Fossil from Madagascar Rewrites Evolution of Mammals

A fossil from Madagascar of a massive, groundhog-like creature is rewriting the evolutionary history of mammals, according to recent research.

Some 66 to 70 million years ago, an unusual veggie-eating mammal named Vintana ("Luck") sertichi lived along carnivorous dinosaurs of the Late Cretaceous. Weighing about 20 pounds, it was roughly twice the size of a modern day groundhog and enormous compared to most other mammals of its era.

Given its strange features, including a huge skull and eye sockets and turned-down snout, scientists say that they could never have predicted its existence. That is, until 2010 when a team of scientists from Stony Brook University stumbled upon a nearly complete cranium of the mammal in Madagascar.

"We know next to nothing about early mammalian evolution on the southern continents," project leader Dr. David Krause said in a statement. "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."

Rewriting History

The new fossil belongs to a group of early mammals known as gondwanatherians, primitive creatures living on the ancient supercontinent known as Gondwana that until now were known only from isolated teeth and jaw fragments.

"Gondwanatherians were completely unknown 30 years ago," Krause told National Geographic.

Not only is the discovery helping to reveal more about poorly understood habits and relationships of gondwanatherians, but the lucky find is also helping paleontologists fill in the mammalian evolutionary tree, especially during the age of the dinosaurs.

"The discovery of Vintana will likely stir up the pot," Krause added in the statement. "Including it in our analyses reshapes some major branches of the 'family tree' of early mammals, grouping gondwanatherians with other taxa that have been very difficult to place in the past." (Scroll to read on...)