''Bailongia'' is an extinct genus of

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

known from a single species ''Bailongia longicaudata'' (''longicaudata'' from Latin: "long-tailed") found in the

Cambrian Stage 4 Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. The lower boundary has not been formally defined by the International Commission o ...

aged Guanshan Biota of

Yunnan Yunnan; is an inland Provinces of China, province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces ...

, China. It was around 5mm long and had a large head shield, nine overlapping tapering

tergites A ''tergum'' (Latin for "the back"; : ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'margin'. ...

and a relatively elongate tailspine. It has been recovered in a relatively basal position within

Artiopoda Artiopoda is a clade 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 Trilobitomor ...

, more derived than ''

Squamacula ''Squamacula'' is an extinct artiopodan arthropod from the Cambrian Series 2. The type species ''S. clypeata'' was described in 1997 from the Chengjiang biota of Yunnan, China. At the time of description there were only two known specimens of ''S ...

'' or Protosutura, but outside Trilobitomorpha or Vicissicaudata.

Phylogeny

After Jiao et al. 2021.

References

Artiopoda Cambrian arthropods of Asia Cambrian China Paleontology in Yunnan Fossil taxa described in 2021 Cambrian genus extinctions {{Paleo-arthropod-stub