The discovery of the fossilized skull of a half-mammal and half-reptile creature may rewrite ancient history, specifically regarding the timeline for the breakup of the supercontinent Pangaea.
The important find follows a similar one earlier this year of a dinosaur fossil in Egypt, which also provided scientists with more clues regarding the Pangaea split.
Scientists Discover Fossilized Skill Of Reptile-Like Mammal
Scientists were uncasting a dinosaur fossil that was excavated in southeastern Utah when they discovered another skull hidden under the foot of the fossilized herbivore.
The fossilized skull, however, did not look like it belonged to a reptile. Upon the inspection of state paleontologist Jim Kirkland, it appeared that the skull belonged to a mammal.
"We've never found a mammal there in these rocks before," said Kirkland, after the discovery was published in the Nature journal. "This one skull turns out to be a complete oddball."
The Importance Of The Half-Mammal, Half-Reptile Skull
The fossilized skull of the reptile-like mammal was unearthed in a rock from the Cretaceous period, from about 145 million to 65 million years ago. The skull itself was 130 million years old, a finding that goes against previous theories on when the supercontinent Pangaea broke up.
The discovery of the fossil likely means that the Pangaea split likely happened more recently than scientists thought. The finding also suggests that a group of reptile-like mammals bridging the transition between reptiles and mammals saw a "burst of evolution" in several continents.
The new species, named the Cifelliodon wahkarmoosuch, is a haramiyid, which are rabbit-like creatures that were present in Eurasia from the Jurassic and Triassic period to the early Cretaceous period, when the land masses had fully broken up. The discovery of the fossilized skull in Utah, however, provides evidence that haramiyids were present in North America at the time, suggesting that the divide of Pangaea continued for about 15 million years later than theorized.
The Cifelliodon is believed to have weighed up to 2.5 pounds, and was about as big as a small hare. It also had teeth that can nip, shear, and crush like those of fruit-eating bats. The Cifelliodon was large for a mammal during its time, since most other mammals were the size of mice.
The new Pangaea breakup theory follows a report from January regarding the gigantic herbivorous dinosaur Mansourasaurus shahinae in the Sahara Desert of Egypt. The discovery of the well-preserved fossil suggested that dinosaurs moved around in Africa and Eurasia even after the movement of continents, and disputed theories that dinosaurs that lived in Africa were completely isolated in the Cretaceous period.
