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Clepsydrops
''Clepsydrops'' is an extinct genus of primitive synapsids from the early Late Carboniferous that was related to ''Archaeothyris''. The name means 'hour-glass appearance' (Greek ''klepsydra'' = "hourglass" + Greek ''ops'' = "eye, face, appearance"). Synapsida is the group (or clade) that includes mammals, but the term is mainly used to refer to its earliest members. Like many other early terrestrial amniotes, it probably had the diet of insects and smaller animals. It probably laid eggs on land rather than in the water, as most amniote tetrapods did. A paleobiological inference model for the femur suggests a terrestrial lifestyle for ''Clepsydrops'', as for its more recent relative ''Ophiacodon''. This is consistent with its rather thin, compact cortex. Its jaws were slightly more advanced than those of other early amniote tetrapods like ''Paleothyris'' and ''Hylonomus''. See also * List of pelycosaurs * Evolution of mammals The evolution of mammals has passed through many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiacodontidae
Ophiacodontidae is an extinct family of early synapsids from the Carboniferous and Permian. '' Archaeothyris'', and '' Clepsydrops'' were among the earliest ophiacodontids, appearing in the Late Carboniferous. Ophiacodontids are among the most basal synapsids, an offshoot of the lineage which includes therapsids and their descendants, the mammals. The group became extinct by the Kungurian or the Roadian, replaced by anomodonts, theriodonts, and the diapsid reptiles. Characteristics The lifestyle of ophiacodonts has long been controversial. Some studies suggested that they were semi-aquatic, and some even suggested a fairly aquatic lifestyle, but a recent study based on a quantitative inference model suggested that both '' Clepsydrops'' and '' Ophiacodon'' were terrestrial. Vertebral morphometric data also support, though ambiguously, a rather terrestrial lifestyle for '' Ophiacodon'', which could reach a length of . '' Archaeothyris'' may also have been terrestrial, but no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Pelycosaurs
This list of pelycosaurs is an attempt to create a comprehensive listing of all Genus, genera that have ever been included in the synapsida excluding therapsida and purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (''nomen dubium, nomina dubia''), or were not formally published (''nomen nudum, nomina nuda''), as well as synonym (zoology), junior synonyms of more established names, and genera that are no longer considered pelycosaurs. The list currently contains 83 generic names. Naming conventions and terminology Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include: * Synonym (zoology), Junior synonym: A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type (zoology), type specimens are later assigned to the same genus, the first to be published (in chronologica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous
The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the Permian Period, Ma. It is the fifth and penultimate period of the Paleozoic era and the fifth period of the Phanerozoic eon (geology), eon. In North America, the Carboniferous is often treated as two separate geological periods, the earlier Mississippian (geology), Mississippian and the later Pennsylvanian (geology), Pennsylvanian. The name ''Carboniferous'' means "coal-bearing", from the Latin ("coal") and ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern "system" names, it was coined by geologists William Conybeare (geologist), William Conybeare and William Phillips (geologist), William Phillips in 1822, based on a study of the British rock succession. Carboniferous is the per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleothyris
''Paleothyris'' was a small, agile, anapsid romeriidan reptile which lived in the Moscovian (Carboniferous) age of the Late Carboniferous in Nova Scotia. Description ''Paleothyris'' had sharp teeth and large eyes, meaning that it was likely a nocturnal hunter. It was about a foot long. It probably fed on insects and other smaller animals found on the floor of its forest home. ''Paleothyris'' was an early sauropsid, yet it still had some features that were more primitive, more labyrinthodont-like than reptile-like, especially its skull, which lacked fenestrae, holes found in the skulls of most modern reptiles and mammals. See also * '' Westlothiana'' * ''Casineria'' * '' Hylonomus'' * ''Petrolacosaurus'' * ''Archaeothyris ''Archaeothyris'' is an extinct genus of ophiacodontid synapsid that lived during the Late Carboniferous and is known from Nova Scotia. Dated to 306 million years ago, ''Archaeothyris'', along with a more poorly known synapsid called ''Echinerpet ...'' * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxa Named By Edward Drinker Cope
In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion, especially in the context of rank-based (" Linnaean") nomenclature (much less so under phylogenetic nomenclature). If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were presumably set forth in prehistoric times by hunter-gatherers, as suggested by the fairly sophisticated folk taxonomies. Much later, Aristotle, and later still ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transitional Fossils
