An arboreal docodont from the Jurassic and mammaliaform ecological diversification

Abstract

Taking advantage of new neighborhoods Mammals are one of the most morphologically diverse organisms, with adaptation to unique ecological conditions creating a wide array of forms, from mice to whales. Two new basal mammals from the mid-Jurassic period suggest that this diversification was well under way millions of years earlier than previously thought. Luo et al. describe a burrowing species with limb and digit modifications similar to those of current burrowers and identify the likely genes and developmental pathways involved. Meng et al. describe an arboreal species with modifications for climbing and that possessed teeth clearly adapted for a herbivorous diet, including the consumption of sap. Science , this issue p. 760 , p. 764