First up, the seller of this egg stated upfront this is a replica, so this isn't a scam warning.   Here, we have an oviraptor egg that could fool even experienced collectors. It looks realistic because it's made out of real oviraptor eggshells. It's even covered with a coating of matrix. This is common practice; I've seen hadrosaur eggs are faked this way, with plaster mixed in to make the egg seem round and heavy.     For reference, here's a real Oviraptor (Elonga