Panlongia
Panlongia was a small-sized marine arthropod. Panlongia lived during the late Lower Cambrian in what is today South China. The genus consists of two species, P. spinosa and P. tetranodus.
Description
Panlongia is a flat, long nektaspid, with an oval-shaped non-calcified exoskeleton. Both the head shield and the tail shield are semi-circular. In between the cephalon and pygidium are four thoracic body segments. The cephalon occupies approximately ⅓ of the body length, the thorax ¼ and pygidium about 45%.
In Panlongia spinosa, the edge of the exoskeleton carries several small sawtooth-like spines, that are absent in P. tetranodusa.
Distribution
Panlongia spinosa is found in the late Lower Cambrian of China.Panlongia tetranodusa occurs in the late Lower Cambrian of China.
Taxonomy
The phylogenetic position of Panlongia remained uncertain due to the lack of appendages until 2024, when more well-preserved specimens with appendages narrowed its placement down to as a nektaspid.
Ecology
Panlongia tetranodusa occurs with the coeloscleritophoran Allonia sp., the vetulicolian Vetulicola gangtoucunensis, lingulate brachiopods Lingulellotreta malongensis, Diandongia pista, Acrothele rara, and Westonia gubaiensis; radiodonts Houcaris saron and Guanshancaris kunmingensis, hyolith Linevitus malongensis, eocrinoid Wudingeocrinus rarus, Trilobites Redlichia yunnanensis, R. mansuyi, R. noetlingi, R. conica, R. shijiangjunensis, Palaeolenus douvillei, and P. lantenoisi; crustaceans: Tuzoia sinensis, T. tylodesa, Branchiocaris sp., Liangshanella liangshanensis, and Neokunmingella sp., and several other arthropods like Longquania bispinosa, Guangweicaris spinatus; Leanchoilia illecebrosa, Isoxys minor and I. wudingensis.