Let's clarify the title a little bit first. I had thought that it was going to be about discoveries that changed the time they were discovered in. Moveable type, for example. Instead, it's about archaeological discoveries that altered contemporary perceptions of previous eras. It's a fine difference, enough that I wouldn't even call the title as is misleading, but I think it does help to know what you're getting into.
For what it is, I think the examples were mostly well chosen. We start with the Rosetta Stone, whose impact is unquestioned and would probably be on any list like this. There's some opinion in the list, of course, but I couldn't really argue with any of the selections. They're arranged in chronological age of the discovery, each section is very brief, but tries to explain the backdrop for the discovery and the impact it had. Overall, it's quite interesting.
I do feel like I have to note that the author really skims over, and is sometimes dismissive of, the very serious issues of art repatriation and artifact smuggling. He seems more concerned that collectors can't authenticate their stolen artifacts than the fact that they're being stolen in the first place, or that museums are often knowingly filled with stolen artifacts. But since this is really a work of pop history, and short, I'm trying not to judge too harshly on opinions that may be quite different if he had space to expand them.