Panlongia

Panlongia was a small-sized marine arthropod. Panlongia lived during the late Lower Cambrian (Botomian) in what is today South China. The genus consists of two species, P. spinosa and P. tetranodus.^[1]

Panlongia Temporal range: lowest Botomian PreꞒ Ꞓ O S D C P T J K Pg N ↓
Panlongia spinosa
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Artiopoda
Order:	Nektaspida
Family:	Incertae sedis
Genus:	Panlongia Liu et al., 2006
Species
P. tetranodusa Liu et al. 2006[1] P. spinosa Liu et al. 2006[1]

Description

Panlongia is a flat, 2 cm (0.8 in) long nektaspid, with an oval-shaped non-calcified exoskeleton. Both the head shield (or cephalon) and the tail shield (or pygidium) are semi-circular. In between the cephalon and pygidium are four thoracic body segments (somites). 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.^[1]

• 
  Panlongia tetranodusa reconstruction

Distribution

• Panlongia spinosa is found in the late Lower Cambrian (Botomian) of China (Wulongqing Formation, only at Gaoloufang Kgs-2).
• Panlongia tetranodusa occurs in the late Lower Cambrian (Botomian) of China (Wulongqing Formation, Gaoloufang Kgs-1, and Shijiangjun Wsh-14, Wuding County, Yunnan, "Guanshan fauna").^[1]

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. ^[2]

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.^[1]

See also

• Cambrian explosion
• Phytophilaspis