If the pun is the lowest form of humor, it's also one of the easiest for kids to get. This third installment of Ice Age is full of wordplay, as when Sid (Leguizamo), a silly sloth, discovers frozen dinosaur eggs and dubs them "eggcicles." I groaned good-naturedly; Fred, my 9-year-old consultant on kids' films, laughed loudly. Dawn of the Dinosaurs is amusing enough, more so for kids than adults, as it sends Sid, Manny the mammoth and Diego the saber-toothed tiger to a land where dinosaurs still trample the earth. Chase scenes, slightly scary bits and a happy ending follow. A day later it's extinct in one's memory.