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Ctenochelyidae
Ctenochelyidae is an extinct family of sea turtles which lived in North America during the Santonian-Maastrichtian stages of the Late Cretaceous. Classification The family is defined as a monophyletic clade arising from the most recent ancestors of ''Ctenochelys'' and ''Peritresius''. Fossils of ctenochelyids are known from the Western Interior Seaway and Mississippi embayment. As of 2025, four genera have been assigned to this family: ''Asmodochelys'', ''Ctenochelys'', ''Peritresius'' and ''Prionochelys''. Below is a cladogram from the analysis by Gentry, Ebersole & Kiernan (2019): References {{Taxonbar, from=Q134542571 Late Cretaceous reptiles of North America Late Cretaceous turtles Prehistoric turtle stubs Chelonioidea Turtle families Extinct turtles Santonian first appearances Maastrichtian extinctions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenochelys
''Ctenochelys'' (meaning "comb tortoise") is an extinct genus of marine turtle ( Cryptodira, Ctenochelyidae), which existed during the Cretaceous period, and lived in the shallow waters of the Western Interior Seaway. Its fossils have been found in the Ripley Formation and Mooreville Chalk of central Alabama, United States. It was first named by C. H. Sternberg in 1904, and contains two species, ''C. stenoporus'' and ''C. acris''. Species ''Ctenochelys stenoporus'' is the type species. It was originally thought to be a species of '' Toxochelys''; ''T. bauri'', until Sternberg declared it a separate genus. The two genera are similar in carapaces. ''Ctenochelys acris'' was first named by Zangerl in 1953 and is now thought to be one of the earliest ancestors of modern cheloniids. Phylogeny ''Ctenochelys'' in a cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prionochelys
''Prionochelys'' is an extinct genus of pancheloniid from the Mooreville Chalk and Eutaw Formations of Alabama. It consists of a single species, ''P. matutina''. Taxonomy ''Prionochelys'' was originally assigned to the family Toxochelyidae. A 2018 paper found it to be on the stem of Chelonioidea, the family to which most modern sea turtles belong, forming a monophyletic grouping named as Ctenochelyidae with '' Ctenochelys'' and ''Peritresius''. Below is a cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ... from the analysis by Gentry, Ebersole & Kiernan (2019): References {{Taxonbar, from=Q123907448 Late Cretaceous turtles of North America Chelonioidea Prehistoric turtle genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Turtle
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, Kemp's ridley, and olive ridley. Six of the seven sea turtle species, all but the flatback, are present in U.S. waters, and are listed as endangered and/or threatened under the Endangered Species Act. They are listed as threatened with extinction globally on the IUCN Red List of Threatened Species. The flatback turtle is found only in the waters of Australia, Papua New Guinea, and Indonesia. Sea turtles can be categorized as hard-shelled ( cheloniid) or leathery-shelled ( dermochelyid).Wyneken, J. 2001. The Anatomy of Sea Turtles. U.S Department of Commerce NOAA Technical Memorandum NMFS-SEFSC-470, 1-172 pp. The only dermochelyid species of sea turtle is the leatherback. Description For each of the seven species of sea turtles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelonioidea
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, Kemp's ridley, and olive ridley. Six of the seven sea turtle species, all but the flatback, are present in U.S. waters, and are listed as endangered and/or threatened under the Endangered Species Act. They are listed as threatened with extinction globally on the IUCN Red List of Threatened Species. The flatback turtle is found only in the waters of Australia, Papua New Guinea, and Indonesia. Sea turtles can be categorized as hard-shelled ( cheloniid) or leathery-shelled ( dermochelyid).Wyneken, J. 2001. The Anatomy of Sea Turtles. U.S Department of Commerce NOAA Technical Memorandum NMFS-SEFSC-470, 1-172 pp. The only dermochelyid species of sea turtle is the leatherback. Description For each of the seven species of sea turtles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asmodochelys
''Asmodochelys'' is an extinct genus of sea turtle which lived in North America during the Late Cretaceous (Campanian-Maastrichtian). Two species are known from the southern United States: ''A. parhami'' from the Demopolis Chalk The Demopolis Chalk is a geological Formation (geology), formation in North America, within the United States, U.S. states of Alabama, Mississippi, and Tennessee. The chalk was formed by pelagic sediments deposited along the eastern edge of the Mi ... and ''A. leviathan'' from the Neylandville Marl. References Chelonioidea Campanian first appearances Maastrichtian extinctions Late Cretaceous turtles of North America Demopolis Chalk Fossil taxa described in 2019 Prehistoric turtle genera {{Paleo-turtle-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peritresius
''Peritresius'' is an extinct genus of sea turtle from the Late Cretaceous deposits in the US Eastern Seaboard. Taxonomy Two species are known, ''Peritresius ornatus'' (Leidy, 1856) and ''P. martini'' Gentry, Parham, Ehret, and Ebersole, 2018, both from Campanian-Maastrichtian age deposits in New Jersey, Alabama, and Mississippi.Leidy J. Notices of remains of extinct turtles of New Jersey collected by Professor Cook of the State Geological Survey. Proceedings of the Academy of Natural Science, Philadelphia. 1856; 8: 303–304. Phylogeny Below is a cladogram from the analysis of Gentry, Ebersole & Kiernan, 2019: References Cheloniidae Cretaceous turtles Extinct animals of the United States Prehistoric turtle genera Taxa named by Joseph Leidy Extinct turtles {{paleo-turtle-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxochelys
''Toxochelys'' () is an extinct genus of marine turtle from the Late Cretaceous period. It is the most commonly found fossilized turtle species in the Smoky Hill Chalk, in western Kansas. Description ''Toxochelys'' had carapace about in length. Two species in the genus are recognized, ''Toxochelys latiremis'' and ''Toxochelys moorevillensis''. Phylogenetic analysis shows that ''Toxochelys'' belong to an extinct lineage of turtles transitional between modern sea turtles and other turtles. ''Toxochelys bauri'' Williston, 1905, based on the skeleton YPM 1786, is a synonym of '' Ctenochelys stenoporus''. ''Toxochelys'' are currently thought to be the oldest member and the last common ancestor of all extinct marine turtles. Even though ''Toxochelys'' shared similar limb characteristics with other species as Cheloniidae and Protostegidae, they evolved independently to pass down new limb features to future generations. These features allowed for advanced mobility of the hand. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protostegidae
Protostegidae is a family of extinct sea turtle, marine turtles that lived during the Cretaceous period. The family includes some of the largest sea turtles that ever existed. The largest ''Archelon'' had a head long. Like most sea turtles, they had flattened bodies and flipper (anatomy), flippers for front appendages; protostegids had minimal carapace, shells like Dermochelyidae, leatherback turtles of modern times. Anatomy As some of the first sea turtle, marine turtles, the protostegids set the general body plan for future species of sea turtles. They had a generally depressed turtle body plan, complete with four limbs, a short tail, and a large head at the end of a relatively short neck. Like other sea turtles, they possessed oar-like front appendages especially evolved for swimming in the open ocean. Similar to the still-extant taxon, extant, possibly closely related Dermochelyidae, protostegids possessed extremely reduced carapaces. Some specimens had skeletal protrusions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct Turtles
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and recover. As a species' potential Range (biology), range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxon, Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the Fossil, fossil record) after a period of apparent absence. Over five billion species are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryotes globally, possibly many times more if microorganisms are included. Notable extinct animal species include Dinosaur, non-avian dinosaurs, Machairodontinae, saber-toothed cats, and mammoths. Through evolution, species arise through the process of specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle Families
Turtles are reptiles of the order Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates that join up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Turtle Stubs
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
