Data from: Carnivorous mammals from the middle Eocene Washakie Formation, Wyoming, USA, and their diversity trajectory in a post-warming world

The middle Eocene Washakie Formation of Wyoming, USA, provides a rare
window, within a single depositional basin, into the faunal transition
that followed the early Eocene warming events. Based on extensive
examination, we report a minimum of 27 species of carnivorous mammals from
this formation, more than doubling the previous taxic count. Included in
this revised list are a new species of carnivoraform, Neovulpavus
mccarrolli, and up to ten other possibly new taxa. Our cladistic analysis
of early Carnivoraformes incorporating new data clarified the array of
middle Eocene taxa that are closely related to crown-group Carnivora.
These anatomically relatively derived carnivoraforms collectively had an
intercontinental distribution in North America and east Asia, exhibiting
notable variations in body size and dental adaptation. This time period
also saw parallel trends of increase in body-size and dental sectoriality
in distantly-related lineages of carnivores spanning a wide range of body
sizes. A new, model-based Bayesian analysis of diversity dynamics
accounting for imperfect detection revealed a high probability of
substantial loss of carnivore species between the late Bridgerian and
early Uintan North American Land Mammal ‘Ages’, coinciding with the
disappearance of formerly common mammals such as hyopsodontids and
adapiform primates. Concomitant with this decline in carnivore diversity,
the Washakie vertebrate fauna underwent significant disintegration as
measured by patterns of coordinated detection of taxa at the locality
level. These observations are consistent with a major biomic transition in
the region in response to climatically-induced opening-up of forested
habitats.