Description and Classification

Chenanisaurus was a large predatory dinosaur, estimated to have been about 7 to 8 meters (23 to 26 feet) long. Like other members of the Abelisauridae family, such as Carnotaurus and Majungasaurus, Chenanisaurus would have had a relatively short and deep skull, very small, almost useless forelimbs, and powerful hind legs. The known lower jawbone (dentary) of Chenanisaurus is robust and deep, suggesting it had a strong bite. Its teeth were stout and slightly curved, suited for gripping and tearing flesh from its prey. The outer surface of the jawbone was rough, which might have supported textured skin or scales.

Chenanisaurus is classified as a theropod dinosaur, belonging to the group Abelisauridae. Abelisaurids were a dominant group of predators in Gondwana (the southern supercontinent) during the Cretaceous period. The discovery of Chenanisaurus in Morocco provides important evidence about the diversity and distribution of these dinosaurs just before their extinction.

Distinguishing Features

Chenanisaurus can be identified by several features, primarily observed in its lower jaw and teeth:

• It possessed a very deep and robust lower jawbone, particularly at the front.
• The front tip of the lower jaw was slightly downturned.
• Its teeth were relatively short and thick, differing in some details from other abelisaurids.
• The jawbone exhibits a unique pattern of grooves and holes on its outer surface, distinct from related species.
• It is significant for being one of the last known non-avian dinosaurs from the African continent.

Paleoenvironment and Diet

Chenanisaurus lived in what is now Morocco during the Late Maastrichtian age, the final stage of the Cretaceous period. The environment at that time was a coastal region with a warm climate. The phosphate deposits where its fossils were found suggest it lived near a shallow sea. This area was home to a variety of marine life, including mosasaurs and plesiosaurs in the nearby waters, as well as pterosaurs and other dinosaurs on land. Other dinosaurs from the same deposits include the sauropod Titanosaurus and possibly other, yet undescribed, theropods.

As a large abelisaurid, Chenanisaurus was a carnivore and likely an apex predator in its ecosystem. Its diet would have consisted of other dinosaurs, such as herbivorous titanosaurs, or any other sizeable terrestrial animals it could hunt. The strong build of its jaw and teeth indicates it was capable of delivering powerful bites to subdue large prey.

Significance and Ongoing Research

The discovery of Chenanisaurus is highly significant because it is one of the youngest known non-avian dinosaurs from Africa, living right up to the Cretaceous-Paleogene (K-Pg) extinction event. This shows that abelisaurid dinosaurs thrived in Africa until the very end of the age of dinosaurs. Its presence in North Africa also helps scientists understand how animal groups were distributed across the ancient supercontinent of Gondwana.

Ongoing research on Chenanisaurus focuses on finding more fossil material to get a more complete picture of its anatomy and appearance. Paleontologists are also studying its relationship to other abelisaurids from South America, India, and Madagascar to learn more about the evolution and dispersal of this fascinating group of predators. Further investigation of the rocks where Chenanisaurus was found will also provide more clues about the ecosystem and environment in North Africa just before the dinosaurs went extinct.