| Thoracoceras |
Temporal range: Carboniferous - L Permian
|Genus:|| Thoracoceras |
Thoracoceras is an extinct genus of orthocerids from the family Kionoceratidae characterized by orthoconic shells marked by prominent longitudinal rounded grooves separated by angular ridges, each which has a single row of blunt spines along its apex, and having a small submarginal siphuncle.
Orthocerida is an order of extinct Orthoceratoid cephalopods also known as the Michelinocerda that lived from the Early Ordovician possibly to the Late Triassic. A fossil found in the Caucasus suggests they may even have survived until the Early Cretaceous. They were most common however from the Ordovician to the Devonian.
Kionoceratidae is a family in the Orthocerida, proposed by Hyatt in 1900 for genera characterized by prominent ornamentation in the form of longitudinal ribs, ridges, or lirae, or combinations thereof, sometimes with similar transverse ornament or faint transverse annulations.
The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and Spirula. In the case of the cuttlefish, the siphuncle is indistinct and connects all the small chambers of that animal's highly modified shell; in the other cephalopods it is thread-like and passes through small openings in the walls dividing the chambers.
Thoracoceras, named by Fischer De Waldheim in 1844, is found in Carboniferous and Lower Permian sediments in the U.S., Europe, and Russia. It is closely related to Kionoceras , Ohioceras , and Polygrammoceras
The Carboniferous is a geologic period and system that spans 60 million years from the end of the Devonian Period 358.9 million years ago (Mya), to the beginning of the Permian Period, 298.9 Mya. The name Carboniferous means "coal-bearing" and derives from the Latin words carbō ("coal") and ferō, and was coined by geologists William Conybeare and William Phillips in 1822.
The Permian is a geologic period and 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 city of Perm.
Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus. Before being deposited, the geological detritus was formed by weathering and erosion from the source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers, which are called agents of denudation. Biological detritus was formed by bodies and parts of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies. Sedimentation may also occur as dissolved minerals precipitate from water solution.
The Dugongidae are a family in the order of Sirenia. The family has one surviving species, the dugong, one recently extinct species, Steller's sea cow, and a number of extinct genera known from fossil records.
Orthoceras is a genus of extinct nautiloid cephalopod restricted to Middle Ordovician-aged marine limestones of the Baltic States and Sweden. This genus is sometimes called Orthoceratites. Note it is sometimes misspelled as Orthocera, Orthocerus or Orthoceros.
Cormohipparion is an extinct genus of horse belonging to the tribe Hipparionini that lived in North America during the late Miocene to Pliocene.
Euclastes is an extinct genus of sea turtles that survived the Cretaceous–Paleogene mass extinction. The genus was first named by Edward Drinker Cope in 1867, and contains three species. E. hutchisoni, was named in 2003 but has since been reassigned to the genus Pacifichelys, while E. coahuilaensis named in 2009 was reassigned as Mexichelys coahuilaensis in 2010.
A caiman is an alligatorid crocodilian belonging to the subfamily Caimaninae, one of two primary lineages within Alligatoridae, the other being alligators.
Chelydrops is an extinct genus of Chelydridae from Miocene of North America. Only one species is described, Chelydrops stricta.
Coahomasuchus is an extinct genus of aetosaurine stagonolepidid aetosaur. Remains of the genus have been found from deposits in Texas and North Carolina that date to the Otischalkian faunachron of the Late Triassic. It was small for an aetosaur, being less than 1.5 metres long. The dorsal plates are distinctively flat and unflexed, and have a faint sub-parallel to radial ornamentation. The genus lacked spines or keels on these plates, features seen in many other aetosaurs. Coahomasuchus was very similar in appearance to the closely related Aetosaurus.
