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Angeac-Charente Bonebed
The Angeac-Charente bonebed is a fossil deposit located near Angeac-Charente in western France. It dates to the Berriasian stage of the Early Cretaceous, and is coeval with the Purbeck Group of Southern England. It has amongst the most diverse assemblages of earliest Cretaceous vertebrates known from Europe. History of discovery Dinosaur bones were first found at the site in 2008. The fossils were exposed during quarrying for overlying Pleistocene aged sand and gravel. After more bones were discovered in 2010, a team was set up composed of people from Musée d’Angoulême, Rennes University and the Muséum national d’Histoire naturelle to excavate the site. Due the promising finds, since 2011 excavations have been conducted at the site annually.Ronan Allain, Romain Vullo, Lee Rozada, Jérémy Anquetin, Renaud Bourgeais, et al.Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay particles, but become hard, brittle and non–plastic upon drying or firing. Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as a reddish or brownish colour from small amounts of iron oxide. Clay is the oldest known ceramic material. Prehistoric humans discovered the useful properties of clay and used it for making pottery. Some of the earliest pottery shards have been dated to around 14,000 BC, and clay tablets were the first known writing medium. Clay is used in many modern industrial processes, such as paper making, cement production, and chemical filtering. Between one-half and two-thirds of the world's population live or work in buildings made with clay, often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pycnodontiform
Pycnodontiformes is an extinct order of primarily marine bony fish. The group first appeared during the Late Triassic and disappeared during the Eocene. The group has been found in rock formations in Africa, Asia, Europe, North and South America. They were small to middle-sized fish, generally with laterally-compressed deep bodies, some with almost circular outlines, adapted for manuverability in reef-like environments. The group was morphologically diverse containing forms such the very short but deep Gebrayelichthyidae and the horned ''Ichthyoceros,'' both from the early Late Cretaceous of Lebanon. Most, but not all members of the groups had jaws with round and flattened teeth, well adapted to crush food items (durophagy), such as echinoderms, crustaceans and molluscs. Some pyncodontiformes developed piranha like teeth used for eating flesh. Most species inhabited shallow marine reef environments, while a handful of species lived in freshwater or brackish conditions. While rare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassochelydia
Thalassochelydia is a clade of extinct marine turtles from the Late Jurassic and earliest Cretaceous of Europe and South America. The group is defined as including ''Eurysternum'', ''Plesiochelys'' and ''Thalassemys'' to the exclusion of ''Pelomedusa'', '' Testudo'' and '' Protostega''. While a clade uniting the families Eurysternidae, Plesiochelyidae and Thalassemydidae had been supported by phylogenetic evidence, a name was not given for the clade until 2017, when Jérémy Anquetin and colleagues coined Thalassochelydia. While inner relationships of the clade are so uncertain as to make the monophyly of the families questionable, the significant diversity of thalassochelydians makes using the potentially invalid terms useful to describe the different morphologies. The monophyly of Thalassochelydia was further supported by a later analysis by Serjocha Evers and Roger Benson in 2019, where the group, represented by '' Solnhofia'' and Plesiochelyidae was sister taxon to Sandown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hylaeochelys
''Hylaeochelys'' is an extinct genus of plesiochelyid turtle that lived during the Late Jurassic-Early Cretaceous in Portugal, Spain, France, and southern England. The type species was originally named by Richard Owen as '' Pleurosternon latiscutatum'' in 1853, before being moved to the new genus ''Hylaeochelys'' by Richard Lydekker in 1889. Other species included in the genus are ''H. belli'', ''H. kappa''A. Pérez-García and F. Ortega. 2014. A new species of the turtle Hylaeochelys (Eucryptodira) outside its known geographic and stratigraphic ranges of distribution. Comptes Rendus Palevol 13(3):183-188 and ''H. lata'', originally named under different genera by Gideon Mantell and Owen, respectively. All species are represented by carapaces, primarily from the Lulworth Formation of the Purbeck Limestone Group that was deposited during the Berriasian In the geological timescale, the Berriasian is an age/stage of the Early/Lower Cretaceous. It is the oldest subdivision in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paracryptodira
__NOTOC__ Paracryptodira is an extinct group of reptiles in the clade Testudinata (which contains modern turtles and their extinct relatives), known from the Jurassic to Paleogene of North America and Europe. Initially treated as a suborder sister to Cryptodira,Gaffney (1975) they were then thought to be a very primitive lineage inside the Cryptodira according to the most common use of the latter taxon.Joyce (2007) They are now often regarded as late-diverging stem-turtles, lying outside the clade formed by Cryptodira and Pleurodira. The paracryptodires are said to have phylogenic relationships, noted as primary subclades, within the Baenidae and Pleurosternidae. Within each subclade, lies many biodiverse turtles that are continuously being investigated and added to the fossil record. Paracryptodires are divided into three main groups, Compsemydidae, known from the Late Jurassic to Paleocene of North America and Europe, Pleurosternidae, known from the Late Jurassic to Early