A Bone From a Dry Sea (1992)

Two girls in Africa--one on the seashore, one in the dry country of East Africa. One girl worried about sharks, the other worried about leopards and snakes and the heat. Both worried about big macho bullies who want to control everything. The only difference is--Li and Vinny live four million years apart.

Vinny has come to visit her divorced father on an archaeological dig in Africa. The country is strange, and so is her situation. She can't even get up to go to the bathroom at night because leopards roam the area then. At the same time, she can't talk to her father about stuff because his colleagues are arguing with him about where to dig for fossils. Things get complicated when Vinny finds a fossil that shouldn't really belong there, and starts to discover more about the sea apes, ape ancestors who lived off food from the sea, and lived in the sea as well as they did on land, in the exact same spot where Vinny's father is digging.

The story jumps back and forth from Vinny to Li, as Vinny speculates what happened to Li, and Li tells her story of fighting for power with the male leader of her tribe of apes. Will the archaeologists in the dig believe that Vinny has found a missing link? Will Li be able to save her tribe from a killer tidal wave headed her way?