Paleontologists have described a new genus of small, bird-like dinosaur that lived in what is now New Mexico approximately 73 million years ago.
Life reconstruction of Dinevenator robustus. Image credit: Sergey Krasovskiy.
The newly described genus, Dinevenator, belongs to a family of bird-like predatory dinosaurs called Troodontidae.
The genus is monospecific, containing only one valid species: Dinevenator robustus.
The species was around 2.4 to 3 m (8-10 feet) in body length and weighed between 70 and 140 kg (150-300 pounds), making it one of the larger troodontids known.
“This new work illustrates the dynamic nature of dinosaur studies as we continue to test what we think we know,” said Dr. Anthony Fiorillo, executive director of the New Mexico Museum of Natural History & Science.
“Furthermore, it demonstrates that New Mexico clearly has a prominent place in those global conversations.”
“This really helps us get a clearer picture of the diversity in this family of dinosaurs during the Late Cretaceous in North America, and it adds to our knowledge of dinosaurs that once roamed New Mexico,” said Dr. Steven Jasinski, paleontology curator at the New Mexico Museum of Natural History & Science and a paleontologist at Harrisburg University.
Dinevenator robustus is known only from a nearly complete left frontal bone, part of the skull, cataloged as SMP VP-1955.
The specimen was unearthed in the summer of 2005 from the De-na-zin Member of the Kirtland Formation in the San Juan Basin of northwestern New Mexico, the United States.
The fossil’s identity has shifted repeatedly since it was first described in 2006, when it was classified as a new species of the raptor-like dromaeosaurid Saurornitholestes.
Later paleontologists disputed that placement, and by 2014 the specimen had been reclassified as belonging to Troodontidae.
Even after the reassignment, some scientists considered the species invalid, and a 2026 study proposed folding it into another troodontid genus, Xenovenator, from Mexico.
Dr. Jasinski and his colleague, Robert Sullivan, concluded that the fossil is distinct enough from Xenovenator and other troodontids to warrant its own genus.
Their phylogenetic analysis placed Dinevenator robustus in a group of large-bodied, thick-skulled troodontids alongside Xenovenator espinosai and the Canadian species Albertavenator curriei.
Rather than being a close relative of Xenovenator, as previously proposed, the analysis found the new species to be the earliest-diverging member of the robust-skulled lineage.
The discovery adds to a growing list of dinosaur species that appear unique to the ecosystems of the San Juan Basin, underscoring the region’s importance for understanding dinosaur diversity in the southern United States during the twilight of the Cretaceous period.
“Recognition of a distinct, large, robust, thick-skulled troodontid adds to the unique nature of the ancient ecosystems of the San Juan Basin,” the authors concluded.
“Different dinosaur groups show closer relationships with species from various other geographic regions, implying a complex interplay between species and systems during the Late Cretaceous of North America.”
The team’s paper was published August 3 in the journal Fossil Studies.
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Steven E. Jasinski & Robert M. Sullivan. 2026. Dinevenator, a New Genus of Troodontid Dinosaur from the Late Cretaceous of New Mexico. Foss. Stud 4 (3): 21; doi: 10.3390/fossils4030021
