Discovery and naming Huabeisaurus

image of skeleton in position when found

limb , girdle elements left , right sides of body closely match each other in size , appropriate size belong same individual vertebrae , ribs. disposition of bones in quarry approximately expected if animal lying on left side in opisthotonic pose, bones show disorientation , disarticulation: cervical vertebrae arranged along curved line, , extending along tight curve (approximately) sit 2 of dorsal vertebrae followed sacrum , caudal vertebrae. sacrum , first 3 caudal vertebrae found in articulation , in line remaining articulated caudal vertebrae; others present after gap of 0.5 metres (1.6 ft). twenty-seven caudal vertebrae shown on quarry map, 30 found in collection, , pre-restoration photos indicate 32 present. many of chevrons found articulated respective caudal vertebrae. left , right scapulae recovered on left , right sides of body, respectively. left radius found midway between pectoral girdle elements. left , right femora, pubes, , ilia located close 1 , of these found near sacrum. sacrum depicted left side facing upwards on quarry map, might have been error because left side of sacrum damaged , left ilium missing. elements of left , right crura found in close association. dorsal rib fragments scattered across quarry area. in sum, degree of dispositioning occurred hbv-20001 before or during burial, resulting in loss , disarticulation of elements, disposition, overall agreement in size, , lack of duplication of bones suggests presence of single sauropod individual @ locality.

multiple views of 2 assigned teeth

two teeth preserved. 1 tooth discovered in quarry during excavation , second found field jackets opened during preparation of specimen @ shijiazhuang university. teeth attributed holotype individual based on close association other bones , lack of evidence transport site. both teeth preserved, exhibiting wrinkled enamel. crowns subcylindrical, slenderness indices of 3.46 , 3.36, more slender described pang , cheng , intermediate in slenderness between broad , narrow-crowned sauropods (e.g., euhelopus , phuwiangosaurus). neither tooth twisted along length in upper teeth of brachiosaurids.

a total of 4 cervical vertebrae recovered holotypic quarry. 2 of these fragmentary, whereas other 2 vertebrae complete. according quarry map, 2 poorly preserved cervical vertebrae articulated when found , belong more anterior part of cervical series complete vertebrae. little anatomical information can gleaned 2 fragmentary cervical vertebrae aside measurements.

only capitula, tubercula, , part of anterior , posterior processes of cervical ribs preserved. ribs fused respective vertebrae. cervical ribs pendant, extending ventrally distance subequal height of centrum, in several other east asian cretaceous sauropods. in both cervical vertebrae, tuberculum notably slender anteroposteriorly, in comparison capitulum. cervical ribs broken, original description notes @ least exceeded centrum length.

parts of 6 dorsal vertebrae preserved: 1 partial anterior dorsal vertebral neural arch, 1 partial dorsal vertebral centrum, 3 posterior dorsal vertebrae complete heavily reconstructed plaster, , 1 has been plastered sacrum. none of dorsal vertebrae have observable neurocentral sutures.

sacrum

a complete sacrum consisting of 6 vertebrae recovered quarry, lacking ribs. original description of huabeisaurus suggested 5 sacral vertebrae present based on number of sacral ribs , intercostal foramina. sacrum heavily restored plaster, pre-restoration photographs show sacrum in 2 oblique dorsal views , right lateral view. these photographs reveal last dorsal vertebra taphonomically shifted posteriorly , right, crushing right first sacral rib. pre-restoration photographs , number of broken sacral neural spines visible indicate sacrum composed of @ least 6 vertebrae. first vertebra crushed sacrum represent seventh sacral vertebra; because ribs of dorsal vertebra not observable firsthand or in photographs, cannot verified whether or not these ribs contacted ilium. vertebra interpreted last dorsal vertebra because: neural spine not appear fused neural spine posterior it, , usual sacral vertebral count basal somphospondylans 6 (with 7 vertebrae in neuquensaurus derived exception).

eleven chevrons listed in holotype of huabeisaurus pang , cheng, thirteen visible in pre-reconstruction photographs, , twelve present in museum of shijiazhuang university. these elements correspond positions covering entire length of preserved caudal vertebral series. chevrons preserved, there distortion , damage. correspondence of chevrons particular caudal vertebrae uncertain.

scapula

although exact orientation of pectoral girdle in vivo uncertain, scapulae , coracoids thought have been oblique major planes of orientation of rest of body, rendering orientational descriptors difficult select. aside glenoid region, damaged or missing in both specimens, preserved parts of left , right scapulae complement 1 give full picture of morphology of element. scapulae consist of broad proximal plate comprising acromion , acromial fossa , blade forms more half length of bone. lateral surface of acromial plate excavated anterior acromial ridge , dorsal glenoid region. acromial ridge posteriorly deflected, such oriented @ acute angle long axis of scapular blade. posterior glenoid articular surface, ventral margin of scapula broad , convex transversely, rapidly narrows merges base of blade. no prominent subtriangular process seems occur along posteroventral edge of proximal scapula, though absence due damage. broad ridge extends longitudinally along proximal third of lateral face of blade. dorsal margin of blade straight, whereas ventral margin expands distally such ratio of maximum minimum blade dorsoventral height 1.7, less described value of ca. 2. development of acromion , distal expansion of blade similar of other somphospondylans , not marked in rebbachisaurids.

the left radius damaged @ proximal , distal ends. radius gracile, midshaft width length ratio of 0.12. in anterior view, lateral face of shaft straight, whereas medial face concave. anteroposteriorly expanded proximal end has prominent ridge on lateral face. proximal end has approximately oval outline pointed anterior process , broadly rounded posterior process. proximomedial margin straight, whereas proximolateral margin concave anteriorly , convex posteriorly. oval cross-section of upper shaft gradually transforms rounded d-shape @ mid-shaft, long axis of cross section extending transversely. ‘d’ shape becomes more anteriorly compressed towards distal end, transversely rounded anterior face , increasingly flattened posterior face. associated strong transverse expansion of distal shaft , distal end of bone, described twisting of bone. strong transverse expansion of distal radius found in titanosaurs (e.g., alamosaurus , jainosaurus) , considered local autapomorphy of huabeisaurus. posterolateral ridges weak absent along distal half of bone , not extend further proximally.