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Sphenodontinae
Sphenodontidae is a family within the reptile group Rhynchocephalia, comprising taxa most closely related to the living tuatara of the genus ''Sphenodon''. Historically the taxa included within Sphenodontidae have varied greatly between analyses, and the group has lacked a formal definition. '' Cynosphenodon'' from the Early Jurassic of Mexico has consistently been recovered as a close relative of the tuatara in most analyses, with the clade containing the two often called Sphenodontinae. The herbivorous Eilenodontinae, otherwise considered part of Opisthodontia, is also sometimes considered part of this family as the sister group to Sphenodontinae. Sphenodontines first appeared during the Early Jurassic, and are characterised by a complete lower temporal bar caused by the fusion of the quadrate/quadratojugal and the jugal The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tika Giacchinoi
''Tika'' is an extinct genus of sphenodontian from the Late Cretaceous Candeleros Formation of Argentina. The type species is ''Tika giacchinoi''. It is considered to be closely related to the tuatara, (''Sphenodon punctatus''), and a member of the Sphenodontinae Sphenodontidae is a family within the reptile group Rhynchocephalia, comprising taxa most closely related to the living tuatara of the genus ''Sphenodon''. Historically the taxa included within Sphenodontidae have varied greatly between analyses .... It is the oldest member of Sphenodontinae known from South America. References {{Sphenodontia Sphenodontia Fossil taxa described in 2021 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchocephalia
Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a diverse group including a wide array of morphologically distinct forms. The oldest record of the group is dated to the Middle Triassic around 238 to 240 million years ago, and they had achieved a worldwide distribution by the Early Jurassic. Most rhynchocephalians belong to the group Sphenodontia ('wedge-teeth'). Their closest living relatives are lizards and snakes in the order Squamata, with the two orders being grouped together in the superorder Lepidosauria. Many of the niches occupied by lizards today were held by sphenodontians during the Triassic and Jurassic, although lizard diversity began to overtake sphenodontian diversity in the Cretaceous, and they had disappeared almost entirely by the beginning of the Cenozoic. While the modern tuat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kawasphenodon
''Kawasphenodon'' is an extinct genus of sphenodontian reptile, known from the Late Cretaceous and Paleocene of Patagonia in South America. The type species, ''K. expectatus'', was described in 2005 from jaw fragments found in late Campanian aged sediments in the Los Alamitos Formation, the jaw when complete was estimated to be 11 cm long, making it among the largest known sphenodontians. A second species, ''K. peligrensis'', around 1/3 the size of the type species, was described in 2014 also from jaw fragments in early Paleocene (Danian) sediments of the Salamanca Formation, making it the youngest known definitive representative of Rhynchocephalia outside of New Zealand. In the original description, it was found to be a member of Sphenodontidae, in other subsequent analyses it was found to be a member of Opisthodontia. A 2020 analysis of rhyncocephalian relationships found it to be outside Opisthodontia, and instead a member of the Sphenodontinae as the closest known relative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenofontis
''Sphenofontis'' is an extinct genus of sphenodontian reptile known from the Late Jurassic of Germany, with a single known species, ''S. velserae''. It is known from a single nearly complete and articulated sub-adult specimen (SNSB-BSPG 1993 XVIII 4), found in the late Kimmeridgian aged Torleite Formation in Brunn quarry in Bavaria, Southern Germany. It is thought to be a close relative of the living tuatara (''Sphenodon puncatus''), tentatively referred to Sphenodontinae. Etymology The genus name combines the prefix "Spheno-", with reference to the taxon being a sphenodontian, and the latin word "fontis"( spring, but also can mean "well"), roughly meaning “the sphenodontian of the well”. This acknowledges the origin of the name of the type locality Brunn, which comes from the German Brunnen (= well). The species name honours Lisa Velser, who discovered and prepared the holotype specimen. Description The holotype of ''Sphenofontis'' comprises a nearly complete and ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zapatadon
''Zapatadon'' is an extinct genus of sphenodontid reptile from the end of the Early Jurassic in the lower part of La Boca Formation of Tamaulipas, Mexico.Marisol Montellano, James A. Hopson and James M. Clark (2008)Late Early Jurassic Mammaliaforms from Huizachal Canyon, Tamaulipas, México ''Journal of Vertebrate Paleontology'', Vol. 28, No. 4 (Dec. 12, 2008), pp. 1130-1143. Is known from a nearly complete skull with mandible of a post-hatchling individual (the specimen IGM 3497, in the Instituto de Geologia, of the Universidad Nacional Autónoma de Mexico), and is one of the smallest skulls between the sphenodontians, with an estimated total length of 11.3 millimetres, a bit smaller than the hatchling individuals observed in the modern tuatara (''Sphenodon''); features like the oblique mandibular symphysis suggests that the holotype is from an individual in a relatively mature stage of ontogenic development. ''Zapatadon'' is diagnosed by their hatchling tooth series located in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pamizinsaurus
