FIGURE 15 in Systematic revision of the trilobite genera Laudonia and Lochmanolenellus (Olenelloidea) from the lower Dyeran (Cambrian Series 2) of western Laurentia

FIGURE 15. Bivariate scatterplots depicting intraspecific variation in various aspects of cephalic morphology of Lochmanolenellus pentagonalis n. sp. Symbols represent phases of cephalic development. 1, Proportional cephalic width, measured as the ratio of the transverse distance between the genal spine bases to glabella length. 2, Orientation of the distal portion of the posterior cephalic margin (distal PCM), quantified as the inner angle between it and a transverse line. 3, Cephalic shape, measured as the ratio of the transverse distance between the intergenal spine bases to the transverse distance between the genal spine bases. 4, Degree of lateral flaring of the genal spine, quantified as the angle between the inner margin of the proximal portion of the genal spine and the distal portion of the posterior cephalic margin (distal PCM).