''Repinaella'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

from a well-known class of

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

marine

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

s, the

trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...

s. It lived during the late

Atdabanian 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 approxi ...

stage.

Distribution

* ''Repinaella siberica'' has been found in the Lower Cambrian of Siberia (Pestrotsvet Formation, Lena River). * cf. ''Repinaella sp.'', the first trilobite to appear in

Laurentia Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America. Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, althoug ...

, has been reported from the Lower Cambrian of Nevada (Northern Clayton Ridge; Andrew Mountain Member of the Montezuma Range, Campito Formation). The occurrence of cf. ''Repinaella'' is approximately correlative with the earliest trilobites in Siberia and western Gondwana.

Taxonomy

Within the "Fallotaspidoidea" superfamily ''Repinaella siberia'' is closest to the common ancestor with the other Olenellina, particularly ''

Pseudojudomia egregia ''Pseudojudomia'' is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived during the late Atdabanian stage, which lasted from 530 to 524 million years ago during the early part of the Cambrian Period ...

'', and the common characters of these two species were probably shared with the common ancestor of all trilobites.

References

Cambrian trilobites Fallotaspidoidea Cambrian trilobites of Asia Cambrian trilobites of Europe Cambrian trilobites of North America {{redlichiida-stub Cambrian genus extinctions