It is hard to picture a wee monkeylike adult creature weighing no more than an ounce. But fossils of the 55.8 million-year-old animal, the earliest known primate to inhabit North America, have emerged from coastal sediments in Mississippi.


It is even harder to imagine that tiny primates of this primitive kind were able to migrate to this continent all the way from their Asian homeland.

The world then was much warmer, however, basking in tropical or subtropical conditions nearly everywhere as continents drifted apart. Over countless generations the tree-dwelling primates slowly crossed to America from Siberia, presumably by the Bering land bridge when it was probably heavily forested.

Some primates apparently continued through Greenland and Scotland, connecting links to Europe at a time of lower sea levels.

This new reconstruction of the early dispersal of primates, the order of mammals that now includes humans and apes, stems from an analysis of a fossil primate discovered in 2001 near Meridian, Miss. The identification and significance of the new species are reported in The Proceedings of the National Academy of Sciences.... (NYT)