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Pseudasturidae
Halcyornithidae or Pseudasturidae is a family of fossil birds, possibly belonging to the order Psittaciformes (parrots and relatives). Members of this family lived in the Eocene, around 55-48 million years ago. Fossil remains are known from the Green River Formation in the United States and from the London Clay formation in the United Kingdom. They were probably the sister group to the owl-like Messelasturidae. Classification *'' Cyrilavis'' *'' Halcyornis'' *'' Pulchrapollia'' *'' Pseudasturides'' *''Precursor''? (probably a chimera Chimera, Chimaera, or Chimaira (Greek for " she-goat") originally referred to: * Chimera (mythology), a fire-breathing monster of Ancient Lycia said to combine parts from multiple animals * Mount Chimaera, a fire-spewing region of Lycia or Cilicia ...) References {{Taxonbar, from=Q49001519 Parrots Eocene birds Prehistoric birds of Europe Prehistoric birds of North America Prehistoric bird families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precursor (bird)
''"Precursor"'' is a controversial prehistoric bird genus from the Early Eocene. It was established based on fossils found in England, including in the famous London Clay deposits. Three species are included in the genus: ''"P." parvus'', the type species, ''"P." magnus'', and ''"P." litorum,'' all named by Colin Harrison and Cyril Walker in 1977. These remains were originally considered to be members of the Charadriiformes, more specifically the earliest representatives of the Glareolidae (pratincoles and coursers). However, several authors have since found this interpretation to be dubious, with the lack of measurements and contradictory wording making the original description's conclusions difficult to verify. At least some of the material, namely the paratype humerus of ''"P." parvus'', has been re-interpreted as belonging to the Pseudasturidae (or Halcyornithidae), a group of stem-parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parrots
Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genus (biology), genera comprising the order (biology), order Psittaciformes (), found mostly in tropics, tropical and subtropics, subtropical regions. The order is subdivided into three superfamilies: the true parrot, Psittacoidea ("true" parrots), the Cockatoo, Cacatuoidea (cockatoos), and the New Zealand parrot, Strigopoidea (New Zealand parrots). One-third of all parrot species are threatened by extinction, with higher aggregate extinction risk (Red List Index, IUCN Red List Index) than any other comparable bird group. Parrots have a generally pantropical distribution with several species inhabiting temperateness, temperate regions in the Southern Hemisphere, as well. The greatest biodiversity, diversity of parrots is in South America and Australasia. Characteristic features of parrots include a strong, curved beak, bill, an upright stance, strong legs, and clawed Dactyly#In birds, zygodactyl f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Popigai impact structure, Siberia and in what is now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green River Formation
The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in the dry season. Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.Bradley, W. H. The varves and climate of the Green River epoch: U.S. Geol. Survey Prof. Paper 158, pp 87–110, 1929. The sedimentary layers were formed in a large area named for the Green River, a tributary of the Colorado River. The three separate basins lie around the Uinta Mountains (north, east, and south) of northeastern Utah: * an area in northwestern Colorado east ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
London Clay
The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 56–49 million years ago) age which crops out in the southeast of England. The London Clay is well known for its fossil content. The fossils from the lower Eocene rocks indicate a moderately warm climate, the tropical or subtropical flora. Though sea levels changed during the deposition of the clay, the habitat was generally a lush forest – perhaps like in Indonesia or East Africa today – bordering a warm, shallow ocean. The London Clay is a stiff bluish clay which becomes brown when weathered and oxidized. Nodular lumps of pyrite are frequently found in the clay layers. Pyrite was produced by microbial activity (sulfate reducing bacteria) during clay sedimentation. Once clay is exposed to atmospheric oxygen, framboidal pyrite with a great specific surface is rapidly oxidized. Pyrite oxidation produces insoluble brown iron oxyhydroxide (FeOOH) and sulfuric acid leading to the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messelasturidae
Messelasturidae is an extinct family of birds known from the Eocene of North America and Europe. Their morphology is a mosiac that in some aspects are strongly convergent with modern hawks and falcons, but in others are more similar to parrots. Initially interpreted as stem-owls, more recent studies have suggested a closer relationship to parrots and passerines. Their ecology is enigmatic. The known messelasturid species are ''Messelastur gratulator'', ''Tynskya eocaena'', and ''T. waltonensis''. Description On the skull, Messelasturidae possessed a raptorial beak and a large supraorbital process. On the feet, messelasturids lacked an ossified supratendineal bridge on the distal tibiotarsus. They also featured raptorlike ungual phalanges. They were likely ground dwelling carnivores. They existed at an age range of 61.7 to 40.4 Ma. ''Tynskya'' is characterized by a distinctive morphology of the tarsometatarsus. Discovery and classification '' Messelastur gratulator'' wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimera (paleontology)
In paleontology, a chimera is a fossil that was reconstructed with elements coming from more than a single species or genus of animal. In other words they are mistakes or sometimes hoaxes made by paleontologists, putting together parts that do not come from the same organism. A now classic example of chimera is ''Protoavis''. List of paleontological chimeras * Archaeoraptor * ''Dalianraptor''? * ''Lametasaurus''? * ''Protoavis'' * Piltdown Man * ''Ultrasauros'' * ''Ornithopsis hulkei'' * Teihivenator * ''Dakotaraptor''? * ''Avalonianus'' * ''Kootenichela''? * ''Polacanthoides''?Nopcsa, F. (1928), "Palaeontological notes on reptiles." Geologica Hungarica, Series Palaeontologica, tomus, 1, -Pasc. 1, p. 1-84 References Paleontological chimeras, {{paleo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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