Mammoth Academy, by Neil Layton, is a chapter book that I nominated for the Cybils in the Middle Grade Reader category because I liked it so much. It is about two mammoths, Oscar and Arabella, who go to a school called Mammoth Academy to learn all the sorts of things we people learn in our schools. There are creatures that aren't mammoths too, like a cave cat, an owl, and a fox. All of the creatures at the academy get along with mammoths. They have very cool adventures, especially Fox and Oscar, like going up a steep mountain and finding a human cave school (humans were very dumb at that time!).
I love the black and white illustrations, and there are lots of them!
This book is an easy reader, but it has too many pages to count in that category the Cybils! It has ten chapters and 149 pages (this is the UK version). This books is for ages 6 and up.
Here's another review, at Jen Robinson's Book Page.