Rare fossils of the mosasaurus Globidens alabamaensis, a predator with strange mushroom-shaped teeth, have been discovered in northeast Texas.
Fossils of a huge and rare mosasaur with giant ball-shaped teeth have been discovered in Texas, a new study has found.
Two fragments of the jaws of an adult animal provide insight into the lifestyle of Globidens alabamaensis, which could reach a length of up to 6 meters. The blunt teeth lining the jaws demonstrate the brute force that mosasaurs applied to their prey. The researchers described the discovery of two jaws in a paper published in the Journal of Paleontological Sciences.
“These structures, with their mushroom shape, are great for impact attacks, for smashing the shell. If something slips through and you break it, that’s it,” said Bethany Burke Franklin, a marine paleontologist and professor at the Texas Museum of Fossils Through Time in Hillsboro. Franklin, who specializes in marine reptiles, was not involved in the study.
During the Late Cretaceous period (100.5–66 million years ago), many iconic marine predators, such as dolphin-like ichthyosaurs and long-necked plesiosaurs, succumbed to climate change and subsequent shifts in the marine ecosystem. Mosasaurs became the dominant predators in the shallow seas of the time, occupying niches once occupied by their more famous predecessors. These reptiles rapidly diversified to fill various niches in a variable, prey-rich environment.
G. alabamaensis was discovered in 1912, but only a few nearly complete specimens of this mosasaur have been discovered. Most of the fossil evidence consists of teeth and small jaw fragments. Four more species of Globidens have since been described.
While most mosasaurs boasted a fearsome set of dagger-shaped teeth, Globidens developed blunt, rounded teeth that were well-suited to crushing the shells of turtles, ammonites, and bivalves. The Western Interior Seaway, which divided what is now North America in the late Cretaceous, would have provided G. alabamaensis with a wide range of armored prey.
The fragments were discovered by a private fossil hunter in 2023 in the Ozan Formation in northeast Texas. The deposit in which they were found dates back to the Campanian era (83.6-72.1 million years ago) and is only 20 centimeters thick. However, it turned out to be rich in fossils, including other mosasaurs.
Preserving even a portion of an animal’s head is exciting, Franklin said. “The skull material tends to compress more, especially in these thin layers,” she explained.
One jaw still has 12 teeth, the other only six. The teeth are about an inch long and rounded, ideal for crushing hard mollusk shells. In one jaw, the embryonic tooth remained below the gum line. It could come later to fill the gap. Scientists believe that, like sharks, mosasaurs shed their teeth and replace them throughout their lives.
Thanks to these unique teeth, they were able to coexist with other large mosasaurs that went after different types of prey, Franklin said.
“Adaptation was probably influenced by the abundance of cephalopods. Multiple species could coexist because they did not use the same resources. [мозазавры] “They were one of the fastest-evolving predators of the time. They filled niches that had been left by other large marine predators – there were huge gaps in the food chain,” he explained.
News about ancient animals.
Before 1938, if you had asked a zoologist to name some of the oldest fish known to science, you would probably have heard of the coelacanth. They first appeared in the early Devonian period, just over 400 million years ago.
What that zoologist didn’t tell you is that these ancient fish can still be found in the ocean today. Scientists, before the rediscovery of the coelacanth in 1938, assumed it became extinct at the end of the Cretaceous period, 65-70 million years ago.
