|©Peter Trusler for Museum Victoria of Australia|
14 January 2017
The Cretaceous amphibian Koolasuchus was not at all a suchian (crocodilian) but it was fairly cool; though it was named for Lesley Kool, not because it was interesting. Evoking the very image of the modern salamanders, Koolasuchus was a member of the temnospondyl group; a large group of tetrapods often considered the most primitive amphibians. Tenospondyls were often mostly aquatic and, while this does not entirely separate them from modern amphibians (think of all f the entirely aquatic amphibians that are still around us today), it was a defining characteristic of many temnospondyls. What does an "entirely aquatic" fossil animal look like though? In the case of Koolsuchus that body type is dorsoventrally flattened and very salamander-like. What I mean by that term is an elongate, smoothed body with somewhat shortened limbs and a tail that, in some instances, is mediolaterally thin and dorsoventrally wide; this aids the salamander in swimming around its environment. Salamanders that are not as aquatic, including some newts, have more conical tails. As we said previously, Koolasuchus was an aquatic animal, making the thin tall tail more realistic.