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Eardasaurus
''Eardasaurus'' is a genus of thalassophonean pliosaurid from the middle Jurassic Oxford Clay Formation. The animal would have measured over long (the tail was not fully preserved) and possessed a high amount of teeth relative to other pliosaurs. Its teeth show distinct ridges formed by the tooth enamel, some of which are very pronounced and similar to carinae, giving the teeth a cutting edge. History and naming The remains of ''Eardasaurus'' were discovered H. Philip Powell in the Oxford Clay Formation near Yarnton in 1994. The only known fossil and holotype, specimen OUMNH PAL-J.2247 (previously listed as OUMNH J.02247), was unearthed from the Peterborough Member of the formation, which indicates that it lived during the Callovian stage of the Jurassic. The specimen is fairly complete and partially articulated, preserving both the cranium and mandible, large parts of the vertebral column as well as ribs and gastralia as well as the remains of the left fore- and hindlimbs. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peloneustes Philarchus
''Peloneustes'' (meaning "mud swimmer") is a genus of pliosaurid plesiosaur from the Middle Jurassic of England. Its remains are known from the Peterborough Member of the Oxford Clay Formation, which is Callovian in age. It was originally described as a species of ''Plesiosaurus'' by palaeontologist Harry Govier Seeley in 1896, before being given its own genus by naturalist Richard Lydekker in 1889. While many species have been assigned to ''Peloneustes'', ''P. philarchus'' is currently the only one still considered valid, with the others moved to different genera, considered '' nomina dubia'', or synonymised with ''P. philarchus''. Some of the material formerly assigned to ''P. evansi'' have since been reassigned to ''"Pliosaurus" andrewsi''. ''Peloneustes'' is known from many specimens, including some very complete material. With a total length of , ''Peloneustes'' is not a large pliosaurid. It had a large, triangular skull, which occupied about a fifth of its body length. T ... [...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] |
Liopleurodon
''Liopleurodon'' (; meaning 'smooth-sided teeth') is an extinct genus of large, carnivorous marine reptile belonging to the Thalassophonea, a clade of short-necked pliosaurid plesiosaurs. ''Liopleurodon'' lived from the Callovian Stage of the Middle Jurassic to the Kimmeridgian stage of the Late Jurassic Period (c. 166 to 155 mya). It was the apex predator of the Middle to Late Jurassic seas that covered Europe. The largest species, ''L. ferox'', is estimated to have grown up to in length, but could have been larger. The name "Liopleurodon" (meaning "smooth-sided tooth") derives from Ancient Greek words: ', "smooth"; ', "side" or "rib"; and ', "tooth". Discovery and species Even before ''Liopleurodon'' was named, material likely belonging to it was described. In 1841, Hermann von Meyer named the species ''Thaumatosaurus oolithicus'' based on a fragmentary specimen consisting of partial teeth, skull elements, vertebrae, and ribs from deposits in Württemberg, Germany poss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stenorhynchosaurus
''Stenorhynchosaurus'' is an extinct genus of pliosaurid plesiosaurs which lived in the Early Cretaceous of South America. The type species and only known is ''Stenorhynchosaurus munozi''. It was a medium-sized pliosaur, reaching an adult body length of . Discovery and naming Fossils from the front of a snout of a plesiosaur were discovered in 2000 on the property of Jorge Muñoz, in Loma La Cabrera, near Villa de Leyva in Boyacá, Colombia, on grounds of marine origin dating from the Late Barremian epoch of the Cretaceous. Muñoz reported the find to the local authorities, who in turn gave notice to staff of the Museo Geológico José Royo y Gómez administered by the Servicio Geológico Colombiano in Bogotá. Then was made the excavation of the nearly complete skeleton between 2004 and 2005, in collaboration with the Fundación Colombiana de Geobiología ("Colombian Geobiology Foundation"), and the remains being then transferred to Bogotá, assigning the catalog number VL ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anguanax Zignoi
''Anguanax'' is an extinct genus of basal pliosaurid known from the Late Jurassic (Oxfordian stage) Rosso Ammonitico Veronese Formation of northern Italy. It contains a single species, ''Anguanax zignoi'', known from a partially complete individual, representing the first articulated skeleton of an Italian plesiosaurian. Discovery and naming ''Anguanax'' is known solely from the holotype MPPL 18797, currently housed at the Museo Paleontologico e della Preistoria ‘P. Leonardi’ in Ferrara. The skeleton, still articulated in several blocks of limestone, consists of a partial skull including the lower jaw, 32 isolated teeth, neck, back and tail vertebrae, a right pectoral girdle, a partial left humerus, a left radius, a left ulna, three left carpals, a partial pelvis, a femur, two epipodials, isolated metapodials and phalanges. It was collected during the 1980s from a nodular and cherty limestone interval at the Kaberlaba quarry in the Asiago Municipality of the Vicenza P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marmornectes Candrewi
''Marmornectes'' is a genus of pliosaurid known from the Middle Jurassic of Bedfordshire, United Kingdom. Description ''Marmornectes'' is known from the holotype BEDFM 1999.201, an articulated partial skeleton which includes the skull. It was collected in 1999 from the ''Sigaloceras enodatum'' ammonoid subzone of the Peterborough Member, Oxford Clay Formation, which dates to the early Callovian stage of the late Middle Jurassic, about 164.7-163.5 million years ago. It was found in the monotypic locality of Quest Pit, east of Stewartby. It was a longirostrine pliosaurid with seven autapomorphies, and is most similar to '' Peloneustes philarchus''. Nevertheless, a cladistic analysis found it to be basal to ''Peloneustes'' and other pliosaurids. An undescribed pliosaurid, NHMUK R2439, was found to be the sister taxon of this genus. Etymology ''Marmornectes'' was first named by Hilary F. Ketchum and Roger B. J. Benson in 2011 and the type species is ''Marmornectes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hauffiosaurus Tomistomimus
