Antarctic Middle-Late Mesozoic marine fossil-bearing units: new reports and future perspectives from Argentine paleontological explorations

GOURIC-CAVALLI SOLEDAD; BIGURRARENA OJEDA, M.A.; BÁRBARA CARIGLINO; MARCELO REGUERO; ARI IGLESIAS

Tasmania

Congreso; SCAR 2020 - Antarctic Science - Global Connections; 2020

SCAR, Scientific Committee on Antarctic Research 'Antarctic Science - Global Connections'

Scientific activity in the Argentine Antarctic Sector has been conducted by the Instituto Antártico Argentino (IAA) since 1951. The Vertebrate Paleontology Research Group (VPRG) comprises several disciplines within the study of vertebrates and incorporates researchers and technicians from different Argentinian institutions. The main objectives of this group are the prospection, collection, and study of fossil vertebrates recovered during the Antarctic Summer field season. The Jurassic in Antarctica is still little explored, even though it represents a key moment for understanding the evolutionary history of certain fish groups. In light of the Jurassic outcrops occurring in Antarctica since 2015 the VPRG, has been exploring some areas with a strong focus on the recovery of fossil fishes. Jurassic marine fishes were known from the Ameghino Formation (=Nordenskjöld) and the Hauberg Mountains Formation. Our preliminary results show that the taxonomic diversity of fishes from the Ameghino Formation is greater than what had been previously reported. Additionally, abundant bromalites with fish remains content have been recovered, as well as other vertebrates and invertebrates previously undescribed at the formation. The studies of the fish material and bromalites might provide information on anatomy, taxonomy, phylogeny, paleoecology, paleobiology and morphological disparity of the taxa. These data are useful to improve the understanding of the Jurassic gap in the evolutionary history of the major clades of fishes in the Southern Hemisphere.