigen Vorkommen aus dem Lopingium (spätes Perm) aus der Paläotethys überein. Darüber hinaus enthalten sie den ältesten Fossilnachweis von kiefertragenden Wirbeltieren aus Griechenland und sind mehr als 50 Millionen Jahre jünger als die bisher bekannten jüngsten Vorkommen.

Schlüsselwörter: spätes Perm; Paläotethys; fossiler Fisch; Hybodontiformes; Hydra; Griechenland

Translator: Eva Gebauer

Arabic

Translator: Ashraf M.T. Elewa

 

 

FIGURE 1. Geographical and geological context of the Hydriot chondrichthyan fossils. 1, Map of Greece showing the location of Hydra Island; 2, Outcrop map of Hydra Island showing the location of the sampled section “EP” south of the village of Episkopi. Outcrop map after Grant et al. (1991); 3, Stratigraphic section of the Episkopi Formation showing the provenance (“EP-Z”) of the examined gnathostome fossils.

 figure1

FIGURE 2. Chondrichthyan material from Hydra. 1-5, Hybodontiformes indet. tooth (AMPG 550) in occlusal (1), basal ( 2), presumed lingual (3), profile (4), and presumed labial (5) views. Scale bar equals 5 mm. 6, Euselachii indet. dermal denticle (AMPG 551) in anterolateral view. Scale bar equals 100 μm.

figure2

 

argyriouThodoris Argyriou. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland. This email address is being protected from spambots. You need JavaScript enabled to view it.

Thodoris completed his B.Sc. in Geology at the National and Kapodistrian University of Athens and his M.Sc. in Evolution and Systematics at the University of Alberta. He is currently pursuing a Ph.D. in Evolutionary Biology at the Paleontological Institute and Museum of the University of Zurich. His research interests lie in the field of paleoichthyology, and more specifically on the early evolutionary history, paleobiology and interrelationships of ray-fin fishes. Other research interests relate to the evolution and systematics of cartilaginous fishes, as well as the evolution and biogeography of the African freshwater ichthyofauna. He has conducted fieldwork in different countries in Europe, North Africa and North America.

divider

romanoCarlo Romano. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland. This email address is being protected from spambots. You need JavaScript enabled to view it.

Carlo studied biology at the University of Zurich, Switzerland, and completed his Master's and doctor's degree in Paleontology. His primary research interest are Permian and Triassic chondrichthyan and osteichthyan fishes, with regard to their diversity, taxonomy and evolution. His secondary research interest is oxygen isotope geochemistry.

divider

carrilloJorge D. Carrillo-Briceño. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland. This email address is being protected from spambots. You need JavaScript enabled to view it.

Jorge is Geographer and Magister in Oceanography with ample field and lab experience in diverse South American countries. He recently earned his Ph.D. in Evolutionary Biology at the Palaeontological Institute and Museum of the University of Zurich. His research interest is the diversity and paleobiology of Mesozoic and Cenozoic Chondrichthyans from Tropical America.

divider

brosseMorgane Brosse. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland. This email address is being protected from spambots. You need JavaScript enabled to view it.

Morgane Brosse completed her Master's degree in geology at the University of Burgundy (France). She is currently finishing her PhD at the Palaeontological Institute and Museum of the University of Zurich (Switzerland). Her research interest is the biotic recovery in the aftermath of the end-Permian mass-extinction. She specialized in Early Triassic conodonts, particularly Griesbachian and Dienerian.

divider

hofmannRichard Hofmann. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, Zürich, 8006, Switzerland; Leibniz Institut für Evolutions und Biodiversitätsforschung, Museum für Naturkunde, Invalidenstraße 43, Berlin, 10115, Germany. This email address is being protected from spambots. You need JavaScript enabled to view it.

Richard Hofmann is a postdoctoral researcher at the Museum für Naturkunde, Berlin. He studied Geology/Palaeontology at the TU Bergakademie Freiberg where he received his Diploma in 2008. From 2009 to 2013, Richard joined the Group of Hugo Bucher at the Palaeontological Institute and Museum of the University of Zurich (Switzerland) to carry out his PhD-research on the palaeoecology of benthic post-extinction faunas of the Early Triassic. After a 2-year postdoc-period in Zurich which led him to study Permian palaeoecology, he works in Berlin since 2015. Richard is interested in the palaeoecology and diversity patterns during diversification and extinction events as well as the palaeobiology of selected fossil groups, most notably bivalves, trace fossils, brachiopods and trilobites. His current focus lies on early Palaeozoic and he prefers a specimen- and field-based approach to palaeontological questions.