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Lagerpetidae
Lagerpetidae (; originally Lagerpetonidae) is a family of basal avemetatarsalians. Though traditionally considered the earliest-diverging dinosauromorphs (reptiles closer to dinosaurs than to pterosaurs), fossils described in 2020 suggest that lagerpetids may instead be pterosauromorphs (closer to pterosaurs). Lagerpetid fossils are known from the Late Triassic of Argentina, Arizona, Brazil, Madagascar, New Mexico, and Texas. They were typically small, although some lagerpetids, like '' Dromomeron gigas'' and a specimen from the Santa Rosa Formation attributed to ''Dromomeron'' sp., were able to get quite large (femoral length ). Lagerpetid fossils are rare; the most common finds are bones of the hindlimbs, which possessed a number of unique features. Description As with most early avemetatarsalians, the most characteristic adaptations of lagerpetids occurred in their hip, leg and ankle bones, likely as a result of these being the bones most commonly preserved. Hip material is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, Ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful sandstone'')'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area and the seventh most populous. Its capital is Brasília, and its most populous city is São Paulo. The federation is composed of the union of the 26 States of Brazil, states and the Federal District (Brazil), Federal District. It is the largest country to have Portuguese language, Portuguese as an List of territorial entities where Portuguese is an official language, official language and the only one in the Americas; one of the most Multiculturalism, multicultural and ethnically diverse nations, due to over a century of mass Immigration to Brazil, immigration from around the world; and the most populous Catholic Church by country, Roman Catholic-majority country. Bounded by the Atlantic Ocean on the east, Brazil has a Coastline of Brazi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euparkeria
''Euparkeria'' (; meaning "Parker's good animal", named in honor of W.K. Parker) is an extinct genus of archosauriform from the Middle Triassic of South Africa. It was a small reptile that lived between 245-230 million years ago, and was close to the ancestry of Archosauria, the group that includes dinosaurs, pterosaurs, birds and crocodilians. ''Euparkeria'' had hind limbs that were slightly longer than its forelimbs, which has been taken as evidence that it may have been able to rear up on its hind legs as a facultative biped. Although ''Euparkeria'' is close to the ancestry of fully bipedal archosaurs such as early dinosaurs, it probably developed bipedalism independently. ''Euparkeria'' was not as well adapted to bipedal locomotion as dinosaurs and its normal movement was probably more analogous to a crocodilian high walk. Palaeobiology Locomotion The hind limbs of ''Euparkeria'' are somewhat longer than its forelimbs, which has led many researchers to conclude that it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archosaurs
Archosauria () is a clade of diapsids, with birds and crocodilians as the only living representatives. Archosaurs are broadly classified as reptiles, in the cladistic sense of the term which includes birds. Extinct archosaurs include non-avian dinosaurs, pterosaurs, and extinct relatives of crocodilians. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants. The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives, and Avemetatarsalia, which includes birds and their extinct relatives (such as non-avian dinosaurs and pterosaurs). Older definitions of the group Archosauria rely on shared morphological characteristics, such as an antorbital fenestra in the skull, serrated teeth, and an upright stance. Some extinct reptiles, such as proterosuchids and euparkeriids, possessed these features yet originate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ixalerpeton Skeletal
''Ixalerpeton'' (meaning "leaping reptile") is a genus of lagerpetid avemetatarsalian containing one species, ''I. polesinensis''. It lived in the Late Triassic of Brazil alongside the sauropodomorph dinosaur ''Buriolestes''. Discovery and naming The holotype specimen of ''Ixalerpeton'', numbered ULBRA-PVT059, consists of parts from the skull, vertebral column, and all four limbs. The specimen comes from the Carnian Santa Maria Formation of Brazil, and it was found alongside two individuals of ''Buriolestes'' as well as a set of femora belonging to second individual of ''Ixalerpeton''. The genus name of ''Ixalerpeton'' combines the Greek words ''ixalos'' ("leaping") and ''erpeton'' ("reptile"), and the species name ''polesinensis'' references the town of São João do Polêsine, where the dig site is located. Description ''Ixalerpeton'' was similar to other lagerpetids (namely ''Dromomeron'' and ''Lagerpeton'') in having long hindlimbs with well-developed muscle attachment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacrum
The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30. The sacrum situates at the upper, back part of the pelvic cavity, between the two wings of the pelvis. It forms joints with four other bones. The two projections at the sides of the sacrum are called the alae (wings), and articulate with the ilium at the L-shaped sacroiliac joints. The upper part of the sacrum connects with the last lumbar vertebra (L5), and its lower part with the coccyx (tailbone) via the sacral and coccygeal cornua. The sacrum has three different surfaces which are shaped to accommodate surrounding pelvic structures. Overall it is concave (curved upon itself). The base of the sacrum, the broadest and uppermost part, is tilted forward as the sacral promontory internally. The central part is curved outward toward the posterior, allowing greater room for the pel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithischia
