Hopes of bringing the oldest blood in existence back to life

dinosaur blood in a preserved mosquito if i remember correctly, however there isnt really much chance of a rampaging giant monster horse the size of a building eating everyone with horse blood.

Horse, frost, maybe something out of Norse mythology?
You're right about the dinosaur blood, but you get the idea

The problem I see is what microbes live in that blood that we have no immunity against.