Variation and covariation of skulls and teeth: Modern carnivores and the interpretation of fossil mammals

Teeth are generally the best-preserved elements among mammal fossil remains and are highly diagnostic characters. Consequently, much mammalian paleontological, systematic, and evolutionary research focuses on teeth, so it is important to understand how they vary and covary with other characters. Dental traits within populations of carnivores appear to be more variable than cranial traits, a pattern that results only partly from their usually smaller size. Furthermore, dental traits, although highly correlated with one another, are not highly correlated with cranial traits, which are also highly correlated with one another. Thus, teeth and cranial bones may be subject to quite different selective pressures and genetic/developmental constraints and may suggest different microevolutionary scenarios. Vestigial teeth show significantly greater variability than expected, reflecting the absence of stabilizing selection.