First giant salamander was a hot hunter
|Aviturus exsecratus (reconstruction) [Credit: Vasilyan/Universitaet Tübingen]|
|Parietal bone of the Mongolian salamander from below (left) and above (right) [Credit: Vasilyan/Universitaet Tübingen]|
|Sketch of the skull of the extant Chinese salamander (blue) and a reconstruction of the fossil Mongolian salamander (yellow) [Credit: Vasilyan/Universitaet Tübingen]|
The scientists suspect that aviturus exsecratus lived on fish and invertebrates in the water -- as suggested by the shape of its lower jaw. At the same time, aviturus probably hunted insects. Terrestrial adaptation is indicated by the animal's heavy bones, long hind legs, a well-developed sense of smell, and palatal dentition typical of a terrestrial salamander. Also, fossil remains of this huge, up to 2m long animal were found in rock typically formed from water's-edge sediments.
The researchers think this drastic individual development in aviturus exsecratus was probably due to a short period of global warming 55.8 million years ago: the Paleocene-Eocene Thermal Maximum. This most sudden climate change since the death of the dinosaurs saw global temperatures rise 6 degrees Celsius within around 20,000 years.
Source: Universitaet Tübingen [September 20, 2012]