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Caenophidia
The Caenophidia are a derived clade of alethinophidian snakes, which contains over 80% of all the extant species of snakes. The largest family is Colubridae, but it also includes at least seven other families, at least four of which were once classified as "Colubridae" before molecular phylogenetics helped us understand their relationships. It has been found to be monophyletic. Although the Caenophidia previously was held to exclude Acrochordidae, researchers have recognized that acrochordids share several traits with the other caenophidians. Hence Caenophidia is usually considered to comprise Acrochordidae plus more the more derived snakes classified as Colubroidea. Recent molecular studies have also found the families Xenophidiidae and Bolyeriidae to be closely related to caenophidians, forming the sister group to Caenophidia rather than being part of Henophidia. Below is a phylogeny of the Caenophidia based on analyses from several studies: References Alethino ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henophidia
Henophidia is a former superfamily of the suborder Serpentes (snakes) that contains boas, pythons and numerous other less-well-known snakes. Snakes once considered to belong to superfamily Henophidia include two families now considered Amerophidia (Aniliidae – red pipe snakes, and Tropidophiidae – dwarf "boas" or thunder snakes), three families now considered Uropeltoidea (Cylindrophiidae – Asian pipe snakes, Anomochilidae – dwarf pipe snakes, and Uropeltidae – shield-tailed snakes and short-tailed snakes), three families now considered Pythonoidea (Pythonidae – pythons, Loxocemidae – Mexican burrowing snake, and Xenopeltidae – sunbeam snakes), at least one family now considered Booidea (Boidae – boas ncluding sand boas and many other lineages often called boas, mostly now considered subfamilies of Boidaeref name="Reynolds14"/>), and Bolyeriidae – Round Island splitjaw snakes. Because these snakes do not form a monophyletic group they can no longer be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snakes
Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads (cranial kinesis). To accommodate their narrow bodies, snakes' paired organs (such as kidneys) appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. Lizards have evolved elongate bodies without limbs or with greatly reduced limbs about twenty-five times independently via convergent evolution, leading to many lineages of legless lizards. These resemble snakes, but several common groups of legless lizards have eyelids and external ears, which snakes lack, although this rule is not universal (see Amphisbaenia, D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colubroides
The Colubroides are a clade in the suborder Serpentes ( snakes). It contains over 85% of all the extant species of snakes. The largest family is Colubridae, but it also includes at least six other families, at least four of which were once classified as "Colubridae" before molecular phylogenetics helped in understanding their relationships. It has been found to be monophyletic. Morphological synapomorphies are defined as such from Zaher et al. (2009): Loss of the right carotid artery; intercostal arteries arising from the dorsal aorta throughout the trunk at intervals of several body segments; specialized expanded costal cartilages; presence of a muscle protractor laryngeus; separate muscle protractor quadrati; separate spinalis and semispinalis portion in the epaxial trunk; spinules or spines covering the hemipenial body. Traditionally, the name "Colubroidea Colubroidea is a superfamily of snakes in the clade Colubroides that includes Colubridae, with some studies spl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colubriformes
The Colubroides are a clade in the suborder Serpentes ( snakes). It contains over 85% of all the extant species of snakes. The largest family is Colubridae, but it also includes at least six other families, at least four of which were once classified as "Colubridae" before molecular phylogenetics helped in understanding their relationships. It has been found to be monophyletic. Morphological synapomorphies are defined as such from Zaher et al. (2009): Loss of the right carotid artery; intercostal arteries arising from the dorsal aorta throughout the trunk at intervals of several body segments; specialized expanded costal cartilages; presence of a muscle protractor laryngeus; separate muscle protractor quadrati; separate spinalis and semispinalis portion in the epaxial trunk; spinules or spines covering the hemipenial body. Traditionally, the name "Colubroidea Colubroidea is a superfamily of snakes in the clade Colubroides that includes Colubridae, with some studies spl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeophis
''Archaeophis'' is an extinct genus of snake from the Eocene of Monte Bolca Monte Bolca is a lagerstätte near Verona, Italy that was one of the first fossil sites with high quality preservation known to Europeans, and is still an important source of fossils from the Eocene. Geology Monte Bolca was uplifted from the T .... References * Recent Vertebrate Carcasses and Their Paleobiological Implications by Johannes Weigelt and Judith Schaefer (page 88) Eocene snakes Fossils of Italy Fossil taxa described in 1859 {{snake-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenodermidae
Xenodermidae is a family of snakes native to East Asia, South Asia, and Southeast Asia. All species in the family Xenodermidae are small or moderately sized snakes, never more than but typically less than in total length (including tail). They are secretive, probably nocturnal, and typically inhabit moist forest habitats. They seem to be opportunistic carnivores, preying on other vertebrates. The correct spelling of the family name is Xenodermidae, not "Xenodermatidae". Taxonomy and systematics Xenodermidae have a basal position in the colubroid radiation. However, their exact position is not yet settled, e.g., that they might be the sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ... of the rest of Colubroidea, or that their sister taxon is Acrochordidae, and tha ... [...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] |
Pareidae
Pareidae is a small family of snakes found largely in southeast Asia, with an isolated subfamily endemic to southwestern India. It encompasses 42 species in four genera divided into two subfamilies: Pareinae and Xylophiinae. Both families are thought to have diverged from one another during the early-mid Eocene, about 40-50 million years ago. Pareidae was once considered a subfamily of Colubridae (called "Pareatinae"), but it is now known that pareids are not closely related to colubrids. The correct spelling is Pareidae, not Pareatidae. Members of the subfamily Pareinae are active, predatory snakes. Many are snail-eating snakes that have asymmetrical lower jaws, allowing them to pry the soft bodies of snails from their spiral shells. One species, ''Pareas iwasakii'', has an average of 17.5 teeth in its left mandible and 25 teeth in its right mandible. Predation by pareids on dextral (clockwise-coiled or "right handed") snails is thought to favor the evolution of sinistral (coun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
