''Vladicaris'' is an

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 ...

known from the Lower

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

Paseky Shale member, Czech Republic, where it occurs alongside other arthropods, namely ''

Kodymirus ''Kodymirus'' is a problematic genus of Early Cambrian arthropod, known from the Czech Republic, which bears some resemblance to eurypterids and aglaspidids. Although it possessed great appendage-like raptorial arms, it was not homologous with t ...

vagans'' and ''Kockurus grandis''. It has been attributed to the

Crustacea Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

, and if it does indeed belong in the

crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

of that subphylum, it would be the earliest known representative of the group. Its position within the Crustacea is unclear – it has been allied with the

Phyllocarida Phyllocarida is a subclass of crustaceans, comprising the extant order Leptostraca and the extinct orders Hymenostraca and Archaeostraca. See also *''Ceratiocaris'' *''Cinerocaris'' *''Vladicaris ''Vladicaris'' is an arthropod known from the ...

and the

Branchiopoda Branchiopoda is a class of crustaceans. It comprises fairy shrimp, clam shrimp, Diplostraca (or Cladocera), Notostraca and the Devonian ''Lepidocaris''. They are mostly small, freshwater animals that feed on plankton and detritus. Description M ...

. The organism has a segmented trunk and an elongate

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

– characters which have led to suggestions that it should be allied to the pectocaridids.

References

Prehistoric crustaceans Cambrian arthropods Arthropod enigmatic taxa Cambrian animals of Europe {{paleo-arthropod-stub Cambrian genus extinctions