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Adriosaurus
''Adriosaurus'' is an extinct genus of squamate which lived in what is now Slovenia and other parts of Europe during the Late Cretaceous. It was snake-like and grew up to in length. This is the first fossil record of vestigial limbs in lizards. It lost its manus and forearm completely in order to elongate its axial skeleton. These unique anatomical features led to discussions of the evolutionary patterns of limb reduction in Squamata.Alessandro Palci and Michael W. Caldwell. 2007. Vestigial Forelimbs and Axial Elongation in a 95 Million-Year-Old Non-Snake Squamate. Journal of Vertebrate Paleontology Vol. 27, No. 1. pp. 1-7 ''Adriosaurus'' includes three species: ''A. microbrachis'' (“micro”, meaning small, and “brachis”, meaning arm, referring to the vestigial forelimb composed of only the humerus), ''A skrbinensis'' (named after the location where they found the fossil, Skrbina, northwest of Komen, Slovenia) and ''A. suessi''. However, ''A. microbrachis'' lacks many cru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acteosaurus
''Acteosaurus'' is an extinct genus of aquatic lizard that lived in the upper Cretaceous period. Its species, ''A. tommasinii'' and ''A. crassicostatus'', were described in 1860 and 1993. Though ''A. crassicostatus'' is probably a junior synonym for '' Adriosaurus suessi'', ''A. tommasinii'' was found to be similar to coniasaurs, mosasauroids, and a sister taxon to modern snakes in 2010. Etymology The primary portion of ''Acteosaurus name comes from Actaeon (; Greek: ), a famous Theban hero who was hunted and killed by the goddess Artemis. The second part of the name is the Greek word ' (), which means " lizard" or " reptile". The type species was named after the botanist Muzio Giuseppe Spirito de Tommasini (1794—1879), the Podestà—or magistrate—of Trieste under the Habsburgs. Taxonomy As a genus, Acteosaurus was described in 1860 by German paleontologist Christian Erich Hermann von Meyer. There exist two known species of Acteosaurus called ''A. tommasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophidiomorpha
Ophidiomorpha is a clade composed of snakes and their primitive and early relatives proposed by Palci and Caldwell (2007)Palci, A., & Caldwell, M. W. (2007). Vestigial forelimbs and axial elongation in a 95 million-year-old non-snake squamate. Journal of Vertebrate Paleontology, 27(1), 1-7. The clade was defined as a node-based clade containing the most recent common ancestor of dolichosaurs, adriosaurs, '' Aphanizocnemus'', and fossil and extant Ophidia and all of its descendants. The existence of Ophidiomorpha as a clade may become problematic as it is placed within the Pythonomorpha, a clade that itself is not universally agreed upon containing mosasaurs and snakes, their most recent common ancestor and all of its descendants. Indeed, most 20th-century herpetologists and paleontologists rejected this idea and sought instead to demonstrate a close relationship between mosasaurs and varanid lizards. Pythonomorpha was later resurrected by a number of paleontologists (Lee, 1997; C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolichosauridae
Dolichosauridae (from Latin, ''dolichos'' = "long" and Greek ''sauros''= lizard) is a family of Cretaceous aquatic ophidiomorphan lizards closely related to the snakes and mosasaurs. Description ''Dolichosaurus'' was a small marine squamate at about 0.5 to 1 meter in total length. ''Coniasaurus'' was similarly sized at about 0.5 meters in length. They were elongated (especially apparent in the neck) marine lizards with reduced limbs and small, thin heads. Dolichosaurs may have occupied a niche similar to the earlier nothosaurs and modern sea snakes, in using their thin heads to feed in crevices and narrow spaces along coral reefs and rocky shores. One of the earliest dolichosaurs, '' Kaganaias'' from Barremian, probably lived in freshwater environment unlike other members in the family. The degree to which the limbs were reduced suggest that the dolichosaurs would have been unable to generate any significant movement on land, and they thus likely spent most of their time u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pythonomorpha
Pythonomorpha was originally proposed by paleontologist Edward Drinker Cope (1869) as a reptilian order comprising mosasaurs, which he believed to be close relatives of Ophidia (snakes). The etymology of the term Pythonomorpha comes from the Greek ''Python'' (a monstrous snake from Greek mythology) and ''morphe'' ("form"), and refers to the generally serpentine body plan of members of the group. Cope wrote, "In the mosasauroids, we almost realize the fictions of snake-like dragons and sea-serpents, in which men have been ever prone to indulge. On account of the ophidian part of their affinities, I have called this order Pythonomorpha." Cope incorporated two families, the Clidastidae (now defunct but including only ''Clidastes'') and the Mosasauridae (including ''Macrosaurus'' Tylosaurus.html"_;"title="=Tylosaurus">''Tylosaurus''_''Mosasaurus.html" ;"title="Tylosaurus">''Tylosaurus''.html" ;"title="Tylosaurus.html" ;"title="=Tylosaurus">''Tylosaurus''">Tylosaurus.html" ;"title="=Ty ... [...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] |
