Eoneophron (meaning "dawn Neophron") is an extinct genus of caenagnathid theropod dinosaur from the Late Cretaceous Hell Creek Formation of South Dakota, US. The genus contains a single species, E. infernalis, known from a partial hindlimb.
Eoneophron (meaning "dawn Neophron") is an extinct genus of caenagnathid theropod dinosaur from the Late Cretaceous Hell Creek Formation of South Dakota, US. The genus contains a single species, E. infernalis, known from a partial hindlimb.
== Discovery and naming == thumb|left|Left femur of the holotype thumb|Osteological thin section of one of the holotype metatarsals of Eoneophron, with observed LAGs outlined in light blue and red The Eoneophron fossil material was discovered in sediments of the Hell Creek Formation in Meade County, South Dakota, United States. The specimen, which consists of a partial right hindlimb, was prepared and initially listed for commercial sale before being purchased in 2020 for $5,000 by Kyle Atkins-Weltman. He then donated the specimen to the Carnegie Museum of Natural History for research. Preliminary observation of the material had suggested that the bones belonged to a juvenile specimen of Anzu, a related dinosaur from the same formation. However, after analyzing the histology of the bones, Atkins-Weltman and colleagues determined that the individual would have been skeletally mature when it died. Based on the observed lines of arrested growth (LAGs), they further estimated that the animal was in the sixth year of life when it died.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).