I managed to make it 123 years this afternoon with the wolf! Pretty thrilled with that. I got to around 80 years a couple different times, but started playing really sloppy and paid the price.
Seems like at around 65 years, everything turns into a nightmarish dinosaur hellscape, and you really need to start playing quite stealthily. It's possible to take down dinos and bigger creatures if you can get that initial stealth kill. Beginning to accumulate some nice gear (especially ATK up) has been good too.
I won't spoil anything, but once you hit 100 years, the game starts doing everything in its power to make sure you die incredibly quickly. I managed to subsist on water and items for way longer than I should have been able to. (There's food, but not a lot!)