''Hauffiosaurus'' is an extinct genus of Early Jurassic (early Toarcian stage) pliosaurid plesiosaur known from Holzmaden of Germany and from Yorkshire of the United Kingdom. It was first named by Frank Robin O’Keefe in 2001 and the type species is ''Hauffiosaurus zanoni''. In 2011, two additional species were assigned to this genus: ''H. longirostris'' and ''H. tomistomimus''. Description The holotype specimen of ''Hauffiosaurus'', housed in the Hauff Museum, is an almost complete and articulated skeleton, found from the Posidonien-Schiefer, dating to early Toarcian stage of the Early Jurassic. The holotype specimen preserved in a single block of the original matrix, exposed in ventral view. The body outline visible around the specimen is an artifact of preparation, not preservation; no remains of soft tissue were preserved. The skeleton was discovered during the early 19th Century, in beds of the famous Posidonien-Schiefer lagerstätte at Holzmaden, Baden-Württemberg, in sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hauffiosaurus Longirostris
''Hauffiosaurus'' is an extinct genus of Early Jurassic (early Toarcian stage) pliosaurid plesiosaur known from Holzmaden of Germany and from Yorkshire of the United Kingdom. It was first named by Frank Robin O’Keefe in 2001 and the type species is ''Hauffiosaurus zanoni''. In 2011, two additional species were assigned to this genus: ''H. longirostris'' and ''H. tomistomimus''. Description The holotype specimen of ''Hauffiosaurus'', housed in the Hauff Museum, is an almost complete and articulated skeleton, found from the Posidonien-Schiefer, dating to early Toarcian stage of the Early Jurassic. The holotype specimen preserved in a single block of the original matrix, exposed in ventral view. The body outline visible around the specimen is an artifact of preparation, not preservation; no remains of soft tissue were preserved. The skeleton was discovered during the early 19th Century, in beds of the famous Posidonien-Schiefer lagerstätte at Holzmaden, Baden-Württemberg, in sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hauffiosaurus Zanoni
''Hauffiosaurus'' is an extinct genus of Early Jurassic (early Toarcian stage) pliosaurid plesiosaur known from Holzmaden of Germany and from Yorkshire of the United Kingdom. It was first named by Frank Robin O’Keefe in 2001 and the type species is ''Hauffiosaurus zanoni''. In 2011, two additional species were assigned to this genus: ''H. longirostris'' and ''H. tomistomimus''. Description The holotype specimen of ''Hauffiosaurus'', housed in the Hauff Museum, is an almost complete and articulated skeleton, found from the Posidonien-Schiefer, dating to early Toarcian stage of the Early Jurassic. The holotype specimen preserved in a single block of the original matrix, exposed in ventral view. The body outline visible around the specimen is an artifact of preparation, not preservation; no remains of soft tissue were preserved. The skeleton was discovered during the early 19th Century, in beds of the famous Posidonien-Schiefer lagerstätte at Holzmaden, Baden-Württemberg, in sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachaucheninae
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 d ... follows an analysis by Benson & Druckenmiller (2014). References Middle Jurassic first appearances Cretac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Enamel
Tooth enamel is one of the four major Tissue (biology), tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the Crown (tooth), crown. The other major tissues are dentin, cementum, and Pulp (tooth), dental pulp. It is a very hard, white to off-white, highly mineralised substance that acts as a barrier to protect the tooth but can become susceptible to degradation, especially by acids from food and drink. Calcium hardens the tooth enamel. In rare circumstances enamel fails to form, leaving the underlying dentin exposed on the surface. Features Enamel is the hardest substance in the human body and contains the highest percentage of minerals (at 96%),Ross ''et al.'', p. 485 with water and organic material composing the rest.Ten Cate's Oral Histology, Nancy, Elsevier, pp. 70–94 The primary mineral is hydroxyapatite, which is a crystalline calcium phosphate. Enamel is formed o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacrimal Bone
The lacrimal bone is a small and fragile bone of the facial skeleton; it is roughly the size of the little fingernail. It is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders. Several bony landmarks of the lacrimal bone function in the process of lacrimation or crying. Specifically, the lacrimal bone helps form the nasolacrimal canal necessary for tear translocation. A depression on the anterior inferior portion of the bone, the lacrimal fossa, houses the membranous lacrimal sac. Tears or lacrimal fluid, from the lacrimal glands, collect in this sac during excessive lacrimation. The fluid then flows through the nasolacrimal duct and into the nasopharynx. This drainage results in what is commonly referred to a runny nose during excessive crying or tear production. Injury or fracture of the lacrimal bone can result in posttraumatic obstruction of the lacrimal pathways. Structure Lateral or orbital surface The lateral or orbital surface i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
