| An analysis of duplomere (= segment) distribution within the cephalon, thorax, and pygidium of Cambrian trilobites was undertaken to determine if the Arthropod Pattern Theory (APT) proposed by Schram & Emerson (1991) applies to Cambrian trilobites. The boundary of the cephalon/thorax occurs within the predicted duplomere node 1 (duplomeres 4 or 6). The boundary between the thorax and pygidium generally occurs within node 2 (duplomeres 11—13) and node 3 (duplomeres 18—20) for corynexochids and ptychopariids, respectively. This boundary occurs within field 4 (duplomeres 21—n) for olenellids and redlichiids. The termination of the body generally occurs within node 3 for corynexochids and within field 4 for olenellids, redlichiids, and ptychopariids. In... |
