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1909 In Paleontology
Arthropods Newly named insects Archosauromorphs Newly named dinosaurs Data courtesy of George Olshevsky's dinosaur genera list. Plesiosaurs New taxa Synapsids Non-mammalian People * Death of Harry Govier Seeley, the paleontologist who invented the Saurischian/Ornithischian 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 st ... dinosaur dichotomy. References {{portal, Paleontology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
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] |
Pliosaurid
Pliosauridae is a family of plesiosaurian marine reptiles from the Latest Triassic to the early Late Cretaceous ( Rhaetian to Turonian stages) of Australia, Europe, North America and South America. The family is more inclusive than the archetypal short-necked large headed species that are placed in the subclade Thalassophonea, with basal forms resembling other plesiosaurs with long necks. They became extinct during the early Late Cretaceous and were subsequently replaced by the mosasaurs. It was formally named by Harry G. Seeley in 1874. Relationships Pliosauridae is a stem-based taxon defined in 2010 (and in earlier studies in a similar manner) as "all taxa more closely related to ''Pliosaurus brachydeirus'' than to '' Leptocleidus superstes'', '' Polycotylus latipinnis'' or ''Meyerasaurus victor''". The family Brachauchenidae has been proposed to include pliosauroids which have very short necks and may include ''Brachauchenius'' and ''Kronosaurus''. However, modern cladisti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassophonea
Thalassophonea is an extinct clade of pliosaurids from the Middle Jurassic to the early Late Cretaceous (Callovian to Turonian) of Australia, Europe, North America and South America. ''Thalassophonea'' was erected by Roger Benson and Patrick Druckenmiller in 2013. The name is derived from Greek ''thalassa'' (θάλασσα), "sea", and ''phoneus'' (φονεύς), "murderer". It is a stem-based taxon defined as "all taxa more closely related to ''Pliosaurus brachydeirus'' than to ''Marmornectes candrewi''". It includes the short necked and large headed taxa that typify the family. Classification The following cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ... follows an analysis by Benson & Druckenmiller (2014). References Middle Jurassic first appearances C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simolestes
''Simolestes'' (meaning "hearkening thief") is an extinct pliosaurid genus that lived in the Middle to Late Jurassic. The type specimen, BMNH R. 3319 is an almost complete but crushed skeleton diagnostic to ''Simolestes vorax'', dating back to the Callovian of the Oxford Clay formation, England. The genus is also known from the Callovian and Bajocian of France (''S.keileni''), and the Tithonian of India (''S.indicus''). The referral of these two species to ''Simolestes'' is dubious, however. Description ''Simolestes'' possessed a short, high, and wide skull which was built to resist torsional forces when hunting. The largest specimens of ''S.vorax'' reached approximately in length, if a head to body ratio similar to ''Liopleurodon'' is applied. ''S.keileni'' was larger, with specimens from France suggesting that some individuals grew more than long. ''S. vorax'' and ''S. keileni'' weighed about , respectively. Palaeobiology Like most Pliosaurs, ''Simolestes'' possessed sal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptoclidid
Cryptoclididae is a family of medium-sized plesiosaurs that existed from the Middle Jurassic to the Early Cretaceous. They had long necks, broad and short skulls and densely packed teeth. They fed on small soft-bodied preys such as small fish and crustaceans. The earliest members of the family appeared during the early Bajocian, and they represented the dominant group of long-necked plesiosaurs during the latter half of the Jurassic. Classification In 2010, two supposed late Cretaceous members of the group were reclassified as other kinds of plesiosauroids. ''Kaiwhekea'' was reclassified to Leptocleididae, and ''Aristonectes'' was transferred to Elasmosauridae. Cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ... based on Ketchum and Benson (2010): References External ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford Clay Formation
The Oxford Clay (or Oxford Clay Formation) is a Jurassic marine sedimentary rock formation underlying much of southeast England, from as far west as Dorset and as far north as Yorkshire. The Oxford Clay Formation dates to the Jurassic, specifically, the Callovian and Oxfordian ages, and comprises two main facies. The lower facies comprises the Peterborough Member, a fossiliferous organic-rich mudstone. This facies and its rocks are commonly known as lower Oxford Clay. The upper facies comprises the middle Oxford Clay, the Stewartby Member, and the upper Oxford Clay, the Weymouth Member. The upper facies is a fossil poor assemblage of calcareous mudstones. Oxford Clay appears at the surface around Oxford, Peterborough and Weymouth and is exposed in many quarries around these areas. The top of the Lower Oxford Clay shows a lithological change, where fissile shale changes to grey mudstone. The Middle and Upper Oxford Clays differ slightly, as they are separated by an argillaceou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callovian
