Some analytic methods in the study of ontogeny in fossils with accretionary skeletons

Publisher Website
Google Scholar
Abstract
Paleontological studies of organisms with accretionary skeletons should take full account of the implications of accretionary growth. These implications are discussed in this paper with examples from the Brachiopoda. Descriptions of morphology should recognize the ‘dynamic’ character of preserved structures as embodying a sequence of previous growth stages; ‘static’ descriptions can result in misleading morphological characters and spurious taxonomic distinctions. Analysis of ontogeny in dynamic terms, and particularly the topological comparison of structures of varied form, can help distinguish true from false homologies, and hence evaluate the probability of inferred phyletic pathways. Such analyses can also be used to infer the morphogenetic ‘rules’ that governed the development of particular structures and, hence, to locate major phyletic innovations and discontinuities in structure. Four distinct classes of functional interpretation are applicable to accretionary structures. Functional analysis of structures developing through ontogeny can help to discriminate between analogical and homological resemblances and to identify functional changes during ontogeny. Likewise, functional interpretation of postulated transformations of structure can be used to evaluate the phylogenies suggested; interpretation of structures that are functionally dependent on absolute size can also help to identify major adaptive innovations and discontinuities.

This publication has 7 references indexed in Scilit: