A reconstruction of the Eocene helmeted frog on the Antarctic Peninsula 40 million years ago.
The New York Times Trilobites column has a story about the discovery of fossil frogs on Antarctica. The frog lived about 40 million years ago in what is now Seymour Island, which sits on the Antarctic Peninsula roughly 700 miles south of Tierra Del Fuego on South America. The specimen was found in 2015 by Thomas Mors, a vertebrate paleontologist at the Swedish Museum of Natural History, while investigating material collected by him and his team during expeditions to the island in 2011, 2012, and 2013. The animal, Australobatrachia, is related to frogs of the genus Calyptocephalella that live in present day South America. Along with this frog, researchers also found fossilized water lily seeds and shark and ray teeth. It all paints a picture of a much warmer Antarctica 40 million years ago during the Eocene Period. Find all the details in a paper which appeared in the journal Nature.
Dr. Mörs found two frog bones: a skull and a hip bone called an ilium. “The ilium is probably the most diagnostic part of a frog skeleton,” said David Wake, a herpetologist at the University of California, Berkeley, who was not involved in the research. “A frog paleontologist wants an ilium.”
The ilium looks like those of a living group of frogs called the helmeted frogs. Helmeted frogs live in Chile in wet woodlands called Nothofagus forests, and their ilia are similar to the Antarctic frog’s ilium. “They’re robust frogs, and this is a robust ilium,” Dr. Wake said.
Seymour Island today is barren and rocky. Dr. Mörs and his team found the frog at a site called “Marsupial Site,” so named because, in 2007, a different team discovered a fossil marsupial there with modern relatives that live in Nothofagus forests in Chile and Argentina.
