Tomorrow a new paper in Science well help to explain the pattern of the origin and radiation of dinosaurs, revealing a much more gradual process than has previously been assumed. Although I’ll save most of my comments until after I get to read the paper (while everyone else is lining up to get their copies of Harry Potter), it could do a lot of good in helping to dispel myths about evolution. The “classic” dinosaur story is that their ancestors were adapted to have their limbs under their bodies, allowing for a much more efficient gait that also freed their hands and allowed them more speed. This adaptation allowed them to quickly overtake all other amniotes of the time, dominating the world for well over a hundred million years, other organisms only becoming large or becoming more specialized after dinosaurs disappeared. Darren at Tetrapod Zoology has done a lot to help dispel the idea that dinosaurs were the be all and end all of Mesozoic critters, and the recently (re)discovered Effigia okeeffeae has shown that dinosaurs were not the only group to develop an advanced bipedal posture.
The LiveScience article announcing the paper doesn’t provide much detail other than the potential shake-up involved for thoughts on evolutionary turnover in the Triassic (as well as the announcement of a “dinosauromorph” named Dromomeron romeri, after the famous paleontologist A.S. Romer). I’m sure more capable bloggers will be able to give some more in-depth insights than I can, but the fact that dinosauromorphs persisted for so long, even coexisting with dinosaurs, requires a bit of re-thinking when it comes to how dinosaurs evolved and became the dominant large animals on the earth. I certainly look forward to learning more tomorrow.