Heterogeneous growth of marginal teeth in the black iguana Ctenosaura similis (Squamata: Iguania)

Marginal teeth of iguanine lizards have been studied to some extent, but some aspects of tooth growth remain poorly known. Growth of marginal teeth in Ctenosaura similis is described based on examination of 22 dry skulls. The number of premaxillary teeth remains constant; the number of maxillary and mandibular teeth increases allometrically; and there is no correlation between number of pterygoid teeth and size. Ontogenetic changes in tooth morphology probably are related to ontogenetic shifts in diet. Larger individuals have large fanglike anterior marginal teeth, which might represent an adaptation for consumption of fleshy plant material and occasional carnivory. Other genera of iguanine lizards are primarily herbivorous throughout life; thus, carnivory and the related ontogenetic changes in tooth morphology are derived features within the iguanine clade.