Bizarre 66 million-year-old fossil from Madagascar provides clues on early mammals

[Judi Lynn]

29-APR-2020

Adalatherium identified as part of enigmatic Southern Hemisphere mammalian group that lived at the time of dinosaurs

UNIVERSITY OF LOUISVILLE



The image was drawn from a complete, 3-dimensional fossil discovered in Madagascar. The unusually large mammal, named Adalatherium, is part of a group of mammals known as gondwanatherians. It lived at the time of dinosaurs, roughly 66 million years ago.


LOUISVILLE, Ky. - Several years ago, Guillermo Rougier, Ph.D., professor in the Department of Anatomical Sciences and Neurobiology at the University of Louisville, was approached by David Krause, Ph.D., curator at the Denver Museum of Nature & Science, to help identify a complete, 3-D fossil he had discovered on Madagascar.

"When Dr. Krause showed it to me in a scientific meeting and asked me for my opinion, I said I had never seen anything like this," Rougier recalled. "This mammal has teeth for which we have no parallel."

Krause and a team of paleontologists discovered the fossil during an expedition in Madagascar and spent more than a decade working to determine where it falls in the long history of mammalian evolution and what it tells us about geography and changes in global fauna over time.

Rougier, a paleontologist who specializes in the study of the skull and teeth of ancient mammals, was intrigued and joined the international team of researchers to thoroughly analyze the fossil. Their analysis was published today in the journal Nature.
More:
https://www.eurekalert.org/pub_releases/2020-04/uol-b6m042920.php

[empedocles]

1. Could not figure out how large was 'unusually large' from the link

[muriel_volestrangler]

2. About 60 cm long, though they think this may have been a juvenile

There's a picture at the link of the fossil, and that has a 5cm ruler on it, if you look carefully. I reckon 60 cm - 2 feet - for nose to tail length.

They believe this particular creature was a juvenile, weighing around seven pounds. But compared to the other Gondwana mammals living at the time, which were the size of mice, it was quite large. And it lived among dinosaurs and ancient crocodiles before the asteroid impact wiped them all out 66 million years ago at the end of the Cretaceous period.

http://www.kten.com/story/42069778/crazy-beast-fossil-discovery-shows-the-evolutionary-weirdness-of-early-mammals

[empedocles]

3. Thank you