Ligabuesaurus leanzai

[Brad McFeeters <archosauromorph2@hotmail.com>]

Bonaparte, J.F., González Riga, B.J. & S. Apesteguía, 2006.  Ligabuesaurus 
leanzai gen. et sp. nov. (Dinosauria, Sauropoda), a new titanosaur from the 
Lohan Cura Formation (Aptian, Lower Cretaceous) of Neuquén, Patagonia, 
Argentina.  Cretaceous Research, in press.

ABSTRACT: *Ligabuesaurus leanzai* gen. et sp. nov. is a new titanosaur 
(Saurischia, Sauropoda) from the Lower Cretaceous of Neuquén Basin, north 
Patagonia, Argentina. The fossil remains were found in the upper section of 
the Lohan Cura Formation, which is regarded as Late Aptian?Albian in age. 
Remains include an incomplete maxilla with ten teeth, six cervical and 
dorsal vertebrae, and several associated girdle and limb bones. 
*Ligabuesaurus* is characterized by: (1) laminar and anteroposteriorly 
compressed neural spines on posterior cervical and anterior dorsal vertebrae 
that are rhomboid in shape and wider than vertebral centra; (2) 
spinoprezygapophyseal laminae in the posterior cervical vertebrae forked to 
form two pairs: the medial laminae contact one another toward the tip of the 
neural spine, and the lateral pair form the lateral border of the neural 
spine; (3) dorsoventrally reduced neural arch pedicels in posterior cervical 
and anterior dorsal vertebrae; and (4) rudimentary prespinal lamina on 
posterior cervical and anterior dorsal vertebrae. A preliminary phylogenetic 
analysis suggests that *Ligabuesaurus* is a basal titanosaur. The 
development of relatively long forelimbs, with a humerus/femur ratio of 0.9, 
indicates that this condition is not an exclusive adaptation of the 
Brachiosauridae.