For Immediate Release Contact: Greg Borzo (312) 665-7100 gborzo@fieldmuseum.org Consisting of teeth and jaw fragments, the fossils were found in the Fayum Depression on the eastern edge of the Sahara Desert in Egypt, the best site for early African fossil mammals. They represent Saharagalago (a bushbaby) and Karanisia (a loris), adding two new genera to only four that were previously known for bushbabies and lorises. The well-preserved teeth date from about 40 million years ago, twice as old as the already known fossils for these two groups of primates. In Karanisia, the teeth at the front of the lower jaw formed a toothcomb like that typically seen in living strepsirrhine primates, which includes bushbabies, lorises and lemurs, as one of their defining characteristics. Amazingly, wear patterns on the teeth indicate that Karanisia used its toothcomb for grooming, just as its modern relatives do today. The authors report that the sides of the teeth show irregularly spaced microscopic grooves created by the passage of hair during grooming. Seiffert and colleagues conclude that the new finds are compatible with the widely accepted view that the lorises and bushbabies (as a group) diverged from lemurs 50 million to 53 million years ago, and that their last common ancestor lived in Afro-Arabia. Martin’s alternative interpretation stems from statistical models indicating that gaps in the fossil record have led scientists to underestimate divergence times throughout the primate evolutionary tree. Furthermore, new molecular trees also indicate that primates originated much earlier than generally accepted. “One possibility is that the strepsirrhine primates originally inhabited Indo-Madagascar, rather than Africa, and that lemurs became isolated when Madagascar separated from India,” Martin says. “Subsequently, lorises could have migrated to Africa after India collided with Asia.” Download Image To download a 200 dpi tif image directly to your computer, click on the thumbnail image below. Caption information may be found under "file/file info" of the Adobe® Photoshop® file. Primate Evolutionary Tree File Info: Tif file format File Size: 7.6 mb Print Size 6x8 inches