Describer

Pang & Cheng, 2000

Time

Cretaceous Late

Classification

Saurischia Sauropodomorpha Sauropoda

Diet

Herbivore

Fossilsite

Huiquanpu Formation, Shanxi and Hebei, China

Info

Genus - Typespecies

Comments by Mickey Mortimer

Etymology

unusual North China reptile\\\" (Huabei= phoenetic annotation of Chinese characters for \\\"North China\\\", allocot= Greek for unusual)

Holotype

(HBV-20001) two teeth, incomplete postcranial skeleton paratype- (HBV-20002) incomplete left humerus material- two teeth, four cervical vertebrae, four dorsal vertebrae, five sacral vertebrae, one complete rib, twenty-one caudal vertebrae, eleven chevrons, scapulae, coracoids, humerus, radius, ilium, pubes, ischia, femora, tibiae, fibulae, broken vertebrae, cervical and dorsal ribs size- 20 meters long, 5 meters high teeth- parallel-sided, no serrations, ridges on anterior and posterior margins, spatulate crown, width/hieght ratio between Dicraeosaurus and Brachiosaurus cervical vertebrae- opisthocoelous, pleurocoelous, ventral surface with lateral ridges, bifurcated neural spines with no central process, centra subcircular in anterior view, cervical ribs longer than centra dorsal vertebrae- oval pleurocoels, undivided neural spines, opisthocoelous, neural spine flatted transversely sacral vertebrae- five caudal vertebrae- amphicoelous, no pleurocoels, neural arch displaced anteriorly, chevrons open and not forked scapulocoracoid- proximal scapula not expanded much, coracoid rounded forelimb- 79% of hindlimb length, no humeral proximolateral process of Upchurch (1998, C160), humerus/femur = .78, radius/humerus = .77 pelvis- preacetabular processes rounded and not flared laterally, dorsal edge of ilium convex, ischial peduncle reduced, ischium 76% of pubic length, not directed ventrally, distal end slightly expanded hindlimb- femur transversely oval in section, lateral bulge present, fourth trochantor on caudolateral edge of shaft, tibia 75% of femur

Systematic position

The authors state Huabeisaurus allocotus is closer to diplodocids and titanosaurids than to vulcanodontids, cetiosaurids, brachiosaurids and camarasaurids using the old system of peg vs. spatulate teeth. They conclude it is most closely related to the titanosaurids (although not Phuwiangosaurus or Opisthocoelicaudia) and say that \\\"Titanosaurus\\\" falloti should be reassigned to Huabeisaurus.

M. Mortimer added Huabeisaurus allocotus to the data matrix of Upchurch (1998) and concluded it to be the sister group to Phuwiangosaurus based on bifurcated cervical neural spines without a small central process and coracoid rounded (reversal). Characters acquired convergently by Huabeisaurus allocotus are: - ventral surface of cervical centra transversely concave and laterally bound by ridges - elongation index values for caudal dorsal centra less than 1.0 (reversal) - neural spines of proximal caudals craniocaudally compressed - proximal end of scapula with small acromial process (reversal) - width across ischial shaft divided by ischial length .2-.3 - tibia/femur ratio more than .7

As for the claim that \\\"Titanosaurus\\\" falloti is close to Huabeisaurus allocotus, Allain et al. (1999) found that this species is indeterminate and assigned it\\\'s materal to a new species, Tangvayosaurus hoffeti, which they placed closest to Phuwiangosaurus.