Attachment Scars of uncinate processes indicate an early origin of avian-like breathing mechanisms in dinosaurs:
Yan-yin Wang, a PhD candidate in the Sullivan Lab at the University of Alberta, will be giving a talk for Science Outreach Athabasca. How did dinosaurs breathe? Yan-yin's research may help to answer that question. He studies Archosauria, a group that originated in the Triassic (around 250 million years ago!), and whose modern representatives include birds and crocodilians. The ribs of archosaurs have a special feature, the uncinate process. This uncinate process has muscles that have been found to be associated with respiratory function in Canada geese and American alligators. The problem with looking at the uncinate process in dinosaurs, however, is that the uncinates are sometimes only made of cartilage, which doesn't often preserve well. Yan-yin has found that the uncinate processes leave a mark on the ribs, which means that even when the processes aren't preserved, they'll be able to tell if they were there! This has allowed Yan-yin to see that uncinate-assisted respiration may have been around since archosaurs first appeared!