Dental Signatures for Exudativory in Living Primates, with Comparisons to Other Gouging Mammals

ABSTRACT Exudativory, the consumption of gums, is an obligate or a facultative dietary niche for some primates and marsupials. Exudativory has been cited as a dietary niche that may have been present in early primates, so finding a dental signature for exudativory is highly desirable. The present study combines exudativorous lorisoids (galagos and lorises) into one sample to compare to closely related, non‐exudativorous lorisoids to search for a consistent dental signature of exudativory. Linear measurements were taken from the toothcomb, P2, M3, upper canine, and P2 from skulls of 295 adult galagids and lorisids. Also, differential distribution of enamel on the anterior teeth was qualitatively investigated as a dental signature for gouging (a behavior that facilitates some exudativory) by micro‐CT scanning one specimen each from two gougers, Nycticebus coucang and Callithrix jacchus, and two non‐gougers, Perodicticus potto, and Saguinus fuscicollis. Non‐primate gouging mammals, the vampire bat Desmodus rotundus and the sugar glider Petaurus breviceps, were compared to non‐gouging relatives. Statistical analysis revealed that exudativorous galagos and lorises had significantly (P < 0.05) reduced M3 relative to non‐exudativorous galagos and lorises. While the sample sizes for assessing enamel thickness were small, preliminary results show that gouging primates and non‐primate mammals have reduced lingual enamel thickness on the anterior dentition compared to non‐gouging relatives. We suggest that reduction of mastication, and, therefore, M3 dimensions are a likely dental signature for exudativory in Primates. While broader samples are needed to statistically confirm, differential distribution of enamel in the anterior dentition may also be a signature of exudativory. Anat Rec, 2019. © 2018 Wiley Periodicals, Inc. Anat Rec, 303:265–281, 2020. © 2018 American Association for Anatomy