Portal talk:Human/@comment-101.98.128.11-20120630082758/@comment-1743498-20120701131112

Well, in the Omni 01 timeline, other than the Titans, there were no spacefaring races at the time the dinosaurs went extinct. What could happen is where DNA samples are recovered from Earth sometime after the meteor hit.

Earth in this universe is more or less an experimental ground, so I would see no problem with this, though humans are unlikely to have cloned them since they left Earth in the late 1980s.