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New megaraptorid genus named from incomplete Late Cretaceous skeleton in northern Patagonia
The animal sits inside Megaraptoridae, a group of medium- to large-sized theropods known for slender hind limbs, strongly curved teeth, and large claws on their hands
From an incomplete skeleton recovered in northern Patagonia, Argentina, researchers have named a new genus and species of megaraptorid dinosaur, Rinconraptor pipoae.
The species sits in Megaraptoridae, a group of medium- to large-sized theropods with slender hind limbs, strongly curved teeth, and large claws on the hands. Comparative work on the preserved bones supports the taxonomic claim. In their 2026 description, CONICET paleontologist Ariel Hernán Méndez and colleagues place Rinconraptor pipoae in the Late Cretaceous, some 83 million years ago.
They locate the find at Cerro Overo, about 50 km (30 miles) southwest of Rincón de los Sauces in Patagonia, Argentina. Méndez and colleagues said the specimens come from the Bajo de la Carpa Formation, an integral unit of the Río Colorado Subgroup within the Neuquén Group, from the Upper Cretaceous of the Neuquén Basin. Throughout the basin, they said, the formation records paleoenvironments shaped by aeolian and fluvial depositional systems.
The main specimen consists of 10 tail vertebrae, part of a bone from the underside of the tail, the lower end of a left upper-arm bone, and the upper end of a right shinbone. The tibia was still embedded in rock, while the other bones lay scattered on the surface within an area of about 4 square meters (roughly 43 square feet). Sci.News. By comparing its vertebrae with those of better-known relatives, the researchers estimate that Rinconraptor pipoae was about 7 m (23 feet) long. Their estimate for the same species also puts the tail at more than 40 to 45 segments. Other megaraptorid bones from the same area that they could not assign to a species carry estimated body lengths from about 6 to 8.5 meters (20 to 28 feet).
Méndez and colleagues noted that megaraptoran fossils are known from Argentina and from Brazil, Australia, Thailand, and Japan. They said the megaraptorid fossil record remains scarce and fragmentary, and that phylogenetic affinities of the group remain debated among specialists. The paper appeared online in 2026 in Palaeontologia Electronica. For Megaraptoridae, that study names the scarce and fragmentary fossil record as the limit.