For the purposes of Kaheera's companion ability, Zetalpa is a Dinosaur card (even though it's also an Elder card), so you can include it in your starting deck if you want to reveal Kaheera as "your companion".
Note that "Elder Dinosaur" is not a creature type separate from "Dinosaur"; rather it's two creature types, Elder and Dinosaur (C.R. 205.3m, 205.3b). See also this thread and this thread.
Note that "Elder Dinosaur" is not a creature type separate from "Dinosaur"; rather it's two creature types, Elder and Dinosaur (C.R. 205.3m, 205.3b). See also this thread and this thread.