''Pamizinisaurus'' is a genus of sphenodontian reptile known from Lower Cretaceous (Albian) Tlayúa Formation of Mexico. A crushed skeleton of a juvenile reptile was found in Tlayua Quarry, in central Mexico. It was named ''Pamizinsaurus tlayuaensis'' by Reynoso in 1997, after the name of the quarry of which it was found. Its skull length is . The fossil was covered in small round osteoderms that could have protected it from predators. Relatives Reynoso (1997) argued that ''Pamizinsaurus'' was a genus of the subfamily Sphenodontinae; grouping it with the modern ''Sphenodon'' (better known as the ''Tuatara''), '' Zapatadon'', '' Cynosphenodon'', '' Homoeosaurus'', '' Sapheosaurus'', and ''Ankylosphenodon ''Ankylosphenodon'' is an extinct species of sphenodontian known from Tepexi de Rodriguez, Mexico. It is known from Early Cretaceous sedimentary deposits from the Tlayua formation. Lifestyle ''Ankylosphenodon'' is thought to have been an aqu ...''. References Ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Navajosphenodon
''Navajosphenodon'' is an extinct genus of sphenodontid reptile from the Early Jurassic Kayenta Formation of Arizona, United States. It is known from a fully articulated skeleton, and is similar in many aspects to the extant tuatara Tuatara (''Sphenodon punctatus'') are reptiles endemic to New Zealand. Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. The name ''tuatara'' is derived from the Māori language and ..., both belonging to the Sphenodontinae, including sharing a complete lower temporal bar. It is one of the oldest known sphenodontines. References Jurassic lepidosaurs Sphenodontia Fossil taxa described in 2022 {{Rhynchocephalia, state=autocollapse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrate Bone
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids (reptiles, birds), and early synapsids. In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms upper part of the jaw joint. The lower jaw articulates at the articular bone, located at the rear end of the lower jaw. The quadrate bone forms the lower jaw articulation in all classes except mammals. Evolutionarily, it is derived from the hindmost part of the primitive cartilaginous upper jaw. Function in reptiles In certain extinct reptiles, the variation and stability of the morphology of the quadrate bone has helped paleontologists in the species-level taxonomy and identification of mosasaur squamates and spinosaurine dinosaurs. In some lizards and dinosaurs, the quadrate is articulated at both ends and movable. In snakes, the quadrate bone has become elongated and very mobile, and contributes greatly to their ability to swallow ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadratojugal Bone
The quadratojugal is a skull bone present in many vertebrates, including some living reptiles and amphibians. Anatomy and function In animals with a quadratojugal bone, it is typically found connected to the jugal (cheek) bone from the front and the squamosal bone from above. It is usually positioned at the rear lower corner of the cranium. Many modern tetrapods lack a quadratojugal bone as it has been lost or fused to other bones. Modern examples of tetrapods without a quadratojugal include salamanders, mammals, birds, and squamates (lizards and snakes). In tetrapods with a quadratojugal bone, it often forms a portion of the jaw joint. Developmentally, the quadratojugal bone is a dermal bone in the temporal series, forming the original braincase. The squamosal and quadratojugal bones together form the cheek region and may provide muscular attachments for facial muscles. In reptiles and amphibians In most modern reptiles and amphibians, the quadratojugal is a prominent, str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthodontia (reptile)
Opisthodontia is a proposed clade of sphenodontian reptiles, uniting '' Opisthias'' from the Late Jurassic-earliest Cretaceous of Europe and North America with the Elienodontinae, a group of herbivorous sphenodontians known from the Late Triassic to Late Cretaceous. Description Teeth and diet Like other sphenodonts, opisthodonts had acrodont teeth which grew directly from the bone. They had one row of teeth on the lower jaw and two rows on the roof of the mouth. When processing food, their mandibular teeth would have slid between the outer ( maxillary) teeth and inner ( palatine) teeth. Some opisthodonts, such as '' Sphenotitan'', also had clusters of small teeth on the pterygoid at the center of the mouth roof. Opisthodont teeth were wide, numerous, and tightly-packed for grinding and shredding tough plant matter. Although wide shredding teeth are also known in a few other sphenodontians, such as '' Clevosaurus'' and '' Pelecymala'', the most diverse and long-lasting grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuatara
Tuatara (''Sphenodon punctatus'') are reptiles endemic to New Zealand. Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. The name ''tuatara'' is derived from the Māori language and means "peaks on the back". The single extant species of tuatara is the only surviving member of its order. Rhynchocephalians originated during the Triassic (~250 million years ago), reached worldwide distribution and peak diversity during the Jurassic and, with the exception of tuatara, were extinct by 60 million years ago. Their closest living relatives are squamates (lizards and snakes). For this reason, tuatara are of interest in the study of the evolution of lizards and snakes, and for the reconstruction of the appearance and habits of the earliest diapsids, a group of amniote tetrapods that also includes dinosaurs (including birds) and crocodilians. Tuatara are greenish brown and grey, and measure up to from head to tail-tip a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jugal Bone
The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anatomy The jugal bone is located on either side of the skull in the circumorbital region. It is the origin of several masticatory muscles in the skull. The jugal and lacrimal bones are the only two remaining from the ancestral circumorbital series: the prefrontal, postfrontal, postorbital, jugal, and lacrimal bones. During development, the jugal bone originates from dermal bone. In dinosaurs This bone is considered key in the determination of general traits in cases in which the entire skull has not been found intact (for instance, as with dinosaurs in paleontology). In some dinosaur genera the jugal also forms part of the lower margin of either the antorbital fenestra or the infratemporal fenestra, or both. Most commonly, this bone art ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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