Scientists surmise most dinosaurs had feathers, not just those that flew — and alligator scales may be the key to figuring out how those feathers evolved.
A recent study revealed that the dinosaur Kulindadromeus zabaikalicus had feathers on its body and because it was bipedal with short arms, didn’t use them for flying. The animal had multiple kinds of feathers — primitive ones that were probably used for warmth, indicating the dinosaur was warm-blooded, and more advanced down-like feathers on its legs that were likely decorative.
Dinosaurs, birds and crocodilians come from a group of animals called archosaurs whose lineage split about 250 million years ago. But while birds continued to evolve, alligators kept their scales and retained a more primitive existence. Now, scientists are learning a lot about evolution through alligators, the oldest relation to archosaurs.
In a study published in Molecular Biology and Evolution, researchers identified the genes that caused scales to become feathers and expressed the genes in embryo alligator skin — in essence, growing feathers from scales.
Identifying the feather-associated genes was a huge first step but the team went above and beyond when they began changing reptile skin.
This research provides strong evidence about how dinosaurs began developing feathers. They began as “proto feathers”, which were primitive, like the ones found on Kulindadromeus zabaikalicus before they developed into full-fledged flying machines.
The alligator skin in the study began to form growths similar to primitive feathers, and while genetics won’t allow for the evolution of completely feather alligator, it is an impressive feat.
The study was led by Professor Cheng-Ming Chuo from the University of Southern California.
“You can see we can indeed induce them to form appendages, although it is not beautiful feathers, they really try to elongate,” Professor Chuo stated to BBC.