Avian diversification has been influenced by global climate change, plate tectonic
movements, and mass extinction events. However, the impact of these factors on the …

Profound environmental and faunal changes are associated with climatic deterioration
during the Eocene-Oligocene transition (EOT) roughly 34 million years ago. Reconstructing …

Ekgmowechashala is a poorly documented but very distinctive primate known only from the
late early Oligocene (early Arikareean) of western North America. Because of its highly …

The John Day region of central Oregon, United States contains∼ 50 million years of near-
continuous, fossiliferous sedimentation, representing one of the world's richest archives of …

Disjunct, pantropical distributions are a common pattern among avian lineages, but
disentangling multiple scenarios that can produce them requires accurate estimates of …

In the middle Eocene, multiple lineages of North American omomyoids independently
evolved body masses greater than 500 g. Most of these large-bodied omomyoids are known …

Until now, the pre-Miocene fossil record of mustelids in North America has been restricted to
specimens attributable to oligobunine taxa and isolated remains tentatively allocated to the …

Over the past decade, we recorded exact locations of in situ fossils and measured
calcareous nodules in paleosols of the Oligocene and lower Miocene (Whitneyan …

Apatemyidae are a rare and enigmatic group of small insectivorous mammals that lived in
North America and Europe in the Paleogene. The last known apatemyids in North America …

Macroevolutionary biologists have classically rejected the notion that higher level patterns of
divergence arise through microevolutionary processes acting within populations. For …