|
Americhelydia
Americhelydia is a clade of turtles that consists of sea turtles, snapping turtles, the Central American river turtle and mud turtles, supported by several lines of molecular work. Prior to these studies some morphological and developmental work have considered sea turtles to be basal members of Cryptodira and kinosternids related to the trionychia Trionychia is a superfamily of turtles which encompasses the species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typic ...ns in the clade Trionychoidea. Americhelydia and Testudinoidea, both clades within Durocryptodira (hardshell turtles), split a part during the early Cretaceous. References Cryptodira {{paleo-turtle-stub ... [...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] |
Cryptodira
The Cryptodira (') are a suborder of Testudines that includes most living tortoises and turtles. Cryptodira is commonly called the "Hidden-Neck Turtles" or the "Inside-Neck Turtles". Cryptodira differ from Pleurodira (side-necked turtles) in that they lower their necks and pull the heads straight back into the shells, instead of folding their necks sideways along the body under the shells' marginals. They include among their species freshwater turtles, snapping turtles, tortoises, softshell turtles, and sea turtles. Neck retraction The Cryptodira are characterized by retraction of the head in the vertical plane, which permits for primarily vertical movements and restricted lateral movements outside of the shell. These motions are largely due to the morphology and arrangement of cervical vertebrae. In all recent turtles, the cervical column consists of nine joints and eight vertebrae. Compared to the narrow vertebrae and the closely positioned zygapophyses of the pleur ... [...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] |
Late Jurassic
The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen 1987. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, ''Malm'' was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units. Subdivisions The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock: Paleogeography During the Late Jurassic Epoch, Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the emergence of the Atlantic Ocean, which initially was relatively narrow. Life forms This epoch is well known for many famous types of d ... [...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] |
Trionychia
Trionychia is a superfamily of turtles which encompasses the species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ... that are commonly referred to as softshelled turtles as well as some others. The group contains two families, Carettochelyidae, which has only one living species, the pig-nosed turtle (''Carettochelys insculpta'') native to New Guinea and Northern Australia, and Trionychidae, the softshelled turtles, containing numerous species native to Asia, North America and Africa. These families likely diverged during the late Jurassic. The oldest known stem-trionychian is '' Sinaspideretes'' from the Late Jurassic of China. Systematics Except for those not assigned to a family, only living genera are listed here. *Family Carettochelyidae ** Subfamily Carettochelyina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central American River Turtle
The hickatee (''Dermatemys mawii'') or in Spanish ''tortuga blanca'' ('white turtle'), also called the Central American river turtle, is the only living species in the family Dermatemydidae. The species is found in the Atlantic drainages of Central America, specifically Belize, Guatemala, southern Mexico, and probably Honduras. It is a relatively large-bodied species, with records of straight carapace length and weights of ; although most individuals are smaller. This is a herbivorous and almost completely aquatic turtle that does not even surface to bask. Bizarrely for reptiles, the eggs can remain viable even after being underwater for weeks -in the recent past, some scientists mistakenly claimed it nests underwater, likely due to visiting Central America during a frequent flood, when nests are often submerged. In the culture of the Ancient Mayan civilisation this species and turtles in general had numerous uses such as being used in warfare, as musical instruments and as fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snapping Turtle
The Chelydridae is a family of turtles that has seven extinct and two extant genera. The extant genera are the snapping turtles, ''Chelydra'' and ''Macrochelys''. Both are endemic to the Western Hemisphere. The extinct genera are '' Acherontemys'', ''Chelydrops'', '' Chelydropsis'', '' Emarginachelys'', '' Macrocephalochelys'', '' Planiplastron'', and ''Protochelydra''. Fossil history The Chelydridae have a long fossil history, with extinct species reported from North America as well as all over Asia and Europe, far outside their present range. The earliest described chelydrid is '' Emarginachelys cretacea'', known from well-preserved fossils from the Maastrichtian stage of the Late Cretaceous of Montana. Another well-preserved fossil chelydrid is the Late Paleocene '' Protochelydra zangerli'' from North Dakota. The carapace of ''P. zangerli'' is higher-domed than that of the recent ''Chelydra'', a trait conjectured to be associated with the coexistence of large, turtle-eating c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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] |
Early Cretaceous
The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 Megaannum#SI prefix multipliers, Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian–Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining Anoxic event#Cretaceous, early Aptian Oceanic Anoxic Event 1a (OAE1a) was dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java Plateau, Ontong Java-Manihiki Plateau, Manihiki-Hikurangi Plateau, Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Onto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panchelonioidea
Panchelonioidea is a clade of marine turtles that includes the 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, loggerh ...s and related taxa. Phylogeny Evers et al. (2019): References {{Turtle-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
