The theory of heterochrony provides a quantitative perspective on the trajectory of biological development. Reduced to an empirical model, heterochrony provide a general characterization the rate and extent of growth of select phenotypic features in developmental time. This is largely achieved by means of linear and non-linear regression. This of course does not allow for the characterization of temporal discontinuities, nor conceptual integration with developmental changes in shape. Dynamical approaches can be used to reconsider of growth and form at the multitude timescales of gene expression, the metamorphic potential of life-history, and phenotypic self-assembly. With a focus on developmental timing, we will explore biological growth with formal techniques such as Delay Dynamical Systems, Lagrangian methods, and mapping differential growth to developmental trees. This will not only enrich our understanding of heterochrony, but of complex developmental processes more generally.