A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. Because of the incompleteness of the fossil record, there is usually no way to know exactly how close a transitional fossil is to the point of divergence. Therefore, it cannot be assumed that transitional fossils are direct ancestors of more recent groups, though they are frequently used as models for such ancestors. In 1859, when Charles Darwin's ''On the Origin of Species'' was first published, the fossil record was poorly known. Darwin described the perceived lack of transitional fossils as "the most obvious and gravest objection which can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous Synapsids Of North America
The Carboniferous ( ) is a geologic period and system of the Paleozoic era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the Permian Period, Ma. It is the fifth and penultimate period of the Paleozoic era and the fifth period of the Phanerozoic eon. In North America, the Carboniferous is often treated as two separate geological periods, the earlier Mississippian and the later Pennsylvanian. The name ''Carboniferous'' means "coal-bearing", from the Latin ("coal") and ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern "system" names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. Carboniferous is the period during which both terrestrial animal and land plant life was well established. Stegocephalia (four-limbed vertebrates including true tetrapods), whose forerunners (tetrapodomorp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Transitional Fossils
A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. Because of the incompleteness of the fossil record, there is usually no way to know exactly how close a transitional fossil is to the point of divergence. Therefore, it cannot be assumed that transitional fossils are direct ancestors of more recent groups, though they are frequently used as models for such ancestors. In 1859, when Charles Darwin's ''On the Origin of Species'' was first published, the fossil record was poorly known. Darwin described the perceived lack of transitional fossils as "the most obvious and gravest objection which can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous Tetrapods
Carboniferous tetrapods include amphibians and reptiles that lived during the Carboniferous Period. Though stem-tetrapods originated in the preceding Devonian, it was in the earliest Carboniferous that the first crown tetrapods appeared, with full scaleless skin and five digits. During this time, amphibians (including many extinct groups unrelated to modern forms, referred to as "basal tetrapods") were the predominant tetrapods, and included the Temnospondyli, Lepospondyli, and Anthracosauria. The first amniotes appeared during the middle Carboniferous ( Early Pennsylvanian) from the lattermost group, and included both sauropsids and synapsids, but it was not until the very end of the Carboniferous, during a rainforest collapse, and afterwards that they began to diversify. Classification The following list of families of Carboniferous tetrapods is based mostly on Benton ed. 1993. The classification followBenton 2004 Superclass Tetrapoda * Basal Tetrapods ** Family Whatchee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution Of Mammals
The evolution of mammals has passed through many stages since the first appearance of their synapsid ancestors in the Pennsylvanian (geology), Pennsylvanian sub-period of the late Carboniferous period. By the mid-Triassic, there were many synapsid species that looked like mammals. The lineage leading to today's mammals split up in the Jurassic; synapsids from this period include ''Dryolestes'', more closely related to extant placentals and marsupials than to monotremes, as well as ''Ambondro mahabo, Ambondro'', more closely related to monotremes. Later on, the eutherian and metatherian lineages separated; the metatherians are the animals more closely related to the marsupials, while the eutherians are those more closely related to the placentals. Since ''Juramaia'', the earliest known eutherian, lived 160 million years ago in the Jurassic, this divergence must have occurred in the same period. After the Cretaceous–Paleogene extinction event wiped out the non-avian dinosaurs (bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hylonomus
''Hylonomus'' (; ''hylo-'' "forest" + ''nomos'' "dweller") is an extinct genus of reptile that lived during the Bashkirian stage of the Late Carboniferous. It is the earliest known crown group amniote and the oldest known unquestionable reptile, with the only known species being ''Hylonomus lyelli''. Despite being amongst the oldest known reptiles, it is not the most primitive member of the group, being a eureptile more derived than either parareptiles or captorhinids. Discovery and naming ''Hylonomus lyelli'' was first described by John William Dawson in 1860. The species' name was given in honor of Dawson's teacher, the geologist Sir Charles Lyell. While it has traditionally been included in the group Protorothyrididae, it has since been recovered outside this group. Formerly assigned species Dawson also attributed two other species ''H. aciedentatus'' and ''H. wymani'' when he described ''H. lyelli'' in 1860, and later described two more species ''H. multidens'' and ''H. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
