THE SOUTHERNMOST OCCURRENCE OF BRACHYCARCHARIAS (LAMNIFORMES, ODONTASPIDIDAE) FROM THE EOCENE OF ANTARCTICA PROVIDES NEW INFORMATION ABOUT THE PALEOBIOGEOGRAPHY AND PALEOBIOLOGY OF PALEOGENE SAND TIGER SHARKS

The first record of one of the most common and widespread Paleogene selachians, the sand tiger shark Brachycarcharias, in the Ypresian strata of the La Meseta Formation, Seymour Island, Antarctica, is provided herein. Selachians from the early Eocene horizons of this deposit represent the southernmo...

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Bibliographic Details
Main Authors: MARRAMÀ, GIUSEPPE, ENGELBRECHT, ANDREA, Mörs, Thomas, REGUERO, MARCELO A., KRIWET, JÜRGEN
Format: Article in Journal/Newspaper
Language:English
Published: Enheten för paleobiologi 2018
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Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-2945
Description
Summary:The first record of one of the most common and widespread Paleogene selachians, the sand tiger shark Brachycarcharias, in the Ypresian strata of the La Meseta Formation, Seymour Island, Antarctica, is provided herein. Selachians from the early Eocene horizons of this deposit represent the southernmost Paleogene occurrences in the fossil record, and are represented by isolated teeth belonging to orectolobiforms, lamniforms, carcharhiniforms, squatiniforms and pristiophoriforms. The combination of dental characters of the 49 isolated teeth collected from the horizons TELMs 2, 4 and 5 supports their assignment to the odontaspidid Brachycarcharias lerichei (Casier, 1946), a lamniform species widely spread across the Northern Hemisphere during the early Paleogene. The unambiguous first report of this lamniform shark in the Southern Hemisphere in the Eocene of the La Meseta Formation improves our knowledge concerning the diversity and paleobiology of the cartilaginous fishes of this deposit, and provides new insights about the biotic turnovers that involved the high trophic levels of the marine settings after the end-Cretaceous extinction and before the establishment of the modern marine ecosystems. The frozen Garden of Eden - Paleogene Mammals from Seymour Island, Antarctica: evidence for Gondwanan biogeography and palaeoclimate