Sentences with phrase «placental mammals based»
J. David Archibald, an evolutionary biologist at San Diego State University, praised the new study as being the most comprehensive analysis yet into the evolution of placental mammals based on the shapes and forms of fossils.
https://www.scientificamerican.com/ Not exact matches
Because so little is known about Gondwanan mammals, Krause is wary of dismissing Rich's interpretation «just because we don't expect, based on current knowledge of early mammalian evolution on Gondwana, to see a placental mammal in the Early Cretaceous of Australia.»
Conventional wisdom holds that the precursors of modern placental and marsupial mammals arose toward the end of the Jurassic in the Northern Hemisphere, based on the ages and locations of the earliest remains of these shrewlike creatures, which are characterized by so - called tribosphenic molars.