Data from: Evidence for a mid-Jurassic adaptive radiation in mammals

A series of spectacular discoveries have transformed our understanding of
Mesozoic mammals in recent years. These finds reveal hitherto-unsuspected
ecomorphological diversity that suggests that mammals experienced a major
adaptive radiation during the Middle to Late Jurassic. Patterns of
mammalian macroevolution must be reinterpreted in light of these new
discoveries, but only taxonomic diversity and limited aspects of
morphological disparity have been quantified. We assess rates of
morphological evolution and temporal patterns of disparity using large
datasets of discrete characters. Rates of morphological evolution were
significantly elevated prior to the Late Jurassic, with a pronounced peak
occurring during the Early to Middle Jurassic. This intense burst of
phenotypic innovation coincided with a stepwise increase in apparent
long-term standing diversity and the attainment of maximum disparity,
supporting a “short-fuse” model of early mammalian diversification. Rates
then declined sharply, and remained significantly low until the end of the
Mesozoic, even among therians. This supports the “long-fuse” model of
diversification in Mesozoic therians. Our findings demonstrate that
sustained morphological innovation in Triassic stem-group mammals
culminated in a global adaptive radiation of crown-group members during
the Early to Middle Jurassic.