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Avisaurus
''Avisaurus'' (meaning "bird lizard") is a genus of enantiornithine bird from the Late Cretaceous of North America. Discovery ''Avisaurus archibaldi'' was discovered in the Late Cretaceous Hell Creek Formation of North America (Maastrichtian, from c.70.6-66 million years ago), making it one of the last enantiornithids. It was collected in 1975 in the UCMP locality V73097, in Garfield County, Montana, USA. The holotype is represented by a single fossil of a tarsometatarsus in the collection of the University of California Museum of Paleontology. It has the catalog number UCMP 117600. The species name honors J. David Archibald, its discoverer, from The University of California, Berkeley. It was initially described as the left tarsometatarsus of a non-avian theropod by Brett-Surman and Paul in 1985. It was later redescribed as the right tarsometatarsus of an enantiornithine bird by Chiappe in 1992.Chiappe, Luis M. (1992) "Enantiornithine (Aves) Tarsometatarsi and the Avian Affinities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avisaurus And Brachychampsa By Tomozsaurus
''Avisaurus'' (meaning "bird lizard") is a genus of enantiornithine bird from the Late Cretaceous of North America. Discovery ''Avisaurus archibaldi'' was discovered in the Late Cretaceous Hell Creek Formation of North America (Maastrichtian, from c.70.6-66 million years ago), making it one of the last enantiornithids. It was collected in 1975 in the UCMP locality V73097, in Garfield County, Montana, USA. The holotype is represented by a single fossil of a tarsometatarsus in the collection of the University of California Museum of Paleontology. It has the catalog number UCMP 117600. The species name honors J. David Archibald, its discoverer, from The University of California, Berkeley. It was initially described as the left tarsometatarsus of a non-avian theropod by Brett-Surman and Paul in 1985. It was later redescribed as the right tarsometatarsus of an enantiornithine bird by Chiappe in 1992.Chiappe, Luis M. (1992) "Enantiornithine (Aves) Tarsometatarsi and the Avian Affinities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avisauridae
Avisauridae is a family of extinct enantiornithine dinosaurs from the Cretaceous period, distinguished by several features of their ankle bones. Depending on the definition used, Avisauridae is either a broad and widespread group of advanced enantiornithines (following Cau & Arduini, 2008), or a small family within that group, restricted to species from the Late Cretaceous of North and South America (following Chiappe, 1992). Description Avisaurids were among the largest and last enantiornithines to have lived, although they are also among the most poorly preserved. The majority of them are known primarily from fossilized tarsometatarsal bones, the part of a bird's leg formed by fused metatarsals (the bones which comprise the foot in humans). As a result, members of this family are distinguished from other enantiornithines exclusively by features of the tarsometatarsal and pedal phalanges (toe bones). Unlike in some prehistoric birds, avisaurid tarsometatarsals were not comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gettyia
''Gettyia'' is an extinct genus of avisaurid enantiornithean bird from the Late Cretaceous of North America. Description ''Gettyia'' is known from a single right tarsometatarsus. This bone was similar to that of other North American avisaurids such as ''Avisaurus'' and ''Mirarce'', but it was much smaller. The second metatarsal had a tubercule (knob-like structure) on its front edge, which likely connected to the ''tibialis cranialis'' muscle which flexes the ankle. Other avisaurids typically had this tubercule located midway on the shaft of the metatarsal, or closer to the ankle than the toes. ''Gettyia'', on the other hand, had its ''tibialis cranialis'' tubercule located more than halfway down the shaft. The third and fourth metatarsals are more extensively fused than in other avisaurids, as fusion occurs not only near the ankle, but also near the toes. Paleobiology The more distally placed ''tibialis cranialis'' tubercule of ''Gettyia'' suggests that it had a more spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enantiornithine
The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over eighty species of Enantiornithes have been named, but some names represent only single bones, so it is likely that not all are valid. The Enantiornithes became extinct at the Cretaceous–Paleogene boundary, along with Hesperornithes and all other non-avian dinosaurs. Discovery and naming The first Enantiornithes to be discovered were incorrectly referred to modern bird groups. For example, the first known species of Enantiornithes, ''Gobipteryx minuta'', was originally considered a paleognath related to ostriches and tinamou. The Enantiornithes were first recognized as a distinct lineage, or "subclass" of birds, by Cyril A. Walker in 1981. Walker mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enantiornithes
