Dental Variation

Sloth teeth are relatively simplistic, being composed of two layers of dentine (ortho- and vasodentine) with differential hardness properties, and an overall lack of enamel. The basic dental formula is also reduced to that of a 5/4 quadrant, and the teeth lack homology with those of other mammals. As such, we refer to their teeth shape as being caniniform (canine-like) and molariform (molar-like). Variations in the dental formula of extant sloths was recently brought to light (see McAfee & Naples, 2012). Sloths, like all mammalian orders with tooth-bearing members, exhibit a set of dental anomalies and much like their overall dentition, they are categorized into two simple types: anodontia (tooth loss/absence) and hyperdontia (extra teeth).

My work in this are has been quanitifying the various types of anomalies that sloths exhibit, which a forthcoming publication outlines some interesting patterns for each extant genus. Additionally, I am looking at how the anomalies effect the chewing and feeding behaviors and also exploring those known anomalies within extant specimens, while also highlighting some anomalies that are unknown and that could affect the taxonomy of some genera and species.
https://d4a59d37-a-45266bd7-s-sites.googlegroups.com/a/onu.edu/robert-mcafee/research/dentalvariation/USNM49591%20right%20lateral%20copy.jpg?attachauth=ANoY7codM0Fri2Y6P486uN_jyXsW0inAr3QWMovFZtLbUbY8oM9f1bD77AzNF7xrghzc-QdBtlZOkVR8dezkiENdTVVKYFGpVP3UIhMN27T98GQFmU9r0mmQdK-6sSbJvVfoatNmzAGNWYtfORrEc8q7XBtmyj2ElJWqu8EjaS5Klnd2HvefXZWCKsSr7RR1VRlwnsj1Mg6m9K9Yp-oWhGBose5LWUgdSPCrjhwveVcCn4H1dbjFa_sBbfhzSxKiKlGl6mtCO2CJ2Bxm2uXKIWrMulD6h6H59g%3D%3D&attredirects=0Mandible of Bradypus showing very unique and rare anomalies in the lower jaw. This specimen (USNM 49591) is missing a tooth (m1) in the left series and has an additional tooth (h'm3) in the right series.
https://d4a59d37-a-45266bd7-s-sites.googlegroups.com/a/onu.edu/robert-mcafee/research/dentalvariation/Figure%206%20copy.jpg?attachauth=ANoY7couGGokD8yo0ekoWXz6vHPSHlDo0JnzHP-c0j4rH5dBbgciwdNms_VRvqCgp0bf8YtliLbK43Y5zH35c6KVBP3VsxCO56Rr4x9QLbbC1XtzjgbQ9mKHB9iIg5lAzjACpC8oJ1tdfibIbacYOgCPZfl8HJqpFdOCX_-qK0ju0045dMwsL6OE2Y9PcjghVqBsReZI7pZ7xyUZ2_3PbHFd8tTXyrs-0-xHzQVXe74CPM_XuMB8kNhKUiSa9_zWXD_29JO0VjOJ&attredirects=0

https://d4a59d37-a-45266bd7-s-sites.googlegroups.com/a/onu.edu/robert-mcafee/research/dentalvariation/AMNH98538%20copy.jpg?attachauth=ANoY7coe84oYsj6phZKniui0CjyVR3ezaDaNKibdcuFOSkOOVFN_m_Y4dgrlfX3i3imx-DpBOaGXT_mXa3cg3Zoy4l55yvHVN-kWbS82SEKl9LIFiYR0K7ejJ1AKVe23HSuo_LWP3B-la61hbbNoL3zhzZUUtQi0trsjUt6-uV0vO-frWP-Q89sQ6CTShZl1q_fzTbVgqtfkQ2L0paZRG1CY1WuxQNRHF3XqYs8S6JhBF9gHIRHA10UfNl-pDUmiSBRFYI1jpmMu&attredirects=0Palatal view of Choloepus (AMNH 98538) exhibiting a supernumerary tooth in the right M1 position.
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