[D] Mendozasaurus neguyelap [sG] [T]
Describer
González Riga, 2003
Time
Cretaceous Late Turonian Coniacian
Classification
Saurischia Sauropodomorpha Sauropoda Titanosauria
Diet
Herbivore
Fossilsite
Rio Neuquen Formation, Neuquén Basin, Neuquén Group, Mendoza Province, Argentina
Info
Genus - Typespecies
Mendozasaurus consist of 22 mostly articulated caudal vertebrae, a dorsal vertebra, numerous disarticulated appendicular bones and osteoderms.
Probable autapomorphies of Mendozasaurus are: (1) subtriangular infrapostzygapophyseal fossae in anterior dorsal vertebrae; (2) postzygapostspinal laminae parallel to the plane of the postzygapophyseal facets in anterior dorsal vertebrae; (3) interzygapophyseal cavity dorsoventrally extended and limited by the spinopostzygapophyseal and spinoprezygapophyseal laminae in anterior caudal vertebrae; (4) middle caudal vertebrae slightly procoelous, with reduced posterior condyles displaced dorsally; (5) laminar mid-posterior caudal neural spines with horizontal and straight dorsal border, and anterodorsal corner forming a right angle; (6) large subconic-spherical osteoderms lacking cingulum. A cladistic analysis permits the inclusion of Mendozasaurus within Titanosauria, according to the phylogenetic definition of this clade.
Although this new species exhibits almost all the titanosaurid synapomorphies proposed by some authors, it lacks prominent posterior condyles in middle caudal centra. This and other plesiomorphic traits suggest that Mendozasaurus is a basal titanosaurid more derived than Malawisaurus in the caudal procoely.
González Riga, 2003
Time
Cretaceous Late Turonian Coniacian
Classification
Saurischia Sauropodomorpha Sauropoda Titanosauria
Diet
Herbivore
Fossilsite
Rio Neuquen Formation, Neuquén Basin, Neuquén Group, Mendoza Province, Argentina
Info
Genus - Typespecies
Mendozasaurus consist of 22 mostly articulated caudal vertebrae, a dorsal vertebra, numerous disarticulated appendicular bones and osteoderms.
Probable autapomorphies of Mendozasaurus are: (1) subtriangular infrapostzygapophyseal fossae in anterior dorsal vertebrae; (2) postzygapostspinal laminae parallel to the plane of the postzygapophyseal facets in anterior dorsal vertebrae; (3) interzygapophyseal cavity dorsoventrally extended and limited by the spinopostzygapophyseal and spinoprezygapophyseal laminae in anterior caudal vertebrae; (4) middle caudal vertebrae slightly procoelous, with reduced posterior condyles displaced dorsally; (5) laminar mid-posterior caudal neural spines with horizontal and straight dorsal border, and anterodorsal corner forming a right angle; (6) large subconic-spherical osteoderms lacking cingulum. A cladistic analysis permits the inclusion of Mendozasaurus within Titanosauria, according to the phylogenetic definition of this clade.
Although this new species exhibits almost all the titanosaurid synapomorphies proposed by some authors, it lacks prominent posterior condyles in middle caudal centra. This and other plesiomorphic traits suggest that Mendozasaurus is a basal titanosaurid more derived than Malawisaurus in the caudal procoely.