Heterochrony and developmental modularity of cranial osteogenesis in lipotyphlan mammals.

Background: Here we provide the most comprehensive study to date on the cranial ossification sequence in Lipotyphla, the group which includes shrews, moles and hedgehogs. This unique group, which encapsulates diverse ecological modes, such as terrestrial, subterranean, and aquatic lifestyles, is used to examine the evolutionary lability of cranial osteogenesis and to investigate the modularity of development.

Results: An acceleration of developmental timing of the vomeronasal complex has occurred in the common ancestor of moles.