Fig. 3
From: Resolving the evolution of the mammalian middle ear using Bayesian inference
Lingual view of the developing and artificially eroded platypus dentary. In early development of the platypus (a) Meckel’s cartilage lies in a deep Meckel’s groove. In a juvenile specimen with Meckel’s groove closed (b), a faint seam on the ventral border of the mandibular canal is present along the length of the dentary. Through relatively minor virtual erosion of the specimen (c–e), this trace is exaggerated into a structure resembling a Meckel’s groove while the detailed topology of the dentary is otherwise retained. Coding Meckel’s groove as present only where it is unambiguously well-developed (see Methods) therefore appears to be the best strategy