Parents need to know that this book is both too delicate, and possibly too scary (on one page the jaws of a T-rex come out at the reader), for young kids. Though thoroughly researched, some of the information presented verbally and pictorially is controversial, though the author is usually careful to indicate this.
Violence:Carnivores and raptors are shown fighting and eating dead prey, including one pop-up where an allosaurus pulls a strip of flesh out of a dead dino as you open the page.