New Jurassic Crocodile Relative Had Needle-Like Teeth

Paleontologists have described Ctenosuchus tenuidens, a new genus and species of teleosaurid based on two fossil specimens discovered in eastern Morocco. The Middle Jurassic predator had an elongated snout lined with unusually thin, needle-like teeth that differ from those of every other known crocodilian relative.

A new teleosaur from Middle Jurassic Morocco

Ctenosuchus tenuidens lived in what is now Morocco approximately 165 million years ago, during the Middle Jurassic period.

The animal was a teleosaur, a group of crocodilian relatives within Thalattosuchia. Teleosaurs lived in a range of environments, including terrestrial, riverine, lacustrine and fully marine habitats. The group was especially notable for its adaptations to semi-aquatic and marine lifestyles.

Some advanced Late Jurassic teleosaurs evolved body plans that resembled those of marine reptiles. Many also had long, slender snouts with a gharial-like appearance.

“Mesozoic crocodilian archosaurs were highly diverse, inhabiting terrestrial, riverine, lacustrine, and fully marine environments,” said Hamza Imran, a paleontologist at the University of Portsmouth, and colleagues.

The geographic range of Thalattosuchia extended from approximately 57.4 degrees north latitude to 39.8 degrees south latitude. However, the group is best documented in northwestern Europe, including Germany, the United Kingdom and France.

Fossils discovered in eastern Morocco

The two specimens of Ctenosuchus tenuidens came from red mudstone deposits in the Tarcint-Anoal region of Morocco’s Figuig Province.

The fossils were purchased from a commercial fossil collector based in Morocco. The collector also supplied the researchers with photographs of the discovery site and regional geological information.

According to the researchers, the area near the town of Tarcint contains a vast expanse of Mesozoic rocks dating from the Early Jurassic to the Late Cretaceous. The region is dominated by Early Jurassic marine limestones and shales, overlain by Middle and Late Jurassic red beds.

Teeth unlike those of any known crocodilian

The most distinctive feature of Ctenosuchus tenuidens is its unusual dentition. The species had teeth unlike those of any other known living or extinct crocodilian relative.

Each tooth was approximately 10 times taller than it was wide, and the teeth were spaced roughly 2.3 millimeters apart. Researchers estimate that the animal had more than 35 teeth on each side of its upper jaw.

By comparison, modern Indian gharials are fish-eating crocodilians with slender snouts, but their upper-jaw teeth are spaced approximately 15 millimeters apart.

The closely packed, needle-like teeth suggest that Ctenosuchus tenuidens may have preyed on small, soft-bodied animals, including small fish, crustaceans and other invertebrates.

The researchers also considered whether the animal may have filtered food from the water, a feeding strategy known in some Jurassic flying reptiles. However, they emphasized that this interpretation remains tentative.

An unusual freshwater teleosaur

Evolutionary analysis placed Ctenosuchus tenuidens within Teleosauridae. The species represents the only freshwater teleosaur currently known from Gondwana and only the second teleosaurid reported from Jurassic Morocco; the other is an undetermined Machimosaurus species.

The discovery expands scientists’ understanding of teleosaur diversity and shows that these crocodilian relatives occupied a wider range of freshwater and marine environments than previously recognized.

The findings are reported in the Journal of Vertebrate Paleontology.

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Hamza Imran et al. A new teleosaurinae (Crocodiformes, Thalattosuchia) with a unique dentition that lived during the Middle Jurassic period of eastern Morocco. Journal of Vertebrate Paleontology, published online October 8, 2026. DOI: 10.1080/02724634.2026.2728670