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Captopodus
''Captopodus'' is an extinct genus of stem-mandibulate known from the Early Devonian. This creature was described in 2012 from four fossils found in the Hunsrück Slate, an early Devonian lagerstätten in Germany that represents one of the few marine sites from the Devonian with soft tissue preservation. Description ''Captopodus'' is a vermiform (worm-like) arthropod, with over 66 trunk segments each containing a biramous limb pair, with the final segment containing a caudal furca. The head region contains two pairs of appendages, one being antennae, and the other resembling the grasping legs of thylacocephalans. It also has cupola-like structures, the function of which is unknown. The animal measures five to ten centimetres long. It is also very similar to, and probably related to the animal ''Acheronauta'', from the Waukesha Biota The Waukesha Biota (also known as Waukesha Lagerstätte, Brandon Bridge Lagerstätte, or Brandon Bridge fauna) is an important fossil site l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acheronauta Stimulapis
''Acheronauta'' is a genus of extinct worm-shaped arthropod that lived in the early Silurian (Telychian-Sheinwoodian stages) Waukesha biota fossil site in southeast Wisconsin. This arthropod was first discovered alongside the biota in 1985, but was not fully described until October 2022. This creature was recognized and described as a possible early mandibulate (the grouping of arthropods including crustaceans and hexapods). This description is very important as much of the fauna of the biota remain undescribed, and its discovery has allowed for paleontologists to get a better grasp of the diversity of the arthropod fauna at the site. Multiple phylogenetic analyses were performed, and it was found that this arthropod forms a previously undiscovered clade with the Devonian stem-arthropod ''Captopodus'', and the somewhat enigmatic group Thylacocephala. ''Acheronauta'' has been assessed as a possible basal mandibulate, which are distinguished from other arthropods due to the presen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thylacocephala
The Thylacocephala (from the Greek or ', meaning " pouch", and or ' meaning "head") are group of extinct probable mandibulate arthropods, that have been considered by some researchers as having possible crustacean affinities. As a class they have a short research history, having been erected in the early 1980s. They typically possess a large, laterally flattened carapace that encompasses the entire body. The compound eyes tend to be large and bulbous, and occupy a frontal notch on the carapace. They possess three pairs of large raptorial limbs, and the abdomen bears a battery of small swimming limbs. Their size ranges from ~15 mm to potentially up to 250 mm. Inconclusive claims of thylacocephalans have been reported from the lower lower Cambrian ('' Zhenghecaris''), but later study considered that genus as radiodont or arthropod with uncertain systematic position. The oldest unequivocal fossils are Upper Ordovician and Lower Silurian in age. As a group, the Thylacocephala s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cascolus
''Cascolus'' is an extinct genus of stem-mandibulate known from the Coalbrookdale Formation. Description ''Cascolus'' is a long, somewhat vermiform arthropod, roughly 9 millimetres long. It has a head segment containing a head shield, stalked eyes and five pairs of limbs, the first similar to megacheirans and the other four biramous with gnathobases, followed by a nine-segmented thorax and two possibly limbless segments near the posterior. The trunk remains similar in size through tergites 1-4, and then decreases in width onwards into the limbless segments. Ecology ''Cascolus'' appears to have been a nektobenthic animal, possibly a scavenger. Etymology ''Cascolus'' was named in honour of Sir David Attenborough. The genus name derives from "castrum" ("stronghold") and "colus" ("dwelling in"), alluding to the Middle or Old English source for the name "Attenborough". The specific name ''ravitis'' derives from "Ratae" (the Roman name for Leicester), "vita" ("life") and "com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tanazios
''Tanazios'' is a genus of Silurian stem-mandibulate from the Coalbrookdale Formation of England. Description ''Tanazios'' has a head shield that is semicircular in shape, divided into a fringe and an axial (central) region. The fringe margins meet somewhat abruptly at the front of the shield, with a long projection pointing from their back corners and six pairs of horn-like structures at the sides. The axial region is semi-ovoid in shape, around 3 times wider than long, and bears a wide furrow running down its length. At the sides there is a narrow ledge which pinches out towards the back and continues as the inner trunk pleurae. No eyes seem to be present. The hypostome is subrectangular and extends from the antennulae to the mandibular gnathobases, with an anterior margin bearing four small spines and a convex posterior margin with a lip-like structure which may be the labrum. The antennulae are very short and uniramous, with the antennae being around five times longer a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandibulata
The clade Mandibulata constitutes one of the major subdivisions of the phylum Arthropoda, alongside Chelicerata. Mandibulates include the crustaceans, myriapods (centipedes and millipedes, among others), and all true insects. The name "Mandibulata" refers to the mandibles, a modified pair of limbs used in food processing, the presence of which are characteristic of most members of the group. The mandibulates are divided between the extant groups Myriapoda (millipedes and centipedes, among others) and Pancrustacea (including crustaceans and hexapods, the latter group containing insects). Molecular phylogenetic studies suggest that the living arthropods are related as shown in the cladogram below. Crustaceans do not form a monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuxianhuiida
Fuxianhuiida is an extinct clade of arthropods from the Cambrian of China. All currently known species are from Cambrian Series 2 aged deposits in Yunnan, Yunnan Province, including the Maotianshan Shales, Chengjiang biota. Although historically suggested to be members of the arthropod stem group recent research has suggested that they may be closely related to Mandibulata, mandibulates. Many specimens are known with exceptional soft tissue preservation, including preserved guts and Nervous tissue, neural tissue, which given their Basal (phylogenetics), basal phylogenetic position makes them important in understanding the evolution of Arthropoda as a whole. They reach a size of up to 15 cm, and are interpreted as Benthic zone, benthic predators and scavengers. The Fuxianhuiid exoskeleton is unmineralised, and the number of Tergum, tergites ranges from 15 to over 40. The Cephalon (arthropod head), cephalon is covered by a head shield and contains stalked eyes connected by the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euthycarcinoidea
