Open Paleo

Pleurocoelus

Marsh, 1888 PLOOR-o-SEEL-us /ˌplʊəroʊˈsiːləs/

From Greek pleurá ('side, rib') and koilos ('hollow'), referring to the deep pleurocoels (lateral hollows) on the vertebrae

113.2–100.5 million years ago Albian, Early Cretaceous
Early Cretaceous stages

Pleurocoelus is a genus of sauropod dinosaur named by O. C. Marsh in 1888 from juvenile remains found in the Arundel Formation of Maryland. Several authors have considered the type species, P. nanus, to be a junior synonym of Astrodon johnstoni, while others regard both as nomina dubia.

Diagnosis

  1. Teeth with compressed or flattened crowns, not spoon-shaped
  2. Dentary bone slender and rounded at symphysis, not massive and deep as in Morosaurus
  3. Dorsal vertebrae elongate and strongly opisthocœlous, with very long deep cavity on each side of centrum
  4. Sacral vertebrae solid with deep pit behind articular surface for rib process
  5. First caudal vertebra with nearly flat articular faces instead of deeply concave
  6. Middle and distal caudals comparatively short with neural arch on front half of centrum

Species

Pleurocoelus nanus Marsh, 1888

Type species

From Latin 'nanus' meaning 'dwarf'. Marsh (1888) described the taxon as 'by far the most diminutive member' of the Sauropoda then known.

Syntypes
USNM 5678, USNM 4968, USNM 4969, USNM 4970 , National Museum of Natural History, Smithsonian Institution
Material
Four isolated vertebral centra (cervical, dorsal, sacral, and caudal), all unfused to their neural arches and ribs, of the appropriate size to belong to one individual; provenance of each bone is uncertain.
Horizon
Arundel Formation, Albian, Early Cretaceous , 113.2–100.5 million years ago
Locality
Prince George's County, Maryland, United States

References

  1. Marsh, O. C. (1888). Notice of a new genus of Sauropoda and other new dinosaurs from the Potomac Formation. American Journal of Science s3-35(205): 89-94. American Journal of Science (AJS). doi:10.2475/ajs.s3-35.205.89 marsh1888a
  2. D'Emic, M. D. (2012). Revision of the sauropod dinosaurs of the Lower Cretaceous Trinity Group, southern USA, with the description of a new genus. Journal of Systematic Palaeontology 11(6): 707-726. Informa UK Limited. doi:10.1080/14772019.2012.667446

    Reviews the type series of Pleurocoelus nanus and identifies the four constituent USNM vertebrae.

    d'emic2012c