The 81st Annual Meeting of the American Association of Physical Anthropologists (2012)

Dental eruption sequences in strepsirrhines


Department of Anthropology, University of Oregon

Friday All day, Plaza Level Add to calendar

Dental eruption sequence (DES), or the order in which permanent teeth erupt, has been used to evaluate life history in primates. Schultz’s rule posits that early molar eruption predicts a fast pace of dental and somatic development. Colobine, platyrrhine, and lemur DES have been evaluated in light of Schultz’s rule with mixed results. For this study, previously unknown DES are described for five strepsirrhine taxa. This research seeks to ultimately provide information for accurate analysis of life history in fossil primates.

Seventy five informative juveniles housed at the AMNH and NMNH were examined for crown eruption height of permanent dentition, per Harvati (2000). Molar eruption in Galago is relatively precocious, with M1 and M2 erupting before replacement of deciduous teeth, while M3 erupts after all replacement teeth except P3 and P4. Otolemur is slightly more altricial, with M2 erupting after the incisors, but before C-P4. Both Loris and Perodicticus have poorly resolved sequences, with M1 equal to the incisors and M2 and M3 generally following the incisors, canine, and P2. Nycticebus also has a poorly resolved sequence, but is interesting for the eruption of the permanent incisors before M1.

These findings show inconsistencies in “fast” and “slow” eruption sequences: the M2 sometimes erupts early, but the M3 erupts relatively altricially. Strepsirrhine dental eruption sequences are evaluated in relation to brain mass, body mass, dietary quality, and age at weaning. These sequences display that Schultz’s rule does not easily predict dental eruption in strepsirrhines.

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