Fossils of various species are found in Lower Cambrian (Toyonian)-aged marine strata from China, Korea, Pakistan, the Himalayas, Iran, Spain, southern Siberia, and Antarctica, and from Middle Cambrian (Ordian)-aged marine strata of Australia.

Redlichia has a rather flat and thinly calcified dorsal exoskeleton of inverted egg-shaped outline, about 1½× longer than wide, measured across the base of the genal spines and disregarding the spine on the 11th segment of the articulated middle part of the body (or thorax).

The headshield (or cephalon) is semicircular, about ⅓× as long as the body, with clear genal spines that are a smooth continuation of the border, that extend backward and outward and curving to be near parallel near their tips, which typically extend to the backhalf of the articulated middle part of the body (or thorax).

Mesodema Whitehouse, 1939, Dongshania Lin in Qiu et al., 1983, and Spinoredlichia Liu, 1975, are all considered to be synonyms of Redlichia.

[4] The type species, R. noetlingi, is found in Lower Cambrian-aged marine strata of Western Pakistan.