Bicharracosaurus

Bicharracosaurus was a genus of macronarian sauropod dinosaur that roamed the Earth during the Late Jurassic period. Its scientific name, Bicharracosaurus dionidei, reflects both its considerable size and the individual who discovered its remains. The genus name itself is derived from the informal Spanish word "bicharraco," meaning "big animal," a fitting descriptor for these massive creatures, combined with the Greek "saurus" for lizard.

Discovery and Naming

The type specimen of Bicharracosaurus, designated MPEF-PV 1730, was unearthed in the Chubut Province of Argentina. Its discovery was first reported in March 2001 by a local farmer named Dionide Mesa, after whom the species is named. Excavation and recovery efforts took place in stages, with significant portions of the partial skeleton, including disarticulated caudal vertebrae, articulated cervical and dorsal vertebrae with ribs, sacral vertebrae, and the ilium, being unearthed between 2002 and 2018. In 2026, Alexandra Reutter and her colleagues formally described Bicharracosaurus dionidei as a new genus and species.

Physical Characteristics

Based on the available fossil evidence, Bicharracosaurus is estimated to have reached a length of approximately 15 meters (49 feet) and a substantial weight of around 20 tonnes (44,000 pounds). Several unique anatomical features, or autapomorphies, have been identified. These include a distinctive triangular pneumatic hole within the middle and rear tail vertebrae, a small, upwardly directed protuberance at the lower end of the postzygodiapophyseal lamina in the rearmost neck vertebrae, and sacral vertebrae that feature boat-shaped joint facets on their centra. The dinosaur is believed to have been a herbivore, consistent with its sauropod classification.