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Hildoceratoidea
Hildoceratoidea, formerly Hildoceratacaea, is a superfamily of compressed or planulate ammonites, some tending to develop acute outer rims; generally with arcuate or sigmoidal ribs. Aptichus were found in place are double-valved.Arkell ''et al.'', Treatise on Invertebrate Paleontology, Part L Ammonoidea, (1956) Hildoceratoidea is an upper Lower to lower Middle Jurassic group belonging to the Ammonitina that unites the Hildoceratidae, Hammatoceratidae, Graphoceratidae, and Sonniniidae. In some taxonomies the name Phymatoceratidae is substituted for the Hammatoceratidae Hildoceratidae, which is the ancestral family, is derived from the Acanthopleuroceratinae, a subfamily in the Eoderoceratoidean family, Polyorphitidae. The Stephanoceratoidea, Perisphinctoidea, and Haploceratoidea Haploceratoidea, formerly Haplocerataceae, is an extinct superfamily of Ammonoidea, ammonoid cephalopods belonging to the Ammonitida that unites three families, Strigoceratidae, Oppeliidae, and Haplocer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erycitidae
Erycitidae is a family of Lower and Middle Jurassic ammonites included in the Hildoceratoidea. The hammatoceratid subfamily Erycitinae is equivalent. Genera include '' Erycites'' (type) and '' Abbasites''. Description Erycitids are generally evolute with all whorls showing and are strongly ribbed with ribs branching on the outer part of the flanks and crossing over the outer rim, or venter. Classification In older taxonomies, e.g. W.J. Arkell ''et al.'', 1964 and D.T. Donovan ''et al.'', 1981, the Hammatoceratidae, which then included erycitid genera, was part of the Hammatoceratoidea. More recently the Erycitidae was reassigned to the Hammatoceratoidea which also includes the Hammatoceratidae, Graphoceratidae and Sonniniidae removed from the Hildoceratoidea, left with only the Hildoceratidae and its included subfamilies. References * W.J. Arkell ''et al.'', 1957. Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hildoceratidae
Hildoceratidae is a family of Ammonoidea, ammonoid cephalopods from the Lower Jurassic, lower Pliensbachian (''Jamesoni'' zone) to lower Bajocian (maybe even upper Bajocian) substages, generally with strongly ribbed, involute shells. They are combined with the Hammatoceratidae (= Phymatoceratidae), Graphoceratidae, and Sonniniidae to make up the Hildoceratoidea. As many as seven subfamilies have been included in late 20th century, principle being the Arieticeratinae, Harpocertinae, Hildoceratinae, to which the Treatise, Part L, adds the Bouleiceratinae, Grammoceratinae, and Tmetoceratinae. Donovan et al. (1981) includes the same and adds the Leioceratinae which the older Treatise includes in the Graphoceratidae. Currently Leioceratinae are again members of Graphoceratidae and into Hildoceratidae are added newly established subfamily Leukadiellinae and Protogrammoceratinae, which has been by Donovan et al. (1981) considered as part of Harpoceratinae.M. K. Howarth 2013. Treatise on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
