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Palaeopleurosaurus
''Palaeopleurosaurus'' is an extinct genus of diapsid reptiles belonging to the group Sphenodontia.Dupret, V. (2004). The pleurosaurs: anatomy and phylogeny. ''Revue de Paléobiologie'', 9: 61-8/ref> ''Palaeopleurosaurus'' fossils were discovered in Germany (Holzmaden and Kerkhofen) from the Lower Toarcian (Early Jurassic), Posidonia Shale, dated to about 182-180 million years ago.R. L. Carroll, R. L. (1985). ''A pleurosaur from the Lower Jurassic and the taxonomic position of the Sphenodontida''. Palaeontographica Abteilung A, 1985. Volume 189. Pages 1-28. The holotype come from the Middle Section, just under the Seagrasschiefer section (=Bifrons subzone) on both localities, probably linked with the coeval measured sea regression. Initially, ''Paleopleurosaurus'' was described to represent an intermediate morphology between Late Triassic-Lower Jurassic terrestrial sphenodontia and the late Jurassic fully aquatic ''Pleurosaurus''. The study of a new specimen provided additional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeopleurosaurus Model
''Palaeopleurosaurus'' is an extinct genus of diapsid reptiles belonging to the group Sphenodontia.Dupret, V. (2004). The pleurosaurs: anatomy and phylogeny. ''Revue de Paléobiologie'', 9: 61-8/ref> ''Palaeopleurosaurus'' fossils were discovered in Germany (Holzmaden and Kerkhofen) from the Lower Toarcian (Early Jurassic), Posidonia Shale, dated to about 182-180 million years ago.R. L. Carroll, R. L. (1985). ''A pleurosaur from the Lower Jurassic and the taxonomic position of the Sphenodontida''. Palaeontographica Abteilung A, 1985. Volume 189. Pages 1-28. The holotype come from the Middle Section, just under the Seagrasschiefer section (=Bifrons subzone) on both localities, probably linked with the coeval measured sea regression. Initially, ''Paleopleurosaurus'' was described to represent an intermediate morphology between Late Triassic-Lower Jurassic terrestrial sphenodontia and the late Jurassic fully aquatic ''Pleurosaurus''. The study of a new specimen provided additional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuatara
Tuatara (''Sphenodon punctatus'') are reptiles endemic to New Zealand. Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. The name ''tuatara'' is derived from the Māori language and means "peaks on the back". The single extant species of tuatara is the only surviving member of its order. Rhynchocephalians originated during the Triassic (~250 million years ago), reached worldwide distribution and peak diversity during the Jurassic and, with the exception of tuatara, were extinct by 60 million years ago. Their closest living relatives are squamates (lizards and snakes). For this reason, tuatara are of interest in the study of the evolution of lizards and snakes, and for the reconstruction of the appearance and habits of the earliest diapsids, a group of amniote tetrapods that also includes dinosaurs (including birds) and crocodilians. Tuatara are greenish brown and grey, and measure up to from head to tail-tip and wei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuatara
Tuatara (''Sphenodon punctatus'') are reptiles endemic to New Zealand. Despite their close resemblance to lizards, they are part of a distinct lineage, the order Rhynchocephalia. The name ''tuatara'' is derived from the Māori language and means "peaks on the back". The single extant species of tuatara is the only surviving member of its order. Rhynchocephalians originated during the Triassic (~250 million years ago), reached worldwide distribution and peak diversity during the Jurassic and, with the exception of tuatara, were extinct by 60 million years ago. Their closest living relatives are squamates (lizards and snakes). For this reason, tuatara are of interest in the study of the evolution of lizards and snakes, and for the reconstruction of the appearance and habits of the earliest diapsids, a group of amniote tetrapods that also includes dinosaurs (including birds) and crocodilians. Tuatara are greenish brown and grey, and measure up to from head to tail-tip and wei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posidonia Shale
The Posidonia Shale (german: Posidonienschiefer, also called Schistes Bitumineux in Luxembourg) geologically known as the Sachrang Formation, is an Early Jurassic (Toarcian) geological formation of southwestern and northeast Germany, northern Switzerland, northwestern Austria, southern Luxembourg and the Netherlands, including exceptionally well-preserved complete skeletons of fossil marine fish and reptiles.W. Etter and O. Kuhn. 2000. An articulated dragonfly (Insecta, Odonata) from the Upper Liassic Posidonia Shale of Northern Switzerland. Palaeontology 43:967-977Henrotay, M., Marques, D., Paicheler, J. C., Gall, J. C., & Nel, A. (1998). Le Toarcien inférieur des régions de Bascharage et de Bettembourg (Grand-Duché du Luxembourg): évidences paléontologiques et sédimentologiques d'environnements restreints proches de l'émersion. Geodiversitas, 20(2), 263-284. The ''Posidonienschiefer'', as German paleontologists call it, takes its name from the ubiquitous fossils of the oyst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurosaurus
