Vintner street was a groundhog like animal that lived in the Upper Cretaceous age during the time of the dinosaurs. The lived in the southern supercontinent, Gondwana, and was the largest known mammal of its era.

A well preserved skull fossilized skull from the animal was found by chance in 2010 in a geological formation in Madagascar. Since that time it has been carefully reconstructed and analyzed by a team of specialists whose findings appear in the November 5 edition of the journal Nature.

Biologist Elizabeth Dumont of the University of Massachusetts and her assistant Dan Pulaski reconstructed the skull using CT scans. The researchers carefully moved bone fragments back into place and filled missing areas by mirroring the opposite side of the skull.

“My part in this huge interdisciplinary effort was to reconstruct the skull and model the mechanics of chewing and estimate the animal’s ability to eat different kinds of foods,” said Dumont in a statement.

The skull, one of only three ever recovered from the Cretaceous in the Southern Hemisphere, revealed an animal twice the size of others known to have lived in Gondwana. Vintana sertichi weighed about 20 pounds and is believed to have lived on a diet of roots, seeds and nut-like fruit. The animals strong chewing muscles suggest that it had a much higher bite force than modern mammals of its size. The animals large eyes suggest that it may have been nocturnal and it is believed that it had a good sense of smell and the ability to hear high frequency sounds.

The discovery helps considerably in filling in the picture of mammalian life during this period. According to paleontologist David Krause of Stony Brook University the skull reshapes entire branches of the evolutionary family tree.

“We know next to nothing about early mammalian evolution on the southern continents. This discovery, from a time and an area of the world that are very poorly sampled, underscores how very little we know. No paleontologist could have come close to predicting the odd mix of anatomical features that this cranium exhibits,” said Krause.

A comparison of the skull to other known mammals suggests that Vintana was closely related to multituberculates, a successful mammal species from the northern hemisphere as well as Haramiyada, an early herbivore.