Fossils Of Ancient, Bizarre Groundhog-Like Creature Discovered In Madagascar

Chuck Bednar for redOrbit.com – Your Universe Online
A fossilized skull discovered in Madagascar belongs to a previously unknown groundhog-like creature that lived alongside dinosaurs and is the largest known mammal of its era, according to research published Wednesday in the journal Nature.
The new fossil, which was discovered by a team of paleontologists led by David Krause of Stony Brook University, belongs to a group of early mammals known as gondwanatherians and has been dubbed Vintana sertichi. The skull is between 66 and 70 million years old, and at nearly five inches long, it is twice the size of other mammals found on what was the southern supercontinent Gondwana during the Age of Dinosaurs, the study authors said.
[ Watch the Video: Paleontologists Discover Fossil Of Bizarre Groundhog-Like Mammal On Madagascar ]
According to Reuters reporter Will Dunham, the researchers report that Vintana sertichi weighed approximately 20 pounds, making it far larger than most other Mesozoic Era mammals. Based on the extremely well preserved fossil, the creature was an active plant eater that had strong jaws, a keen sense of smell, well-developed hearing and excellent eyesight under what would have been low-light conditions, Dunham added.
Krause told National Geographic reporter Nadia Drake that the creature had “bizarre features” and was “humongous,” comparing its appearance to the semiaquatic rodents known as nutria or an oversized groundhog, quipping that it was “Punxsutawney Phil on steroids.” He also said the discovery will help paleontologists fill in gaps in the mammalian evolutionary tree, especially during the era of the dinosaurs.
“Throw together some anatomical features from ancient mammal-like reptiles, Pleistocene ground sloths, an extant rodent and maybe a few bits and pieces from the Muppets on ‘Sesame Street’ and you might get something that resembles the cranium of Vintana,” Krause told Dunham, adding that it is only loosely related to modern mammals and was not a member of any of the three existing groups: placentals, marsupials and monotremes.
The researchers noted that gondwanatherians were completely unknown creatures up until 30 years ago, and Drake added that prior to this discovery, this group of mammals was represented by only a handful of teeth and a couple of jaw fragments. There was not even enough data to place them on the evolutionary tree, she said. With this discovery, however, Krause’s team has found that gondwanatherians are closely related to multituberculates, a group of rodent-like creatures believed to be the most diversified and long-lasting mammals in natural history.

Image Above: The skull of the newly discovered mammal Vintana sertichi at an early stage of excavation. Credit: Joseph Groenke
As for the name given to the creature, the Associated Press (AP) reported that the first part of the name means “luck” in the Malagasy language of Madagascar. It was chosen because the skull was unexpectedly discovered in a massive sandstone block during a CT scan in which Krause and his colleagues were searching for fish fossils. The latter part of the name was chosen in honor of Joseph Sertich, who is currently a curator at the Denver Museum of Nature & Science and was the man who found the sandstone block in 2010.
Once the skull was discovered, Stony Brook scientist Joe Groenke spent six months extracting it from the sandstone, then Krause and his associates conducted a comprehensive analysis of the fossil using micro-computed tomography and scanning electron microscopy to reveal minute aspects of its anatomy, the National Science Foundation (NSF) said in a statement. They then compared the skull to hundreds of other fossils and mammal bones, and based on its teeth, eye sockets, braincase, and inner ear, they discovered that Vintana was probably a large-eyed herbivore that was agile and had extremely keen senses.
Zhe-Xi Luo, an expert on mammalian evolution from the University of Chicago who reviewed the study, told Reuters that this was the “discovery of the decade… This mammal helps to stretch our imagination of what is possible by evolution beyond our stereotypes from the extant mammals. Early mammal history is our own history – that is why a discovery of this kind is important, because it may prompt us to re-think our own evolutionary past.”
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