SC Connecticut News

Yale researchers have uncovered new insights into the evolutionary link between dinosaurs and modern birds, focusing on the fibula bone in bird legs. Armita Manafzadeh, a postdoctoral researcher at Yale, led the study published in Nature. She explained that the shortened fibula allows birds to twist and turn when not flying, drawing parallels to drumsticks often seen on Thanksgiving tables.

Manafzadeh noted, "Under the meat of a drumstick, you’ll find two bones — the tibia, which is long and thick, and the fibula, which is much shorter and thinner." This adaptation has been overlooked historically but plays a crucial role in bird mobility.

Bhart-Anjan Bhullar, an associate professor at Yale and co-author of the study, emphasized that neglected structures like the fibula can reveal significant evolutionary stories. He stated, "The fibula is often neglected in the study of vertebrate form and function."

The research team used X-ray videos of various animals to analyze joint movements. They discovered that bird knees maintain smooth contact even during extensive twisting due to their unique joint structure. Manafzadeh observed, "You can see that the fibula of birds is moving completely differently from that of other living reptiles."

The study traced these features back to certain dinosaur species like Rahonavis ostromi and Ichthyornis dispar. These avian ancestors had similar knee joint structures as modern birds. Bhullar remarked on this evolutionary process: "We found that the very features that appeared in early dinosaurs to stiffen the leg ended up being co-opted in birds."

This research builds on ongoing studies by Bhullar and Manafzadeh into animal motion evolution using innovative visualization techniques.