Leptocleidia is a clade of plesiosauroids.[1] The group was erected in 2007 as Leptocleidoidea.[2] Although established as a clade, the name Leptocleidoidea implies that it is a superfamily. Leptocleidoidea is placed within the superfamily Plesiosauroidea, so it was renamed Leptocleidia by Hilary F. Ketchum and Roger B. J. Benson (2010) to avoid confusion with ranks. Leptocleidia is a node-based taxon which was defined by Ketchum and Benson as "Leptocleidus superstes, Polycotylus latipinnis, their most recent common ancestor and all of its descendants".[1]

Temporal range: Cretaceous, 145–66 Ma
Nichollssaura BW.jpg
Life restoration of the leptocleidian Nichollssaura borealis
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Superorder: Sauropterygia
Order: Plesiosauria
Clade: Xenopsaria
Clade: Leptocleidia
Ketchum and Benson, 2010


  1. ^ a b Ketchum, H.F.; Benson, R.B.J. (2010). "Global interrelationships of Plesiosauria (Reptilia, Sauropterygia) and the pivotal role of taxon sampling in determining the outcome of phylogenetic analyses". Biological Reviews. 85 (2): 361–392. doi:10.1111/j.1469-185X.2009.00107.x. PMID 20002391.
  2. ^ Druckenmiller, P.S.; Russel, A.P. (2007). "A phylogeny of Plesiosauria (Sauropterygia) and its bearing on the systematic status of Leptocleidus Andrews, 1922" (PDF). Zootaxa. 1863: 1–120. ISBN 978-1-86977-262-8. ISSN 1175-5334. Archived from the original (PDF) on 2011-10-04.