Anguidae
Anguidae refers to a large and diverse family of lizards native to the Northern Hemisphere. Common characteristics of this group include a reduced supratemporal arch, striations on the medial faces of tooth crowns, osteoderms, and a lateral fold in the skin of most taxa. The group includes the slowworms, glass lizards, and alligator lizards, among others. The family is divided into two subfamilies (Anguinae and Gerrhonotinae), and contains about 87 species in 8 genera. Morphology and reproduction Anguids have hard osteoderms beneath their scales giving them an armored appearance. Many of the species have reduced or absent limbs, giving them a snake-like appearance, while others are fully limbed. Body type varies among species, with sizes ranging from 10 cm to 1.5 m. The group includes oviparous and viviparous species, both of which can be observed in a single genus at times. Feeding and habitat These lizards are known carnivorous or insectivorous foragers, feeding p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontosaurus
''Pontosaurus'' is a now extinct genus of pythonomorph from the Late Cretaceous period. It was originally named ''Hydrosaurus'', but that name was preoccupied by an agamid lizard, so it was renamed. It is known from two species, both Cenomanian in age, the type ''P. lesinensis'' which is known from Hvar in Croatia, the other ''P. kornhuberi'' is known from the Sannine Formation in Lebanon. Both species were relatively small. ''P. krohuberi'' reached in length and in body mass, while ''P. lesinensis'' reached in length and in body mass. See also * List of mosasaurs This list of mosasaurs is a comprehensive listing of all Genus, genera that have ever been included in the family Mosasauridae or the parent clade Mosasauroidea, excluding purely vernacular terms. The list includes all commonly accepted genera, bu ... References External links Oceans of Kansas Mosasaurs Extinct reptiles of New Zealand Mosasaurs of Asia Fossil taxa described in 1892 Taxa named by Dragu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolichosaurus
''Dolichosaurus'' (meaning "long lizard") is an extinct genus of marine squamate of the Upper Cretaceous Cenomanian chalk deposits of England. Sister-group relationships between coniasaurs, dolichosaurs, Aigialosauridae and Mosasauridae are an unresolved polytomy. The paleobiology of ''Dolichosaurus'' is reconstructed as similar to coniasaurs, nothosaurs, and modern sea snakes Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, where ....Michael W. CaldwellOn the aquatic squamate ''Dolichosaurus longicollis'' Owen, 1850 (Cenomanian, Upper Cretaceous), and the evolution of elongate necks in squamates ''Journal of Vertebrate Paleontology'' 20(4):720-735. 2000. doi: https://dx.doi.org/10.1671/0272-4634(2000)020 720:OTASDL.0.CO;2 References Cretaceous lizards Late Cretaceous lepidosau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coniasaurus
''Coniasaurus'' is an extinct genus of Late Cretaceous marine squamates that range in age from Cenomanian to Santonian. It was first described by Richard Owen in 1850 from lower Cenomanian chalk deposits in southeast England (Sussex). Two species have been described from this genus: ''C. crassidens'' (Owen, 1850), known from Cenomanian to Santonian deposits from southeast England, Germany and North America, and ''C. gracilodens'' (Caldwell, 1999) from the Cenomanian of southeast England. ''Coniasaurus'' has only been described from incomplete specimens, but it is known to have had a relatively elongate skull with specialised teeth. By comparison with ''Dolichosaurus'', it may have had four short limbs and an elongate neck and body. A maximum length between has been proposed. Phylogenetic analysis suggests that ''Coniasaurus'' is a sister group to the Mosasauroidea within the clade Pythonomorpha Pythonomorpha was originally proposed by paleontologist Edward Drinker Cope (1869 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aigialosauridae
Aigialosauridae (from Greek, ''aigialos'' = "seashore" and ''sauros''= lizard) is a family of Late Cretaceous semiaquatic pythonomorph lizards closely related to the mosasaurs. Regarded by some paleontologists as a distinct monophyletic group and by others as an adaptive grade within the basal mosasauroids, recent molecular and morphological data suggests that they are the oldest known members of the lineage leading to the mosasaurs. The family is recognized as containing two species, normally classified into two genera; ''Aigialosaurus'' and ''Opetiosaurus''. When used as an adaptive grade rather than as an actual monophyletic group, many other basal mosasauroids of uncertain affinities are occasionally referred to as "aigialosaurs", such as the genera ''Komensaurus'', ''Haasiasaurus'', ''Carsosaurus'' and ''Dallasaurus'' and even entire mosasaur clades, such as the Tethysaurinae. The term "plesiopedal mosasaurs" or "mosasaurs with a plesiopedal limb condition" is a more formal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
