Lohuecotitan

Lohuecotitan is an extinct genus of titanosaurian sauropod dinosaur which lived during the Late Cretaceous in Spain. The only species known in the genus is Lohuecotitan pandafilandi, described and named in 2016.

Lohuecotitan was recognized by its describers as having a number of unique characteristics (autapomorphies) not seen in other titanosaurs. In the dorsal vertebrae, the edges of the postspinal laminae extend outwards. In the first several caudal vertebrae, the medial spinoprezygapophyseal and spinopostzygapophyseal laminae respectively connect to the prespinal and postspinal laminae on the bottom surface. In addition, due to the way that the prespinal and postspinal laminae project upwards, the neural spine of the vertebra appears to be V-shaped from the side, and resemble a Greek cross in cross-section. Each middle caudal vertebra has two roughened structures that extend from the top of the back face onto the top surface of the vertebra. Finally, the bottom portion of each half of the haemal arches in the posterior caudal vertebrae is split fully into two articular facets. These traits form a unique combination not seen in other titanosaurs, along with the centrodiapophyseal laminae being widened on the top and bottom edges in the front and middle dorsal vertebrae (as also seen in Saltasaurus), and a rounded protrusion being present between the front and side trochanters of the fibula (also seen in Jainosaurus).

A number of the bones of Lohuecotitan were internally pneumatized, including the cervical vertebrae, sacral vertebrae, and ilium. As is common in somphospondylans, the pneumatic fossae on the cervical vertebrae are shallow; this was also the case in the dorsal vertebrae. The cervical and dorsal vertebrae are opisthocoelous; the caudal vertebrae were procoelous (a characteristic common in Lithostrotia). The seventh and eighth tail vertebrae are fused together; this probably represents a pathology. As in other titanosauriforms, the dorsal ribs are compressed and blade-like. The ulna was robust, and the bottom surface of the tibia was oval-shaped, as is common in titanosaurs.