Waukeshaaspis is an extinct genus of trilobite (a diverse group of marine arthropods) known from the lower Silurian aged Waukesha Biota.

A single species is currently known, Waukeshaaspis eatonae, which is known from strata belonging to the Telychian aged Brandon Bridge Formation in Wisconsin.

This genus is rather unique, as it is the only common trilobite found within the Waukesha Biota, and is usually preserved in a more complete state compared to other contemporary genera.

Unlike other members of the dalmanitid family, the pygidium (posterior section) of this genus lacks a terminal spine, instead possessing an embayment which may have helped with respiration when the arthropod was enrolled.

[1] Within the formation exists the smaller Waukesha Biota, a Konservat-Lagerstätten fossil site known for its exceptional preservation of soft-bodied and lightly sclerotized organisms that are not normally found in Silurian strata.

[2][3] A unique trait of the biota is its taphonomy, being that the majority of hard-shelled organisms (which are normally found in Silurian strata), are poorly preserved, or entirely absent.

[2] Before it was named, Waukeshaaspis was recognized as one of the most common organisms within the Waukesha Biota, only behind several unnamed members of the Leperditicopida (a group of bivalved arthropods sometimes associated with the ostracods).

[3][6][5][2] This arthropods genus name, Waukeshaaspis, is derived from the city of Waukesha, and the Greek word aspís, meaning "round shield".

[3] The trilobites pair of eyes, which were schizochroal in appearance, sat on the posterior margin of the cephalon, and were composed of around 32 files, which bore eight distinct lenses.

[12] Waukeshaaspis represents an anomaly among the other Waukesha trilobites, as many of the other genera known, including Distyrax, Meroperix, and Arctinurus are comparatively more rare, and not as well preserved.

[3] The embayment on the pygidium may have filled a number of roles, including aiding respiration, allowing the antennae to protrude out, and for the release of fecal matter.