Jianfengia is an extinct genus of Middle Cambrian (Atdabanian) megacheiran arthropod found in the Maotianshan Shale Lagerstätte of China. It contains the single species Jianfengia multisegmentalis. The body is extremely elongated, though the animal itself was relatively small at less than 4 centimetres (1.6 in) in length. The head has a pair of stalked eyes, a hypostome/labrum complex, a pair of great appendages with five podomeres, and four pairs of biramous limbs. The maximum known number of trunk segments is 27, though most known specimens have 20, which are associated with pairs of biramous appendages, and the body ends with a telson spine. It has been placed as a member of the family Jiangfengiidae, alongside Fortiforceps and Sklerolibyon as well as possibly Parapeytoia.
Fuxianhuia is a genus of Lower Cambrian fossil arthropod known from the Chengjiang fauna in China. Its purportedly primitive features have led to its playing a pivotal role in discussions about the euarthropod stem group. Nevertheless, despite being known from many specimens, disputes about its morphology, in particular its head appendages, have made it one of the most controversial of the Chengjiang taxa, and it has been discussed extensively in the context of the arthropod head problem.
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.
Plenocaris plena is a Cambrian arthropod with a bivalved carapace, and is known from the Burgess shale and Chengjiang. Originally described as a species of Yohoia by Walcott in 1912, it was placed into its own genus in 1974.
Clypecaris is genus of bivalved Cambrian arthropod known from the Chengjiang biota of Yunnan, China. The genus was initially described for the type species C. pteroidea by Hou, 1999. A second species C. serrata was described by Yang et al. in 2016. The species are primarily distinguished by the presence of a serrated edge on the front of the carapace of C. serrata. C. serrata is noted for the modification of an anterior pair of limbs into spined grasping appendages, indicating a predatory lifestyle. It is unknown whether a similar structure was present in C. pteroidea.Clypecaris is considered to likely be a member or a close relative of Hymenocarina, and is closely related to Perspicaris. As well as to Ercaicunia.
Ercaicunia is genus of bivalved Cambrian arthropod from the Chengjiang biota of Yunnan, China. It contains a single species, E. multinodosa that was described by Luo et al. in 1999. The total length of the body ranges from 8 to 11 millimetres. The bivalved carapace covered about a third of the total body-length, and has up to six serrations on its forward edge. The head has a pair of large uniramous antennae, as well as a smaller pair of secondary antennae, as well as pair of mandibles and maxillae. The trunk has 16 pairs of biramous appendages. Specimens were CT scanned in 2019, which suggested it to be a stem-group crustacean. Other subsequent studies have recovered it as a member of Hymenocarina, which contains other bivalved Cambrian arthropods.
Isoxys is a genus of extinct bivalved Cambrian arthropod; the various species of which are thought to have been freely swimming predators. It had a pair of large spherical eyes, and two large frontal appendages used to grasp prey.
Jianshania is genus of Cambrian arthropod known from the Chengjiang biota, containing the single species J. furfactus. It was described by Luo et al. in 1999. In 2020, a specimen originally assigned to the species was found to represent the separate fuxianhuiid taxon Xiaocaris pending revision of the type specimen.
Occacaris oviformis is an extinct nektonic predatory arthropod from the Lower Cambrian Maotianshan shale Lagerstätte. It bears a superficial resemblance to the Cambrian arthropod, Canadaspis, though, was much smaller, and had a pair of "great appendages", with which it may have grasped prey. It was originally considered to belong to Megacheira, however it is questioned in later study.
Vetulicola rectangulata is a species of extinct animal from the Early Cambrian of the Chengjiang biota of China. Regarded as a deuterostome, it has characteristic rectangular anterior body on which the posterior tail region is attached. It was described by Luo Huilin and Hu Shi-xue in 1999.
Chengjiangocaris is an extinct genus of fuxianhuiid arthropod known from the Cambrian of South China. It contains two species, C. longiformis which was described in 1991. C. kunmingensis was described in 2013 by Javier Ortega-Hernández and colleagues. One specimen of C. kunmingensis shows detailed evidence of a nervous system. The nervous system of the chengjiangocaris is and has always been very complex to understand but a recent discovery of the ladder like ventral nerval cords and segmental ganglia of the related chengjiangocaris together with the brain provide the most comprehensive reconstruction of any lower Cambrian arthropod.
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. 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.
Retifacies abnormalis is an extinct arthropod that lived in the lower Cambrian. Its fossil remains have been found in the Maotianshan Shales of Yunnan, China. It is a member of the Artiopoda, and closely related to Pygmaclypeatus.
Hymenocarina is an order of extinct arthropods known from the Cambrian. They possess bivalved carapaces, typically with exposed posteriors. Members of the group are morphologically diverse and had a variety of ecologies, including as filter feeders and as predators. Recent research has generally considered them to be stem or crown group members of Mandibulata, due the presence of mandibles in at least some species.
Alacaris is an extinct genus of fuxianhuiid arthropod known from the Cambrian period. It is only known from the type species Alacaris mirabilis from the Cambrian Stage 3 aged Xiaoshiba Lagerstätte in Yunnan Province, China. It is morphologically similar to Chengjiangocaris, with which it forms a clade within Fuxianhuiida. Individuals reach a maximum of 12 centimetres in length, with a trunk consisting of 13 tergites. The basal region of the post-deutocerebral limbs were used in feeding, with the rhythmic movement of the legs guiding food towards the mouth along the food groove between the limbs, with gnathobases present near the mouth to macerate food.
Guangweicaris is an extinct genus of fuxianhuiid arthropod known from the Cambrian period. It is only known from the type species Guangweicaris spinatus, which is known from the Cambrian Stage 4 Guanshan Biota near Kunming. It is currently the latest known fuxianhuiid. It was first described in 2007, and was given a comprehensive re-description in 2020. It is currently known from over 150 specimens. Within the fuxianhuiids it is sister to Fuxianhuia, together forming the clade Fuxianhuiidae. In comparison to Fuxianhuia it has a wide, oval shaped opisthothorax and a proportionally longer, narrow tail-like abdomen, with 3 prothoracic tergites, 5 opisthothoracic tergites and 7 abdominal tergites, it also possesses a row of spines running down the central axis of the body from the second opisthothoracic tergite.
Luolishania is an extinct genus of lobopodian panarthropod and known from the Lower Cambrian Chiungchussu Formation of the Chengjiang County, Yunnan Province, China. A monotypic genus, it contains one species Luolishania longicruris. It was discovered and described by Hou Xian-Guang and Chen Jun-Yuan in 1989. It is one of the superarmoured Cambrian lobopodians suspected to be either an intermediate form in the origin of velvet worms (Onychophora) or basal to at least Tardigrada and Arthropoda. It is the basis of the family name Luolishaniidae, which also include other related lobopods such as Acinocricus, Collinsium, Facivermis, and Ovatiovermis. Along with Microdictyon, it is the first lobopodian fossil discovered from China.
Deuteropoda is a proposed clade of arthropods whose members are distinguished from more basal stem-group arthropods like radiodonts by an anatomical reorganization of the head region, namely the appearance of a differentiated first appendage pair, a multisegmented head, a hypostome/labrum complex, and by bearing pairs of segmented biramous limbs.
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 trilobites.
Isoxyids are members of the order Isoxyida and the family Isoxyidae, a group of basal arthropods that existed during the Cambrian period. It contains two genera, Isoxys, with 20 species found worldwide, and Surusicaris known from a single species found in the Burgess Shale of Canada. They are distinguished by their bivalved carapaces and pair of upward curving grasping frontal appendages.
