Question

Why are there otherkin for dragons and other mythological creatures but not for obscure extinct animals?

Grace Slagle Community Answer

There are, but not very many. Also, the fact that these animals are obscure plays a big part. For example, somebody could actually be an extinct pterosaur and not know. All they would know is that they were a huge reptile with wings, and "dragon" is usually the best they can come up with with that little information.