Wikipedia
Cathetosaurus is a dinosaur sauropod genus that contains one species: Cathetosaurus lewisi that was thought to be within the Camarasaurus genus. The holotype specimen was originally described by James Jensen and is now in the Brigham Young University collection. The holotype specimen of Cathetosaurus lewisi is contemporary with the middle of the C. grandis age range. It is supposedly different from other species due to the bifurcation (split) of its neck vertebrae starting at a different point in the neck, and bony tendons present in the hip region. However, no other Camarasaurus specimens are well preserved enough to be sure the supposedly distinct neck vertebrae are really distinct, and bony hip tendons are also known in large, mature specimens of C. lentus and C. supremus, indicating that this difference may be a feature that changed with age. This species was originally named as Cathetosaurus lewisi and later synonymized with Camarasaurus. More recent research has split the two genera again, based on the recognition of a second specimen.
The diagnostic characters for Cathetosaurus are:
- the pelvis is rotated anteriorly, such that the pubis projects posteroventrally, and the ischium projects posteriorly,
- lateroventrally projecting spurs in the neural spines of the last dorsals;
- posterior cervical and anterior dorsal diapophyses bearing an anterior projection lateral to the prezygapophysis.
- frontals with anterior midline projection into the nasals;
- trapezoidal supraoccipital (more expanded dorsally than ventrally),
- lateral spur on the dorsal part of the lacrimal, iv) fenestrated pterygoid;
- the large pineal foramen between the frontals.