Ornithischia () is an extinct order of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek stem ' (), meaning "of a bird", and ' (), plural ', meaning "hip joint". However, birds are only distantly related to this group as birds are theropod dinosaurs. Ornithischians with well known anatomical adaptations include the ceratopsians or "horn-faced" dinosaurs (e.g. ''Triceratops''), the pachycephalosaurs or "thick-headed" dinosaurs, the armored dinosaurs (Thyreophora) such as stegosaurs and ankylosaurs, and the ornithopods. There is strong evidence that certain groups of ornithischians lived in herds, often segregated by age group, with juveniles forming their own flocks separate from adults. Some were at least partially covered in filamentous (hair- or feather- like) pelts, and there is much debate over whether these filaments fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pubis (bone)
In vertebrates, the pubic region ( la, pubis) is the most forward-facing (ventral and anterior) of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ramus, and a body. Structure The pubic region is made up of a ''body'', ''superior ramus'', and ''inferior ramus'' (). The left and right coxal bones join at the pubic symphysis. It is covered by a layer of fat, which is covered by the mons pubis. The pubis is the lower limit of the suprapubic region. In the female, the pubic region is anterior to the urethral sponge. Body The body forms the wide, strong, middle and flat part of the pubic region. The bodies of the left and right pubic regions join at the pubic symphysis. The rough upper edge is the pubic crest, ending laterally in the pubic tubercle. This tubercle, found roughly 3 cm from the pubic symphysis, is a distinctive feature on the lower part of the abdominal wall; important ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetabulum
The acetabulum (), also called the cotyloid cavity, is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint. Structure There are three bones of the ''os coxae'' (hip bone) that come together to form the ''acetabulum''. Contributing a little more than two-fifths of the structure is the ischium, which provides lower and side boundaries to the acetabulum. The ilium forms the upper boundary, providing a little less than two-fifths of the structure of the acetabulum. The rest is formed by the pubis, near the midline. It is bounded by a prominent uneven rim, which is thick and strong above, and serves for the attachment of the acetabular labrum, which reduces its opening, and deepens the surface for formation of the hip joint. At the lower part of the ''acetabulum'' is the acetabular notch, which is continuous with a circular depression, the acetabular fossa, at the bottom of the cavity of the ''acetabulum''. The re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ilium (bone)
The ilium () (plural ilia) is the uppermost and largest part of the hip bone, and appears in most vertebrates including mammals and birds, but not bony fish. All reptiles have an ilium except snakes, although some snake species have a tiny bone which is considered to be an ilium. The ilium of the human is divisible into two parts, the body and the wing; the separation is indicated on the top surface by a curved line, the arcuate line, and on the external surface by the margin of the acetabulum. The name comes from the Latin (''ile'', ''ilis''), meaning "groin" or "flank". Structure The ilium consists of the body and wing. Together with the ischium and pubis, to which the ilium is connected, these form the pelvic bone, with only a faint line indicating the place of union. The body ( la, corpus) forms less than two-fifths of the acetabulum; and also forms part of the acetabular fossa. The internal surface of the body is part of the wall of the lesser pelvis and gives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Rosa Formation, New Mexico
The Santa Rosa Formation is a geologic formation exposed in New Mexico that was deposited in the Carnian Age of the late Triassic Period. Description The formation consists mostly of white to brown sandstone and mudstone with some interbedded conglomerate. The formation lies on the Anton Chico Formation and is overlain by the Garita Creek Formation. The total thickness of the formation is . The formation is divided into (in ascending stratigraphic order) the ''Tecolotito Member'', which is primarily sandstone; the ''Los Esteros Member'', which is primarily mudstone; and the ''Tres Lagunas Member'', which is primarily sandstone. The sandstone members are interpreted as alluvial sheets deposited by braided streams. The Los Esteros Member is interpreted as a lacustrine deposit in lakes that formed due to local subsidence from dissolution of underlying Permian salt beds. Paleocurrents were primarily to the south in the Tecolotito Member and northeast in the Tres Lagunas Member bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromomeron Gigas
''Dromomeron'' (meaning "running femur") is a genus of lagerpetid avemetatarsalian which lived around 220 to 211.9 ± 0.7 million years ago. The genus contains species known from Late Triassic-age rocks of the Southwestern United States and northwestern Argentina. It is described as most closely related to the earlier ''Lagerpeton'' of Argentina, but was found among remains of true dinosaurs like ''Chindesaurus'', indicating that the first dinosaurs did not immediately replace related groups. Based on the study of the overlapping material of ''Dromomeron'' and ''Tawa hallae'', Christopher Bennett proposed that the two taxa were conspecific, forming a single growth series of ''Dromomeron''. However, noting prominent differences between their femurs which cannot be attributed to variation with age, Rodrigo Muller rejected this proposal in 2017. He further noted that, while ''D. romeri'' is known from juveniles only, it shares many traits in common with ''D. gigas'', which is known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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