How do you prove that Earth is older than 10,000 years?

Mesosaurus fossil. Probably dating back to the early Permian Period, roughly 300 million years ago. [Image source]

Planet Earth formed around 4.5 billion years ago. The first primitive forms of life appeared about 4 billion years ago. Natural selection did the rest, giving rise to species increasingly better adapted to their environment. Evidence, as they say, is overwhelming.

Or is it?