Describer

Wedel & Cifelli and Sanders, 2000

Time

Cretaceous Early Aptian Albian

Classification

Saurischia Sauropodomorpha Sauropoda Brachiosauridae

Diet

Herbivore

Fossilsite

Antlers Formation south eastern Oklahoma, US

Info

Genus - Typespecies

Holotype

OMNH 53062, the material consists of a series of four cervical vertebrae between 17 and 18 feet long; the longest individual vertebra is five feet long. This extrapolates to a neck 39-40 feet long, which would be about as long as or even longer than the extrapolated neck lengths for the Chinese sauropods Mamenchisaurus sinocanadorum and Hudiesaurus sinojapanorum. This would make it one of the longest known necks of any terrestrial vertebrate. The length of the animal was about 100 feet (30,5 meter).

Sauroposeidon most likely lived during the Early Cretaceous probably during the Albian period (112 to 97 million years ago) in the delta of a massive river system.

Sauroposeidon proteles is most similar to Brachiosaurus; particularly noteworthy are the neural spines, which are set forward on the centra and are not bifurcate, and the extremely elongate cervical ribs. Sauroposeidon and Brachiosaurus also share a derived pattern of pneumatic vertebral ultrastructure and a mid-cervical transition point, at which neural spine morphology changes from very low (anteriorly) to very high (posteriorly).

Autapomorphies of Sauroposeidon include posterior placement of the diapophyses, hypertrophied pneumatic fossae in the lateral faces of the neural spines and centra, and an extraordinary degree of vertebral elongation (e.g., C8 = 1.25 m; 25% longer than Brachiosaurus).

Additional sauropod material from the Early Cretaceous Cloverly Formation may be referrable to the new Oklahoma sauropod, which appears to be the last of the giant North American sauropods and represents the culmination of brachiosaurid trends towards lengthening and lightening of the neck.