Tichvinskia Temporal range: Early Triassic | |
---|---|
Tichvinskia vjatkensis | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | † Parareptilia |
Order: | † Procolophonomorpha |
Family: | † Procolophonidae |
Genus: | † Tichvinskia Ivakhnenko, 1973 |
Type species | |
†Tichvinskia vjatkensis Ivakhnenko, 1973 |
Tichvinskia is an extinct genus of procolophonid parareptile from the Early Triassic of Russia. [1]
The Mesozoic Era, also called the Age of Reptiles and the Age of Conifers, is the second-to-last era of Earth's geological history, lasting from about 252 to 66 million years ago and comprising the Triassic, Jurassic and Cretaceous periods. It is characterized by the dominance of archosaurian reptiles, like the dinosaurs; an abundance of conifers and ferns; a hot greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of three eras since complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic.
The Phanerozoic Eon is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 541 million years to the present, and it began with the Cambrian Period when animals first developed hard shells preserved in the fossil record. The time before the Phanerozoic, called the Precambrian, is now divided into the Hadean, Archaean and Proterozoic eons.
The Permian–Triassicextinction event, also known as the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as well as between the Paleozoic and Mesozoic eras, approximately 251.9 million years ago. It is the Earth's most severe known extinction event, with the extinction of 57% of biological families, 83% of genera, 81% of marine species and 70% of terrestrial vertebrate species. It was the largest known mass extinction of insects.
The Triassic is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.36 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.
The Triassic–Jurassic (Tr-J) extinction event, sometimes called the end-Triassic extinction, marks the boundary between the Triassic and Jurassic periods, 201.3 million years ago, and is one of the major extinction events of the Phanerozoic eon, profoundly affecting life on land and in the oceans. In the seas, the entire class of conodonts and 23–34% of marine genera disappeared. On land, all archosauromorphs other than crocodylomorphs, pterosaurs, and dinosaurs went extinct; some of the groups which died out were previously abundant, such as aetosaurs, phytosaurs, and rauisuchids. Some remaining non-mammalian therapsids and many of the large temnospondyl amphibians had gone extinct prior to the Jurassic as well. However, there is still much uncertainty regarding a connection between the Tr-J boundary and terrestrial vertebrates, due to a paucity of terrestrial fossils from the Rhaetian (latest) stage of the Triassic. What was left fairly untouched were plants, dinosaurs, pterosaurs and mammals; this allowed the dinosaurs and pterosaurs to become the dominant land animals for the next 135 million years.
Therapsida is a major group of eupelycosaurian synapsids that includes mammals and their ancestors. 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. The earliest fossil attributed to Therapsida used to be Tetraceratops insignis from the Lower Permian. However in 2020, a new study has found that Tetraceratops is not actually a true Therapsid, but should be considered to be a member of the more ancient Sphenacodontia from which the therapsids evolved.
The cynodonts are a clade of therapsids that first appeared in the Late Permian, and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variety of lifestyles, including carnivory and herbivory. Mammals are cynodonts, as are their extinct ancestors and close relatives, having evolved from advanced probainognathian cynodonts during the Late Triassic. All other cynodont lines went extinct, with the last known non-mammalian cynodont group, the Tritylodontidae having its last records in the Early Cretaceous.
Herrerasauridae is a family of carnivorous basal saurischian dinosaurs. They are among the oldest known dinosaurs, first appearing in the fossil record around 233.23 million years ago, before becoming extinct by the end of the Triassic period. Herrerasaurids were relatively small-sized dinosaurs, normally no more than 4 metres (13 ft) long, although the holotype specimen of "Frenguellisaurus ischigualastensis" is thought to have reached around 6 meters long. The best known representatives of this group are from South America, where they were first discovered in the 1930s in relation to Staurikosaurus and 1960s in relation to Herrerasaurus. A nearly complete skeleton of Herrerasaurus ischigualastensis was discovered in the Ischigualasto Formation in San Juan, Argentina, in 1988. Less complete possible herrerasaurids have been found in North America, and they may have inhabited other continents as well.
