Palaeontologists from the University of Bath and elsewhere have described a new genus and species of kritosaurine hadrosaur dinosaur from a partial skull discovered in the Late Cretaceous Cerro del Pueblo Formation.

The newly described species is Coahuilasaurus lipani. It has an estimated overall length of 8 metres (26.2 ft).

It dates back about 72.5 million years ago, towards the end of the Campanian stage of the Late Cretaceous Period.

Coahuilasaurus lipani belongs to Kritosaurs, a unique family of duck-billed dinosaurs (Hadrosauridae), Kritosaurus navajovius and their relatives.

“Kritosaurus is one of the most diverse lineages of North American hadrosaurs, represented by numerous species that lived during the Late Cretaceous of the Western Interior,” they said. Dr Nicholas Longrich Researchers from the University of Bath and their colleagues.

“The striking changes in jaw morphology suggest different ecological niches and dietary specialization.”

“The diversity of cranial vault morphology among kritosaurs suggests that sexual selection may have driven the evolution of kritosaurs, similar to the crested lambeosaurs and ceratopsids.”

“Although klitosaurins’ bone protuberances are not very sophisticated, klitosaurins may have had sophisticated soft-tissue structures.”

“The function of the Kritosaurus crest is unclear,” the paleontologist said.

“Because it is conspicuous, it probably functioned as a display. In modern birds, skull ornaments are sometimes used in intraspecific combat, for example in hornbills, and the relatively robust crest feathers may have served a similar function.”

“As in lambeosaurids, the elaborate nasal cavity may have also been involved in vocalization.”

Part of a skull Coahuilasaurus lipani comes from the Cerro del Pueblo Formation in Coahuila, Mexico.

“The Cerro del Pueblo Formation harbors a diverse assemblage of dinosaurs, including theropods and ornithischians,” the researchers said.

“Theropods include tyrannosaurs and deinocheirs. Paraxenisaurus normalensis, Ornithomimidae, Caenagnatidae, Dromaeosauridae, and Troodontidae.”

“The ornithischian family includes ankylosaurs, ceratopsids, thescelosaurs, and hadrosaurs.”

According to the team’s analysis, Coahuilasaurus lipani is distinct from the kritosaurs found further north on Laramidia.

It may be related to the kritosaurid hadrosaurids, Gryposaurus monumentensis. This suggests that it is part of a distinct southern kritosaur lineage.

“With specimens from the Naashoibito Formation of the Kirtland Formation in New Mexico, Coahuilasaurus lipani ,”This study shows that kritosaurs survived in the south of Laramidia after local extinction in the north, a pattern also seen in parasaurolophus and lambeosaurines,” the scientists said.

“The southern fauna not only has different species but also different patterns of diversity change compared to the northern Laramidia fauna.”

“Differences in species composition and community structure in different regions of Laramidia mean that further studies on dinosaurs from Mexico and the southwestern United States are needed to understand the evolution of dinosaur diversity in western North America.”

“Southern dinosaur faunas may have been characterized by higher origination rates and lower extinction rates than northern faunas.”

of study Published in the journal on September 1, 2024 Diversity.

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Nicholas R. Longrich others2024. Coahuilasaurus lipania new species of kritosaurine hadrosaurid from the Upper Campanian Cerro del Pueblo Formation, northern Mexico. Diversity 16 (9): 531; doi: 10.3390/d16090531