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Hoplitosaurus Marshi
''Hoplitosaurus'' (meaning "Hoplite lizard") was a genus of armored dinosaur related to ''Polacanthus''. It was named from a partial skeleton found in the Barremian-age Lower Cretaceous Lakota Formation of Custer County, South Dakota, Custer County, South Dakota. It is an obscure genus which has been subject to some misinterpretation of its damaged remains. Although there was a push to synonymize it with ''Polacanthus'' in the late 1980s-early 1990s, ''Hoplitosaurus'' has been accepted as a valid albeit poorly known genus in more recent reviews. History and Taxonomy The holotype specimen, USNM 4752, was discovered in 1898 by Nelson Horatio Darton, near Buffalo Gap Station, and consisted of ribs, caudal vertebrae, part of a right scapulocoracoid, parts of both humerus, humeri, a right femur, and a variety of armour (zoology), armor (including tall spines).Lucas, F.A. (1901). A new dinosaur, ''Stegosaurus marshi'', from the Lower Cretaceous of South Dakota. ''Proceedings of the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous
The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 Megaannum#SI prefix multipliers, 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 Anoxic event#Cretaceous, early Aptian Oceanic Anoxic Event 1a (OAE1a) was 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 Plateau, Ontong Java-Manihiki Plateau, Manihiki-Hikurangi Plateau, Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Onto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
