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Kaiwhekea Katiki
''Kaiwhekea'' () is an extinct genus of plesiosaur from the Late Cretaceous (Maastrichtian age) of what is now New Zealand. History of discovery The type species, ''Kaiwhekea katiki'', was first described by Arthur Cruickshank and Ewan Fordyce in 2002. ''Kaiwhekea'' was approximately long and weighed in body mass. It lived around the middle Maastrichtian. The single known specimen, found in the Katiki Formation near Shag Point on the coast of Otago, is nearly complete, and is on display at the Otago Museum in Dunedin, New Zealand. Classification ''Kaiwhekea'' has been placed as an aristonectine plesiosaur close to ''Aristonectes'' (O'Keefe and Street, 2009). In 2010, ''Kaiwhekea'' was transferred to Leptocleididae, but more recent analyses do not find the same result. The following cladogram shows the placement of ''Kaiwhekea'' within Elasmosauridae following an analysis by Rodrigo A. Otero, 2016: See also * List of plesiosaur genera * Timeline of plesiosaur research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristonectes
''Aristonectes'' (meaning 'best swimmer') is an extinct genus of plesiosaur from the Late Cretaceous Paso del Sapo Formation of what is now Argentina, the Quiriquina Formation of Chile and the Lopez de Bertodano Formation of Antarctica. The type species is ''Aristonectes parvidens'', first named by Cabrera in 1941. Description Analysis of a specimen from the Lopez de Bertodano Formation indicates that ''Aristonectes'' was one of the largest plesiosaurs ever to exist, with an estimated body length of and body mass of per Paul and per O'Gorman and his colleagues. Classification ''Aristonectes'' was classified variously since its original 1941 description, but a 2003 review of plesiosaurs from Patagonia conducted by Gasparini ''et al.'' (2003) found that ''Aristonectes'' was most closely related to elasmosaurid plesiosaurs like ''Elasmosaurus''. The authors also considered '' Morturneria'' a junior synonym of ''Aristonectes'' because the former's holotype has unfu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morturneria Seymourensis
''Morturneria'' is an extinct genus of plesiosaur from the Late Cretaceous of what is now Antarctica. History of research The Lopez de Bertodano Formation is located on Seymour Island, Antarctica, with exposures present in all but the northernmost third of the island. During the summers of 1981–1982, 1983–1984, and 1984–1985, paleontological expeditions recovered eight partial plesiosaur skeletons in the formation. One of these, TTU P9219, consisted of a skull and some cervical vertebrae. It was found in the upper part of the formation, informally known as the 'molluscan units', high up in a ravine. It was preserved within a tough, calcareous nodule, from which it was difficult to remove. While excavating the specimens, the dig teams faced difficulty in removing the strata above the fossils, due to the presence of permafrost. The cold temperatures also prevented the plaster from setting, so the teams used camp stoves and aluminium foil to heat it up, allowing it to harden. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexandronectes Zealandiensis
''Alexandronectes'' is a genus of elasmosaurid plesiosaur, a type of long-necked marine reptile, that lived in the oceans of Late Cretaceous New Zealand. It contains one species, ''A. zealandiensis''. Fossils of ''Alexandronectes'' were found in the Conway Formation of Canterbury, at .org which can be dated to the Early stage of the . Fossils of it were found around 1872 near the Waip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Futabasaurus Suzukii
''Futabasaurus'' is a genus of plesiosaur from the Late Cretaceous of Fukushima, Japan. It was described and named in 2006, and was assigned to the family Elasmosauridae. The genus contains one species, ''F. suzukii''. Description The size of ''Futabasaurus'' has been estimated within the range of in length and in body mass. It can be distinguished from other elasmosaurids by the following characteristics: there is a long distance between the eye sockets and nostrils; the interclavicles and clavicles are fused, and the anterior edge is bent; the humerus is relatively long; and the femora are slim and show prominent muscle scars. Discovery and naming ''Futabasaurus'' is the first elasmosaurid found in Japan. It was originally known as either "Wellesisaurus sudzuki" or "Futaba-ryu" before publication. The type specimen of ''Futabasaurus'' was found in the Irimazawa Member of the Tamayama Formation, in the Futaba Group of Fukushima Prefecture, Japan. The rocks in which it were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrotherosaurus Alexandrae
''Hydrotherosaurus'' (meaning "water beast lizard") is an extinct genus of elasmosaurid plesiosaur from the Upper Cretaceous (Maastrichtian stage) Moreno Formation of Fresno County, California, USA. The only known species, ''H. alexandrae'', was named for its discoverer, Annie Montague Alexander, by Samuel Paul Welles. Description ''Hydrotherosaurus'' measured approximately in length. It has one of the longest necks relative to total length among elasmosaurids, with 60 vertebrae in total. It had a small head that measured about long, a streamlined body, and four large flippers that were specially designed to help the huge animal balance, move, and accelerate itself. See also * List of plesiosaur genera * 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassomedon Haningtoni
''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 a total length of for the holotype. There is a larger skull, however, suggesting a much larger animal, potentially up to . Gregory S. Paul proposed that a long individual would have weighed , while O'Gorman and his colleagues proposed that a long individual would have weighed more than . 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 to theorize that they were used for ballast or digestion. If the latter, stomach action would cause the stone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuarangisaurus Keyesi
''Tuarangisaurus'' ( mi, tuarangi "ancient" + el, σαῦρος, sauros "lizard") is an extinct genus of elasmosaurid known from New Zealand. The type and only known species is ''Tuarangisaurus keyesi'', named by Wiffen and Moisley in 1986. Discovery ''Tuarangisaurus'' is known from the holotype NZGS CD425, a nearly complete skull and mandible, and from NZGS CD426, nine anterior-most cervical vertebrae. Some postcranial remains of juveniles were also attributed to ''Tuarangisaurus''. It was collected from the Maungataniwha Sandstone Member of the Tahora Formation, dating to the upper Campanian to lower Maastrichtian stage of the Late Cretaceous. A second species, ''T. australis'', was named in 2005; however, it was moved to the genus ''Eromangasaurus'' in 2007, becoming the senior synonym of ''E. carinognathus''. A third species, ''T.? cabazai'', was also referred to ''Tuarangisaurus'' by the original description; however, it was most recently reassigned to an indeterminat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Libonectes Morgani
''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, and means "southern," translated to English. "''Nectes''," the suffix, is also from Greek, 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. C.G. Morgan is credited with the discovery of the first ''Libonectes'' fossils, and it was for this reason that ''morgani'' was chosen as its binomial name. Description The animal was very similar to the related '' Thalassomedon'', though the structure of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callawayasaurus Colombiensis
''Callawayasaurus'' is a genus of plesiosaur from the family Elasmosauridae. When the holotype was first described by Samuel Paul Welles in 1962, it was described as ''Alzadasaurus colombiensis'' before being moved into its current genus by Kenneth Carpenter in 1999.Carpenter, K. 1999. "Revision of North American elasmosaurs from the Cretaceous of the Western Interior". ''Paludicola'' 2(2):148-173. Etymology ''Callawayasaurus'' is named in honor of the paleontologist Jack M. Callaway, editor of ''Ancient Marine Reptiles'' who, as Carpenter put it, "in his brief career as a vertebrate paleontologist, did much to improve our understanding of marine reptiles." The familiar suffix, ''-saurus'' comes from the Greek ' (), meaning "lizard" or "reptile." Description ''Callawayasaurus'' was a large plesiosaur, with a skull length of , body length of and body mass of . The nares of ''Callawayasaurus'' are elongated and positioned over the maxilla, which has 3-5 teeth. The neck con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eromangasaurus Carinognathus
''Eromangasaurus'' is an extinct genus of elasmosaurid known from northern Queensland of Australia. Description ''Eromangasaurus'' is a medium-sized elasmosaurid, measuring in length and in body mass. It is known from the holotype QM F11050, a nearly complete but badly crushed skull and mandible. It was collected in Maxwelton, from the Toolebuc Formation of the Eromanga Basin, dating to the late Albian stage of the Early Cretaceous, about 103 million years ago. Sven Sachs mentioned some referred material from the same locality as the holotype, QM F12216-19, an anterior cervical vertebra and QM F12217&2, associated posterior cervical vertebrae. Discovery ''Eromangasaurus'' was first named by Benjamin P. Kear in 2005 and the type species is ''Eromangasaurus australis''. Benjamin P. Kear originally named QM F11050 as ''Eromangasaurus carinognathus''. However, earlier in 2005, Sven Sachs named a second species of ''Tuarangisaurus'', ''Tuarangisaurus australi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasmosauridae
Elasmosauridae is an extinct family of plesiosaurs, often called elasmosaurs. They had the longest necks of the plesiosaurs and existed from the Hauterivian to the Maastrichtian stages of the Cretaceous, and represented one of the two groups of plesiosaurs present at the end of the Cretaceous alongside Polycotylidae. Their diet mainly consisted of crustaceans and molluscs. Description The earliest elasmosaurids were mid-sized, about . In the Late Cretaceous, elasmosaurids grew as large as , such as '' Styxosaurus'', ''Albertonectes'', and '' Thalassomedon''. Their necks were the longest of all the plesiosaurs, with anywhere between 32 and 76 (''Albertonectes'') cervical vertebrae. They weighed up to several tons. Classification Early three-family classification Though Cope had originally recognized ''Elasmosaurus'' as a plesiosaur, in an 1869 paper he placed it, with ''Cimoliasaurus'' and ''Crymocetus'', in a new order of sauropterygian reptiles. He named the group Streptos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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