This has been a debate for centuries(?) among experts and lay-people alike. My estimation is humans are omnivorous because we have both canines for tearing flesh apart or off a carcass as well as molars to crunch up nuts and other vegetarian foods. The old adage seems to ring true here, “The simplest answer is usually the right one”. If a zoologist was to judge an animal’s diet that is now extinct, my guess would be that they look at the teeth to determine it. Put that in your pipe and don’t smoke it!