Figure 1. (a) Points and segments used to obtain length ratios of parapodial processes employed in this work. Each parapodial process (excluding cirri) has an inscribed triangle where the length of the triangle's edges are used to obtain length ratios among parapodial structures; (b) summary of parapodial length ratios used herein. The procedure to draw vertices and edges are detailed in the Material and methods section; (c) length and width segments in a homogomph shaft; (d) length and width segments in a sesquigomph shaft; (e) length and width segments in a heterogomph shaft. Abbreviations in (a): Ax, Bx, and Cx = vertices of each parapodial process; mAxBx = midpoint of segment AxBx; a = ventral length of the referred structure, b = dorsal length of the referred structure, c = basal length of the referred structure. Abbreviations in (b): DC = dorsal cirrus; NaL = neuroacicular ligule; NeV = neuropodial ventral ligule; NoD = notopodial dorsal ligule; NoV = notopodial ventral ligule; PoL = neuropodial postchaetal lobe; PreL = notopodial prechaetal lobe; VC = ventral cirrus. Abbreviations in (c–e): BL = boss length; BW = boss width; CiL = inner collar length; CoL = outer collar length; CoW = outer collar width.