Page 84 - The Restless Earth Fossils

Fossils in the human Family 3

Intimate Guide to Human Origins, “is like a mosaic of many
tiles, some extremely old and some very new.” One of our oldest
features, it turns out, is the way we walk. A 3.2-million-year-old
fossil skeleton nicknamed “Lucy” (after lyrics in a popular Beatles
song) and a set of incredible trace fossils confirms this idea. Lucy’s
limb and hip bones implied that she walked upright. Parallel tracks

Here is what happened: 3.7 million years ago, Sadiman, a now-
extinct volcano, belched a puff of volcanic ash that deposited about
a half-inch of fine cinders. Then it rained and the ash turned into
natural, gooey cement. The sky cleared, the ash dried a little, and
then a bunch of animals—including elephants, giraffes, rhinos, pigs,
birds—walked on it . . . including at least two hominins who walked
close together, perhaps nervously eyeing the volcano that had scared
them a short time before. Then, the tracks dried, and the volcano
belched again, preserving them with another ash layer until a game
of “throw the elephant dung” many years later.

An interpreter points out the 3.7-million-year-old hominin
footprints that were fossilized in volcanic rock to a group of Masai
women at the Laetoli site in northern Tanzania.

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