Tanazios

Tanazios is a genus of Silurian stem-mandibulate.

Description
Tanazios has a head with five pairs of appendages, these being the antennae, antennules, mandibles with gnathobasic coxae and two biramous limb pairs similar to those of the trunk, with a large projection in the hypostome's centre. The trunk consists of 64 segments and has 60 appendage pairs, with a small telson on the end that holds the anus and a caudal ramus. Tanazios lacks second antennae, which character shared with hexapods.

Ecology
Tanazios has been proposed to be either a benthic or demersal scavenger.

Etymology
Tanazios is a combination of the words "tanaos", meaning "long", "zoon", meaning "animal" and "pelagios", meaning "of the sea". The species name dokeron is a combination of "dodeka" ("twelve"), "kerouchos" ("horned") and "epikranon" ("helmet").

Distribution
Tanazios is known from two reconstructed specimens from the Coalbrookdale Formation (as the concretions fossils are found in cannot be studied easily, fossils have to be reconstructed digitally via grinding then scanning them).

Classification
Tanazios was originally considered as stem-group crustacean. According to phylogenic analysis in Pulsipher et al. (2022), it is considered as stem-mandibulate instead.