Dyoplax is an extinct genus of pseudosuchian archosaur. Fossils have been found from the type locality within the upper Schilfsandstein Formation in Stuttgart, Germany. The formation was deposited during the early Carnian stage of the Late Triassic 228 million years ago in a lagoonal paleoenvironment. Numerous bivalves, chondrichthyean fish such as Palaeobates, trematosaurian temnospondyls such as Metoposaurus, a phytosaur, and plants such as Neocalamites and Equisetites were also present in the paleoenvironment that existed at the time. The holotype specimen was a cast of a nearly complete skeleton that lacked only parts of the tail and limb bones.
Eopneumatosuchus is an extinct genus of basal crocodyliform. Fossils have been found from two localities within the Kayenta Formation of Arizona. Both localities are around 20 miles southeast of the Grand Canyon and in close proximity to one another. The localities probably date back to the Early Jurassic, most likely during the Sinemurian stage.
Bolotridon is an extinct genus of epicynodontian cynodont. It was renamed from its original genus designation of Tribolodon, which was already occupied by a genus of cyprinid fish named in 1883 by Sauvage. The name Bolotridon was coined by Brian W. Coad in a 1977 publication as an anagram of Tribolodon.
Ulemica is an extinct genus of venjukoviid therapsids. It was a basal member of the suborder Anomodontia that existed during the Middle Permian in Russia. The type species, U. invisa, was assigned to the genus Venjukovia prior to being placed within its own genus in 1996. This small anomonodont is only known from a partial skull.
Lumkuia is an extinct genus of probainognathian cynodonts. It is the earliest and most basal known member of Probainognathia, with fossils being found from the Cynognathus Assemblage Zone of the Beaufort Group in the South African Karoo Basin that date back to the early Middle Triassic. Lumkuia is not as common as other cynodonts from the same locality such as Diademodon and Trirachodon. Previously, early probainognathians were only known from younger strata in South America that were deposited in the late Middle and Late Triassic. The genus has been placed in its own family, Lumkuiidae.
Micropholis is an extinct genus of dissorophoid temnospondyl. Fossils have been found from the Lystrosaurus Assemblage Zone of the Karoo Basin in South Africa, and date back to the Early Triassic.
Procolophonoidea is an extinct superfamily of procolophonian parareptiles. Members were characteristically small, stocky, and lizard-like in appearance. Fossils have been found worldwide from many continents including Antarctica. The first members appeared during the Late Permian in the Karoo Basin of South Africa.
Pseudhesperosuchus is a genus of sphenosuchian, a type of basal crocodylomorph, the clade that comprises the crocodilians and their closest kin. It is known from a partial skeleton and skull found in rocks of the Norian-age Upper Triassic Los Colorados Formation, Argentina.
Mandasuchus is an extinct genus of loricatan pseudosuchian from the Manda Formation of Tanzania, which dates back to the Ladinian or Anisian stage of the Middle Triassic.
Parrishia is an extinct genus of sphenosuchian crocodylomorph known from the Late Triassic Chinle, Dockum, and Santa Rosa Formations in Arizona and New Mexico.
Astrophocaudia is a genus of somphospondylan sauropod known from the late Early Cretaceous of Texas, United States. Its remains were discovered in the Trinity Group. The type species is Astrophocaudia slaughteri, described in 2012 by Michael D. D’Emic while a doctoral student at the Museum of Paleontology of the University of Michigan, USA.
Montirictus is an extinct genus of tritylodonts known from the Early Cretaceous Kuwajima Formation of Japan. It is currently the latest surviving tritylodontid species, and is closely relates to the earlier Xenocretosuchus from mainland Asia, and the Jurassic Stereognathus from the UK. It may be a species of the genus Stereognathus, but resolution of its affinities conditions upon the discovery of additional material.
The Treatise on Invertebrate Paleontology published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and covering every phylum, class, order, family, and genus of fossil and extant invertebrate animals. The prehistoric invertebrates are described as to their taxonomy, morphology, paleoecology, stratigraphic and paleogeographic range. However, genera with no fossil record whatsoever have just a very brief listing.
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