225-Million-Year-Old Fossils Rewrite Early Mammalian Evolution

New Brazilian fossils reveal that key mammalian jaw and middle ear features evolved independently and earlier than previously thought.

Fossils of Brasilodon quadrangularis and Riograndia guaibensis provide new insights into mammalian jaw and middle ear evolution.
CT scans show Riograndia had a 'mammalian-style' jaw joint 17 million years earlier than previously known.
The study indicates that mammalian jaw features evolved multiple times in different cynodont groups.
Findings suggest early mammalian evolution was more complex and varied than previously understood.
Researchers plan further investigations into South America's rich fossil record to deepen understanding of mammalian origins.