| 词条 | Leurospondylus |
| 释义 |
| image = Leurospondylus.jpg | 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 = incertae sedis | familia_authority = | genus = Leurospondylus | genus_authority = | subdivision_ranks = Species | subdivision =
}} Leurospondylus is a genus of plesiosaur whose family is currently disputed, but is suggested to be Plesiosauridae. EtymologyThe name Leurospondylus comes from a fusion of two Greek words, leuros (λευρός) meaning "even", "flat" or "smooth", and spondylos (σπόνδυλος) meaning "vertebra."[1] 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."[1] DescriptionThe first described Leurospondylus was a juvenile.[2] The fossil included 12 vertebrae but the animal is thought to have had twice that number,[2] and was estimated to be roughly 2 meters long as a juvenile.[2] Samuel Paul Welles noted that the vertebrae are short and similar to those of pliosaurs,[3] while the scapulae and coracoids bear resemblance to those of elasmosaurids,[3] thus making it difficult to determine to which family it belongs.[3] There is some speculation that the Leurospondylus specimen is either a juvenile of a known species, or in its own, unrecognized taxonomic group.[1] DistributionThe 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.[1] 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.[1] 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.[1] See also{{Portal|Paleontology}}
References1. ^1 2 3 4 5 {{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}} 2. ^1 2 "A new plesiosaur, Leurospondylus, from the Edmonton Cretaceous of Alberta". Bulletin of the AMNH; v. 32, article 40. 3. ^1 2 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. External links
2 : Late Cretaceous plesiosaurs of North America|Plesiosauria incertae sedis |
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