Overview
- Researchers formally described Bicharracosaurus dionidei in PeerJ after fossils surfaced in the Cañadón Calcáreo of northwest Chubut, Argentina.
- Dionide Mesa, a local horseman, spotted the bones and alerted the Museo Paleontológico Egidio Feruglio, inspiring the name that honors his role.
- The partial skeleton includes vertebrae, dorsal ribs, and hip fragments from an adult estimated at 15–20 meters long and about 20 tonnes.
- The animal dates to roughly 155–160 million years ago in the Late Jurassic, and its unusually elongated, compressed neural spines set it apart from known sauropods.
- Phylogenetic work places it within Macronaria, a group that includes Brachiosaurus and Patagotitan, and the authors propose a possible Jurassic brachiosaurid in South America that remains under study, with the fossils curated at MEF in Trelew by an Argentina–Germany team backed by the DFG.