A fossil, Megachirella wachtleri, from the Dolomites appears to be a lizard-like animal that gave rise to all the squamates (lizards, snakes and worm lizards) of modern times. What is remarkable is that the fossil is from Triassic rocks lain down some 75 million years before the great extinction event that took out the dinosaurs and many other land and marine organisms (https://www.theguardian.com/science/2018/may/30/worlds-oldest-lizard-fossil-forces-rethink-of-reptile-family-tree). Prior to this study that combines fossil skeletal anatomy and DNA studies, it was assumed that the squamates evolved after the extinction event. It now appears that their characteristics (being generally small and, perhaps, in some cases, devoted to burrowing) meant they were in a position to survive the conditions of the extinction event. In that respect, their history is not too different from the mammals who also evolved in the time of the dinosaurs but flourished after their extinction.
No comments:
Post a Comment