Paleontologists in Brazil have examined the well-preserved fossilized remains of two mammal-precursor species: Brasilodon quadrangularis and Riograndia guaibensis. The findings offer critical insights into the development of the mammalian jaw and middle ear, revealing evolutionary experiments that occurred millions of years earlier than previously thought. An artist’s impression of Brasilodon quadrangularis (left) and Riograndia guaibensis. Image...
