|
Sphenacodon
''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related '' Dimetrodon'', ''Sphenacodon'' was a carnivorous member of the Eupelycosauria family Sphenacodontidae. However, ''Sphenacodon'' had a low crest along its back, formed from blade-like bones on its vertebrae (neural spines) instead of the tall dorsal sail found in ''Dimetrodon''. Fossils of ''Sphenacodon'' are known from New Mexico and the Utah–Arizona border region in North America. Researchers currently recognize two species: ''Sphenacodon ferox'' (the type species) and ''Sphenacodon ferocior''. ''Sphenacodon ferocior'' can be up to 40% larger in overall size (at about long) compared to ''Sphenacodon ferox'' (at about ). In addition, the dorsal spines in ''Sphenacodon ferocior'' are proportionately 45% taller than in ''Sphenacodon ferox''. The recent discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodon Ferox 1
''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related ''Dimetrodon'', ''Sphenacodon'' was a carnivorous member of the Eupelycosauria family Sphenacodontidae. However, ''Sphenacodon'' had a low crest along its back, formed from blade-like bones on its vertebrae (neural spines) instead of the tall dorsal sail found in ''Dimetrodon''. Fossils of ''Sphenacodon'' are known from New Mexico and the Utah–Arizona border region in North America. Researchers currently recognize two species: ''Sphenacodon ferox'' (the type species) and ''Sphenacodon ferocior''. ''Sphenacodon ferocior'' can be up to 40% larger in overall size (at about long) compared to ''Sphenacodon ferox'' (at about ). In addition, the dorsal spines in ''Sphenacodon ferocior'' are proportionately 45% taller than in ''Sphenacodon ferox''. The recent discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodon2
''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related ''Dimetrodon'', ''Sphenacodon'' was a carnivorous member of the Eupelycosauria family Sphenacodontidae. However, ''Sphenacodon'' had a low crest along its back, formed from blade-like bones on its vertebrae (neural spines) instead of the tall dorsal sail found in ''Dimetrodon''. Fossils of ''Sphenacodon'' are known from New Mexico and the Utah–Arizona border region in North America. Researchers currently recognize two species: ''Sphenacodon ferox'' (the type species) and ''Sphenacodon ferocior''. ''Sphenacodon ferocior'' can be up to 40% larger in overall size (at about long) compared to ''Sphenacodon ferox'' (at about ). In addition, the dorsal spines in ''Sphenacodon ferocior'' are proportionately 45% taller than in ''Sphenacodon ferox''. The recent discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodon Scale
''Sphenacodon'' (meaning "wedge point tooth") is an extinct genus of synapsid that lived from about 300 to about 280 million years ago (Ma) during the Late Carboniferous and Early Permian periods. Like the closely related ''Dimetrodon'', ''Sphenacodon'' was a carnivorous member of the Eupelycosauria family Sphenacodontidae. However, ''Sphenacodon'' had a low crest along its back, formed from blade-like bones on its vertebrae (neural spines) instead of the tall dorsal sail found in ''Dimetrodon''. Fossils of ''Sphenacodon'' are known from New Mexico and the Utah–Arizona border region in North America. Researchers currently recognize two species: ''Sphenacodon ferox'' (the type species) and ''Sphenacodon ferocior''. ''Sphenacodon ferocior'' can be up to 40% larger in overall size (at about long) compared to ''Sphenacodon ferox'' (at about ). In addition, the dorsal spines in ''Sphenacodon ferocior'' are proportionately 45% taller than in ''Sphenacodon ferox''. The recent discover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimetrodon
''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontidae. The most prominent feature of ''Dimetrodon'' is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It walked on four legs and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the Southwestern United States, the majority coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, its fossils have been found in Germany. Over a dozen species have been named since the genus was first erected in 1878. ''Dimetrodon'' is often mistaken for a dinosaur or as a contemporary of dinosaurs in popular culture, but it became extinct some 40 million years before the first appearance of dinosaurs. Reptile-li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodontidae
Sphenacodontidae (Greek: "wedge point tooth family") is an extinct family of small to large, advanced, carnivorous, Late Pennsylvanian to middle Permian pelycosaurs. The most recent one, ''Dimetrodon angelensis'', is from the late Kungurian or early Roadian San Angelo Formation. However, given the notorious incompleteness of the fossil record, a recent study concluded that the Sphenacodontidae may have become extinct as recently as the early Capitanian. Primitive forms were generally small (60 cm to 1 meter), but during the later part of the early Permian these animals grew progressively larger (up to 3 meters or more), to become the top predators of their environments. Sphenacodontid fossils are so far known only from North America and Europe. Characteristics The skull is long, deep and narrow, an adaptation for strong jaw muscles. The front teeth are large and dagger-like, whereas the teeth in the sides and rear of the jaw are much smaller (hence the name of the well-kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapsid
Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptiles and birds. The group includes mammals and every animal more closely related to mammals than to sauropsids. Unlike other amniotes, synapsids have a single temporal fenestra, an opening low in the skull roof behind each eye orbit, leaving a bony arch beneath each; this accounts for their name. The distinctive temporal fenestra developed about 318 million years ago during the Late Carboniferous period, when synapsids and sauropsids diverged, but was subsequently merged with the orbit in early mammals. Traditionally, non-mammalian synapsids were believed to have evolved from reptiles, and therefore described as mammal-like reptiles in classical systematics, and primitive synapsids were also referred to as pelycosaurs, or pelycosaur-gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eupelycosauria
Eupelycosauria is a large clade of animals characterized by the unique shape of their skull, encompassing all mammals and their closest extinct relatives. They first appeared 308million years ago during the Early Pennsylvanian epoch, with the fossils of ''Echinerpeton'' and perhaps an even earlier genus, ''Protoclepsydrops'', representing just one of the many stages in the evolution of mammals,Kemp. T.S., 1982, ''Mammal-like Reptiles and the Origin of Mammals''. Academic Press, New York in contrast to their earlier amniote ancestors. Eupelycosaurs are synapsids, animals whose skull has a single opening behind the eye. They are distinguished from the Caseasaurian synapsids by having a long, narrow supratemporal bone (instead of one that is as wide as it is long) and a frontal bone with a wider connection to the upper margin of the orbit. Laurin, M. and Reisz, R. R., 1997Autapomorphies of the main clades of synapsids- Tree of Life Web Project The only living descendants of basal e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenospondylus
''Ctenospondylus'' ("comb vertebra") is an extinct genus of sphenacodontid synapsid Species were about three meters (ten feet) long. The genus is known only from the 'Seymouran' Land Vertebrate Faunachron, which is equivalent to the upper part of the Artinskian stage and the lowermost Kungurian stage of the Early Permian. Its fossils were found in the U.S. states of Ohio and Texas. It was a carnivore and preyed upon animals close to its size. ''Ctenospondylus'' had a long tail, short back spines, and a very deep yet narrow skull with massive jaws that had sharp teeth. Because of its large size, it was probably the apex predator in its environment, and might have competed with other predators like ''Dimetrodon'' for food. A sphenacodontid, it was a close relative of ''Dimetrodon''. In 1936, Alfred Sherwood Romer named the type species ''Ctenospondylus casei''. The generic name, from Greek κτείς, ''kteis'', "comb", and σφόνδυλος, ''sphondylos'', "vertebra", refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Museum Of Natural History
The Field Museum of Natural History (FMNH), also known as The Field Museum, is a natural history museum in Chicago, Illinois, and is one of the largest such museums in the world. The museum is popular for the size and quality of its educational and scientific programs, and its extensive scientific-specimen and artifact collections. The permanent exhibitions, which attract up to two million visitors annually, include fossils, current cultures from around the world, and interactive programming demonstrating today's urgent conservation needs. The museum is named in honor of its first major benefactor, Marshall Field, the department-store magnate. The museum and its collections originated from the 1893 World's Columbian Exposition and the artifacts displayed at the fair. The museum maintains a temporary exhibition program of traveling shows as well as in-house produced topical exhibitions. The professional staff maintains collections of over 24 million specimens and objects tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therapsids
Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more underneath the body, as opposed to the sprawling posture of many reptiles and salamanders. Therapsids evolved from "pelycosaurs", specifically within the Sphenacodontia, more than 279.5 million years ago. They replaced the "pelycosaurs" as the dominant large land animals in the Middle Permian through to the Early Triassic. In the aftermath of the Permian–Triassic extinction event, therapsids declined in relative importance to the rapidly diversifying reptiles during the Middle Triassic. The therapsids include the cynodonts, the group that gave rise to mammals ( Mammaliaformes) in the Late Triassic, around 225 million years ago. Of the non-mammalian therapsids, only cynodonts survived beyond the end of the Triassic, with the only othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant species of mammals have been described divided into 29 orders. The largest orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla ( cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, seals, and others). In terms of cladistics, which reflects evolutionary history, mammals are the only living members of the Synapsida (synapsids); this clade, together with Saur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids ( reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
