''Primicaris'' is genus of
Cambrian arthropod from the
Chengjiang biota of China and the
Burgess Shale
The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fo ...
of Canada. It contains a single described species, ''P. larvaformis''. Its specimens were once thought to be meraspids of ''
Naraoia
''Naraoia'' is a genus of small to average size (about 2-4½ cm long) marine arthropods within the family Naraoiidae, that lived from the early Cambrian to the late Silurian period. The species are characterized by a large alimentary system and ...
spinosa''. Its phylogenetic position has been described as "problematic".
Some studies have suggested them to be
marrellomorph
Marrellomorpha are an extinct group of arthropods known from the Cambrian to the Early Devonian. They lacked mineralised hard parts, so are only known from areas of exceptional preservation, limiting their fossil distribution. The best known me ...
s belonging to the subgroup Acerostraca.
See also
*
Arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...
*
Cambrian explosion
*
Chengjiang biota
**
List of Chengjiang Biota species by phylum
This is a list of fossils found at Maotianshan Shales, whose most famous assemblage of organisms are referred to as the Chengjiang biota.
Phylum Arthropoda
80 species, not counting Dinocarida, Nektaspida and Trilobita
* '' Acanthomerid ...
References
Cambrian animals
Maotianshan shales fossils
Prehistoric arthropod genera
{{paleo-arthropod-stub
Cambrian genus extinctions