[D] Haplocanthosaurus priscus [sG] [T]
Jurassic Late Kimmeridgian Tithonian
Saurischia Sauropodomorpha Sauropoda Cetiosauridae Cetiosaurinae
Morrison Formation, Colorado, Wyoming, US
Genus - Typespecies
Haplocanthosaurus priscus (Hatcher, 1903) = Haplocanthus priscus (Hatcher, 1903 name preoccupied) >> Haplocanthosaurus utterbacki (Hatcher, 1903)
Haplocanthosaurus priscus > Haplocanthosaurus delfsi (McIntosh & Williams, 1988) >> Morosaurus agilis NN (Marsh, 1889)
2 partial skeletons without skulls.
Unusual because it was a survivor of the verry primitive Cetiosauridae, among its more advanced descendants is was a kind of \\\"living fossil\\\". Haplocanthosaurus resembled Brachiosaurus in its high shoulders, fairly long neck, and short tail, the back was quite long, containing 14 vertebrae.
\\\"simple-spined lizard\\\" Haplocanthosaurus represents a holdover of the Cetiosauridae into the Late Jurassic of the US. No part of the skull or teeth can yet be assigned with certainty to this animal, nor can any of the limb or foot bones save the femur.
Hatcher, 1903 estimated the number of cervicals to be 15 (as in Diplodocus), but examination of the most complete neck of this form suggests that this number may be to large. There are 14 dorsal vertebrae. As in all cetioaurids, the proximal end of the scapula is less developed then in other sauropods, and the angle of its ridge with the shaft is large.
Replacement name for supposedly preoccupied Haplocanthus (because of Haplacanthus Agassiz 1845); conserved by ICZN Opinion #1633. Long referred to as a cetiosaurid, the genus appears to be related to Camarasaurus instead.