Pronunciation: BOW-nuh-part-SOR-us
Meaning: Bonaparte lizard
Author/s: Cruzado-Caballero and Powell (2017)
Synonyms: None known
First Discovery: Río Negro, Argentina
Discovery Chart Position: #949
Bonapartesaurus rionegrensis
Bonapartesaurus, named in honour of Argentine paleontologist José Bonaparte, is a hadrosaurid ornithopod that roamed Patagonia during the Campanian to Maastrichtian stages of the Late Cretaceous, approximately 70 million years ago. Initially referred to Willinakaqe, the specimen was reassigned in 2017 by Cruzado-Caballero and Powell after a detailed reevaluation revealed that the former was actually a chimera of multiple critters.
The partial skeleton, discovered in 1984 at Salitral Moreno, revealed not only features typical of saurolophine hadrosaurs but also signs of pathology. A striking cauliflower-like growth on one foot bone (metatarsal) was initially thought to be a fracture, but closer scrutiny under microscope (histological analysis) and CT scans later suggested it was likely an abnormal lump of growing cells (neoplasm)—possibly a type of bone cancer (osteosarcoma). Additionally, two tail vertebrae showed signs of healed fractures, indicating the dinosaur had survived significant trauma, potentially accompanied by infection and excruciating pain.
The partial skeleton, discovered in 1984 at Salitral Moreno, revealed not only features typical of saurolophine hadrosaurs but also signs of pathology. A striking cauliflower-like growth on one foot bone (metatarsal) was initially thought to be a fracture, but closer scrutiny under microscope (histological analysis) and CT scans later suggested it was likely an abnormal lump of growing cells (neoplasm)—possibly a type of bone cancer (osteosarcoma). Additionally, two tail vertebrae showed signs of healed fractures, indicating the dinosaur had survived significant trauma, potentially accompanied by infection and excruciating pain.
(Bonaparte lizard fron Rio Negro)Etymology
Bonapartesaurus is derived from "Bonaparte" (for Argentine palaeontologist José Bonaparte) and the Greek "sauros" (lizard). The species epithet, rionegrensis, means "from Río Negro" in Latin.
Discovery
The remains of Bonapartesaurus were discovered in the Allen Formation (Malargüe Group) at Salitral Moreno, Río Negro Province, Argentina.
The holotype (MPCA-Pv SM 2) is a partial skeleton including back, hip and tail vertebrae, ossified ligaments, ribs, a left shoulder blade, a partial hip (right ilium and ischium), thigh, shin and shank bones, ankle and heel bones, and a left foot. It was initially assigned to Willinakaqe salitralensis.
