whales, seals, penguins – the seas of the Antarctic to feed a lush Fauna. In the Land of the frozen continent, by contrast, offers just habitats for the tiny creepy-crawlies, the best case for beetles, flies and spiders. In the middle Eocene, as in Germany in rivers and lakes crocodiles lurked and urpferd Chen slipped through the semi-tropical undergrowth, saw it quite differently. Although grew up in the Interior of the Antarctic, probably glacier. At the tip of the Antarctic Peninsula thrived in front of around forty million years ago, but still dense forests with Beautiful. That there was at that time a temperate climate with average temperatures even in the coldest month above the freezing point, is now also the first Fossil of a Froschlurchs from this time, was found on Seymour Island. It is the representative of a group, which is on the one hand, to be found in South America, on the other hand, in Tasmania, Australia, and new Guinea.
From the early tertiary, from the Eocene in the Antarctic are already two species of ungulates and ten of the smaller mammals known. Of amphibians, each track was missing so far, however. Although seeds of pond testify to Rosen that the tip of the Antarctic Peninsula once held ready quite suitable biotopes. At the pond roses-occurrence on Seymour Island, Thomas Mörs of the University of Stockholm and Marcelo Reguero tracked by the Instituto Antártico Argentino in Buenos Aires now, fossil Remains of a frog. However, there is a only a few millimeters large Fragment of a hip and a skull sparse: each bone.
The Swedish-Argentine research group found together with Davit Vasilyan of the University of Fribourg that the bone pieces of the genus Calyptocephalella can be assigned to. These frogs are characterized by an unusually massive skull bones, which bear on the upper side of the eye-catching studs. How Mörs and his colleagues in the “Scientific Reports”, the reports were of such a thick skull so far only from South America is known. The oldest fossils come from Argentina from the time of the upper Cretaceous (around 100 to 66 million years ago).
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As documented by numerous archaeological finds, bustling around anurans of the genus Calyptocephalella first of all, to the East of the Andes. During the ice age, they showed up in the temperate climate zone to the West of this mountain range. Nowadays, they live there in the form of the helmet of water Calyptocephalella gayi toad. This stately animal populated standing and slowly flowing waters in Valdivia American rain forest. Of South beeches of the genus Nothofagus dominated, only this lush forest extended originally over a large area of the Chilean Pacific coast to the foot of the Andes.
Endangered descendants of the former Antarctic inhabitants
Typically, most of the fossils of the genus Calyptocephalella from layers of rock, the leaves of the Beautiful mountains. According to the assessment of Mörs, and his colleagues, there is much to suggest that the thick schädelige frog lurch of the Antarctic Peninsula in a very similar biotope at home like today, helmet, water toad. Possible that the genus Calyptocephalella is once formed in the Antarctic. Perhaps the now hostile continent in the age of the dinosaurs, even a center of frog evolution in the southern hemisphere. As molecular genes show tables analyses, have separated ancestors of Calyptocephalella already about 100 million years ago by the Australian Südfröschen (Myobatrachidae). At that time, Antarctica was free of glaciers and closely with Australia and South America connected.
As a global cooling was the ancestral habitat of the thick-headed frog amphibians gradually disappear, was Calyptocephalella still not homeless. Your forest had conquered new Terrain, before he had to soft on the old completely: As the climate in Antarctica was to frosty, survived the Beautiful embossed rain forests in present-day Patagonia. Later, when the Andes rose to such a height that they blocked most of the rain clouds all the way to the East, was able to assert itself in the temperate Latitudes to the West of the mountains is still dense forest.