June 21 , 2016

Obligate exudativory, including active wounding of bark to acquire gum and/or sap, is rare among extant mammals and does not show a consistent dental signature. A recently described Middle Jurassic docodont Agilodocodon was reconstructed as an exudativore based on proposed similarities of its lower anterior dentition to some extant New World monkeys, specifically marmosets, spider monkeys, and howler monkeys. Oddly enough, of these, only marmosets are exudate-feeders. In our reinvestigation, we did not find any significant resemblance in the lower (and upper) anterior dentition between the Middle Jurassic fossil and these extant New World monkeys. The marmosets, the only obligate platyrrhine exudativores, have lower and upper incisors that are distinguished from Agilodocodon and other New World monkeys by having enamel restricted to the labial surface. Differential wear between the enamel and softer dentine maintains a chisel-like tooth that marmosets use in gouging bark. Additional comparisons of the anterior dentition of Agilodocodon and other extant mammals were conducted. The lower and upper anterior teeth of Agilodocodon were found to be most similar to some elephant shrews and South American marsupials, which have a primarily insectivorous diet. Agilodocodon does not show any dental adaptations found in extant mammals for exudativory.

Wible, J.R. and Burrows, A.M. (2016)
Does the Jurassic Agilodocodon (Mammaliaformes, Docodonta) have any exudativorous dental features?
Palaeontologia Polonica 67: 289–299.
doi: 10.4202/pp.2016.67_289