Figure 19. Results of an adaptive semilandmark interpolation analysis in which the Argyroplecus and Sternoptyx outlines, originally sampled with 250 semilandmark points, were interpolated using 13 landmark points located on the outline (blue = boundary outline termination landmarks, red = landmarks). Use of these landmark points breaks the outline into 12 segments which can then be interpolated separately using n equally spaced semilandmark points (green) where n equals the number of semilandmark points required to ensure a geometric fidelity fit of 95% of the length of the original (digitized) curve. This procedure ensures all aspects of the boundary outline are matched exactly at, and in the vicinity of the landmark points and ensures that all segments of the outline are represented to a consistent geometric representational standard. In order to meet these criteria over the entire outline for both forms 83 points were necessary. The eye, gill opercula dorsal terminus and the pectoral fin were excluded from this analysis, but could easily be added using identical criteria to constrain their representation, as could additional landmark points.

Published as part of MacLeod, Norman, 2017, Morphometrics: History, development methods and prospects, pp. 4-33 in Zoological Systematics 42 (1) on page 25, DOI: 10.11865/zs.201702, http://zenodo.org/record/5365842