Discrete dental morphology among members of the extant Erinaceidae (Mammalia; Lipotyphla) is comprehensively reviewed in order to ascertain its phylogenetic resolving power. This analysis responds to the need to better understand the nature of the characters—discrete dental morphology—most commonly used to diagnose erinaceid fossil taxa, and reconstruct their evolutionary histories. This investigation attempts to set the parameters for a phylogenetic analysis of both fossil and living erinaceids.

The first phase of this investigation reviews 246 descriptive discrete dental transformation series—the majority of which were gathered primarily from the literature and are (or have been) considered apomorphies at various taxonomic levels within the family Erinaceidae. These characters were reviewed across 10 species of hedgehogs: a minimum of two species per extant genus (excluding the rare species), of which all are represented by series of individuals. The data were compiled and analyzed for each individual for inter- and intraspecific variation (including asymmetry), and its possible covariation with sex, relative age (based on tooth eruption and wear stage), and geographic location.

The second phase tests the phylogenetic resolving power of the discrete dental transformation series when considered as the sole body of evidence for hypotheses of evolutionary relationships. The discovered phylogenies of parsimony analyses of the discrete dental data are compared to previous hypotheses of relationships based on all known morphological evidence.

Results suggest that dental variation is intemperant both inter- and intraspecifically within the Erinaceidae and cannot unequivocally be attributed to any one of the variables considered (see above); and, more specifically, the phylogenetic resolving power of the dental data (across the considered taxa) is contingent on the inclusion of other data (i.e., cranial and postcranial material). Consequently, the applicability of this character set to the erinaceid fossil record as the sole source of evidence for phylogenetic inference is challenged.