Cretac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurosternidae
Pleurosternidae is an extinct family of freshwater turtles belonging to Paracryptodira. They are definitively known from the Late Jurassic to Early Cretaceous (Albian) of Western Europe and North America. Genera Valid taxa *''Dinochelys'' Morrison Formation, United States, Late Jurassic (Tithonian) *''Dorsetochelys'' Purbeck Group, England, Early Cretaceous (Berriasian) Bückeberg Formation, Germany, Berriasian *''Glyptops'' Morrison Formation, United States, Late Jurassic (Tithonian) *'' Pleurosternon'' Purbeck Group, England, Early Cretaceous (Berriasian), Ágreda locality, Spain, Tithonian-Berriasian, France, Tithonian-Berriasian *'' Riodevemys'' Villar del Arzobispo Formation, Spain, Late Jurassic (Tithonian) *''Selenemys'' Lourinhã Formation, Portugal, Late Jurassic (Kimmeridgian) *'' Toremys'' Escucha Formation, Spain, Early Cretaceous (Albian) ''Uluops'' from the Late Jurassic of North America may also belong to Pleurosternidae. Invalid taxa * '' Desmemys'' Bü ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurosternon
''Pleurosternon'' is an extinct genus of freshwater pleurosternid turtle from the latest Jurassic to earliest Cretaceous of Europe. Its type species, ''P. bullocki'' was described by the paleontologist Richard Owen (noted for coining the word '' Dinosauria'') in 1853. Since then, and throughout the late 19th century, many fossil turtles were incorrectly assigned to this genus, though only two are currently considered valid. Taxonomy ''Pleurosternon bullocki'' fossils were first described by Richard Owen in 1841 from specimens found in the earliest Cretaceous (Berriasian) aged Purbeck Group of the Isle of Purbeck, of Dorset in southern England, under the living genus ''Platemys''. It was not until 1853 however, that it was published under the name ''Pleurosternon'' in a paper Owen presented to the Palaeontographical Society. ''P. portlandicum'' named by Richard Lydekker in 1889 from the latest Jurassic (Tithonian) aged Portland Stone of the Isle of Portland, Dorset, is now consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squamata
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species, it is also the second-largest order of extant (living) vertebrates, after the perciform fish. Members of the order are distinguished by their skins, which bear horny scales or shields, and must periodically engage in molting. They also possess movable quadrate bones, making possible movement of the upper jaw relative to the neurocranium. This is particularly visible in snakes, which are able to open their mouths very wide to accommodate comparatively large prey. Squamata is the most variably sized order of reptiles, ranging from the dwarf gecko (''Sphaerodactylus ariasae'') to the Reticulated python (''Malayopython reticulatus'') and the now-extinct mosasaurs, which reached lengths over . Among other reptiles, squamates are most close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudata
The Caudata are a group of amphibians containing the extant salamanders (Urodela) and all extinct species of amphibians more closely related to salamanders than to frogs. They are typically characterized by a superficially lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. Disagreement exists between different authorities as to the definition of the terms "Caudata" and "Urodela". Some maintain that Urodela should be restricted to the crown group, with Caudata being used for the total group. Others restrict the name Caudata to the crown group and use Urodela for the total group. The former approach seems to be most widely adopted and is used in this article. Evolution The origins and evolutionary relationships between the three main groups of amphibians ( apodans, urodeles and anurans) is a matter of debate. A 2005 molecular phylogeny, based on rDNA analysis, suggest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frog
A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is known from the Early Triassic of Madagascar, but molecular clock, molecular clock dating suggests their split from other amphibians may extend further back to the Permian, 265 Myr, million years ago. Frogs are widely distributed, ranging from the tropics to subarctic regions, but the greatest concentration of species diversity is in tropical rainforest. Frogs account for around 88% of extant amphibian species. They are also one of the five most diverse vertebrate orders. Warty frog species tend to be called toads, but the distinction between frogs and toads is informal, not from Taxonomy (biology), taxonomy or evolutionary history. An adult frog has a stout body, protruding eyes, anteriorly-attached tongue, limb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albanerpetontidae
The Albanerpetontidae are an extinct family of small amphibians, native to the Northern Hemisphere during the Mesozoic and Cenozoic. The only members of the order Allocaudata, they are thought to be allied with living amphibians belonging to Lissamphibia. Despite a superficially salamander-like bodyform, their anatomy is strongly divergent from modern amphibians in numerous aspects. The fossil record of albanerpetontids spans over 160 million years from the Middle Jurassic to the beginning of the Pleistocene, about 2.13-2 million years ago. History of Research The earliest specimen of an albanerpetontid to be discovered was that of '' Celtedens megacephalus'' from the Early Cretaceous (Albian) Pietraroja Plattenkalk of Italy, described by Oronzio Gabriele Costa in 1864, and originally placed in the genus ''Triton,'' a junior synonym of the salamander genus ''Triturus''. Jaw elements of albanerpetontids from the Cretaceous of North America were assigned to the salamander g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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