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Eurycleidus Arcuatus
''Eurycleidus'' is an extinct genus of large-bodied rhomaleosaurid known from the Early Jurassic period (most likely earliest Hettangian stage) of the United Kingdom. It contains a single species, ''E. arcuatus''. Like other plesiosaurs, ''Eurycleidus'' probably lived on a diet of fish, using its sharp needle-like teeth to catch prey. Its shoulder bones were fairly large, indicating a powerful forward stroke for fast swimming. Phylogeny Most phylogenetic analyses find the type species of the genus, ''Eurycleidus arcuatus'', to be a relatively basal rhomaleosaurid. A second species, ''E. megacephalus'' (Stutchbury, 1846 Rhomaleosaurus.html" ;"title="riginally ''Rhomaleosaurus">riginally ''Rhomaleosaurus megacephalus'', was reassigned to this genus by Smith (2007). However, most analyses find ''E. megacephalus'' to represent an unnamed genus, which is distinct from both ''Eurycleidus'' and ''Rhomaleosaurus''. ''E. megacephalus'' was moved to its own genus ''Atychodracon'' by Ada ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Jurassic
The Early Jurassic Epoch (in chronostratigraphy corresponding to the Lower Jurassic Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.1 Ma. Certain rocks of marine origin of this age in Europe are called "Lias" and that name was used for the period, as well, in 19th-century geology. In southern Germany rocks of this age are called Black Jurassic. Origin of the name Lias There are two possible origins for the name Lias: the first reason is it was taken by a geologist from an English quarryman's dialect pronunciation of the word "layers"; secondly, sloops from north Cornish ports such as Bude would sail across the Bristol Channel to the Vale of Glamorgan to load up with rock from coastal limestone quarries (lias limestone from South Wales was used throughout North Devon/North Cornwall as it conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliosauridae
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 clad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 during the Mesozoic Era. The first scientifically documented plesiosaur fossils were discovered during the early 19th century by Mary Anning. Plesiosaurs were actually discovered and described before dinosaurs. They were also among the first animals to be featured in artistic reconstructions of the ancient world, and therefore among the earliest prehistoric creatures to attract the attention of the lay public. Plesiosaurs were originally thought to be a kind of primitive transitional form between marine life and terrestrial reptiles. However, now plesiosaurs are recognized as highly derived marine reptiles descended from terrestrial ancestors. Early researchers thought that plesiosaurs laid eggs like most reptiles. They commonly imagined p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhomaleosaurus Zetlandicus
''Rhomaleosaurus'' (meaning "strong lizard") is an extinct genus of Early Jurassic ( Toarcian age, about 183 to 175.6 million years ago) rhomaleosaurid pliosauroid known from Northamptonshire and from Yorkshire of the United Kingdom. It was first named by Harry Seeley in 1874 and the type species is ''Rhomaleosaurus cramptoni''. It was one of the earliest large marine reptile predators which hunted in the seas of Mesozoic era, with the type species ''R. cramptoni'' measuring long and weighing . Like other pliosaurs, ''Rhomaleosaurus'' fed on ichthyosaurs, ammonites and other plesiosaurs. Species ''R. cramptoni'' In July 1848, a fossil of a large plesiosaur was unearthed in an Alum quarry at Kettleness, near Whitby, in Yorkshire, England. It was collected from the ''A. bifrons'' ammonite zone of the Whitby Mudstone Formation, dating to the early Toarcian age, about 183 to 180 million years ago. The complete skeleton which preserved the skull, NMING F8785, wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhomaleosaurus Thorntoni
''Rhomaleosaurus'' (meaning "strong lizard") is an extinct genus of Early Jurassic (Toarcian age, about 183 to 175.6 million years ago) rhomaleosaurid pliosauroid known from Northamptonshire and from Yorkshire of the United Kingdom. It was first named by Harry Seeley in 1874 and the type species is ''Rhomaleosaurus cramptoni''. It was one of the earliest large marine reptile predators which hunted in the seas of Mesozoic era, with the type species ''R. cramptoni'' measuring long and weighing . Like other pliosaurs, ''Rhomaleosaurus'' fed on ichthyosaurs, ammonites and other plesiosaurs. Species ''R. cramptoni'' In July 1848, a fossil of a large plesiosaur was unearthed in an Alum quarry at Kettleness, near Whitby, in Yorkshire, England. It was collected from the ''A. bifrons'' ammonite zone of the Whitby Mudstone Formation, dating to the early Toarcian age, about 183 to 180 million years ago. The complete skeleton which preserved the skull, NMING F8785, was kept for five ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhomaleosaurus Cramptoni
''Rhomaleosaurus'' (meaning "strong lizard") is an extinct genus of Early Jurassic (Toarcian age, about 183 to 175.6 million years ago) rhomaleosaurid pliosauroid known from Northamptonshire and from Yorkshire of the United Kingdom. It was first named by Harry Seeley in 1874 and the type species is ''Rhomaleosaurus cramptoni''. It was one of the earliest large marine reptile predators which hunted in the seas of Mesozoic era, with the type species ''R. cramptoni'' measuring long and weighing . Like other pliosaurs, ''Rhomaleosaurus'' fed on ichthyosaurs, ammonites and other plesiosaurs. Species ''R. cramptoni'' In July 1848, a fossil of a large plesiosaur was unearthed in an Alum quarry at Kettleness, near Whitby, in Yorkshire, England. It was collected from the ''A. bifrons'' ammonite zone of the Whitby Mudstone Formation, dating to the early Toarcian age, about 183 to 180 million years ago. The complete skeleton which preserved the skull, NMING F8785, was kept for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeonectrus Rostratus
