AN ICHTHYOSAUR BREEDING GROUND IN SOUTHERNMOST GONDWANA (TYNDALL GLACIER, SOUTHERN CHILE)

J. PARDO-PÉREZ; E. MAXWELL; C. GASCÓ; H. ORTÍZ; J. KALUZA; M. CÁCERES; C. ASTETE; D. LOMAX; J. MUNGIA; E. BELTRAN-GANDARA; M. ARÉVALO

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Conferencia; XIX Annual Conference of the European Association of Vertebrate Palaeontologists; 2022

European Association of Vertebrate Palaeontologists

Since 2004, paleontological expeditions have been conducted to the Tyndall Glacier in Torres delPaine National Park, Chilean Patagonia, resulting in the discovery of almost a hundred ichthyosaurskeletons to date. The ichthyosaurs are exposed in the rocks as a consequence of the ongoingmelting of the glacier caused by climate change. Most of the ichthyosaurs in this locality are completeand articulated. Invertebrates such as ammonites and belemnites, as well as different types offishes, have been found associated with the ichthyosaurs. According to a previously developedhypothesis, this area was used as a breeding ground for ichthyosaurs in southernmost Gondwanaduring the Early Cretaceous. To date, eight years since the hypothesis was published, we have yetto find marine reptiles other than ichthyosaurs, most find corresponding to neonates and smalljuveniles. Pregnant females have also been recorded. These data, in addition to the abundance offood and the apparent absence of predators, allow us to support the idea of a breeding ground. Thediscovery of glendonites, correlated with cold to freezing water conditions, suggests that the sitemay have only been inhabited during the summer months. Regarding taphonomy, many of theskeletons have skulls that penetrate the sedimentary layers, indicating headfirst arrival at theseafloor. Several skulls show breakage consistent with high-speed collision with the bottom. Thefrequency and depth of embedded skulls suggest relatively soft sediments on the sea floor.This research was funded by Agencia Nacional de Investigación y Desarrollo (ANID), projectPAI77200036 awarded to JPP.