Abstract: In South America, most titanosaur species are represented by incomplete skeletal elements lacking well-preserved cervical vertebrae. In this context, the discovery of cervical remains assigned to Mendozasaurus neguyelap González Riga is relevant from a systematic viewpoint. The fossils were found in the paleontological site and assemblage of the holotype, Río Neuquén Subgroup, late Turonian – late Coniacian from Mendoza Province, Argentina.
The cervical vertebrae of Mendozasaurus exhibit differences with those of most titanosaurs; however, they share with Isisaurus colberti (Jain and Bandyopadhyay) from Maastrichthian of India the presence of: a) short vertebral centra (ratio: total length/height of cotyle less than 2.5), b) large and deep supradiapophyseal fossa, and c) relatively tall neural spines (ratio: vertebral height/centrum length more than 1.5).
The fossils recovered show an autapomorphic character that enlarges the diagnosis of Mendozasaurus: tall, laminar and transversally expanded mid-posterior cervical neural spines that are wider than vertebral centra and ‘fan-like' or ‘subrhomboid' in shape due to lateral expansions and a subrounded dorsal border.
Thanks to Dr. Eric Snively for pointing out this older but still interesting paper to the Palaeoblog!