The Early Jurassic epoch is the earliest of three epochs of the Jurassic period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma, and ends at the start of the Middle Jurassic 174.1 Ma.
Lepidosauromorpha is a group of reptiles comprising all diapsids closer to lizards than to archosaurs. The only living sub-group is the Lepidosauria, which contains two subdivisions, Squamata, which contains lizards and snakes, and Rhynchocephalia, the only extant species of which is the tuatara.
Lystrosaurus is an extinct genus of herbivorous dicynodont therapsids from the late Permian and Early Triassic epochs. It lived in what is now Antarctica, India, China, Mongolia, European Russia and South Africa. Four to six species are currently recognized, although from the 1930s to 1970s the number of species was thought to be much higher. They ranged in size from that of a small dog to 2.5 meters long.
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between 251.902 Ma and 247.2 Ma. Rocks from this epoch are collectively known as the Lower Triassic series, which is a unit in chronostratigraphy.
In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between 247.2 Ma and 237 Ma. It is preceded by the Early Triassic epoch and followed by the Late Triassic epoch. The Middle Triassic is divided into the Anisian and Ladinian ages or stages.
The Late Triassic is the third and final epoch of the Triassic Period in the geologic timescale. The Triassic-Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. The corresponding series is known as the Upper Triassic. In Europe the epoch was called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age. The Late Triassic spans the time between 237 Ma and 201.3 Ma. It is preceded by the Middle Triassic epoch and is followed by the Early Jurassic epoch. The Late Triassic is divided into the Carnian, Norian and Rhaetian ages.
Dinosauromorpha is a clade of avemetatarsalian archosaurs that includes the Dinosauria (dinosaurs) and some of their close relatives. It was originally defined to include dinosauriforms and lagerpetids, with later formulations specifically excluding pterosaurs from the group. Birds are the only dinosauromorphs which survive to the present day.
Procolophon is a genus of lizard-like procolophonid reptiles that first appeared in the Late Permian (Lopingian) of South Africa, Brazil, and Antarctica. It persisted through the Permian–Triassic extinction event, but went extinct in the early Triassic. The type species is P. trigoniceps.
Lapillopsidae is a family of Temnospondyli.
Kuehneosauridae is an extinct family of small, lizard-like gliding diapsids known from the Triassic period of Europe and North America. They are distinguished from other diapsids by their 'wings' formed by elongated ribs. These allowed the animal to glide and parachute similar to living gliding lizards. They were most likely insectivorous, judging from their pin-like teeth. They are often, but not always, placed in the group Lepidosauromorpha, though other studies have recovered them in other positions within Sauria, including Archosauromorpha. The oldest and most primitive known member is Pamelina from the Early Triassic of Poland, which already has vertebrae with characteristics consistent with gliding or parachuting. Icarosaurus is known from a single specimen from the Carnian-aged Lockatong Formation of New Jersey. The Late Triassic kuehneosaurids from England, Kuehneosaurus and Kuehneosuchus, are very similar and can be distinguished from one another primarily on the length of their "wing" ribs, relatively short and massive in Kuehneosaurus but longer and more gracile in Kuehneosuchus. Kuehneosaurus was likely only capable of parachuting, while Kuehneosuchus could probably glide. Rhabdopelix may have been a kuehneosaurid; however, the fossils were lost, and the characteristics described are not entirely consistent with the other family members.
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.
Kapes is an extinct genus of procolophonid parareptile from the Lower and Middle Triassic of the United Kingdom and Russia. It is a member of the subfamily Procolophoninae. The type species K. amaenus was named in 1975 from the banks of the Vychegda River in the Komi Republic of Russia. In 1983, a new species was brought into the genus, K. majmesculae. K. majmesculae was first named in 1968 as a member of the genus Tichvinskia. A third Russian species, K. serotinus, was named in 1991. In 2002, Kapes bentoni was named from the Middle Triassic Otter Sandstone Formation of Devon, England, extending the geographic range of Kapes. In the same paper, K. serotinus was synonymized with K. majmesculae and another Russian species was assigned to Kapes called K. komiensis. K. komiensis was first named in 1975 as a member of the genus Macrophon.