Between 8 and 6 million years ago, there was a global increase in the biomass of plants
using C 4 photosynthesis as indicated by changes in the carbon isotope ratios of fossil tooth …

There is a growing interest in the biological implications of body size in animals. This
parameter is now being used to make inferences and predictions about not only the habits and …

The surface uplift of mountain belts is generally assumed to reflect progressive shortening
and crustal thickening, leading to their gradual rise. Recent studies of the Andes indicate that …

The family Equidae have an extensive fossil record spanning the past 58 million years, and
the evolution of the horse has frequently been used as a classic example of long-term …

The mystery of how migrating animals find their way over unfamiliar terrain has intrigued
people for centuries, and has been the focus of productive research in the biological sci ences …

The oxygen isotopic compositions of carbonates deposited in the northern Altiplano
demonstrate a rapid change in late Miocene time, which we attribute to an increase in elevation. …

Medium- to large-bodied mammalian herbivores are taxonomically diverse and comprise a
large component of the highly fossiliferous Neogene terrestrial sedimentary sequence from …

The Eocene–Oligocene transition towards a cool climate (∼33.5 million years ago) was one
of the most pronounced climate events during the Cenozoic era 1 . The marine record of …

Six sympatric species of 5-million-year-old (late Hemphillian) horses from Florida existed
during a time of major global change and extinction in terrestrial ecosystems. Traditionally, …

A fortunate fact of human history is that we have been amassing an abundance of information
on the biodiversity of our planet—as institutional collections of specimens—for hundreds of …