The discovery of a skull fossil in Utah estimated to be about 130 million years old suggests that the supercontinent of Pangaea might have split up at a more gradual rate than once believed.
In a study published recently in the journal Nature, a team of researchers led by University of Southern California assistant professor Adam Huttenlocker detailed the discovery of a nearly intact fossilized skull of a species that was named Cifelliodon wahkarmoosuch. The skull was found in eastern Utah's Cretaceous beds and got its name from paleontologist Richard Cifelli, and the Ute tribe's word for "yellow cat."
As further noted by Phys.org, the species is believed to have weighed only about 2.5 pounds at the most, and while that makes it tiny compared to present-day mammals, its weight suggests that it was a "giant" in the early Cretaceous Period, when mammals were extremely tiny, especially when compared to the dinosaurs that roamed our planet at that time. Its teeth closely resemble those of fruit-eating bats, and its diet might have included some plants, which it would have crushed with its distinctive teeth.
Not much was mentioned on the Phys.org report about the methodologies used by Huttenlocker and his colleagues, except for their use of high-resolution CT scanners to study the animal's skull. But it is believed that Cifelliodon lived close to 130 million years ago, and was part of the Haramiyida family that was one of the many vertebrate groups that lived during the Jurassic-Cretaceous transition. As such, it's highly likely that these early mammals would have only been able to migrate via Pangaean landmasses in the Early Cretaceous period."Based on the unlikely discovery of this near-complete fossil cranium, we now recognize a new, cosmopolitan group of early mammal relatives," Huttenlocker said in a statement.
"For a long time, we thought early mammals from the Cretaceous (145 to 66 million years ago) were anatomically similar and not ecologically diverse. This finding by our team and others reinforce that, even before the rise of modern mammals, ancient relatives of mammals were exploring specialty niches: insectivores, herbivores, carnivores, swimmers, gliders."As Cifelliodon's skull represented the first example of a near-intact Haramiyida skull fossil from the Early Cretaceous that was found in North America, the research suggests that this family of animals might have been found all over the world during the Jurassic-Cretaceous transition. With the corridors of migration from one Pangaea landmass to the next thought to have stayed intact until the Early Cretaceous, according to Science Alert, the study also suggests that Pangaea might have taken an extra 15 million years or so to break up, in relation to the continental drift hypothesis that states the supercontinent started breaking up around 225 to 200 million years ago.