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Planocephalosaurus
''Planocephalosaurus'' is an extinct genus of rhynchocephalian. Fossils of the genus were found in the Tecovas Formation of Texas and the Magnesian Conglomerate of England. ''Planocephalosaurus'' was one of the first sphenodonts and bore a strong resemblance to the extant tuatara, albeit much smaller, at only in length. The creature is presumed to have fed on large invertebrates and small vertebrates. Dentition ''Planocephalosaurus'' exhibits very interesting dentition. Initially, it was believed to have been attached to the bone via acrodont tooth implantation, however, after this specimen was exposed to X-radiography it was determined that this animal has a combination of different tooth implantation types. Similar to another rhynchocephalian, ''Diphydontosaurus'', it possesses acrodont teeth in the posterior portion of the jaw, and pleurodont dentition in the anterior portion. ''Planocephalosauruss teeth were also fused with the cartilage, unlike its only extant Extant is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphydontosaurus
''Diphydontosaurus'' is an extinct genus of rhynchocephalian reptile from the Late Triassic of England and Italy. This small animal was related to the living tuatara (''Sphenodon''). It may have grown to a length of . It is more derived than ''Gephyrosaurus'', yet more primitive than ''Planocephalosaurus'', and shares traits with both of them. Description ''Diphydontosaurus'' was a small sphenodontian, measuring up to long. It had long, sharp claws to help it catch its prey, and peg-like piercing teeth to help it eat insects. These features are shared with the other primitive rhynchocephalians ''Gephyrosaurus'' and ''Planocephalosaurus''. Classification ''Diphydontosaurus'' is known from many mostly complete specimens, which means that its classification as a rhynchocephalian is quite certain. In an analysis by Oliver Rahut and colleagues in 2012, it was found that ''Diphydontosaurus'' is the second most basal rhynchocephalian, after ''Gephyrosaurus'', and the most primitive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchocephalian
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 tuatara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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