|
Strabopida
Strabopidae is the only Family (biology), family of the order Strabopida, an extinct group of arthropods known from the Cambrian period. The order Strabopida contains three valid genera and one doubtful, ''Khankaspis'', ''Paleomerus'', ''Parapaleomerus'' and ''Strabops'', all assigned in the family Strabopidae. Previously, it also contained the genera ''Caryon'', ''Lemoneites'' and ''Neostrabops'', but after a study, they were reassigned as a trilobite, a Glyptocystitida, glyptocystitid echinoderm and a cheloniellid arthropod, respectively. Paleomeridae was also previously included as a family, but after the discovery of a fourth ''Paleomerus'' Biological specimen, specimen and its study, Paleomeridae was synonymized into Strabopidae. Although often suggested to be closely related to Aglaspidida, aglaspidids due to their similar morphology, their exact phylogenetic placement is uncertain due to the poor preservation of all known strabopids. A 2013 attempt to place them in a phylo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleomerus
''Paleomerus'' is a genus of strabopid, a group of extinct arthropods. It has been found in deposits from the Cambrian period (geology), period (Atdabanian Epoch (geology), epoch). It is classified in the Family (biology), family Strabopidae of the monotypic Order (biology), order Strabopida. It contains two species, ''P. hamiltoni'' from Sweden and ''P. makowskii'' from Poland. The generic name is composed by the Ancient Greek words παλαιός (''palaiós''), meaning "ancient", and μέρος (''méros''), meaning "part" (and therefore, "ancient part"). ''Paleomerus'' is one of the oldest arthropods, being sometimes interpreted as the model of the first arachnomorphs. It is part of the order Strabopida, a poorly known group closely related to the aglaspidids of uncertain affinities, often being ignored by researchers and authors due to the poor preservation and abundance of their fossils. It has been suggested that ''Paleomerus'' and the closely related ''Strabops'' could be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strabops Thacheri
''Strabops'' is a genus of strabopid, an extinct group of arthropods. ''Strabops'' is known from a single specimen from the Late Cambrian (Furongian age) of the Potosi Dolomite, Missouri, collected by a former professor, Arthur Thacher. It is classified in the family Strabopidae of the monotypic order Strabopida, a group closely related to the aglaspidids with uncertain affinities. The generic name is composed by the Ancient Greek words στραβός, meaning "squinting", and ὄψῐς, meaning "face" (and therefore, "squinting face"). The history of ''Strabops'' has been turbulent and confusing since its original description by Charles Emerson Beecher, who classified it as a eurypterid. Many authors do not agree with this and have classified ''Strabops'' and its allies as part of the Aglaspidida order, while others classify them in their own order. Although the latter is the taxonomic position currently accepted, other paleontologists prefer to simply omit the strabopids f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strabopida
Strabopidae is the only Family (biology), family of the order Strabopida, an extinct group of arthropods known from the Cambrian period. The order Strabopida contains three valid genera and one doubtful, ''Khankaspis'', ''Paleomerus'', ''Parapaleomerus'' and ''Strabops'', all assigned in the family Strabopidae. Previously, it also contained the genera ''Caryon'', ''Lemoneites'' and ''Neostrabops'', but after a study, they were reassigned as a trilobite, a Glyptocystitida, glyptocystitid echinoderm and a cheloniellid arthropod, respectively. Paleomeridae was also previously included as a family, but after the discovery of a fourth ''Paleomerus'' Biological specimen, specimen and its study, Paleomeridae was synonymized into Strabopidae. Although often suggested to be closely related to Aglaspidida, aglaspidids due to their similar morphology, their exact phylogenetic placement is uncertain due to the poor preservation of all known strabopids. A 2013 attempt to place them in a phylo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Khankaspis
''Khankaspis'' is a poorly preserved arthropod genus that contains one species, ''K. bazhanovi'', recovered from the Snegurovka Formation of Siberia, Russia. Some authors have placed ''Khankaspis'' within the order Strabopida, but poorly preserved material precludes detailed comparisons with other Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ... arthropods. References Cambrian arthropods Cambrian animals of Asia Fossils of Russia Fossil taxa described in 1969 Controversial taxa Cambrian genus extinctions {{paleo-arthropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parapaleomerus
