S. Renaud et al., Patterns of size and shape differentiation during the evolutionary radiation of the European Miocene murine rodents, LETHAIA, 32(1), 1999, pp. 61-71
Fourier analysis applied to the outlines of the first upper and lower molar
s of European Miocene murine rodents was used to quantify the size and shap
e variations associated with their radiation and to determine the evolution
ary relationships among the taxa. The results suggested the occurrence of t
wo lineages involving different evolutionary patterns. Size exhibits a rapi
d diversification in both lineages, probably because of selective pressures
related to increasing competition among species. With regard to shape, one
of the lineages is characterized by a conservative morphology, and the oth
er by a tooth evolution oriented toward broader molars, which is interprete
d as an adaptive specialization. Size and shape evolution are diversely ass
ociated during the radiation, and they may be related to the morphological
differentiation of co-existing species and the avoidance of interspecific c
ompetition.