Habelia

Habelia is a genus of extinct arthropod from the Middle Cambrian, thought to be one of the earliest known relatives of chelicerates.

The head, which is 25% wider than it is long, makes up about 30% of the total body length, and has a bulging shape, with triangular genal spines projecting outward at its edges.

The endopods of these limbs increased in size posteriorly, and had seven segments/podomeres, with the terminating segment being a claw, with podomeres 5 and 6 having borne a brush of inward facing setae.

The exopods of these limbs were elongate and thin rami, increasing in size posteriorly, each composed of 7 or more podomeres, which bore setae at the segment joints.

The segments of the post-thorax bore pairs of exopods decreasing in size posteriorly, but there are no visible endopods, meaning that they were either reduced or entirely absent.