An ancient genus of Cretaceous mosasaurs has been discovered in Morocco. An extinct species of large aquatic reptile, it is a marine lizard measuring between 2 and 3 meters long known for its unusual-looking teeth: low, rectangular and compressed.
According to a recent scientific study, the creature would have lived in the geographical area of Morocco at the end of the Maastrichtian Cretaceous period, around 67 million years ago. The fossilized remains were unearthed in the phosphate mine of Sidi Chennane, province of Khouribga, in the region of Béni Mellal-Khénifra.
Carinodens is a recently discovered species of primitive basal mosasaurids with “small, conical, curved teeth, an adaptation for hunting relatively small prey such as fish and soft-bodied cephalopods,” the University of California paleontologist wrote. Bath, Nicholas Longrich, and colleagues.
In a paper published in the journal Diversity, they point out that unlike early basal mosasaurids, this newly discovered species is characterized by “high-crowned teeth, triangular apices, and broad bases.” The data suggest that the species evolved greatly, showing “an emerging pattern of mosasaurid hyperdiversity in the late Maastrichtian of Morocco.”
Hyperdiversity of marine reptiles in Morocco
“A revised faunal list, including extensions of the stratigraphic range of Khinjaria and Stelladens to the upper Maastrichtian of Layer III of the Moroccan Phosphates, suggests that at least 16 species of mosasauroids coexisted here,” we can read in the same article. This great diversity and evolution is widely observed in the teeth of these marine lizards, their main weapon.
“By the end of the Cretaceous, mosasaurs developed very diverse dental morphologies,” the researchers noted. These various shapes include massive, conical teeth for grabbing and tearing prey, others blunt for crushing bones, others shaped like knives and blades for stabbing and cutting large prey, saw-shaped for cutting, or low and bulbous to crush hard-shelled invertebrates.
One of the most unusual shapes in the species’ teeth is seen on the recently discovered fossilized remains, “the durophagous mosasaurid Carinodens.” This is “characterized by a relatively small size, long and thin jaws and a unique dental morphology among mosasaurids or other vertebrates,” adds the article.
“The diversity of mosasaurs in Morocco is exceptional and suggests that they continued to live, shortly before their mass extinction at the end of the Cretaceous. Mosasaurids may be more specific and more diverse than other Mesozoic marine clades,” the research concludes.
Indeed, the same researchers, under the direction of Longrich, discovered the Xenodens calminechari in 2021. It is also a species of mosasaur, fossilized in the phosphate deposits of Morocco. This species, like its congeners, has unique short teeth, laterally compressed and hooked, forming a saw-shaped blade.
