''Parvibellus'' is an extinct genus of panarthropod animal known from the

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

of China. It is known from only a single species, ''P. atavus'', found in the

Cambrian Stage 3 Cambrian Stage 3 is the still unnamed third stage of the Cambrian. It succeeds Cambrian Stage 2 and precedes Cambrian Stage 4, although neither its base nor top have been formally defined. The plan is for its lower boundary to correspond approxima ...

aged

Chengjiang Biota The Maotianshan Shales () are a series of Early Cambrian sedimentary deposits in the Chiungchussu Formation or Heilinpu Formation, famous for their '' Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized orga ...

of Yunnan, China.

Morphology

''Parvibellus'' is small panarthropod with length of around . The head bore a pair of small frontal appendages and ventrally directed circular mouth. There is no evidence that ''Parvibellus'' had eyes. The elongated trunk possesses 11 pairs of lateral appendages and a pair of terminal projections. In the original description, The trunk appendages were interpreted as swimming flaps, which suggest a nektonic life style and close relationship with stem-group

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 ...

s such as the "gilled

lobopodia 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 ...

ns" ''

Kerygmachela ''Kerygmachela kierkegaardi'' is a Kerygmachelidae, kerygmachelid Lobopodia#Gilled lobopodians, gilled lobopodian from the Cambrian Stage 3 aged Sirius Passet Lagerstätte in northern Greenland. Its anatomy strongly suggests that it, along with i ...

'' and ''

Pambdelurion ''Pambdelurion'' is an extinct genus of Panarthropoda, 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 closel ...

'', opabiniids and radiodonts. However, recent research suggests it may instead be a larval siberiid, a group of

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

lobopodian nest within arthropod stem-group, and the trunk appendages were re-interpreted as stout lobopods. Since it may represent the larva of any described siberiids from the same strata (e.g. ''

Megadictyon ''Megadictyon'' is a genus of Cambrian lobopodian with similarities to ''Jianshanopodia'' and '' Siberion''. The name of the genus is occasionally mis-spelt as ''Magadictyon''. Description ''Megadictyon'' is a large lobopodian, with a body le ...

'', ''

Jianshanopodia ''Jianshanopodia ''is a monotypic genus of Cambrian lobopodian, discovered from Maotianshan Shales of Yunnan, China. Description ''Jianshanopodia'' resemble the closely-related siberiid ''Megadictyon''. The head possess a pair of frontal, g ...

'') and cannot be accurately identified, ''Parvibellus'' is considered to be a ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium,'' it may be impossible to determine whether a ...

''.

References

{{Taxonbar, from=Q111521905 Fossil taxa described in 2022 Panarthropoda Dinocaridida Nomina dubia