Lobopodians are members of the informal group Lobopodia, or the formally erected phylum Lobopoda Cavalier-Smith (1998). They are panarthropods with stubby legs called lobopods, a term which may also be used as a common name of this group as well. While the definition of lobopodians may differ between literatures, it usually refers to a group of soft-bodied, marine worm-like fossil panarthropods such as Aysheaia and Hallucigenia.
Dinocaridida is a proposed fossil taxon of basal arthropods that flourished in the Cambrian period with occasional Ordovician and Devonian records. Characterized by a pair of frontal appendages and series of body flaps, the name of Dinocaridids refers to the suggested role of some of these members as the largest marine predators of their time. Dinocaridids are occasionally referred to as the 'AOPK group' by some literatures, as the group compose of Radiodonta, Opabiniidae, and the "gilled lobopodians" Pambdelurion and Kerygmachelidae. It is most likely paraphyletic, with Kerygmachelidae and Pambdelurion more basal than the clade compose of Opabiniidae, Radiodonta and other arthropods.
Anomalocaris is an extinct genus of radiodont, an order of early-diverging stem-group arthropods.
Amplectobelua is an extinct genus of late Early Cambrian amplectobeluid radiodont, a group of stem arthropods that mostly lived as free-swimming predators during the first half of the Paleozoic Era.
Anomalocarididae is an extinct family of Cambrian radiodonts, a group of stem-group arthropods.
Pambdelurion is an extinct genus of panarthropod from the Cambrian aged Sirius Passet site in northern Greenland. Like the morphologically similar Kerygmachela from the same locality, Pambdelurion is thought to be closely related to arthropods, combining characteristics of "lobopodians" with those of primitive arthropods.
Parapeytoia is a genus of Cambrian arthropod. The type and only described species is Parapeytoia yunnanensis, lived over 518 million years ago in the Maotianshan shales of Yunnan, China. Unidentified fossils from the same genus also had been discovered from the nearby Wulongqing Formation.
Megacheira is an extinct class of predatory arthropods defined by their possession of spined "great appendages". Their taxonomic position is controversial, with studies either considering them stem-group euarthropods, or stem-group chelicerates. The homology of the great appendages to the cephalic appendages of other arthropods is also controversial. Uncontested members of the group were present in marine environments worldwide from the lower to middle Cambrian.
Schinderhannes bartelsi is a species of hurdiid radiodont (anomalocaridid) known from one specimen from the lower Devonian Hunsrück Slates. Its discovery was astonishing because previously, radiodonts were known only from exceptionally well-preserved fossil beds (Lagerstätten) from the Cambrian, 100 million years earlier.
Radiodonta is an extinct order of stem-group arthropods that was successful worldwide during the Cambrian period. They may be referred to as radiodonts, radiodontans, radiodontids, anomalocarids, or anomalocaridids, although the last two originally refer to the family Anomalocarididae, which previously included all species of this order but is now restricted to only a few species. Radiodonts are distinguished by their distinctive frontal appendages, which are morphologically diverse and used for a variety of functions. Radiodonts included the earliest large predators known, but they also included sediment sifters and filter feeders. Some of the most famous species of radiodonts are the Cambrian taxa Anomalocaris canadensis, Hurdia victoria, Peytoia nathorsti, Titanokorys gainessii, Cambroraster falcatus and Amplectobelua symbrachiata, the Ordovician Aegirocassis benmoulai and the Devonian Schinderhannes bartelsi.
Stanleycaris is an extinct, monotypic genus of hurdiid radiodont from the middle Cambrian (Miaolingian). The type species is Stanleycaris hirpex. Stanleycaris was described from the Stephen Formation near the Stanley Glacier and Burgess Shale locality of Canada, as well as Wheeler Formation of United States. The genus was characterized by the rake-like frontal appendages with robust inner spines.
Cucumericrus ("cucumber-leg") is an extinct genus of stem-arthropod. The type and only species is Cucumericrus decoratus, with fossils discovered from the Maotianshan Shales of Yunnan, China.
Caryosyntrips ("nutcracker") is an extinct genus of stem-arthropod which known from Canada, United States and Spain during the middle Cambrian.
Diania is an extinct genus of lobopodian panarthropod found in the Lower Cambrian Maotianshan shale of China, represented by a single species - D. cactiformis. Known during its investigation by the nickname "walking cactus", this organism belongs to a group known as the armoured lobopodians, and has a simple worm-like body with robust, spiny legs. Initially, the legs were thought to have a jointed exoskeleton and Diania was suggested to be evolutionarily close to early arthropods, but many later studies have rejected this interpretation.
Amplectobeluidae is a clade of Cambrian radiodonts. It currently includes five definitive genera, Amplectobelua, Lyrarapax, Ramskoeldia, Guanshancaris and a currently unnamed genus from the lower Cambrian aged Sirius Passet site in Greenland. There is also a potential fifth genus, Houcaris, but that genus has become problematic in terms of its taxonomic placement.
Ramskoeldia is a genus of amplectobeluid radiodont described in 2018. It was the second genus of radiodont found to possess gnathobase-like structures and an atypical oral cone after Amplectobelua. It was discovered in the Chengjiang biota of China, the home of numerous radiodontids such as Amplectobelua and Lyrarapax.
Kylinxia is a genus of extinct arthropod described in 2020. It was described from six specimens discovered in Yu'anshan Formation in southern China. The specimens are assigned to one species Kylinxia zhangi. Dated to 518 million years, the fossils falls under the Cambrian period. Announcing the discovery on 4 November 2020 at a press conference, Zeng Han of the Nanjing Institute of Geology and Paleontology, said that the animal "bridges the evolutionary gap from Anomalocaris to true arthropods and forms a key ‘missing link’ in the origin of arthropods," which was "predicted by Darwin’s evolutionary theory." The same day the formal description was published in Nature.
Houcaris is a possibly paraphyletic radiodont genus, tentatively assigned to either Amplectobeluidae, Anomalocarididae or Tamisiocarididae, known from Cambrian Series 2 of China and the United States. It contains two species, Houcaris saron and Houcaris magnabasis, both of which were originally named as species of the related genus Anomalocaris. The genus Houcaris was established for the two species in 2021 and honors Hou Xianguang, who had discovered and named the type species Anomalocaris saron in 1995 along with his colleagues Jan Bergström and Per E. Ahlberg.
Laminacaris is a genus of extinct stem-group arthropods (Radiodonta) that lived during the Cambrian period. It is monotypic with a single species Laminacaris chimera, the fossil of which was described from the Chengjiang biota of China in 2018. Around the same time, two specimens that were similar or of the same species were discovered at the Kinzers Formation in Pennsylvania, USA. The first specimens from China were three frontal appendages, without the other body parts.
Wufengella is a genus of extinct camenellan "tommotiid" that lived during the Early Cambrian. Described in 2022, the only species Wufengella bengtsonii was discovered from the Maotianshan Shales of Chiungchussu (Qiongzhusi) Formation in Yunnan, China. The fossil indicates that the animal was an armoured worm that close to the common ancestry of the phyla Phonorida, Brachiozoa and Bryozoa, which are collectively grouped into a clade called Lophophorata.
