|Lesser Mouse-deer (Tragulus kanchil) at Singapore Zoo|
Photo by Bjørn Christian Tørrisen (CC)
A new paper in PLoS One re-examines the European fossil fauna and shows tragulids already were on the way out in the Oligocene (full text here). The focus of the study is on a narrow time period called MP28 (MP stands for Mammal Palaeogene zone). This was a period of global warming that led to wooded environments being replaced by more open habitats and the appearance of seasonality including a dry season.
Pecorans have an additional forestomach, the omasum, and this may have given them the edge over tragulids in exploiting new resources.
|Placenta of Lesser Mouse-deer showing binucleate cells stained with|
anti-bovine lactogen. From the Benirschke web site.