Parksosauridae
Thescelosauridae is a clade of neornithischians from the Cretaceous of Asia, North America and possibly South America. The group was originally used as a name by Charles M. Sternberg in 1937, but was not formally defined until 2013, where it was used by Brown and colleagues as the group uniting ''Thescelosaurus'' and ''Orodromeus'', based on their phylogenetic results. During a phylogenetic revision of neornithischians by Clint Boyd in 2015, the authorship of Thescelosauridae was given to Brown and colleagues, which meant that the similar name Parksosauridae, informally defined in 2002 by Buchholz, would have had priority over Thescelosauridae. The two clades had slightly different definitions, with Parksosauridae referring to all animals closer to ''Parksosaurus'' than ''Hypsilophodon'', but they contained the same taxa so Boyd used Parksosauridae under the assumption it had priority. However, in formalizing the clade following the regulations of the PhyloCode, Madzia, Boyd, and c ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Neornithischia
Neornithischia ("new ornithischians") is a clade of the dinosaur order Ornithischia. It is the sister group of the Thyreophora within the clade Genasauria. Neornithischians are united by having a thicker layer of asymmetrical enamel on the inside of their lower teeth. The teeth wore unevenly with chewing and developed sharp ridges that allowed neornithischians to break down tougher plant food than other dinosaurs. Neornithischians include a variety of basal forms historically known as "hypsilophodonts", including the Parksosauridae; in addition, there are derived forms classified in the groups Marginocephalia and Ornithopoda. The former includes clades Pachycephalosauria and Ceratopsia, while the latter typically includes ''Hypsilophodon'' and the more derived Iguanodontia. Classification Neornithischia was first named by Cooper in 1985 and defined as "all genasaurians more closely related to ''Parasaurolophus walkeri'' than to ''Ankylosaurus magniventris'' or ''Stegosaurus stenop ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Neornithischia
Neornithischia ("new ornithischians") is a clade of the dinosaur order Ornithischia. It is the sister group of the Thyreophora within the clade Genasauria. Neornithischians are united by having a thicker layer of asymmetrical enamel on the inside of their lower teeth. The teeth wore unevenly with chewing and developed sharp ridges that allowed neornithischians to break down tougher plant food than other dinosaurs. Neornithischians include a variety of basal forms historically known as "hypsilophodonts", including the Parksosauridae; in addition, there are derived forms classified in the groups Marginocephalia and Ornithopoda. The former includes clades Pachycephalosauria and Ceratopsia, while the latter typically includes ''Hypsilophodon'' and the more derived Iguanodontia. Classification Neornithischia was first named by Cooper in 1985 and defined as "all genasaurians more closely related to ''Parasaurolophus walkeri'' than to ''Ankylosaurus magniventris'' or ''Stegosaurus stenop ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Parksosaurus
''Parksosaurus'' (meaning " William Parks's lizard") is a genus of neornithischian dinosaur from the early Maastrichtian-age Upper Cretaceous Horseshoe Canyon Formation of Alberta, Canada. It is based on most of a partially articulated skeleton and partial skull, showing it to have been a small, bipedal, herbivorous dinosaur. It is one of the few described non-hadrosaurid ornithopods from the end of the Cretaceous in North America, existing around 70 million years ago. Description Explicit estimates of the entire size of the animal are rare; in 2010 Gregory S. Paul estimated the length at 2.5 meters, the weight at forty-five kilograms.Paul, G.S., 2010, ''The Princeton Field Guide to Dinosaurs'', Princeton University Press p. 277 William Parks found the hindlimb of his ''T. warreni'' to be about the same length overall as that of ''Thescelosaurus neglectus'' (93.0 centimeters (3.05 ft) for ''T. warreni'' versus 95.5 centimeters (3.13 ft) for ''T. neglect ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Yandusaurus
''Yandusaurus'' is a genus of herbivorous basal neornithischian dinosaur from the Bathonian age (middle Jurassic, approximately 168 to 162 Ma) of China. Discovery and naming In January 1973 the Museum of the Salt Industry at Zigong in Sichuan was warned that during construction activities with a composter at Jinzidang near the Honghe dam inadvertently a dinosaur skeleton had been processed. A team of the museum managed to salvage some heavily damaged remains. Though locally this animal was at first referred to as "Yubasaurus" or "Honghesaurus", in 1979 Beijing professor He Xinlu named and described it as the type species ''Yandusaurus hongheensis''. The generic name is derived from ''Yandu'', the ancient name for Zigong. This name is a contraction of ''yan'', "salt", and ''du'', "capital", occasioned by the fact that Zigong was historically the centre of Chinese salt mining. In this way ''Yandusaurus'' indirectly also refers to the Salt Museum. The specific name refers to th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Hexinlusaurus
''Hexinlusaurus'' is a genus of basal ornithischian dinosaur from the Middle Jurassic of China. The holotype (ZDM T6001, Zigong Dinosaur Museum, Dashanpu, People's Republic of China), consists of an almost complete, articulated skull and some postcranial material, collected from a terrestrial sandstone within the Lower Shaximiao Formation (?Bajocian) at the famous dinosaur-bearing quarries at Dashanpu. A paratype (ZDM T6002) consists of a partial skull and postcranial remains. Previously, it had been described as a species of ''Yandusaurus'', ''Y. multidens'' (He and Cai, 1983), but was reclassified as a new taxon by Paul M. Barrett, Richard J. Butler and Fabien Knoll in 2005, who diagnosed this anatomically conservative species as follows: "A small ornithischian dinosaur distinguished from all other basal ornithischians by a single autapomorphy, the presence of a marked concavity that extends over the lateral surface of the postorbital." The etymology of the genus name honors Pr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Agilisaurus
