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Trilobitomorpha
The Artiopoda is a grouping 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. Hou and Bergström used the name Lamellipedia as a superclass to replace Trilobitomorpha that was originally erected at the subphylum level, which they considered inappropriate. Trilobites, in part due to their mineralising exoskeletons, are by far the most diverse and long lived members of the clade, with most records of other members, which lack mineralised exoskeletons, being from Cambrian deposits. Description According to Stein and Selden (2012) artiopods are recognised by the possession of filiform antennulae, limbs with bilobate exopods, with the proximal lobe being elongate and bearing a lamella, while the distal lobe is paddle-shaped and setiforous (bearing hair-or bristle like structures). The limb endopod has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bailongia
''Bailongia'' is an extinct genus of arthropod known from a single species ''Bailongia longicaudata'' (''longicaudata'' from Latin: "long-tailed") found in the Cambrian Stage 4 aged Guanshan Biota of Yunnan, China. It was around 5mm long and had a large head shield, nine overlapping tapering tergites and a relatively elongate tailspine. It has been recovered in a relatively basal position within Artiopoda, more derived than ''Squamacula ''Squamacula'' is an extinct artiopodan arthropod from the Cambrian Series 2. The type species ''S. clypeata'' was described in 1997 from the Chengjiang biota. At the time of description there were only two known specimens of ''S. clypeata'', b ...'' or Protosutura, but outside Trilobitomorpha or Vicissicaudata. Phylogeny After Jiao et al. 2021. References Artiopoda Cambrian arthropods of Asia Cambrian China Paleontology in Yunnan Fossil taxa described in 2021 Cambrian genus extinctions {{Paleo-arthropod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paradoxides
''Paradoxides'' is a genus of large to very large trilobite found throughout the world during the Middle Cambrian period. One record-breaking specimen of ''Paradoxides davidis'', described by John William Salter in 1863, is . The cephalon was semicircular with free cheeks ending in long, narrow, recurved spines. Eyes were crescent shaped providing an almost 360° view, but only in the horizontal plane. Its elongate thorax was composed of 19-21 segments and adorned with longish, recurved pleural spines. Its pygidium was comparatively small. ''Paradoxides'' is a characteristic Middle-Cambrian trilobite of the 'Atlantic' (Avalonian) fauna. Avalonian rocks were deposited near a small continent called Avalonia in the Paleozoic Iapetus Ocean. Avalonian beds are now in a narrow strip along the East Coast of North America, and in Europe. Description The exoskeleton of ''Paradoxides'' is large to very large, relatively flat, and about one and a half times longer than wide, with greates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nektaspida
Nektaspida (also called Naraoiida, Nektaspia and Nectaspida) is an extinct order of non- mineralised artiopodan arthropods. They are known from the mid-Cambrian to the upper Silurian. Originally classified as trilobites, which they superficially resemble, they are now placed as close relatives as members of the Trilobitomorpha within Artiopoda. The order is divided into three major families; Emucarididae, Liwiidae, and Naraoiidae. Naming history and taxonomic placement The order was originally proposed by Raymond in 1920 as Nektaspia. Størmer corrected it to Nectaspida for the 1959 ''Treatise on Invertebrate Paleontology'' to conform with the names of the other trilobite orders. Whittington described it in 1985 with the spelling Nektaspida; the revised 1997 Treatise by Raymond and Fortey uses this spelling, as do other modern works. Whittington (1985) placed the order in the Trilobita. Cotton & Braddy (2000) place it in a new "Trilobite clade" containing the Trilobita, recog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kwanyinaspis
''Kwanyinaspis'' is a genus of arthropod from the Cambrian aged Chengjiang biota of Yunnan, China. It was described in 2005 based on a single specimen, ELI-2004001. Around 6 cm long, It has twelve trunk tergites with well developed posterior facing pleural spines, along with a tail spine and ventral eyes. In the original description, it was tenatively considered a member of Aglaspidida. However, later studies have considered it a trilobitomorph, and possibly the closest known relative of 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 ...s. References {{Artiopoda Artiopoda Prehistoric arthropod genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pygmaclypeatus
''Pygmaclypeatus'' is a genus of trilobite-like arthropod from the Cambrian aged Chengjiang biota of southern China. It is less than 20 mm in length. The carapace is flat and broad, and slightly shorter than it is wide. The trunk has 6 tergites, along with a terminal pygidium associated with a segmented short tailspine. The well developed paddle-like exopodites on the trunk limbs along with its small size suggests that it was an effective swimmer with a strong power stroke, and that it probably had a nektobenthic mode of life, swimming close to the ocean floor. Given its delicate spinose endites on the limbs it likely only consumed soft food and organic particles. It is considered to be closely related to ''Retifacies'' from the same deposit with shared characters including a segmented tailspine. It has been placed as a member of Artiopoda, possibly along with ''Retifacies'' the earliest diverging lineage of the Trilobitomorpha The Artiopoda is a grouping of extinct arthropods th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saperion
''Saperion'' is an extinct genus of trilobite-like arthropod. It lived during the late Atdabanian stage, which lasted from 521 to 514 million years ago during the early part of the Cambrian Period The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million .... It was found in the Maotianshan Shales ''Saperion'' reached 151 mm in length and had nearly 25 pairs of limbs for walking. References Cambrian trilobites {{trilobite-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tegopelte
''Tegopelte gigas'' (from the Greek tegos, “tile,” and pelte, “leather-shield,” referring to the shape of the dorsal body covering; gigas – from the Greek gigas, “giant,” due to the huge size of the animalTegopelte gigas. A giant trilobite-like arthropod The Burgess Shale.) is a species of large (1 complete specimen was 27 cm) soft-bodied known from two specimens from the . [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmetia
''Helmetia'' is an extinct genus of arthropod from the middle Cambrian. Its fossils have been found in the Burgess Shale of Canada and the Jince Formation of the Czech Republic. Fossils are both rare and poorly known; the genus was described by Walcott in 1918 and has not been reexamined, though it was briefly reviewed in the 1990s and has been included in a number of cladistic analyses. It has been lumped with the arachnomorphs. One analysis has resolved the Helmetiiida as a robust clade and the closest relatives of trilobites. The most complete specimen of ''Helmetia'' is 19 cm long, and has six thoracic segments. There is a head shield and a large tail shield, making the animal leaf-shaped. Unlike trilobites, the margin of the head shield is concave, ending in a spine on each corner. There is an oval structure with two spots at the anterior center of the head shield, behind which are two eyes. The whole animal is broad and flat with a thin exoskeleton. The central regio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luohuilinella
''Luohuilinella'' is an extinct genus of xandarellid artiopodan arthropod known from the Chengjiang biota of China. The type species ''Luohuilinella rarus'' was described in 2012. A second species ''Luohuilinella deletres'' was described in 2018. Both taxa are rare components of the assemblage. Like other Xandarellids and most artiopodans, it possessed an unmineralised exoskeleton. The type and currently only known specimen of ''L. rarus'' is known from a dorsal exoskeleton, around 17 mm long and 9 mm wide which consists of 27 tergites with pronounced pleural spines. ''L. deletres'' is much larger, with specimens being over 10 cm long, ''L. deletres'' possessed at least 11 pairs of biramous appendages. Both taxa are dorsoventrally flattened, making a benthic or nektobenthic lifestyle probable. Both taxa have pronounced notches in the cephalon Cephalon, Inc. was an American biopharmaceutical company co-founded in 1987 by pharmacologist Frank Baldino, Jr., n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
