Soon After Dinosaur Decimation, Our Primate Ancestors Began Pouncing on Prey
Nails helped them climb trees quietly, and forward-facing eyes helped with depth perception to aid in precise leaping
Riley Black
Science Correspondent
November 14, 2022
A mouse lemur grasps onto a tree branch in Madagascar. Scientists looked to characteristics in such modern primates to form a hypothesis about how primates behaved after an asteroid wiped out non-avian dinosaurs. Gilles MARTIN / Gamma-Rapho via Getty Images
A hunger for crunchy insects may have led our early primate ancestors to develop the signature traits that we inherited.
Small primates like Teilhardina, which lived in the forest canopy of ancient China 55 million years ago, were early adopters of some of our evolutionary family’s most famous characteristics. Looking much more like lemurs than monkeys, they had forward-facing eyes, grasping hands and nails that would become hallmarks of many later primate species—including ourselves. How such traits evolved in the first place has long been controversial among fossil primate experts, but a new hypothesis suggests that sneakily hunting up in the treetops had a lot to do with it.
Investigations of human origins often center on our ancient hominin relatives such as “Lucy,” but many of the characteristics that make us unique among mammals are much, much older. “Humans represent a mosaic of traits that have evolved at various points throughout the 66-million-year history of primates,” says University of Toronto paleontologist Mary Silcox.
Our gifts of depth perception, dexterous hands and more can be drawn back to a time much closer to the dinosaurian heyday than the present. The first primate with a grasping toe dates back to 56 million years ago, the first big increase in brain size occurred 55 million years ago and the number of teeth we have can be traced back to 30 million years ago, Silcox points out. But exactly why our early ancestors came to have such telltale traits has been debated by experts for decades.
More:
https://www.smithsonianmag.com/science-nature/soon-after-dinosaur-decimation-our-primate-ancestors-began-pouncing-on-prey-180981107/