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Trinucleidae
Trinucleidae is a family of small to average size asaphida, asaphid trilobites that first occurred at the start of the Ordovician and became extinct at the end of that Period (geology), period. It contains approximately 227 species divided over 51 genera in 5 subfamilies. The most conspicuous character is the wide perforated fringe of the head. Description Trinucleids have a relatively large headshield, that is characterized by a highly vaulted pear-shaped glabella, separated by deep furrows from the cheeks that are often vaulted too, but less so. To the front and sides of this tri-nucleate centre is a wide seam (or fringe), that often inclinates towards the outer margin, and is perforated by funnel shaped pits. These pits are only in one row at the front in the first occurring genera, irregularly distributed in early species, but in later species these are largely arranged in several rows parallel to the margin, and in arches more or less perpendicular to the margin. The thorax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Costonia
''Costonia'' is a genus of trilobites in the family Trinucleidae. The species ''C. elegans'' is from the Ordovician of South Shropshire, England. See also * List of trilobite genera References External links * * ''Costonia'' at insectoid.info Trinucleidae Asaphida genera {{Asaphida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptolithus
''Cryptolithus'' is a genus of extinct trinucleid trilobites that lived during the Ordovician period. They were mostly blind. They are found in the United States, Canada, Venezuela, the United Kingdom, France, the Czech Republic, Morocco and Turkey. Species Valid species of ''Cryptolithus'' include: * '' Cryptolithus bellulus'' (Ulrich, 1879) * '' Cryptolithus carimatus'' * '' Cryptolithus fittsi'' (Ulrich & Whittington) * '' Cryptolithus goldfussi'' ( Barrande) * '' Cryptolithus inopinatus'' (Whittard) * '' Cryptolithus intertetus'' (Whittard) * '' Cryptolithus lorerainensis'' (Ruedemann) * '' Cryptolithus lorettensis'' (Foerste, 1924) * '' Cryptolithus ornatus'' (Sternberg) * '' Cryptolithus portlockii'' ** '' Cryptolithus portlockii girvanensis'' * '' Cryptolithus quadrillatus'' * '' Cryptolithus recurvus'' (Ulrich, 1919) * '' Cryptolithus tessellatus'' (Green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bettonolithus
Bettonolithus is a genus of trilobites of the Order Asaphida. It is in the family Trinucleidae. Fossil specimens have been found in the Lower Ordovician rocks of Gilwern Hill in Powys, Wales. Anatomical evidence suggests this Trilobite sifted organic matter on the seabed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of .... References Trinucleidae Asaphida genera Fossils of Great Britain Ordovician trilobites {{Asaphida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asaphida
Asaphida is a large, morphologically diverse order of trilobites found in marine strata dated from the Middle Cambrian until their extinction during the Silurian. Asaphida contains six superfamilies (Anomocaroidea, Asaphoidea, Cyclopygoidea, Dikelocephaloidea, Remopleuridoidea and Trinucleioidea), but no suborders. Asaphids comprise some 20% of described fossil trilobites. In 2020, the superfamily Trinucleoidea was proposed to be raised to an order ( Trinucleida) and removed from Asaphida. Morphology The Asaphids generally have cephalon (head) and pygidium (tail) parts similar in size, and most species have a prominent median ventral suture. Heads are often flat, and carapace furrows in the head area are often faint or not visible. Thoracic segments typically number 5 - 12, though some species have as few as two and some as many as 30. They also generally have a wide doublure, or rim, that surrounds the cephalon. This causes some specimens to be described as having a char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furcalithus
''Furcalithus'' is an extinct genus from a well-known class of fossil marine arthropods, the trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...s. It lived during the early part of the Arenig stage of the Ordovician Period, a faunal stage which lasted from approximately 478 to 471 million years ago. References Trinucleidae Asaphida genera Ordovician trilobites Fossils of Great Britain {{Asaphida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Famatinolithus
''Famatinolithus'' is an extinct genus from a well-known class of fossil marine arthropods, the trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the At ...s. It lived during the early part of the Arenig stage of the Ordovician Period, a faunal stage which lasted from approximately 478 to 471 million years ago. References Trinucleidae Asaphida genera Ordovician trilobites of South America Fossils of Argentina {{Asaphida-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anebolithus
''Anebolithus'' is a genus of trilobites found in Gilwern Hill, Powys, Wales Wales ( cy, Cymru ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by England to the Wales–England border, east, the Irish Sea to the north and west, the Celtic Sea to the south west and the .... ''Anebolithus'', like other trinucleids, was blind. References Trinucleidae Asaphida genera Fossils of Great Britain Fossils of Wales Powys {{Wales-stub Paleontology in Wales ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should clearly demons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
