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Elasmosaurids
Elasmosauridae, often called elasmosaurs or elasmosaurids, is an extinct family (biology), family of plesiosaurs that lived from the Hauterivian Stage (stratigraphy), stage of the Early Cretaceous to the Maastrichtian stage of the Late Cretaceous Period (geology), period (c. 130 to 66 mya (unit), mya). The taxon was initially erected in 1869 by Edward Drinker Cope to include the type genus ''Elasmosaurus'' with the related ''Cimoliasaurus'', although he did not argued in detail why. Over the following years, many authors recognized this classification on the basis of predominantly postcranial features, becoming one of the three groups in which plesiosaurs were often classified during the 19th century, along with the Pliosauridae and the Plesiosauridae. However, most of these traits led to many genera since recognized as belonging to other plesiosaur families being classified as elasmosaurids. Another family historically considered as distinct, the Cimoliasauridae, has since 2009 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasmosaurus
''Elasmosaurus'' () is a genus of plesiosaur that lived in North America during the Campanian stage of the Late Cretaceous period, at about 80.6 to 77million years ago. The first specimen was discovered in 1867 near Fort Wallace, Kansas, US, and was sent to the American paleontologist Edward Drinker Cope, who named it ''E.platyurus'' in 1868. The Generic name (biology), generic name means "thin-plate reptile", and the specific name (zoology), specific name means "flat-tailed". Cope originally reconstructed the skeleton of ''Elasmosaurus'' with the skull at the end of the tail, an error which was made light of by the paleontologist Othniel Charles Marsh, and became part of their "Bone Wars" rivalry. Only one incomplete ''Elasmosaurus'' skeleton is definitely known, consisting of a fragmentary skull, the spine, and now lost pectoral girdle, pectoral and pelvic girdles, and a single species is recognized today; other species are now considered invalid or have been moved to other gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassomedon
''Thalassomedon'' (from Greek, ''thalassa'', "sea" and Greek, ''medon'', "lord" or "ruler", meaning "sea lord") is a genus of plesiosaur, named by Welles in 1943. Description ''Thalassomedon'' is among the largest elasmosaurids, with the holotype measuring long and weighing more than . There is a larger skull, however, suggesting a much larger animal, potentially up to .Smith, Elliott Armour. (2020). "Revision of the Genus Styxosaurus and Relationships of the Late Cretaceous Elasmosaurids (Sauropterygia: Plesiosauria) of the Western Interior Seaway". Theses, Dissertations and Capstones. 1335. https://mds.marshall.edu/etd/1335 The neck is also very long; it comprises 62 vertebraeCarpenter, K. (1999). "Revision of North American elasmosaurs from the Cretaceous western interior." ''Paludicola'', 2(2): 148-173. and is about - over half of the total length. The skull is long, with long teeth. The flippers were about long. Stones have been found in its stomach area leading some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphrosaurus
''Aphrosaurus'' was an extinct genus of plesiosaur from the Maastrichtian. The type species is ''Aphrosaurus furlongi'' (LACM 2748), named by Welles in 1943. The holotype specimen was discovered in the Moreno Formation in Fresno County, California in 1939 by rancher Frank C. Piava. A second specimen - LACM 2832 - was also found in the same formation and initially diagnosed as a juvenile of the same species, but has since been removed from the genus. Discovery In 1943, Samuel Welles described ''Aphrosaurus furlongi'' along with several other plesiosaurs from the same fossil assemblage in Fresno County, California. ''Aphrosaurus'' was found below a different juvenile species, '' Morenosaurus stocki'', within the Tierra Loma Member of the Panoche Hills. The Moreno Formation dates back to the early Maastrichtian, and is composed of depositional layers of turbidite, sandstone, and shale. It is part of the larger Chico Formation, which contacts the Panoche Formation and, during th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styxosaurus
''Styxosaurus'' is a genus of plesiosaur of the family Elasmosauridae. ''Styxosaurus'' lived during the Campanian age of the Cretaceous period. Three species are known: ''S. snowii'', ''S. browni'', and ''S. rezaci''. Discovery The holotype specimen of ''Styxosaurus snowii'' a complete skull and 20 vertebrae and was first described by S.W. Williston ''Styxosaurus'' is named for the mythological River Styx ('), which separated the Greek underworld from the world of the living. The ''-saurus'' part comes from the Greek ' (), meaning "lizard" or "reptile." The type specimen was found on Hell Creek in Logan County, Kansas, which is the source of the genus name coined by Samuel Paul Welles, who described the genus in 1943. Another more complete specimen, SDSMT 451, was discovered near Iona, South Dakota, also in the US, in 1945. The specimen was originally described and named ''Alzadasaurus pembertoni'' by Welles and Bump (1949) and remained so until it was synonymized with ''S. s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrotherosaurus
''Hydrotherosaurus'' (meaning "fisherman lizard") is an extinct genus of elasmosauridae, elasmosaurid plesiosaur from the Upper Cretaceous (Maastrichtian stage) Moreno Formation of Fresno County, California, USA. The only known species, ''H. alexandrae'', was named for Annie Montague Alexander in 1943 by Samuel Paul Welles. Discovery and naming The first remains of ''Hydrotherosaurus'' to be found were several vertebrae discovered by Frank C. Paiva on his own property in the Panoche Hills of Fresno County, California, which were taken to Berkeley, California, Berkeley in the spring of 1937 by W. M. Tucker, who was the Chairman of the Department of Geology of Fresno State College. Afterwards, Fresno State College and the University of California Museum of Paleontology organized a joint expedition which would uncover a nearly complete fossilized skeleton of the animal, with only parts of the skull, shoulder girdle, flippers and certain vertebral elements missing. This specimen, des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Libonectes
''Libonectes'' is an extinct genus of sauropterygian reptile belonging to the plesiosaur order. It is known from specimens found in the Britton Formation of Texas (USA) and the Akrabou Formation of Morocco, which have been dated to the lower Turonian stage of the late Cretaceous period. Nomenclature The prefix "''libo''" comes from Greek (''lips''), and means "southern (wind)," translated to English. "''Nectes''," the suffix, is also from Greek (''nektes''), and translates to "swimmer." In its entirety, ''Libonectes'' can be interpreted as "southern swimmer." ''Libonectes'' was an elasmosaurid plesiosaur, with many specimens unearthed in southern parts of North America- as a result, it was labeled with such a name as described in the preceding sentence. Charles Gill Morgan is credited with the acquiring and preparation of the first ''Libonectes'' fossils, found by tenant farmer T.W. Tidwell in the late 1930s, and it was for this reason that ''morgani'' was chosen as the specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traskasaura
''Traskasaura'' (meaning "Trask lizard") is an extinct genus of Basal (phylogenetics), basal elasmosaurid plesiosaurs from the Late Cretaceous (Santonian age) Haslam Formation of British Columbia, Canada. The genus contains a Monotypic taxon, single species, ''Traskasaura sandrae'', known from three partial skeletons. It is the first elasmosaurid discovered in and named from British Columbia. Discovery and naming The ''Traskasaura'' fossil material was discovered in outcrops of the Haslam Formation (Nanaimo Group) on Vancouver Island of British Columbia, Canada. The first discovered specimen was found in November 1988 by Michael Trask and his daughter Heather on the bank of the Puntledge River near Courtenay, British Columbia, Courtenay. Supported by Grant (money), grants from the province of British Columbia, the specimen began to be excavated and studied by Trask with assistance from paleontologists Rolf Ludvigsen and Elizabeth Nicholls. More than 40 local volunteers also as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
