20 February 2016
Back in 2007 Raul Martin illustrated Effigia for National Geographic. Martin's interpretation of Effigia looks nothing like any kind of crocodylian animal that we know, fossil or extant. The reason for that is that Effigia was not very similar to its soon-to-be descendants. During the Triassic era reptiles were beginning to truly take command of the land and even the skies. The most successful forms of reptiles at the time were those walking on two legs at least facultatively; that does not mean that there were no successful quadrupedal reptiles at this time. Therefore, many of the reptiles that would become known as the ancestors of lepidosaurs, dinosaurs, pterosaurs, and even crocodylians were similarly built animals with powerful hindlegs, long balancing tails, and mouths filled with little reptilian teeth. As an early member of the then developing suchian line, Effigia espoused these typical reptilian traits, but was also in the process of incorporating the precursors of crocodilian traits such as a similarly proportioned manus and an anteriorly articulating femoral head. Dinosaurs possess an articulation of the femoral head that is oriented medially in the hip socket. The astragalus, the reptilian "heel" bone (we call it the calcaneus), of Effigia is morphologically similar to the bone as it is seen in alligators.