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Tangvayosaurus

Allain et al., 1999 tahng-VIE-o-SAWR-us

Named after Tang Vay, the locality in Savannakhet Province, Laos, where it was found, combined with Greek sauros, "lizard" — means "Tang Vay lizard"

121.4–100.5 million years ago Aptian–Albian, Early Cretaceous
Early Cretaceous stages

Tangvayosaurus is a genus of sauropod dinosaur from the Lower Cretaceous (Aptian to Albian ages) Grès supérieurs Formation of Savannakhet Province, Laos. It was a basal somphospondylan, measuring about 15 m (49 ft) long, and is known from the remains of two or three individuals.

Diagnosis

  1. Approximately 15 m long titanosaur
  2. Posterior dorsal vertebrae with unforked neural spines
  3. Neural arches positioned anteriorly in mid- and posterior caudal centra
  4. Caudal vertebrae amphicoelous
  5. Puboischial contact deep dorsoventrally
  6. Ischial distal shafts dorsoventrally flattened and nearly coplanar
  7. Ischium/pubis length ratio less than 0.9
  8. Femur with proximal one-third of shaft deflected medially
  9. Fibular condyle located medially relative to lateral femoral margin
  10. Tibia with extremely expanded proximal extremity, more than twice as long transversely as anteroposteriorly

Species

Tangvayosaurus hoffeti Allain et al., 1999

Type species

Named for Joshua Hoffet, the French paleontologist associated with early study of the fossil-bearing formation in Laos.

Holotype
TV4-1, TV4-2, TV4-3, TV4-4, TV4-5, TV4-6, TV4-7, TV4-8, TV4-9, TV4-10, TV4-11, TV4-12, TV4-13, TV4-14, TV4-15, TV4-16, TV4-17, TV4-18, TV4-19, TV4-20, TV4-21, TV4-22, TV4-23, TV4-24, TV4-25, TV4-26, TV4-27, TV4-28, TV4-29, TV4-30, TV4-31, TV4-32, TV4-33, TV4-34, TV4-35, TV4-36 , Savannakhet Dinosaur Museum
Material
Partial skeleton of one individual comprising several posterior dorsal vertebrae, one of the foremost caudal vertebrae, a few ribs, the distal end of a humerus, both pubes, both ischia, a femur, and a fragment of fibula.
Horizon
Grès supérieurs Formation, Aptian–Albian, Early Cretaceous , 121.4–100.5 million years ago
Locality
Tang Vay 4, Savannakhet, Laos

References

  1. Allain, R.; Taquet, P.; Battail, B.; Dejax, J.; Richir, P.; Véran, M.; Limon-Duparcmeur, F.; Vacant, R.; Mateus, O.; Sayarath, P.; Khenthavong, B.; Phouyavong, S. (1999). Un nouveau genre de dinosaure sauropode de la formation des Grès supérieurs (Aptien-Albien) du Laos [A new genus of sauropod dinosaur from the Grès supérieurs Formation (Aptian–Albian) of Laos]. Comptes Rendus de l'Académie des Sciences - Series IIA - Earth and Planetary Science 329(8): 609-616. Elsevier BV. doi:10.1016/s1251-8050(00)87218-3 allain1999a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the mass and hip height estimates.

    jones2026b