The Enantiornithes, also known as enantiornithines or enantiornitheans in literature, are a group of extinct avialans ("birds" in the broad sense), the most abundant and diverse group known from the Mesozoic era. Almost all retained teeth and clawed fingers on each wing, but otherwise looked much like modern birds externally. Over eighty species of Enantiornithes have been named, but some names represent only single bones, so it is likely that not all are valid. The Enantiornithes became extinct at the Cretaceous–Paleogene boundary, along with Hesperornithes and all other non-avian dinosaurs. Discovery and naming The first Enantiornithes to be discovered were incorrectly referred to modern bird groups. For example, the first known species of Enantiornithes, ''Gobipteryx minuta'', was originally considered a paleognath related to ostriches and tinamou. The Enantiornithes were first recognized as a distinct lineage, or "subclass" of birds, by Cyril A. Walker in 1981. Walker mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soroavisaurus
''Soroavisaurus'' is a genus of enantiornithean birds related to '' Avisaurus''. It lived during the Late Cretaceous of Argentina. The only known species, ''S. australis'', is known from fossils collected from the Lecho Formation (Maastrichtian age) of Estancia El Brete, in the southern tip of the province of Salta, Argentina. A binominal name of this animal means "Southern sister Avisaur". Description The specimens are in the collection of the Fundación-Instituto Miguel Lillo, Tucumán. They are cataloged as PVL-4690, a -long left tarsometatarsus, and PVL-4048, which includes another left tarsometatarsus, -long and associated with the whole hallux, or digit I, and four intermediate phalanges. PVL-4048 was previously described as ''"Avisaurus sp."'' (see '' Avisaurus'').Chiappe, Luis M. (1993) "Enantiornithine (Aves) Tarsometatarsi from the Cretaceous Lecho Formation of Northwestern Argentina." "American Museum Novitates" December 27, 1993 Number 3083, 27pp. PVL-4048, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuquenornis
''Neuquenornis volans''Chiappe, Luis M.,Calvo, Jorge O. (1994) "Neuquenornis volans, a New Late Cretaceous Bird (Enantiornithes: Avisauridae) from Patagonia, Argentina""Journal of Vertebrate Paleontology" Vol. 14, No. 2 (Jun. 22, 1994), pp. 230-246 https://www.jstor.org/stable/4523563 is a species of enantiornithean birds which lived during the late Cretaceous period in today's Patagonia, Argentina. It is the only known species of the genus ''Neuquenornis''. Its fossils were found in the Santonian Bajo de la Carpa Formation, dating from about 85-83 million years ago. This was a sizeable bird for its time, with a tarsometatarsus 46.8mm long. Informal estimates suggest that it measured nearly 30 cm (12 in) in length excluding the tai Etymology The naming means "Flying bird from Neuquén Province". ''Neuquenornis'', from Neuquén Province + Ancient Greek ''ornis'' (όρνις) "bird". ''volans'', Latin for "flying" in reference to the species' well-developed wing skel ... [...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] |
Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). The Cretaceous–Paleogene extinction event (formerly known as the Cretaceous–Tertiary extinction event) occurred at the end of this age. In this mass extinction, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as well as many other lesser-known groups, died out. The cause of the extinction is most commonly linked to an asteroid about wide colliding with Earth, ending the Cretaceous. Stratigraphic definitions Definition The Maastrichtian was introduced into scientific literature by Belgian geologist André Hubert Dumont in 1849, after studying rock strata of the Chalk Group c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern subregion of a single continent called America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana. In addition, the ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Ascension and Tristan da Cunha, a British Overseas Territory), Bouvet Island ( dependency of Norway), Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Interior Seaway
The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that split the continent of North America into two landmasses. The ancient sea, which existed from the early Late Cretaceous (100 million years ago) to the earliest Paleocene (66 Ma), connected the Gulf of Mexico, through the United States and Canada, to the Arctic Ocean. The two land masses it created were Laramidia to the west and Appalachia to the east. At its largest extent, it was deep, wide and over long. Origin and geology By Late-Cretaceous times, Eurasia and the Americas had separated along the south Atlantic, and subduction on the west coast of the Americas had commenced, resulting in the Laramide orogeny, the early phase of growth of the modern Rocky Mountains. The Western Interior Seaway may be seen as a downwarping of the continental crust ahead of the growing Laramide/Rockies mountain chain. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
