Turiasauria

Turiasauria is an unranked clade of sauropod dinosaurs, named for the genus Turiasaurus, a gigantic eusauropod from southwestern Europe. The clade also includes two other known members, Galveosaurus and Losillasaurus. All three taxa thus far referred to Turiasauria have come from the Villar del Arzobispo Formation (Tithonian-Berriasian) of Spain. Turiasuria was defined as: all Eusauropoda closer to Turiasaurus riodevensis than to Saltasaurus loricatus.

Cladistic analysis (Royo-Torres et al., 2006; 1927) of 309 characters and 33 taxa suggests that the turiasaurians lie outside the Neosauropoda and form a monophyletic group. The clade is diagnosed by the presence of vertical neural spines, posterior centroparapohyseal laminae on the dorsal vertebrae, the absence of pre- and postspinal laminae on the dorsal vertebrae, the absence of a scapular acromial crest, the presence of a prominent humeral deltopectoral crest, medial deflection of the proximal end of the humerus, and a distinct vertical ridge on the caudal side of the distal half of the ulna.

The biogeographic and stratigraphic ranges of the Turiasauria remain unclear, but Royo-Torres et al. (2006; 1927) hypothesize that the clade probably represents a pre-Tithonian sauropod radiation originating in Europe. As yet unrecognized members of the group may be indicated by Turiasaurus-like teeth from the Jurassic of Portugal, France, and England (presently referred to the genera Neosodon and Cardiodon).

Turiasaurus demonstrates that the evolution of enormous body size was not restricted to neosauropod clades such as the Diplodocidae and Titanosauria, but developed independently at least once in a lineage of more basal sauropods, the turiasaurians.

In 2009 a thesis published by José Barco proposed that neither Galveosaurus nor Losillasaurus were turiasaurians. Later, a master thesis by Francisco Gascó (2009) and also a new paper published in Palaeontology by Royo-Torres et al. (2009) concluded that Turiasauria was a valid clade.