''Parapaleomerus'' is a genus of strabopid of small size found in Chengjiang biota, China. It contains one species, ''Parapaleomerus sinensis''. Unlike the other members of Strabopida, ''Parapaleomerus'' lacks dorsal eyes and only possesses ten trunk tergites. The telson has been described as trapezoidal. All the trunk tergites are straight and increasingly curve backwards abaxially from T4–10. Specimens of ''Parapaleomerus sinesis'' are typically dorsoventrally compressed. The exoskeleton An exoskeleton () . is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs, in contrast to an internal endoskeleton (e.g. human skeleton, that ... of ''P. sinensis'' has a semi-elliptical head shield that lacks any indication of the presence of dorsal eyes. The largest specimen described is recorded as 9.2 cm long, with a maximum width of 9 cm. References Strabopida Fossi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metamerism (biology), metameric) Segmentation (biology), segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They form an extremely diverse group of up to ten million species. Haemolymph is the analogue of blood for most arthropods. An arthropod has an open circulatory system, with a body cavity called a haemocoel through which haemolymph circulates to the interior Organ (anatomy), organs. Like their exteriors, the internal organs of arthropods are generally built of repeated segments. They have ladder-like nervous systems, with paired Anatomical terms of location#Dorsal and ventral, ventral Ventral nerve cord, nerve cord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aglaspidida
Aglaspidida is an extinct order of marine arthropods known from fossils spanning the Middle Cambrian to the Upper Ordovician. Initially considered chelicerates, modern anatomical comparisons demonstrate that the aglaspidids cannot be accommodated within this group, and that they lie instead within the Artiopoda, thus placing them closer to the trilobites, being placed in the artiopod subgroup Vicissicaudata. With 38 known valid species as of 2017, they represent one of the most diverse groups of early Paleozoic arthropods, after trilobites.Lerosey-Aubril, R., Ortega-Hernández, J., Van Roy, P., Zhu, X., (2017)The Aglaspidida: a poorly-known, yet important order of early Palaeozoic arthropods ''International Workshop on Evolution of Cambrian Arthropods - Taxonomy, Ontogeny and Phylogeny''. 1-6 Sep. 2017, Xian, China. Aglaspidid fossils are found in North America (United States and Canada), Europe, Australia, and China. Description The exoskeletons of aglaspidids have frequently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arachnomorpha
Arachnomorpha is a proposed subdivision or clade of Arthropoda, comprising the group formed by the trilobites and their close relatives (Artiopoda), Megacheira (which may be paraphyletic) and chelicerates. Under this proposed classification scheme, Arachnomorpha is considered the sister group to Mandibulata (including insects, crustaceans and myriapods). The arachnomorph concept has been challenged by suggestions that the artiopods are more closely related to mandibulates, forming the clade Antennulata instead. There is no consensus as to assigning Arachnomorpha a formal Linnean rank. Classification Arachnomorpha Lameere, 1890 Arachnata Paulus, 1979, = Palaeopoda Packard, 1903*†'' Nettapezoura'' *†'' Dicranocaris'' *† Trilobita Walch, 1771 *† Megacheira Hou & Bergstrom, 1997 *† Strabopida Hou & Bergström, 1997 *† Aglaspida Walcott, 1911 *† Cheloniellida Broili, 1932 *Chelicerata Heymons 1901 **Family † Sanctacarididae Legg & Pates, 2017 **Class Pycnogoni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artiopoda
Artiopoda is a clade of extinct arthropods that includes trilobites and their close relatives. It was erected by Hou and Bergström in 1997 to encompass a wide diversity of arthropods that would traditionally have been assigned to the Trilobitomorpha. Trilobites, in part due to abundance of findings owing to their mineralized exoskeletons, are by far the best recorded, diverse, and long lived members of the clade. Other members, which lack mineralised exoskeletons, are known mostly from Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ... deposits. Description According to Stein and Selden (2012) artiopods are recognised by the possession of filiform antennulae, limbs with bilobate exopods (upper branches), with the proximal (closest to base of the limb) lobe being elong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lemoneites
''Lemoneites'' is a genus of glyptocystitid, a group of extinct blastozoan echinoderms, known from the Ordovician period. The genus was first described in 1969 by Rousseau H. Flower. It contains a single species, ''L. mirabilis'', known from fossils found in the lower part of the Scenic Drive Formation within the El Paso Group of the Franklin Mountains in Texas. The fossils are preserved as silica replacements etched in dolomite. The genus was originally described as an aglaspidid within its own family, Lemoneitidae. It was also described as a xiphosuran. Later, it would be assigned to the order Strabopida Strabopidae is the only Family (biology), family of the order Strabopida, an extinct group of arthropods known from the Cambrian period. The order Strabopida contains three valid genera and one doubtful, ''Khankaspis'', ''Paleomerus'', ''Parapal ..., but after a study, ''Lemoneites'' was classified as an echinoderm. The genus originally contained three additional specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthropods including decapods (shrimps, prawns, crabs, lobsters and crayfish), seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods (insects and entognathans) emerged deep in the Crustacean group, with the completed pan-group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans ( oligostracans and multicrustaceans). The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