''Archaeonectrus'' is an extinct genus of pliosaur from the Early Jurassic (Sinemurian) of what is now southeastern England. The type species is ''Archaeonectrus'' (originally ''"Plesiosaurus"'') ''rostratus'', first named by Sir Richard Owen in 1865, which was moved to its own genus by N.I. Novozhilov in 1964. It was a relatively small plesiosaur, measuring long. Classification The cladogram below shows ''Archaeonectrus'' phylogenetic position among other plesiosaurs, following Benson ''et al.'' (2012). See also * Timeline of plesiosaur research * List of plesiosaur genera This list of plesiosaurs is a comprehensive listing of all genera that have ever been included in the order Plesiosauria, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered inv ... References * Sepkoski, J.J. (2002). "A compendium of fossil marine animal genera". ''Bulletins of American Paleontology'' 363: 1-560. External links ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atychodracon Megacephalus
''Atychodracon'' is an extinct genus of rhomaleosaurid plesiosaurian known from the Late Triassic - Early Jurassic boundary (probably early Hettangian stage) of England. It contains a single species, ''Atychodracon megacephalus'', named in 1846 originally as a species of ''Plesiosaurus''. The holotype of ''"P." megacephalus'' was destroyed during a World War II air raid in 1940 and was later replaced with a neotype. The species had a very unstable taxonomic history, being referred to four different genera by various authors until a new genus name was created for it in 2015. Apart from the destroyed holotype and its three partial casts (that survived), a neotype and two additional individuals are currently referred to ''Atychodracon megacephalus'', making it a relatively well represented rhomaleosaurid. History of discovery The type species of ''Atychodracon'' was first described and named by Samuel Stutchbury in January 1846, as a species of the wastebasket taxon ''Plesiosaurus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maresaurus Coccai
''Maresaurus'' is an extinct genus of plesiosaur from the Middle Jurassic (Bajocian) Los Molles Formation of Argentina. The type species, ''Maresaurus coccai'', was named by Gasparini in 1997. Recent phylogenetic analysis found ''Maresaurus'' to be a rhomaleosaurid.Smith AS, Dyke GJ. 2008. The skull of the giant predatory pliosaur ''Rhomaleosaurus cramptoni'': implications for plesiosaur phylogenetics. ''Naturwissenschaften'' e-published 2008. It was about long and weighed . See also * List of plesiosaur genera * 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 External links * Smith, Adam S. and Dyke, Gareth J. (2008)The skull of the giant predatory pliosaur ''Rhomaleosaurus cramptoni'': implications for plesiosaur phylogenet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meyerasaurus Victor
''Meyerasaurus'' is an extinct genus of rhomaleosaurid known from Holzmaden, Baden-Württemberg of southwestern Germany. Description ''Meyerasaurus'' is known from the holotype SMNS 12478, articulated and complete skeleton which preserved the skull, exposed in ventral view. It has a skull length of , a body length of and a body mass of . It was collected from the ''Harpoceras elegantulum-falciferum'' ammonoid subzones, ''Harpoceras falcifer'' zone, of the famous Posidonien-Schiefer lagerstätte (Posidonia Shale), dating to the early Toarcian stage of the Early Jurassic, about 183-180 million years ago. Etymology ''Meyerasaurus'' was first named by Adam S. Smith and Peggy Vincent in 2010 and the type species is ''Meyerasaurus victor''. It was originally classified as a species of ''Plesiosaurus'', later as the second named species of ''Thaumatosaurus'' (defunct name, meaning "wonder reptile") and ultimately as a species of ''Eurycleidus'' or ''Rhomaleosaurus''. The gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avalonnectes Arturi
''Avalonnectes'' is an extinct genus of small-bodied rhomaleosaurid known from the Early Jurassic period (most likely earliest Hettangian stage) of the United Kingdom. It contains a single species, ''A. arturi''. Discovery ''Avalonnectes'' is known from the holotype specimen NHMUK 14550, which consists of the posterior portion of a skull, and a nearly complete, three-dimensionally preserved and articulated postcranial skeleton. Another partial postcranial skeleton which was referred to it is AGT uncatalogued. Both specimens were collected at Street, of Somerset, from the Pre-''Planorbis'' beds of the Blue Lias Formation of the Lower Lias Group. These beds likely occur below the first occurrence of the ammonite ''Psiloceras planorbis''. Thus, they probably fall within the earliest Hettangian ''P. tilmanni'' Chronozone, which is about 199.6-198 million years old, immediately following the Triassic–Jurassic Boundary. Plesiosaurs fossils which were discovered at Stre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macroplata Tenuiceps
''Macroplata'' (meaning "big plate") is an extinct genus of Early Jurassic rhomaleosaurid plesiosaur which grew up to in length and weighed up to . Like other plesiosaurs, ''Macroplata'' probably lived on a diet of fish, using its sharp needle-like teeth to catch prey. Its shoulder bones were fairly large, indicating a powerful forward stroke for fast swimming. ''Macroplata'' also had a relatively long neck, twice the length of the skull, in contrast to pliosaurs. A different species, ''Macroplata longirostris'' (previously called ''Plesiosaurus longirostris''), which lived somewhat later, during the Toarcian stage, was also included in the genus; however, in 2011, Benson ''et al.'' reclassified it as a pliosaurid in the genus ''Hauffiosaurus'', ''H. longirostris''. Description ''Macroplata'' bore an elongated skull, with more than half of its cranial length taken up by a roughly triangular snout. The premaxillae (front upper jaw bones) bear six teeth each, with the first being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
