Landmark based geometric morphometrics has developed as a powerful set of statistical and visual tools for the study of the covariance patterns of organismal shape change with a range of variables or factors. The approach is limited in the kinds of shape information accessible to it, however, by the need to employ discrete landmarks as the basis for comparison. In particular, curves and complex outlines are difficult to address using strictly landmark-based methods. Information about curves may be incorporated into the study of shape by the use of semi-landmark methods, which allow information about curved surfaces to be incorporated into the framework of landmark-based geometric morphometrics. We present a discussion of several software and statistical approaches needed to carry out combined landmark and semi-landmark analysis. In particular, we demonstrate several approaches to semi-landmark alignment (including the “edgewarp” method) and compare these to standard landmark based methods utilizing a regression analysis of the Ordovician trilobite Triarthrus becki. Abundant landmarks on the cranidium of T. becki allow landmark methods to represent the shape of that structure effectively, making it a good test case for combined landmark and semi-landmark methods. We verify that patterns of ontogenetic change implied by regression models using varying combinations of landmark and semi-landmark information are consistent with one another. Thus, semi-landmark methods and standard landmark based geometric morphometric methods yield commensurate information about this ontogenetic shape transformation. These results suggests that semi-landmark methods show substantial promise for rigorously testing hypotheses that involve the comparison of shapes when an adequate set of landmarks is not available.