''Penarosa'' is an
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
genus from a well-known class of
fossil marine
arthropods, the
trilobites. It lived during the
Middle Cambrian (''Ptychagnostus atavus'' Zone to ''Ptychagnostus punctuosus'' Zone),
approximately 505 to 500 million years ago.
References
Ptychoparioidea
Ptychopariida genera
Cambrian trilobites of Australia
{{cambrian-animal-stub