[D] Phuwiangosaurus sirindhornae [sG] [T]
Martin, Buffetaut & Suteethorn, 1994
Cretaceous Early Berriasian
Saurischia Sauropodomorpha Sauropoda Diplodocidae Dicraeosaurinae
Sao Khua Formation, Phu Wiang, Phu Patru Teema, Thailand
15 > 20 meter
Martin, V., Suteethorn, V. & Buffetaut E. (1999) Description of the type and referred material of Phuwiangosaurus sirindhornae
The type specimen of Phuwiangosaurus sirindhornae Martin, Buffetaut and Suteethorn, 1994 is an incomplete, partly articulated, skeleton discovered in the Phu Wiang area of northeastern Thailand). Most of the abundant sauropod material from the Sao Khua Formation (Early Cretaceous), collected on the Khorat Plateau, in northeastern Thailand, is referable to this species.
Phuwiangosaurus is a middle-sized sauropod, which is clearly different from the Jurassic Chinese sauropods (Euhelopodidae). On the basis of a few jaw elements and teeth, Phuwiangosaurus sirindhornae may be considered as an early representative of the family [Nemegtosauridae].
A pertly articulated skeleton. This genus is verry different from the Late Jurassic Chinese sauropods. Abundant juvinile remains attributed to Phuwiangosaurus sirindhornae provide some data on the hitherto poorly known sauropod babies.
The taxon is based on a partly articulated skeleton, which consists of three cervical vertebrae , four dorsal vertebrae, several ribs, the left scapula and the distal and of the right one, the left humerus and part of the left ulna, bot sides of the pelvis both femora and the left fibula.
From Suteethorn, S., Le Loeuff, J., Buffetaut, E., Suteethorn, V.m Talubmook, C. & Chonlakman, C. (2009)
SM PW1-0001 to SM PW1-0022; partly articulated skeleton including three cervical vertebrae, three dorsal vertebrae, scapulae, left humerus, left ulna, ilia, pubes, ischia, femora, left fibula, coracoid, chevron and rib.
Most of the abundant sauropod bones found in the Phu Wiang and Kalasin areas, including the baby and juvenile material described by Martin (1994) and Martin et al. (1999). All sauropod specimens from K11 (SM K11-0001 to SM K11-0167) as follows. Cranial elements including SM K11-0001, right frontal; SM K11-0002, right postorbital; SM K11-0003, right squamosal; SM K11-0004, left quadrate; SM K11-0005, right quadrate; SM K11-0006, co-ossified braincase consisting of supraoccipital, exoccipital–opisthotic, prootic, basioccipital and basisphenoid–parasphenoid; SM K11-0007, laterosphenoid–orbitosphenoid; SM K11-0008, an isolated tooth. Postcranial skeleton with partly articulated caudal dorsal and sacral centra lacking two or three cervical vertebrae, cranial dorsal vertebrae, most of cranial and middle caudal vertebrae, forelimbs and distal hind limbs. The catalogue numbers of specimens are available as supplementary material.
Phu Wiang Site PW1, Sao Khua Formation, northeastern Thailand. Age. Early Cretaceous, Barremian–Aptian (Racey & Goodall 2009).
Middle-sized sauropod (15–20 m long); postorbital with short and acute caudal process; hook-shaped squamos with vertical flat rostral process and L-shaped caudal process; robust quadrate condyle with deep uadrate fossa that faces caudolaterally and a prominent bulge on medial margin; exoccipital with a foot-like structure that participates to the occipital condyle; heartshaped occipital condyle; paroccipital process extended caudolaterally with rounded distal end; triangular basal tubula flattened with lateral rugose surface; basipterygoid process directed rostroventrally; anterior cervical vertebrae with a very low and wide neural arch; diapophyses and parapophyses very developed lateroventrally; large zygapophyses situated low and far from each other, firmly diverging laterally from the centrum; neural spine of the posterior cervical vertebrae widely bifurcated with no median spine; cervical vertebrae with a well-developed system of laminae and cavities; centra of the dorsal vertebrae opisthocoelous with deep pleurocoels; posterior dorsal vertebrae with unforked neural spine; neural spine elongated craniocaudally; long diapophyses directed more dorsally than laterally, nearly reaching the level of the spine; hyposphene–hypantrum system present; elongated scapula with lateral ridge on the proximal extremity at right angle with the shaft, and slight distal expansion; humerus similarly expanded at both ends; anterior blade of the ilium well developed; pubic peduncle of the ilium straight, long and directed at right angle to the direction of the blade; ischiatic peduncle of the ilium faintly marked; pubis with very open angle between the axis of the shaft and the ischiatic border; well-marked curvature of the caudal border of the shaft of the ischium; femur flattened anteroposteriorly with the head situated slightly above the level of the great trochanter; fourth trochanter crest-shaped, located medially above the midlength of the shaft; very large lateral epicondyle at the distal end of the femur; slight lateral bending of the shaft of the fibula.