Leurospondylus

Taxobox

---

image_width = 250px
image_caption = Dorsal view of the spine of "Leurospondylus"
name = "Leurospondylus"
fossil_range = Late Cretaceous
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Sauropterygia
ordo = Plesiosauria
subordo = Plesiosauroidea
familia = unknown
familia_authority =
genus = "Leurospondylus"
genus_authority =
subdivision_ranks = Species
subdivision =
* "L. ultimus" Brown, 1913 (type)

"Leurospondylus" is a genus of plesiosaur whose family is not known for certain, but is thought to be Plesiosauridae.

Etymology

The name "Leurospondylus" comes from a fusion of two Greek words, "leuros" (λευρός) meaning "even", "flat" or "smooth", and "spondylos" (σπόνδυλος) meaning "vertebra."cite web
url=http://www.ppne.co.uk/index.php?m=show&id=12527
title= ppne.co.uk entry on "Leurospondylus"
accessdate=2008-05-20] The name of the type species "L. ultimus" comes from the Latin "ultimus" meaning "last." It was so named because this genus was the latest known occurrence of a fossil plesiosaur when it was described in 1913."]

Description

The first described "Leurospondylus" was a juvenile.A new plesiosaur, Leurospondylus, from the Edmonton Cretaceous of Alberta. Bulletin of the AMNH ; v. 32, article 40. ] It was found with 12 vertebrae but is thought to have had twice that number, and was estimated to be roughly seven feet long as a juvenile. Samuel Paul Welles noted that the vertebrae are short and similar to those of pliosaurs,Welles, S. P. 1962. A new species of elasmosaur from the Aptian of Columbia and a review of the Cretaceous plesiosaurs. University of California Publications in Geological Science 46, 96 pp.] while the scapulae and coracoids bear resemblance to those of elasmosaurids, thus making it difficult to determine to which family it belongs. There is some speculation that the "Leurospondylus" specimen is either a juvenile of a known species, or in its own, unrecognized taxonomic group.

Distribution

The first "Leurospondylus" was found in the brackish paleoenvironment represented by the Edmonton beds located on the present-day Red Deer River. This area is part of the Horseshoe Canyon Formation in Alberta, Canada. The occurrence of this juvenile fossil in an identifiably brackish environment led to the conclusion that plesiosaurs spent their early lives in rivers and estuaries. However, some plesiosaurs spent their adult lives in fresh water also; whether "Leurospondylus" grew up and then left, or grew up and stayed in a fresh water ecosystem has not been determined.

References

External links

*http://www.plesiosaur.com/database/pdf/brown1913Leurospondylus.pdf
*http://www.ppne.co.uk/index.php?m=show&id=12527