In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma (million years ago) and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian. Stratigraphic definitions The Callovian Stage was first described by French palaeontologist Alcide d'Orbigny in 1852. Its name derives from the latinized name for Kellaways Bridge, a small hamlet 3 km north-east of Chippenham, Wiltshire, England. The base of the Callovian is defined as the place in the stratigraphic column where the ammonite genus ''Kepplerites'' first appears, which is the base of the biozone of '' Macrocephalites herveyi''. A global reference profile (a GSSP) for the base had in 2009 not yet been assigned. The top of the Callovian (the base of the Oxfordian) is at the first appearance of ammonite species '' Brightia thuouxensis''. Subdivision The Callovian is often subdivided into three substages ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picrocleidus
''Picrocleidus'' is an extinct genus of plesiosaur. It is known only from the type species ''P. beloclis'' from the Middle Jurassic Oxford Clay Formation (Callovian stage) of the United Kingdom.Andrews, Charles W 1910. A descriptive catalogue of the marine reptiles of the Oxford Clay, Part 2. British Museum (Nat. Soc.) 13:139-149. See also * Timeline of plesiosaur research This timeline of plesiosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, taxonomic revisions, and cultural portrayals of plesiosaurs, an order of marine reptiles that flourished duri ... References {{Taxonbar, from=Q9059430 Middle Jurassic plesiosaurs of Europe Fossil taxa described in 1892 Cryptoclidids Taxa named by Harry Seeley Sauropterygian genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nodosaurid
Nodosauridae is a family of ankylosaurian dinosaurs, from the Late Jurassic to the Late Cretaceous period in what is now North America, South America, Europe, and Asia. Description Nodosaurids, like their close relatives the ankylosaurids, were heavily armored dinosaurs adorned with rows of bony armor nodules and spines (osteoderms), which were covered in keratin sheaths. All nodosaurids, like other ankylosaurians, were medium-sized to large, heavily built, quadrupedal, herbivorous dinosaurs, possessing small, leaf-shaped teeth. Unlike ankylosaurids, nodosaurids lacked mace-like tail clubs, instead having flexible tail tips. Many nodosaurids had spikes projecting outward from their shoulders. One particularly well-preserved nodosaurid "mummy", known as the Suncor nodosaur (''Borealopelta markmitchelli''), preserved a nearly complete set of armor in life position, as well as the keratin covering and mineralized remains of the underlying skin, which indicate reddish dorsal pigmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobrara Formation
The Niobrara Formation , also called the Niobrara Chalk, is a geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the Late Cretaceous. It is composed of two structural units, the Smoky Hill Chalk Member overlying the Fort Hays Limestone Member. The chalk formed from the accumulation of coccoliths from microorganisms living in what was once the Western Interior Seaway, an inland sea that divided the continent of North America during much of the Cretaceous. It underlies much of the Great Plains of the US and Canada. Evidence of vertebrate life is common throughout the formation and includes specimens of plesiosaurs, mosasaurs, and pterosaurs as well as several primitive aquatic birds. The type locality for the Niobrara Chalk is the Niobrara River in Knox County in northeastern Nebraska. The formation gives its name to the Niobrara cycle of the Western Interior Seaway. History of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The Santonian is preceded by the Coniacian and is followed by the Campanian.Gradstein ''et al.'' (2004) Stratigraphic definition The Santonian Stage was established by French geologist Henri Coquand in 1857. It is named after the city of Saintes in the region of Saintonge, where the original type locality is located. The base of the Santonian Stage is defined by the appearance of the inoceramid bivalve ''Cladoceramus undulatoplicatus''. The GSSP (official reference profile) for the base of the Santonian Stage is located near Olazagutia, Spain; it was ratified by the Subcommission on Cretaceous Stratigraphy in 2012. The Santonian's top (the base of the Campanian Stage) is informally marked by the extinction of the crinoid '' Marsupites tes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
