|
Sidneyia
''Sidneyia'' is an extinct marine arthropod known from fossils found from the Early to the Mid Cambrian of China and the Mid Cambrian Burgess Shale of British Columbia, Canada. Description Sidneyia size comparison.svg, Size comparison of ''Sidneyia'' species Rsos211134f08 d.jpg, Biramous limb of ''Sidneyia inexpectans'' ''Sidneyia inexpectans'' reached lengths of at least . The largest known specimen of ''S. minor'' is around long and wide, while the largest specimen of ''S. malongensis'' is long and wide. The head shield is short, with notches present on the sides to accommodate stalked eyes, with the underside having a Hypostome (trilobite), hypostome. The head has a pair of segmented antennae, as well as three pairs of post-antenal appendages. This was followed by a thorax, which had eight to ten segments/Tergum, tergites, each associated with a pair of biramous (two branched) appendages, this was followed with one to three abdomen segments/tergites, with the body termi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vicissicaudata
Vicissicaudata is an unranked group of artiopodan arthropods, containing Cheloniellida, Aglaspidida and several other genera outside these groups like ''Sidneyia'' and ''Emeraldella.'' Description Vicissicaudatans are similar to most other artiopods in shape, with rounded bodies consisting of many wide tergites, sometimes with a distinguishable axis along the midline. This clade is defined by a differentiated posterior region, often ending in a telson and caudal appendages. The morphology of this posterior region varies between clades. Aglaspidids, alongside '' Eozetetes'' and '' Carimersa'', have long styliform telsons and relatively small, flap-like caudal appendages while cheloniellids and '' Tardisia'' have much longer caudal appendages similar to the caudal furcae of various taxa, alongside much smaller telsons more resembling the postabdominal segments. The paraphyletic "xenopods" are more similar to those of aglaspidids, also with long telsons and flap-like caudal app ... [...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] |
Emeraldella
''Emeraldella'' is a genus of arthropod known from the Middle Cambrian of North America. The type species ''E. brocki'' was described in 1912 from the Burgess Shale. 21 specimens of ''Emeraldella'' are known from the Greater Phyllopod bed, where they comprise < 0.1% of the community. A re-study on the species was done in 2012. A second species ''E. brutoni'' is known from the Wheeler Shale, which was described in 2011. An additional specimen of ''E. brutoni'' was described in 2019, which revealed more of the anatomy. It has been placed as a basal member of the clade Vicissicaudata within Artiopoda, a group of arthropods containing trilobites and their relatives. Description [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sirius Passet
Sirius Passet is a Cambrian Lagerstätte in Peary Land, Greenland. The Sirius Passet Lagerstätte was named after the Slædepatruljen Sirius, Sirius sledge patrol that operates in North Greenland. It comprises six places in Nansen Land, on the east shore of J.P. Koch Fjord in the far north of Greenland. It was discovered in 1984 by A. Higgins of the Geological Survey of Denmark and Greenland, Geological Survey of Greenland. A preliminary account was published by Simon Conway Morris and others in 1987 and expeditions led by J. S. Peel and Conway Morris have returned to the site several times between 1989 and the present. A field collection of perhaps 10,000 fossil specimens has been amassed. It is a part of the Buen Formation. Age The fauna is inevitably compared to that of the Burgess Shale, although it is probably ten to fifteen million years older – vs. ) – and more closely contemporaneous with the fauna of the Maotianshan shales from Chengjiang, which are dated to . Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thulaspis Diagram
''Thulaspis'' is an extinct genus of artiopodan arthropod from the Cambrian Stage 3 aged Sirius Passet site in Greenland. It is thought to be a close relative of '' Squamacula'', and is possibly one of the most basal members of Artiopoda. Description ''Thulaspsis'' was relatively large-sized. The largest specimen is about wide and long. The carapace is overall oval-shaped was convex and likely stiff in life, with a raised central axis. The head is broad and bears a pair of antennae, which have at least 20 rectangular segments, and likely two pairs of biramous (two branched) limbs.The body has 15 thoracic segments, which curve forwards in the first few segments, before becoming straight in the fourth and fifth segments, then increasingly posteriorly curved in subsequent segments. At least the first 11 thoracic segments are associated with pairs of biramous limbs. The biramous limbs have robust endopods (lower, leg-like branches), and flap-shaped exopods (upper branches). The b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most successful of all early animals, existing in oceans for almost 270million years, with over 22,000 species having been described. Because trilobites had wide diversity and an easily fossilized mineralised exoskeleton made of calcite, they left an extensive fossil record. The study of their fossils has facilitated important contributions to biostratigraphy, paleontology, evolution, evolutionary biology, and plate tectonics. Trilobites are placed within the clade Artiopoda, which includes many organisms that are morphologically similar to trilobites, but are largely unmineralised. The relationship of Artiopoda to other arthropods is uncertain. Trilobites evolved into many ecological niches; some moved over the seabed as predators, scavengers, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spence Shale
The Spence Shale is the middle member of the Langston Formation in southeastern Idaho and northeastern Utah. It is exposed in the Bear River Range, the Wasatch Range and the Wellsville Mountains. It is known for its abundant Cambrian trilobites and the preservation of Burgess Shale-type fossils. The type locality is Spence Gulch in southeastern Idaho, near the town of Liberty. It was first described by Charles Doolittle Walcott in 1908. Stratigraphy The Spence Shale spans the '' Albertella'' and '' Glossopleura'' biozones. Fauna Generic list of the fauna of the Spence Shale:Hammersburg, S.R., Hasiotis, S.T., Robison, R.R. 2018. Ichnotaxonomy of the Cambrian Spence Shale Member of the Langston Formation, Wellsville Mountains, Northern Utah, USA. Paleontological Contributions, 20, 1–66. Arthropoda Soft-bodied *''Anomalocaris'' *'' Canadaspis'' *''Caryosyntrips'' *'' Dioxycaris'' *'' Hurdia'' *''Isoxys'' *''Leanchoilia'' *'' Meristosoma'' *'' Mollisonia'' *''Sidneyia' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biramous
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, : ''coxae''), ''trochanter'', ''femur'' (: ''femora''), ''tibia'' (: ''tibiae''), ''tarsus'' (: ''tarsi''), ''ischium'' (: ''ischia''), ''metatarsus'', ''carpus'', ''dactylus'' (meaning finger), ''patella'' (: ''patellae''). Homologies of leg segments between groups are difficult to prove and are the source of much argument. Some authors posit up to eleven segments per leg for the most recent common ancestor of extant arthropods but modern arthropods have eight or fewer. It has been argued that the ancestral leg need not have been so complex, and that other events, such as successive loss of function of a ''Hox''-gene, could result in parallel gains of leg segments. In arthropods, each of the leg segments articulates with the next seg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chengjiang Biota
The Maotianshan Shales () are a series of Early Cambrian sedimentary deposits in the Chiungchussu Formation or Heilinpu Formation, famous for their '' Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized organisms or traces. The Maotianshan Shales form one of some forty Cambrian fossil locations worldwide exhibiting exquisite preservation of rarely preserved, non-mineralized soft tissue, comparable to the fossils of the Burgess Shale of British Columbia, Canada. They take their name from Maotianshan Hill () in Chengjiang County, Yunnan Province, China. The most famous assemblage of organisms are referred to as the Chengjiang biota for the multiple scattered fossil sites in Chengjiang. The age of the Chengjiang Lagerstätte is locally termed Qiongzhusian, a stage correlated to the late Atdabanian Stage in Siberian sequences of the middle of the Early Cambrian. The shales date to ≤. Along with the Burgess Shale, the Maotianshan Shales ar ... [...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] |
