I review a lot of textbooks. I have yet to see one that claimed Piltdown Man was a human ancestor.
The big problem was that it was the exact opposite of what evolutionary theory predicted. A humanlike jaw with a small cranium would have fit the theory. Instead there was a ape's jaw with a large skull.
Hence the fact that it got such short shrift in so many textbooks. It just didn't fit the theory or the evidence. Which is why it was eventually debunked. No way to make it fit.
The big problem was that it was the exact opposite of what evolutionary theory predicted. A humanlike jaw with a small cranium would have fit the theory. Instead there was a ape's jaw with a large skull.
Hence the fact that it got such short shrift in so many textbooks. It just didn't fit the theory or the evidence. Which is why it was eventually debunked. No way to make it fit.