Dear Aunt Debbie,
I'm going to have to outsource some of the research on this subject -- I've asked a couple of friends with dino-mad sons to give me their recommendations, too.
The only other dinosaur book we own is a pretty amazing 3-D one meant for ages 8 and up: Uncover A T. Rex, by Dennis Schatz. It falls into the second of your dino categories, the books which focus on facts and conveying scientific information. The book contains a plastic model of a T. Rex, and each page focuses on one of its systems: skeletal, cardiopulmonary, etc. It's written in factoid form, with lots of questions and answers and bullet points ("How fast did T. Rex run?" "What was T. Rex's posture like?") As you turn each page, the system described lifts up to reveal the next system below: the nervous system disappears to reveal the muscles. Eleanor is still too young for it, but she likes to look at the model parts inside, and I'm hoping it will prove useful in a few years.
In heavy rotation at the moment is the Matthew Van Fleet touch-and-feel spectacular Cat, which has recently become 10 1/2 month old Isabel's favorite book. She pats and hits and tears at and touches the book intently, all the while saying "Ghat!" I'm wary of ascribing language to a baby that young (though we are positive she is now saying "Hi!"), but when I took her to a friend's house a couple of days ago and she saw a couple of real cats, she perked right up, pointed at them, and said, "Ghat!"
It's a very engaging book, illustrated with photos (by Brian Stanton) of real cats in various positions, some with furry patches a baby can touch, others with a paw or tail that moves when you pull a lever. Isabel has already pulled off one moving tail, crowing proudly. (Eleanor objected, until I reminded her that she had pulled off the pig's tail with the same construction in Van Fleet's book Tails at about the same age.) The text, in rhyming couplets, highlights concepts and opposites, and the pictures are great.
In my own reading life, I just picked up and sped through Rebecca Stead's When You Reach Me, which you wrote about a little while ago. What a totally satisfying book. Thanks for that one.