''Agilisaurus'' (; 'agile lizard') is a genus of ornithischian dinosaur from the Middle Jurassic Period of what is now eastern Asia. It was about 3.5–4 ft (1.2-1.7 m) long, 2 ft (0.6 m) in height and 40 kg in weight. It has leaf-shaped teeth that were well-adapted to their abrasive, plant-based diets. Most surprisingly, the wavy enamel of the teeth of ''A. louderbacki'' and all other ornithopods, presumably to make it more resistant to wear, was previously thought to be exclusive to the hadrosaurs. This is also the case for ''Changchunsaurus parvus''.Jun Chen, Aaron R. H. LeBlanc, Liyong Jin, Timothy Huang, Robert R. Reisz. Tooth development, histology, and enamel microstructure in Changchunsaurus parvus: Implications for dental evolution in ornithopod dinosaurs. PLOS ONE, 2018; 13 (11): e0205206 DOI: 10.1371/journal.pone.0205206 Description Its tibia (lower leg bone) 207.0 mm in length, was longer than its femur (upper leg bone) 199.0 mm in length, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lesothosaurus
''Lesothosaurus'' is a monospecific genus of ornithischian dinosaur that lived during the Early Jurassic in what is now South Africa and Lesotho. It was named by paleontologist Peter Galton in 1978, the name meaning " lizard from Lesotho". The genus has only one valid species, ''Lesothosaurus diagnosticus''. ''Lesothosaurus'' is one of the most completely-known early ornithischians, based on numerous skull and postcranial fossils from the Upper Elliot Formation. It had a simpler tooth and jaw anatomy than later ornithischians, and may have been omnivorous in some parts of the year. Discovery and naming Fossils referrable to ''Lesothosaurus'' may have been known from as early as 1959, when a right dentary (lower jawbone) fragment bearing three teeth was collected by French geologist Jean Fabre from the Red Beds of the Upper Elliot Formation near Mapheteng in Lesotho, Southern Africa, dating to the Early Jurassic (199(?)-190 million years ago).Ginsburg, L., (1964), "Decouvert ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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2018 In Paleontology
Flora Plants Fungi Cnidarians Research * New three dimensionally phosphatized microfossils of coronate scyphozoan '' Qinscyphus necopinus'', including a new type of fossil embryo, are described from the Cambrian (Fortunian) Kuanchuanpu Formation (China) by Shao ''et al.'' (2018), who interpret their findings as indicating that ''Qinscyphus'' underwent direct development. * A study on the morphology of the conulariid species '' Carinachites spinatus'' based on a new specimen collected from the lower Cambrian Kuanchuanpu Formation (China) is published by Han ''et al.'' (2018). * Revision of stony corals from the Lower Cretaceous (Berriasian) Oehrli Formation (Austria and Switzerland) is published by Baron-Szabo (2018), who compares this fauna with five additional Berriasian coral faunas. New taxa Arthropods Bryozoans New taxa Brachiopods Research * Studies on the ontogenetic development of early acrotretoid brachiopods based on well preserved specimens of t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Hypsilophodon Foxii
''Hypsilophodon'' (; meaning "''Hypsilophus''-tooth") is a neornithischian dinosaur genus from the Early Cretaceous period of England. It has traditionally been considered an early member of the group Ornithopoda, but recent research has put this into question. The first remains of ''Hypsilophodon'' were found in 1849; the type species, ''Hypsilophodon foxii'', was named in 1869. Abundant fossil discoveries were made on the Isle of Wight, giving a good impression of the build of the species. It was a small, agile bipedal animal with an herbivorous or possibly omnivorous diet, measuring long and weighing . It had a pointed head equipped with a sharp beak used to bite off plant material, much like modern day parrots. Older studies have given rise to a number of misconceptions about ''Hypsilophodon'' that it was an armored, arboreal animal and that it could be found in areas outside of Wight. During the past decades, new researches have gradually shown this to be incorrect. Discov ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Iguanodon Bernissartensis
''Iguanodon'' ( ; meaning 'iguana-tooth'), named in 1825, is a genus of iguanodontian dinosaur. While many species have been classified in the genus ''Iguanodon'', dating from the late Jurassic Period to the early Cretaceous Period of Asia, Europe, and North America, taxonomic revision in the early 21st century has defined ''Iguanodon'' to be based on one well-substantiated species: ''I. bernissartensis'', which lived from the late Barremian to the earliest Aptian ages (Early Cretaceous) in Belgium, Germany, England, Spain, and possibly elsewhere in Europe, between about 126 and 122 million years ago. ''Iguanodon'' was a large, bulky herbivore, measuring up to in length and in body mass. Distinctive features include large thumb spikes, which were possibly used for defense against predators, combined with long prehensile fifth fingers able to forage for food. The genus was named in 1825 by English geologist Gideon Mantell but discovered by William Harding Bensted, based o ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |