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Pariguana
''Pariguana'' (meaning "near ''Iguana''" in Greek) is an extinct genus of iguanid lizard from the Late Cretaceous of western North America. It is known from a single type species, ''Pariguana lancensis'', named in 2012 on the basis of a partial lower jaw from the Lance Formation in eastern Wyoming. This jaw bone comes from a layer dated approximately 650,000 years before the Cretaceous–Paleogene extinction event. ''Pariguana'' is the oldest definitive iguanid from North America, and may represent the first stage of the iguanian evolutionary radiation An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, that may or may not be associated with an increase in morphological disparity. Radiations may affect one clade or many, and be rapid ... from Asia into North America. References Cretaceous lizards Iguanidae Late Cretaceous lepidosaurs of North America Fossil taxa described in 2012 {{paleo-lizard-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguanidae
The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana. Taxonomy Iguanidae is thought to be the sister group to the collared lizards (family Crotaphytidae); the two groups likely diverged during the Late Cretaceous, as that is when ''Pristiguana'' and ''Pariguana'', the two earliest fossil genera, are known from. The subfamily Iguaninae, which contains all modern genera, likely originated in the earliest Paleocene, at about 62 million years ago. The most basal extant genus, '' Dipsosaurus,'' diverged from the rest of Iguaninae during the late Eocene, about 38 million years ago, with '' Brachylophus'' following a few million years later at about 35 million years ago, presumably after its dispersal event to the Pacific. All other modern iguana genera formed in the Neogene period. A phylogenetic tree of Iguaninae is shown here: Description Iguanas and iguana-type species are divers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguanid
The Iguanidae is a family of lizards composed of the iguanas, chuckwallas, and their prehistoric relatives, including the widespread green iguana. Taxonomy Iguanidae is thought to be the sister group to the collared lizards (family Crotaphytidae); the two groups likely diverged during the Late Cretaceous, as that is when ''Pristiguana'' and ''Pariguana'', the two earliest fossil genera, are known from. The subfamily Iguaninae, which contains all modern genera, likely originated in the earliest Paleocene, at about 62 million years ago. The most basal extant genus, '' Dipsosaurus,'' diverged from the rest of Iguaninae during the late Eocene, about 38 million years ago, with ''Brachylophus'' following a few million years later at about 35 million years ago, presumably after its dispersal event to the Pacific. All other modern iguana genera formed in the Neogene period. A phylogenetic tree of Iguaninae is shown here: Description Iguanas and iguana-type species are diverse i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2012 In Paleontology
Note: In 2012, the International Code of Zoological Nomenclature was amended, with new regulations allowing the publication of new names and nomenclatural acts in zoology after 2011, in works "produced in an edition containing simultaneously obtainable copies by a method that assures (...) widely accessible electronic copies with fixed content and layout", provided that the work is registered in ZooBank before it is published, the work itself states the date of publication with evidence that registration has occurred, and the ZooBank registration states both the name of an electronic archive intended to preserve the work and the ISSN or ISBN associated with the work. New scientific names appearing in electronic works are not required to be registered in ZooBank, only the works themselves are. Works containing descriptions of some of the taxa listed below were not printed on paper in 2012; however, the taxa that were described in works which were registered in ZooBank in 2012 are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguana
''Iguana'' (, ) is a genus of herbivorous lizards that are native to tropical areas of Mexico, Central America, South America, and the Caribbean. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti in his book ''Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena''. Two species are placed in the genus, the green iguana, which is widespread throughout its range and a popular pet, and the Lesser Antillean iguana, which is native to the Lesser Antilles. Genetic analysis indicates that the green iguana may comprise a complex of multiple species, some of which have been recently described, but the Reptile Database considers all of these as subspecies of the green iguana. The word "iguana" is derived from the original Taino name for the species, ''iwana''. In addition to the two species in the genus ''Iguana'', several other related genera in the same family have common names of the species including the word "ig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Language
Greek ( el, label=Modern Greek, Ελληνικά, Elliniká, ; grc, Ἑλληνική, Hellēnikḗ) is an independent branch of the Indo-European family of languages, native to Greece, Cyprus, southern Italy (Calabria and Salento), southern Albania, and other regions of the Balkans, the Black Sea coast, Asia Minor, and the Eastern Mediterranean. It has the longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system is the Greek alphabet, which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic, and many other writing systems. The Greek language holds a very important place in the history of the Western world. Beginning with the epics of Homer, ancient Greek literature includes many works of lasting impo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia although some lizards are more closely related to these two excluded groups than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3-meter-long Komodo dragon. Most lizards are quadrupedal, running with a strong side-to-side motion. Some lineages (known as "legless lizards"), have secondarily lost their legs, and have long snake-like bodies. Some such as the forest-dwelling ''Draco'' lizards are able to glide. They are often territorial, the males fighting off other males and signalling, often with bright colours, to attract mates and to intimidate rivals. Lizards are mainly carnivorous, often being sit-and-wait predators; many smaller species eat insects, while the Komodo eats mammals a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s). Article 67.1 A similar concept is used for suprageneric groups and called a type genus. In botanical nomenclature, these terms have no formal standing under the code of nomenclature, but are sometimes borrowed from zoological nomenclature. In botany, the type of a genus name is a specimen (or, rarely, an illustration) which is also the type of a species name. The species name that has that type can also be referred to as the type of the genus name. Names of genus and family ranks, the various subdivisions of those ranks, and some higher-rank names based on genus names, have such types. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lance Formation
The Lance (Creek) Formation is a division of Late Cretaceous (dating to about 69 - 66 Ma) rocks in the western United States. Named after Lance Creek, Wyoming, the microvertebrate fossils and dinosaurs represent important components of the latest Mesozoic vertebrate faunas. The Lance Formation is Late Maastrichtian in age (Lancian land mammal age), and shares much fauna with the Hell Creek Formation of Montana and North Dakota, the Frenchman Formation of southwest Saskatchewan, and the lower part of the Scollard Formation of Alberta. The Lance Formation occurs above the ''Baculites clinolobatus'' ammonite marine zone in Wyoming, the top of which has been dated to about 69 million years ago, and extends to the K-Pg boundary, 66 million years ago. However, the characteristic land vertebrate fauna of the Lancian age (which take its name from this formation) is only found in the upper strata of the Lance, roughly corresponding to the thinner equivalent formations such as the Hell C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous–Paleogene Extinction Event
The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary extinction) was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. With the exception of some ectothermic species such as sea turtles and crocodilians, no tetrapods weighing more than survived. It marked the end of the Cretaceous Period, and with it the Mesozoic era, while heralding the beginning of the Cenozoic era, which continues to this day. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the K–Pg boundary, which can be found throughout the world in marine and terrestrial rocks. The boundary clay shows unusually high levels of the metal iridium, which is more common in asteroids than in the Earth's crust. As originally proposed in 1980 by a team of scientists led by Luis Alvarez and his son Walter, it is now generally thought that the K–Pg extinction was cause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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