|
Neural Spine Sail
A neural spine sail is a large, flattish protrusion from the back of an animal formed of a sequence of extended vertebral spinous processes and associated tissues. Such structures are comparatively rare in modern animals, but have been identified in many extinct species of amphibians and amniotes. Paleontologists have proposed a number of ways in which the sail could have functioned in life. Function Varying suggestions have been made for the function of the sail. Thermoregulation The structure may have been used for thermoregulation. The base of the spines have a channel which may have contained a blood vessel supplying abundant blood to the sail. The animal could have used the sail's large surface area to absorb heat from the sun in the morning. As ectotherms they required heat from an external source before their muscles would start to function properly. A predator would thus have an advantage over its slower moving prey. The sail could be used in reverse if the animal wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimetrodon Incisivum 01
''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] |
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] |
Lotosauridae
''Lotosaurus'' is an extinct genus of sail-backed poposauroid known from Hunan Province of central China. Discovery ''Lotosaurus'' is known from the holotype IVPP V 4881 (or possibly V 4880), an articulated and well-preserved skeleton. Other referred specimens include IVPP V 48013 (a skull) as well as many articulated and disarticulated skeletal remains concentrated in a bonebed which is almost completely composed of ''Lotosaurus'' bones. All known specimens of this genus were collected from this bonebed, known as the ''Lotosaurus'' site, which belongs to the Batung Formation (or alternatively Xinlingzhen Formation of the Badong Group). Further excavations in 2018 revealed many more specimens, as well as geological and environmental details of the ''Lotosaurus'' site. At least 38 individuals of various ages died within this one location. ''Lotosaurus'' was first named by Fa-kui Zhang in 1975 and the type species is ''Lotosaurus adentus''. ''Lotosaurus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenosauriscidae
Ctenosauriscidae is an extinct family (biology), family of pseudosuchian archosaurs within the clade Poposauroidea. Ctenosauriscids existed in Africa, Asia, Europe and North America during the Early Triassic to the Middle Triassic period (latest Olenekian to Anisian stages). All species had large "sails" on their backs. Ctenosauriscids are among some of the earliest archosaurs and represent the first global radiation of the group. Genera Phylogeny Ctenosauriscidae was named by Oskar Kuhn in 1964 in paleontology, 1964 to include the genus ''Ctenosauriscus''. It is a stem-based taxon defined by Richard J. Butler, Stephen L. Brusatte, Mike Reich, Sterling J. Nesbitt, Rainer R. Schoch and Jahn J. Hornung in 2011 as "the most inclusive clade containing ''Ctenosauriscus koeneni'' but not ''Poposaurus gracilis'', ''Effigia okeeffeae'', ''Postosuchus kirkpatricki'', ''Crocodylus niloticus'', ''Ornithosuchus longidens'', or ''Aetosaurus ferratus''". The cladograms below follows a 2011 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poposauroidea
Poposauroidea is a clade of advanced pseudosuchians (archosaurs closer to crocodilians than to dinosaurs). It includes poposaurids, shuvosaurids, ctenosauriscids, and other unusual pseudosuchians such as ''Qianosuchus'' and ''Lotosaurus''. However, it excludes most large predatory quadrupedal "rauisuchians" such as rauisuchids and "prestosuchids". Those reptiles are now allied with crocodylomorphs (crocodile ancestors) in a clade known as Loricata, which is the sister taxon to the poposauroids in the clade Paracrocodylomorpha. Although it was first formally defined in 2007, the name "Poposauroidea" has been used for many years. The group has been referred to as Poposauridae by some authors, although this name is often used more narrowly to refer to the family that includes ''Poposaurus'' and its close relatives. Poposauroids went extinct at the end of the Triassic period along with other non-crocodylomorph pseudosuchians. However, they were among the most diverse and long-lasting ... [...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] |
Edaphosauridae
Edaphosauridae is a family of mostly large (up to 3 meters or more) Late Carboniferous to Early Permian synapsids. Edaphosaur fossils are so far known only from North America and Europe. Characteristics They were the earliest known herbivorous amniotes and, along with the Diadectidae, the earliest known herbivorous tetrapods. The head is small in relation to the bulky body, and there is a tall sail along the back, which may have functioned as a thermoregulatory device. Classification The interrelationships of Edaphosauridae was investigated in details by David M. Mazierski and Robert R. Reisz (2010). The cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... below is modified after their phylogenetic analysis. Below is a cladogram modified from the analysis of Benson (in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platyhystrix
''Platyhystrix'' (from el, πλατύς , 'flat' and el, ῠ̔́στρῐξ , 'porcupine') was a temnospondyl amphibian with a distinctive sail along its back, similar to the unrelated synapsids, ''Dimetrodon'' and ''Edaphosaurus''. It lived during the boundary between the latest Carboniferous and earliest Permian periods in Red Beds of Texas and Oklahoma, Texas, about 300 million years ago. Palaeobiology ''Platyhystrix'' may have been preyed upon by larger temnospondyls such as ''Eryops'', or by larger carnivorous reptiles, which were becoming more common and diverse in the drier climate of the Permian. The skull was large and strongly built, with a frog-like face. ''Platyhystrix'' had a compact body, reaching long including the tail, and its short, sturdy legs indicate a mainly terrestrial life. ''Platyhystrix'' appeared rather unusual: the dorsal vertebrae were extraordinarily lengthened, and in life they probably formed a skin-covered sail. This structure was possibly for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinosaurus In Japan Expo
''Spinosaurus'' (; ) is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian stages of the Late Cretaceous period, about 99 to 93.5 million years ago. The genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. The original remains were destroyed in World War II, but additional material came to light in the early 21st century. It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is ''S. aegyptiacus'' from Egypt, although a potential second species, ''S. maroccanus'', has been recovered from Morocco. The contemporary spinosaurid genus ''Sigilmassasaurus'' has also been synonymized by some authors with ''S. aegyptiacus'', though other researchers propose it to be a distinct taxon. Another possible junior synonym is ''Oxalaia'' from the Alcântara Formation in Brazil. ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horn (anatomy)
A horn is a permanent pointed projection on the head of various animals that consists of a covering of keratin and other proteins surrounding a core of live bone. Horns are distinct from antlers, which are not permanent. In mammals, true horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae (pronghorn) and Bovidae (cattle, goats, antelope etc.). Cattle horns arise from subcutaneous connective tissue (under the scalp) and later fuse to the underlying frontal bone. One pair of horns is usual; however, two or more pairs occur in a few wild species and in some domesticated breeds of sheep. Polycerate (multi-horned) sheep breeds include the Hebridean, Icelandic, Jacob, Manx Loaghtan, and the Navajo-Churro. Horns usually have a curved or spiral shape, often with ridges or fluting. In many species, only males have horns. Horns start to grow soon after birth and continue to grow throughout the life of the animal (except in pronghorns, which shed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