Euthycarcinoidea are an enigmatic group of extinct, possibly amphibious arthropods that ranged from Cambrian to Triassic times. Fossils are known from Europe, North America, Argentina, Australia, and Antarctica. Description The euthycarcinoid body was divided into a cephalon (head), preabdomen, and postabdomen. The cephalon consisted of two segments and included mandibles, antennae and presumed eyes. The preabdomen consisted of five to fourteen tergites, each having up to three somites. Each somite had in turn a pair of uniramous, segmented legs. The postabdomen was limbless and consisted of up to six segments and a terminal tail spine. Affinities Due to its particular combination of characteristics, the position of the Euthycarcinoidea within the Arthropoda has been ambiguous; previous authors have allied euthycarcinoids with crustaceans (interpreted as copepods, branchiopods, or an independent group), with trilobites, or the merostomatans (horseshoe crabs and sea scorpion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odaraia
''Odaraia'' is an extinct genus of bivalved Hymenocarina, hymenocarine arthropod with a single known species ''Odaraia alata'', found in the Middle Cambrian Burgess Shale in British Columbia, Canada. History of research and taxonomy The genus and species were first described by Charles Doolittle Walcott, Charles Walcott in 1912. It was placed into its own family, Odaraiidae by Simonetta and Delle Cave in 1975,Simonetta AM, Delle Cave L . 1975 The Cambrian non-trilobite arthropods from the Burgess Shale of British Columbia: a study of their comparative morphology, taxonomy and evolutionary significance. ''Palaeontogr. Ital.'' which has been used to include other genera of bivalved Cambrian arthropods. The species was redescribed by Derek Briggs 1981, and again redescribed in 2024 by Izquierdo-López and Caron. While originally ''Odaraia'' and other odaraiids have been interpreted as Basal (phylogenetics), basal euarthropods not closely related to any living arthropod group, the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waptia
''Waptia'' is an extinct genus of marine arthropod from the Middle Cambrian of North America. It grew to a length of , and had a large bivalved carapace and a segmented body terminating into a pair of tail flaps. It was an active swimmer and likely a predator of soft-bodied prey. It is also one of the oldest animals with direct evidence of Parental investment, brood care. ''Waptia fieldensis'' is the only species classified under the genus ''Waptia'', and is known from the Burgess Shale ''Lagerstätte'' of British Columbia, Canada. Specimens of ''Waptia'' are also known from the Spence Shale of Utah, United States. Based on the number of individuals, ''Waptia fieldensis'' is the third most abundant arthropod from the Burgess Shale Formation, with thousands of specimens collected. It was among the first fossils found by the American paleontologist Charles D. Walcott in 1909. He described it in 1912 and named it after two mountains near the discovery site – Wapta Mountain and Moun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nereocaris
''Nereocaris'' is an extinct genus of bivalved hymenocarine arthropod that lived in the Cambrian aged Burgess Shale in what is now British Columbia around 506 million years ago. Two species are known. History and nomenclature The holotype and paratype were found in the Burgess Shale Lagerstätte, in the Tulip Beds; it was later described in 2012, by Legg ''et al,'' as a basal hymenocarine, naming the type species ''Neroecaris exilis.'' In 2013, a second ''Nereocaris briggsi'' was described by Legg and Caron. The generic name, ''Nereocaris'' comes from Greek: , Nereus the Greek god of waves; and , "shrimp" or "crab", meaning "Nereus's shrimp". The specific name ''exilis'' comes from Latin, meaning slim; while the second species' name ''briggsi'' means "of Briggs", referring to professor Derek Briggs, an expert on Cambrian arthropods. Description According to the diagnosis of Legg and Caron (2013), the genus including both species is diagnosed by the presence of two latera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiocaris
''Branchiocaris'' is an extinct genus of Cambrian bivalved arthropod. The type and best known species, ''Branchiocaris pretiosa,'' was described from the Burgess Shale of British Columbia, Canada, in 1929, originally placed in '' Protocaris'', and was placed into its own distinct genus by Briggs in 1976. Several other possible species have been described from Cambrian deposits in China, and it is also possibly known from Cambrian deposits in Utah. ''Branchiocaris pretiosa'' is around in length, with a highly segmented trunk, consisting of at least 44 ring-like segments, terminating in a forked tail telson. At the front of the animal is a pair of short segmented tapered antennules with at least 20 segments, as well as a pair of claw appendages. It was likely an active swimmer, and used the claw appendages to bring food to the mouth. The discovery of '' Tokummia'' from the Burgess Shale, believed to be a close relative of ''Branchiocaris'', has shed light on the evolutionary plac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokummia
''Tokummia'' is a genus of fossil hymenocarine arthropod, known only by one species, ''Tokummia'' ''katalepsis'', from the middle Cambrian (508 million years old) Burgess Shale as found in a quarry in Marble Canyon in Canada. Etymology The genus name ''Tokummia'' named after Tokumm Creek which runs through the Marble Canyon where it was found. The species name ''katalepsis'' is a Greek word for "seizing", "gasping" or "holding". Morphology ''Tokummia'' has a cylindrical body, with the anterior half covered by a long bivalved carapace. At the front of the animal, there are a pair of antennae, possible eyes, mouthparts (mandibles, maxillule and maxilla) and prominent pincer-like maxillipeds. These shows the oldest record of arthropod pincers. Posterior to the maxillipeds are 50 leg-bearing trunk segments. Each of its biramous leg has 5-segmented basipods, followed by an exopod (flap-like outer branch) and 7-segmented endopod (leg-like inner branch). The anterior 10 leg pair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
