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Afrovenator Reconstruction
''Afrovenator'' (; "African hunter") is a genus of megalosaurid theropod dinosaur from the Middle Jurassic, Middle or Late Jurassic Period on the Tiouraren Formation, Tiourarén Formation and maybe the Irhazer II Formation of the Niger Sahara region in Western Africa. ''Afrovenator'' represents the only properly identified Gondwanan megalosaur, with proposed material of the group present in the Late Jurassic on Tacuarembó Formation of Uruguay and the Tendaguru Formation of Tanzania. Discovery and naming The remains of ''Afrovenator'' were discovered in 1993 in the Tiouraren Formation, Tiourarén Formation of the department of Agadez (department), Agadez in Niger. The Tiourarén was originally thought to represent the Hauterivian to Barremian stages of the early Cretaceous Period, or approximately 132 to 125 million years ago (Sereno et al. 1994). However, re-interpretation of the sediments showed that they are probably Middle to Late Jurassic in age, dating ''Afrovenator'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Jurassic
The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations containing land animal fossils include the Forest Marble Formation in England, the Kilmaluag Formation in Scotland,British Geological Survey. 2011Stratigraphic framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf: research report RR/11/06 British Geological Survey, Keyworth, Nottingham. the Calcaire de Caen of France, the Daohugou Beds in China, the Itat Formation in Russia, the Tiouraren Formation of Niger, and the Isalo III Formation of western Madagascar. Rocks of the Middle Jurassic were formerly (until about 1980s) in Europe called ''Dogger'' or ''Brown Jurassic''. Paleogeography During the Middle Jurassic Epoch, Pangaea began to separate into Laurasia and Gond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afrovenator Skeleton
''Afrovenator'' (; "African hunter") is a genus of megalosaurid theropod dinosaur from the Middle or Late Jurassic Period on the Tiourarén Formation and maybe the Irhazer II Formation of the Niger Sahara region in Western Africa. ''Afrovenator'' represents the only properly identified Gondwanan megalosaur, with proposed material of the group present in the Late Jurassic on Tacuarembó Formation of Uruguay and the Tendaguru Formation of Tanzania. Discovery and naming The remains of ''Afrovenator'' were discovered in 1993 in the Tiourarén Formation of the department of Agadez in Niger. The Tiourarén was originally thought to represent the Hauterivian to Barremian stages of the early Cretaceous Period, or approximately 132 to 125 million years ago (Sereno et al. 1994). However, re-interpretation of the sediments showed that they are probably Middle to Late Jurassic in age, dating ''Afrovenator'' to the Bathonian to Oxfordian stages, between 167 and 161 mya. The sauropo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandible
In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone is the skull's only movable, posable bone, sharing Temporomandibular joint, joints with the cranium's temporal bones. The mandible hosts the lower Human tooth, teeth (their depth delineated by the alveolar process). Many muscles attach to the bone, which also hosts nerves (some connecting to the teeth) and blood vessels. Amongst other functions, the jawbone is essential for chewing food. Owing to the Neolithic Revolution, Neolithic advent of agriculture (), human jaws evolved to be Human jaw shrinkage, smaller. Although it is the strongest bone of the facial skeleton, the mandible tends to deform in old age; it is also subject to Mandibular fracture, fracturing. Surgery allows for the removal of jawbone fragments (or its entirety) as well a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent parts: the neurocranium and the facial skeleton, which evolved from the first pharyngeal arch. The skull forms the frontmost portion of the axial skeleton and is a product of cephalization and vesicular enlargement of the brain, with several special senses structures such as the eyes, ears, nose, tongue and, in fish, specialized tactile organs such as barbels near the mouth. The skull is composed of three types of bone: cranial bones, facial bones and ossicles, which is made up of a number of fused flat and irregular bones. The cranial bones are joined at firm fibrous junctions called sutures and contains many foramina, fossae, processes, and sinuses. In zoology, the openings in the skull are called fenestrae, the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holotype
A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept. For example, the holotype for the butterfly '' Plebejus idas longinus'' is a preserved specimen of that subspecies, held by the Museum of Comparative Zoology at Harvard University. In botany and mycology, an isotype is a duplicate of the holotype, generally pieces from the same individual plant or samples from the same genetic individual. A holotype is not necessarily "ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jobaria
