Babies can be loud, smelly, and unpredictable, but they also give older siblings a chance to become role models. These are familiar topics, but Esbaum (Frankenbunny) and Boldt (There-s Nothing to Do!) infuse them with fresh comedy by transplanting them to a dinosaur household, where readers meet a newly minted older sibling with orange scales, a huge head, expressive eyes, and a toothy grin. The hero struggles to find footing with the baby (who is pink and quite adorable in its dino diaper), but Esbaum offers the reminder that -you-re the perfect one to teach that baby everything.- Some of the older sibling-s ideas work better than others: presented with the family-s pet saber-toothed cat, the baby promptly turns it into a teether. But soon a happy friendship is forged. Esbaum combines the classic cheerleading tone of the how-to genre with shouted choruses of -Good news!- and -Bad news!- that reflect the peaks and valleys of siblinghood. It-s an ideal setup for Boldt-s broadly funny digital paintings, which include an entire spread devoted to dinosaur tantrums. Ages 2-5. Author-s agent: Tricia Lawrence, Erin Murphy Literary. Illustrator-s agent: Jennifer Rofé, Andrea Brown Literary. (Jan.)