''Pleurosaurus'' (meaning "side lizard") is an extinct genus of diapsid reptiles belonging to the group Sphenodontia, extinct relatives of the modern tuatara. ''Pleurosaurus'' fossils were discovered in the Solnhofen Limestone of Bavaria, Germany and Canjuers, France. It contains two species, ''P. goldfussi'' and ''P. ginsburgi''.Dupret, V. (2004). The pleurosaurs: anatomy and phylogeny. ''Revue de Paléobiologie'', 9: 61-8/ref> ''Pleurosaurus'' is one of the few known aquatic animal, aquatic sphenodontians. Its body was approximately long, and elongated for hydrodynamic streamlining, with comparatively short limbs and a powerful tail. The body was heavily modified from those of other rhynchocephalians, including an elongated triangular skull. It swam via the use of poorly efficient axial undulatory anguilliform locomotion (the movement of the body side to side) in shallow marine environments, and was probably piscivorous. It had only small limbs, which probably did not aid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toarcian
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian Age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age. It is believed to have ended with a global cooling event known as the Comptum Cooling Event, although whether it represented a worldwide event is controversial. Stratigraphic definitions The Toarcian takes its name from the city of Thouars, just south of Saumur in the Loire Valley of France. The stage was introduced by French palaeontologist Alcide d'Orbigny in 1842, after examining rock strata of this age in a quarry near Thouars. In Europe this period is represented by the upper part of the Lias. The base of the Toarcian is defined as the place in the stratigraphic record where the ammonite genus '' Eoda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachyostosis
Pachyostosis is a non-pathological condition in vertebrate animals in which the bones experience a thickening, generally caused by extra layers of lamellar bone. It often occurs together with bone densification (osteosclerosis), reducing inner cavities. This joint occurrence is called pachyosteosclerosis. However, especially in the older literature, "pachyostosis" is often used loosely, referring to all osseous specializations characterized by an increase in bone compactness and/or volume. It occurs in both terrestrial and, especially, aquatic or semi-aquatic vertebrates. In aquatic animals, such as seacows (manatees and dugongs), ''Thalassocnus'', and plesiosaurs, pachyostosis in the thoracic region provides (or provided) ballast against the air-filled lungs. This maintains neutral buoyancy in aquatic habitats. Most giant deer showed pronounced pachyostosis of the mandible and skull. It has been suggested that this served to store minerals for antler growth. Many Pachycephalosau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Germany
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Lepidosaurs
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassic, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toarcian Life
The Toarcian is, in the ICS' geologic timescale, an age and stage in the Early or Lower Jurassic. It spans the time between 182.7 Ma (million years ago) and 174.1 Ma. It follows the Pliensbachian and is followed by the Aalenian. The Toarcian Age began with the Toarcian turnover, the extinction event that sets its fossil faunas apart from the previous Pliensbachian age. It is believed to have ended with a global cooling event known as the Comptum Cooling Event, although whether it represented a worldwide event is controversial. Stratigraphic definitions The Toarcian takes its name from the city of Thouars, just south of Saumur in the Loire Valley of France. The stage was introduced by French palaeontologist Alcide d'Orbigny in 1842, after examining rock strata of this age in a quarry near Thouars. In Europe this period is represented by the upper part of the Lias. The base of the Toarcian is defined as the place in the stratigraphic record where the ammonite genus '' Eoda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Reptile Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histology
Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope. Although one may divide microscopic anatomy into ''organology'', the study of organs, ''histology'', the study of tissues, and ''cytology'', the study of cells, modern usage places all of these topics under the field of histology. In medicine, histopathology is the branch of histology that includes the microscopic identification and study of diseased tissue. In the field of paleontology, the term paleohistology refers to the histology of fossil organisms. Biological tissues Animal tissue classification There are four basic types of animal tissues: muscle tissue, nervous tissue, connective tissue, and epithelial tissue. All animal tissues are considered to be subtypes of these four principal tissue types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
