The remains, unearthed last year, could offer new insights into the extinct marine reptile, which crushed molluscs and shelled creatures with its massive spherical tooth.
About eighty million years ago, a massive sea monster swam across present-day Texas. With that land submerged beneath an inland channel, the predator roamed the waters, searching for molluscs, turtles and other shelled creatures to overwhelm with its globular tooth.
That creature, known as Globidens alabamaensis, is now extinct. But the newly discovered fossilised remains provide new insights into the beast’s lifestyle and behaviour, according to a paper recently published in the journal Paleontological Sciences.
OMG! Rare Jaw Fossils Unveiled in Texas
Researchers first described G. alabamaensis in 1912, because then, however, only a few fossils belonging to the species had been found, leaving scientists in the dark about the mysterious creature. But last year, a private fossil hunter named Courtney Travanini made an unprecedented find in northeast Texas: jaw fragments from an adult G. alabamaensis, with the tooth still attached.
Travanini found the elusive fossils in the North Sulphur River channel near the town of Ladonia, Texas. They were embedded in the Ozan Formation, an 8-inch-thick deposit that preserves fossils from the Campanian Era, which lasted from 83.6 million to 72.1 million years ago. Travanini lent the two jaw fragments to a team of researchers who studied the fossils for clues to the existence of G. alabamaensis.
The creature had “robust and large” jaw bones equipped with strong, rounded teeth, they write in the paper. Some of the teeth measured about an inch long. Meanwhile, the entire animal would have reached 20 feet in length and likely used its teeth to weigh down the shells of molluscs, turtles and other sea creatures. The fossils also suggest that G. alabamaensis lost and shed its teeth during its lifetime, much like modern sharks, reports Richard Pallardy from the University of Nottingham’s Department of Technology.
G. alabamaensis was a species of mosasaur, a group of large, extinct aquatic reptiles that roamed during the late Cretaceous, between 100 and 66 million years ago. As the climate changed and other marine predators began to falter, mosasaurs adapted and thrived. With their slender bodies, long tails and paddle-like limbs, they became top predators in shallow seas. Some mosasaur species developed sharp, serrated teeth that helped them cut through the flesh of their prey, while others, such as G. alabamaensis, developed rounded, mushroom-shaped teeth that were better suited to shredding. These unique tooth types allowed the unique mosasaurs to thrive at the same time.
For example, G. alabamaensis likely took advantage of an “overabundance of cephalopods,” says Bethany Burke Franklin, a marine palaeontologist at the Texas Through Time Fossil Museum who was not involved in the studies, to follow the science.
“Multiple species could coexist because they weren’t using the same resources,” she adds.
Mosasaurs went extinct at the same time as the dinosaurs and were also wiped out by the ecological fallout from a large asteroid that hit Earth about 66 million years ago.
Globidens mosasaurs are some of the rarest in North America, recognized primarily by isolated teeth and preserved jaw fragments. Along with G. alabamaensis, only four other known species make up the genus. However, while only a few fossils of these creatures have been unearthed, fossils of other forms of mosasaurs are more common.
In 2022, for example, fossil hunter Stephen Kruse found a mosasaur spine, skull, and lower jaw sticking out of a dry creek bed near the North Sulphur River, the same waterway where G. alabamaensis jaw fragments had recently been identified. While mosasaurs were still alive, northeast Texas was submerged under “beautiful warm, almost tropical oceans and seas full of fish, reptiles, clams, oysters, and marine life,” Ron Tykoski, who helped excavate Kruse’s finds and serves as curator of vertebrate palaeontology at the Perot Museum of Nature and Science in Dallas, told FOX4 in 2022.
“It was a wonderful place to live if you were a big, hungry, predatory reptile,” he added.