Figure 5
Bivariate plot diagrams of Gunnia sp.
All measured specimens represented by fine points either in (a) or (b) show an approximately isometric growth pattern, with some figured specimens labeled (e.g., 2a representing Fig. 2a; 3n representing Fig. 3n, etc.). (a) 41 cephala and cranidia (including 19 protocephala). The boundary for Protaspid/Meraspid is defined by early instar specimens dealt with here; without enough material, the boundary in (b) for Meraspid/Holaspid is determined by matching the width of the posterior margin of a cranidium to that of a pygidium situated near the boundary. (b) 53 pygidia (including 19 protopygidia). The growth ratio (1.15) is determined by measuring all of early meraspides and then this ratio is applied to the division of succeeding meraspid degrees and holaspid stages. The number in the slope line indicates the visible axial rings of a pygidium correspondingly. The original measurement of all specimens applied for making this figure can be found from Supplementary Tables S1 and S2 in the online version.
