Megactenopetalus Temporal range: | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Holocephali |
Order: | † Petalodontiformes |
Family: | † Pristodontidae |
Genus: | † Megactenopetalus David, 1944 |
Megactenopetalus is an extinct genus of petalodont fish which lived from the late Early Permian through the Late Permian. [1] It is known from a single species: M. kaibabanus. It was one of the last and largest petalodonts; estimates place it at 1.6 meters or 5.2 feet in length with a 20 centimeter or 7 inch mouth. It is known from the southwest of the United States, the Middle East, and China. The holotype was an upper left dentary which came from the Kaibab Formation on the northern rim of the Grand Canyon. [2] It is probably closely related to Ctenoptychius . [3]
The Permian is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period 298.9 million years ago (Mya), to the beginning of the Triassic Period 251.902 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 Triassic is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic.
Therapsida is a clade comprising a major group of eupelycosaurian synapsids that includes mammals and their ancestors and close 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, resulting in a more "standing" quadrupedal posture, as opposed to the lower sprawling posture of many reptiles and amphibians.
Janassa is an extinct genus of petalodont cartilaginous fish that lived in marine environments in what is now central United States of America and Europe during the Carboniferous and upper Permian.
Petalodontiformes is an extinct order of marine cartilaginous fish related to modern day chimaera found in what is now the United States of America and Europe.
Campylocephalus is a genus of eurypterid, a group of extinct aquatic arthropods. Fossils of Campylocephalus have been discovered in deposits ranging from the Carboniferous period in the Czech Republic to the Permian period of Russia. The generic name is composed of the Greek words καμπύλος (kampýlos), meaning "curved", and κεφαλή (kephalē), meaning "head".
Gnathorhiza is an extinct genus of prehistoric lobe-finned fish (lungfish) which lived from the Carboniferous period to the Early Triassic epoch. It is the only known lungfish genus to have crossed the Permo-Triassic boundary. Several species have been described, ranging in size from 5 to 50 centimeters.
Knoxosaurus is an extinct genus of non-mammalian synapsids containing the species Knoxosaurus niteckii that existed approximately 279.5 to 268 million years ago. It was named by American paleontologist Everett C. Olson in 1962 on the basis of fragmentary fossils from Middle Permian-age deposits in the San Angelo Formation of Texas in the United States. Olson placed Knoxosaurus in a new infraorder called Eotheriodontia, which he considered a transitional group between the more reptile-like "pelycosaurs" and the more mammal-like therapsids. Knoxosaurus and Olson's other eotheriodonts were later considered to be undiagnostic remains of basal synapsids, no more closely related to therapsids than are other pelycosaur-grade synapsids.
Oromycter is an extinct genus of caseid synapsids from the Early Permian of Oklahoma. The sole and type species, Oromycter dolesorum, was named in 2005 by Robert R. Reisz.
Paleontology in Oklahoma refers to paleontological research occurring within or conducted by people from the U.S. state of Oklahoma. Oklahoma has a rich fossil record spanning all three eras of the Phanerozoic Eon. Oklahoma is the best source of Pennsylvanian fossils in the United States due to having an exceptionally complete geologic record of the epoch. From the Cambrian to the Devonian, all of Oklahoma was covered by a sea that would come to be home to creatures like brachiopods, bryozoans, graptolites and trilobites. During the Carboniferous, an expanse of coastal deltaic swamps formed in areas of the state where early tetrapods would leave behind footprints that would later fossilize. The sea withdrew altogether during the Permian period. Oklahoma was home a variety of insects as well as early amphibians and reptiles. Oklahoma stayed dry for most of the Mesozoic. During the Late Triassic, carnivorous dinosaurs left behind footprints that would later fossilize. During the Cretaceous, however, the state was mostly covered by the Western Interior Seaway, which was home to huge ammonites and other marine invertebrates. During the Cenozoic, Oklahoma became home to creatures like bison, camels, creodonts, and horses. During the Ice Age, the state was home to mammoths and mastodons. Local Native Americans are known to have used fossils for medicinal purposes. The Jurassic dinosaur Saurophaganax maximus is the Oklahoma state fossil.
The Kupferschiefer or Kupfermergel, is an extensive and remarkable sedimentary unit in Central Europe. The relatively monotonous succession is typically 30 to 60 centimetres and maximum 2 metres (6.6 ft) thick, but extends over an area of 600,000 square kilometres (230,000 sq mi) across the Southern Permian Basin. The Kupferschiefer can be found in outcrop or in the subsurface straddling six countries, including parts of the southern North Sea. The lateral equivalent outcropping in England is called Marl Slate.
The Corona Formation is a geologic formation of the Carnian Alps at the border of Austria and Italy. It preserves fossils dated to the Gzhelian stage of the Late Carboniferous period.
Corystosperms are a group of extinct seed plants belonging to the family Corystospermaceae assigned to the order Corystospermales or Umkomasiales. They were first described based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. Corystosperms are typified by a group of plants that bore forked Dicroidium leaves, Umkomasia cupulate ovulate structures and Pteruchus pollen organs, which grew as trees that were widespread over Gondwana during the Middle and Late Triassic. Other fossil Mesozoic seed plants with similar leaf and/or reproductive structures have also sometimes been included within the "corystosperm" concept sensu lato, such as the "doyleoids" from the Early Cretaceous of North America and Asia. A potential corystosperm sensu lato, the leaf genus Komlopteris, is known from the Eocene of Tasmania, around 53-50 million years old, over 10 million years after the Cretaceous–Paleogene extinction event.
The Whitehill Formation, alternatively written as White Hill Formation and formerly known as White Band or Whitehill or White Hill Member, is a regional Early Permian geologic formation belonging to the Ecca Group in the southeastern ǁKaras Region of southeastern Namibia and Eastern, Northern and Western Cape provinces of South Africa.
Antliodus is an extinct genus of petalodont from the Carboniferous Period. It is known from the Mississippian of the United States, Britain, and Belgium Though many species have been reported in the past, a lack of recent revisions means some may be dubious.
Bransonella is an extinct genus of marine Xenacanth which lived during the Paleozoic era. It is known only from teeth which are easily distinguished from related genera by ornamentation on the cusp shaped like an inverted "V" and fin spines Teeth attributed to this genus are small, no greater than 2 millimeters. This suggests a small body size likely not exceeding a meter in length. It has been suggested their lifestyle was similar to modern Catsharks. It was used to erect a new order along with Barbclabornia based on ornamentation.
Ictidosaurus was a therapsid genus found in the Abrahamskraal Formation of South Africa, which lived during the middle Permian period. Fossils of the type species were found in the Tapinocephalus, and the base of the Eodicynodon assembly zones, of the Karoo Basin. Older classifications of the species, along with many other specimens found in the Iziko South African Museum archives, were originally classified within therocephalian family names, in this case the Ictidosauridae, which has been reclassified as belonging to the Scylacosauridae. The type species is I. angusticeps.
Geinitziidae is an extinct family of polyneopteran insects, known from the Permian to Cretaceous. They are currently considered to be members "Grylloblattida" a poorly defined group of extinct insects thought to be related to modern ice crawlers (Grylloblattidae). Other authors place them in the extinct order Reculida. Unlike modern ice crawlers, which are wingless, they had large wings, bearing a superficial resemblance to cockroaches, and are thought to have been day-active above ground predators.