OXFORD, U.K.—Scientists have smashed through another time barrier in their search for ancient proteins from fossilized teeth and bones, they said yesterday, adding to growing excitement about the promise of using proteins to study extinct animals and humans that lived more than 1 million years ago. Until now, the oldest sequenced proteins are largely acknowledged to come from a 700,000-year-old horse in Canada’s Yukon territory, despite claims of extraction from much older dinosaurs. In two talks at the seventh International Symposium on Biomolecular Archaeology here yesterday, geneticists reported that their teams had extracted proteins from 3.8-million-year-old ostrich egg shells in Laetoli, Tanzania, and from the 1.7-million-year-old tooth enamel of several extinct animals in Dmanisi, Georgia. The teeth, buried at the fossil site that houses the earliest hominin remains outside Africa (above), came from extinct horses, rhinos, and deer. Geneticist Enrico Cappellini of the University of Copenhagen and biochemist Matthew Collins of the University of York in the United Kingdom said their team had extracted and decoded 5000 amino acids from a half-dozen proteins, which they will now analyze to determine the animals’ sex, species, and other traits. Collins also reported that his team has extracted proteins from 3.8-million-year-old ostrich eggshells from Laetoli, the site of some of the world’s earliest human footprints. Although such ancient proteins have not yet been recovered form hominin fossils, these studies prove that such ancient proteins can survive—and are fast becoming a resource to mine for information about the biology of organisms too old to produce ancient DNA.