''Jobaria'' is a genus of sauropod dinosaur that lived in what is now Niger during the middle Jurassic Period, between 164 and 161 million years ago. ''Jobaria'' is currently the only known valid sauropod from the Tiouraren, where it was discovered in 1997. Discovery Discovered in the fall of 1997, during a four-month expedition to the Sahara desert led by paleontologist Dr. Paul Sereno, it was found in a mass-death site in the Tiourarén Formation of Niger. With over 95% of its skeleton preserved it is among the most complete sauropods ever found. The genus is named after a local mythical giant beast, Jobar, whose bones some Tuaregs believed the fossils to be. The specific name ''tiguidensis'' comes from the cliff of Tiguidi, the site of discovery. The sediments in which it was found were originally thought to represent the Hauterivian to Barremian stages of the early Cretaceous Period, dating ''Jobaria'' to approximately 132 million years ago. However, re-interpretatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropod
Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their body), and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include '' Apatosaurus'', '' Argentinosaurus'', '' Alamosaurus'', ''Brachiosaurus'', '' Camarasaurus'', '' Diplodocus,'' and '' Mamenchisaurus''. The oldest known unequivocal sauropod dinosaurs are known from the Early Jurassic. '' Isanosaurus'' and '' Antetonitrus'' were originally described as Triassic sauropods, but their age, and in the case of ''Antetonitrus'' also its sauropod status, were subsequently questioned. Sauropod-like sauropodomorph tracks from the Fleming Fjord Formation (Greenland) might, however, indicate the occurrence of the g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iullemmeden Basin
The Iullemmeden Basin (Berber language: Iwellemmedden) is a major sub-Saharan inland basin in West Africa, extending about north to south and east to west. It covers western Niger and parts of Algeria, Mali and Nigeria. It is named after the Iullemmeden, a federation of Tuareg people who live in the central region of Niger. Its geographic range is largely coincident with the Azawagh region.Paris, 1995 Description The area of the Iullemmeden Basin seems to have started to subside in Permian-Triassic extinction, Permo-Triassic times, and to have experienced gradual downwarping during the Late Cretaceous to Paleogene times, while steadily filling with sediment. Two prominent fault trends run NNE-SSW through the center of the basin, while WSW-ENE faults trends are found in the northeast of the basin near the Aïr Mountains. Stratigraphy The sediments from Cambrian to Pleistocene times are thick, with alternating layers formed when the basin was undersea and above sea level. Pot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxfordian (stage)
The Oxfordian is, in the International Commission on Stratigraphy, ICS' geologic timescale, the earliest age (geology), age of the Late Jurassic epoch (geology), Epoch, or the lowest stage (stratigraphy), stage of the Upper Jurassic series (stratigraphy), Series. It spans the time between 161.5 ± 1.0 Annum#SI prefix multipliers, Ma and 154.8 ± 0.8 Ma (million years ago). The Oxfordian is preceded by the Callovian and is followed by the Kimmeridgian. Stratigraphic definitions The Oxfordian Stage was called "Clunch Clay and Shale" by William Smith (1815–1816); in 1818 W. Buckland described them under the unwieldy title "Oxford, Forest or Fen Clay". The term Oxfordian was introduced by Alcide d'Orbigny in 1844. The name is derived from the English city of Oxford, where the beds are well developed, but they crop out almost continuously from Dorset to the coast of Yorkshire, generally forming low, broad valleys. They are well exposed at Weymouth, Dorset, Weymouth, Oxford, Bedfor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathonian
In the geologic timescale the Bathonian is an age (geology), age and stage (stratigraphy), stage of the Middle Jurassic. It lasted from approximately 168.2 ±1.2 annum, Ma to around 165.3 ±1.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. Stratigraphic definitions The Bathonian Stage takes its name from Bath, Somerset, Bath, a spa town in England built on Jurassic limestone (the Latinized form of the town name is ''Bathonium''). The name was introduced in scientific literature by Belgian geologist Jean Baptiste Julien d'Omalius d'Halloy, d'Omalius d'Halloy in 1843. The original type locality (geology), type locality was located near Bath. The French palaeontologist Alcide d'Orbigny was in 1852 the first to define the exact length of the stage. The base of the Bathonian is at the first appearance of ammonite species ''Parkinsonia (ammonite), Parkinsonia (Gonolkites) convergens'' in the stratigraphic column. The global referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high Sea level#Local and eustatic, eustatic sea levels that created numerous shallow Inland sea (geology), inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
