[D] Brachytrachelopan mesai [sG] [T]
Rauhut, Remes, Fechner, Cladera, and Puerta, 2005
Jurassic Late Tithonian
Saurischia Sauropodomorpha Sauropoda Diplodocidae Dicraeosaurinae
Cañadón Calcareo Formation, Patagonia, Argentina
Genus - Typespecies
Brachytrachelopan mesai from the Greek for short-necked, and Pan, in honor of Daniel Mesa, the Patagonian shepard who found the specimen while searching for some sheep. Brachytrachelopan mesai had 12 neck vertebrae, but the individual vertebrae were shortened.it was most likely an adult specimen and consistst out of mostly axial material--nearly all of the limb elements were eroded away.
From brachytrachelos (Greek, short-necked), in reference to the short neck of the animal, and Pan (the Greek shepherd god), in reference to the fact that the specimen was found by Daniel Mesa while looking for stray sheep. The species name, mesai, honours Daniel Mesa and his family, who found the specimen.
Museo Paleontolo´ gico Egidio Feruglio (Trelew) MPEF-PV 1716; an articulated partial skeleton, including 8 cervical, 12 dorsal, and 3 sacral vertebrae, the proximal parts of the posterior cervical and all dorsal ribs, the right ilium, distal part of the left femur, and proximal end of the left tibia.
Horizon and locality
The specimen comes from a fluvial sandstone within the Cañadón Calcareo Formation, Upper Jurassic (Tithonian). It was found on the summit of a hill about 25 km north-northeast of the village of Cerro Condor. Exact locality data are available from the authors on request.
Brachytrachelopan mesai differs from all other sauropods in its very short neck, with individual cervical vertebrae being as long as, or shorter in anteroposterior length than, high posteriorly. Further apomorphies of the taxon include a pronounced, pillarlike centropostzygapophyseal lamina in the cervical vertebrae, a pronounced anterior inclination of the mid-cervical neural spines, with the tip of the spine extending beyond the anterior end of the centrum, and anterior dorsal neural spines one to six with vertical bases and anteriorly flexed tips.