Fossil Reptiles from the Late Cretaceous (Campanian-Maestrichtian) of Vega Island, Antarctic Peninsula

该奖项由极地计划办公室南极地质和地球物理计划提供，支持对南极半岛地区维加岛的恐龙和海洋爬行动物化石进行古生物学研究。1997-98年南极夏季野外工作在南极半岛的维加岛晚白垩世沉积物中发现了大量脊椎动物和无脊椎动物化石。这些化石代表了晚白垩世动物群的广泛多样性。不仅在南极洲发现了第一只鸭嘴龙，而且还发现了几种海洋爬行动物（蛇颈龙和沧龙）的标本，其中许多被发现。迄今为止，南极洲的海洋爬行动物知之甚少，只有一个物种被描述过。该奖项支持维加岛上洛佩斯德贝尔托达诺组古动物群中爬行动物部分的准备、保护和研究。爬行动物化石标本，包括许多幼体，是在对维加岛晚白垩世哺乳动物进行野外研究时意外发现的（见NSF授予M. O. Woodburne和J.A.案例）。至少发现了两种不同的沧龙，两种蛇颈龙，以及鸭嘴龙类恐龙的第一个证据。 鸭嘴龙表明，至少在最晚的马斯特里赫特期（马斯特里赫特期包括大约7400万至6600万年前的时期），一条传播路线为陆地生物从北美通过南美至少传播到南极洲提供了一条途径，并有助于假设的澳大利亚路线。海洋爬行动物还展示了以前未被认识到的古地理关系，对这些关系的追求构成了该奖项下继续进行实地工作的基础。至少有一个沧龙分类群似乎在冈瓦纳大陆存在的时间更长，而另一个可能与北方分类群有更密切的亲缘关系。来自南极洲的蛇颈龙似乎也在冈瓦纳大陆之间有残余分布，因为大多数北方亲戚在白垩纪灭绝。在这一点上，这些古地理关系是工作的假设，必须通过恢复额外的标本和冈瓦纳海洋爬行动物的历史和分布的研究来检验。由于南极洲在晚白垩世处于冈瓦纳大陆的中心，因此对它的研究对于了解海洋爬行动物的分布至关重要。该奖项支持现有收藏品的进一步工作，以及恢复上一个野外季节发现的恐龙和海洋爬行动物化石的新野外工作。

This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports paleontological research on dinosaur and marine reptile fossils from Vega Island in the Antarctic Peninsula region. Field work during the 1997-98 austral summer field season yielded substantial numbers vertebrate and invertebrate fossils from the late Cretaceous deposits of Vega Island on the Antarctic Peninsula. The fossils represent a wide diversity of Late Cretaceous fauna. Not only was the first hadrosaur dinosaur from Antarctica discovered, but several specimens of marine reptiles (plesiosaurs and mosasaurs) were found and many were recovered. Heretofore, marine reptiles had been poorly known from Antarctica, with only one species having been described. This award supports the preparation, conservation, and research concerning the reptilian portion of the paleofaunal assemblages of the Lopez de Bertodano Formation on Vega Island.The fossil reptile specimens, including numerous juveniles, were an unexpected discovery during field research on late Cretaceous mammals on Vega Island (see NSF awards OPP-9615236 to M. O. Woodburne and OPP-9615933 to J. A. Case). At least two different mosasaurs were found, two plesiosaurs, and the first evidence of a hadrosaurian dinosaur. The hadrosaur indicates that a dispersal route at least by the latest Maastrichtian (the Maastrichtian encompasses the period from about 74 to 66 million years ago) provided an avenue for dispersal of terrestrial creatures from North America through South America to at least Antarctica, and aids in the postulated route to Australia. The marine reptiles also demonstrate previously unrecognized paleogeographic relationships, and the pursuit of these relationships forms the basis for continued field work under this award. At least one mosasaur taxon appears to persist longer in Gondwana, whereas the other may have closer affinities with northern taxa. The plesiosaurs from Antarctica also appear to have relict distribution among the Gondwanan continents, as most northern relatives are extinct by the Cretaceous. At this point, these paleogeographic relationships are working hypotheses which must be tested by the recovery of additional specimens and by study of the history and distribution of Gondwanan marine reptiles. Because of Antarctica's position at the center of Gondwana during the Late Cretaceous, its study is crucial to the understanding of the distribution of marine reptiles. This awards supports further work on the existing collections as well as new field work for recovery of the dinosaur and marine reptile fossils located last field season.