Open Paleo

Amazonsaurus

Carvalho et al., 2003 AM-uh-zuhn-SOR-uhs /ˌæməzənˈsɔːrəs/

Named after the Amazon region of South America where fossils were found, combined with Greek 'sauros' meaning 'lizard'; meaning 'Amazon lizard'

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

Amazonsaurus is a genus of diplodocoid sauropod dinosaur from the Early Cretaceous Period of what is now South America. It would have been a large-bodied quadrupedal herbivore with a long neck and whiplash tail. Although more derived diplodocoids were some of the longest animals ever to exist, Amazonsaurus was probably not more than 12 meters (40 ft) long. Gregory S. Paul estimated in 2010 its weight at 5000 kg.

Diagnosis

  1. Anterior caudal neural spines with 'lateral' laminae formed by coalescence of the spinoprezygapophyseal (SPRL) and postzygodiapophyseal (PODL) laminae
  2. Anterior caudal 'lateral' laminae (SPRL+PODL) bent anteriorly so that the anterior surface is concave and the posterior surface is convex
  3. Caudal neural spines straight and posteriorly inclined
  4. Thickness of the 'lateral' laminae constant from base to top of the spine (unlike Rebbachisaurus tessonei)

Species

Amazonsaurus maranhensis Carvalho et al., 2003

Type species

Named after the Brazilian state of Maranhão, where the fossil remains were found in the Itapecuru Formation.

Holotype
MN 4555-V, MN 4556-V, MN 4558-V, MN 4559-V, MN 4560-V, MN 4562-V, MN 4564-V, UFRJ-DG 58-R/1, UFRJ-DG 58-R/2, UFRJ-DG 58-R/3, UFRJ-DG 58-R/4, UFRJ-DG 58-R/5, UFRJ-DG 58-R/7, UFRJ-DG 58-R/9, UFRJ-DG 58-R/10 , Museu Nacional
Material
Two dorsal neural spines; two dorsal centra; neural spine of anterior caudal vertebra; one mid caudal vertebra; one mid-posterior caudal vertebra; two posterior caudal vertebrae; eight chevrons; an ilium; a partial pubis; three ribs
Horizon
Itapecuru Formation, Aptian–Albian, Early Cretaceous , 121.4–100.5 million years ago
Locality
Mata, Maranhão, Brazil

References

  1. Carvalho, I. D. S.; Avilla, L. D. S.; Salgado, L. (2003). Amazonsaurus maranhensis gen. et sp. nov. (Sauropoda, Diplodocoidea) from the Lower Cretaceous (Aptian-Albian) of Brazil. Cretaceous Research 24: 697-713. doi:10.1016/j.cretres.2003.07.005 carvalho2003a