''Microcleidus'' is an extinct genus of
sauropterygia
Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became ...
n reptile belonging to the
Plesiosauroidea
Plesiosauroidea (; Greek: 'near, close to' and 'lizard') is an extinct clade of carnivorous marine reptiles. They have the snake-like longest neck to body ratio of any reptile. Plesiosauroids are known from the Jurassic and Cretaceous period ...
. The species has 40 neck vertebrae and a short tail of 28 vertebrae. Fossils of the genus have been found in France, the
Posidonia Shale
The Posidonia Shale (german: Posidonienschiefer, also called Schistes Bitumineux in Luxembourg) geologically known as the Sachrang Formation, is an Early Jurassic (Toarcian) geological formation of southwestern and northeast Germany, northern Swit ...
in Germany and Luxembourg, and the
Alum Shale Formation
The Alum Shale Formation (also known as alum schist and alum slate) is a formation of black shale of Middle Cambrian to Tremadocian (Lower Ordovician) in age found predominantly in southern Scandinavia. It is shale or clay slate containing pyrit ...
of England.
Description
The type species, ''M. homalospondylus'', was the largest, measuring long and weighing . Other species were smaller: ''M. tournemirensis'' was about long and weighed , and ''M. melusinae'' was about long and weighed .
Classification
Species include: ''Microcleidus homalospondylus'' (Owen 1865) and ''Microcleidus macropterus'' (Seeley 1865).
''Occitanosaurus tournemirensis'' (originally ''"Plesiosaurus" tournemirensis''), was named by Sciau ''et al.'' in 1990, based on a nearly complete skeleton of an animal approximately 4 meters (13 ft) long.[Ketchum HF, Benson RBJ. Global interrelationships of Plesiosaur (Reptilia, Sauropterygia) and the pivotal role of taxon sampling in determining the outcome of phylogenetic analyses. Biological Reviews
] It was later found to be a species of ''Microcleidus''.
The following cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...
follows an analysis by Ketchum & Benson, 2011.
See also
* List of plesiosaur genera
This list of plesiosaurs is a comprehensive listing of all genera that have ever been included in the order Plesiosauria, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered inv ...
* Timeline of plesiosaur research
This timeline of plesiosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, taxonomic revisions, and cultural portrayals of plesiosaurs, an order of marine reptiles that flourished duri ...
References
Bibliography
* Bardet, Nathalie; Fernandez, Marta; Garcia-Ramos, Jose Carlos; Superbiola, Xabier Pereda; Pinuela, Laura; Ruiz-Omenaca, Jose Ignacio; and Vincent, Peggy (2008).
A juvenile plesiosaur from the Pliensbackian (Lower Jurassic) of Asturias, Spain
. ''Journal of Vertebrate Paleontology'' 28(1): 258–263
Plesiosaur.com 13 Oct 2006
Palæos.com 13 Oct 2006
Plesiosauroids
Early Jurassic plesiosaurs of Europe
Toarcian genera
Jurassic England
Fossils of England
Jurassic France
Fossils of France
Jurassic Germany
Fossils of Germany
Posidonia Shale
Fossil taxa described in 1909
Sauropterygian genera
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