Name: 【TED】Kenneth Lacovara: Hunting for dinosaurs showed me our place in the universe (Hunting for dinosaurs showed me our place in the universe | Kenneth Lacovara)
Uploaded: 2016-11-03T18:22:15.000Z
Duration: 15 min 50 s
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And the answer relies on a formula that all paleontologists use.

Second, those rocks must be sedimentary rocks.

And third, layers of those rocks must be naturally exposed.

Find those three things and get yourself on the ground,

chances are good that you will find fossils.

Organisms exist only during certain geological intervals.

So you have to find rocks of the right age,

you have to find the really, really old rocks of the Paleozoic --

rocks between a half a billion and a quarter-billion years old.

don't look in the Paleozoic, you won't find them.

You have to find the younger rocks of the Mesozoic,

Now, it's fairly easy to find rocks of the right age at this point,

because the Earth is, to a coarse degree,

The annals of Earth history are written in rocks,

Now, were it quite that easy, geologists would rejoice.

myriad geological processes offer every possible insult

Most pages are destroyed soon after being written.

creating difficult-to-decipher palimpsests of long-gone landscapes.

Pages that do find sanctuary under the advancing sands of time

Unlike the Moon -- our dead, rocky companion --

the Earth is alive, pulsing with creative and destructive forces

Lunar rocks brought back by the Apollo astronauts

all date back to about the age of the Solar System.

Earth rocks, on the other hand, face the perils of a living lithosphere.

through some combination of mutilation, compression,

Thus, the volumes of Earth history are incomplete and disheveled.

And it was this tattered complexity in the rock record

that obscured its meaning until relatively recently.

Nature provided no card catalog for geologists --

Five thousand years after the Sumerians learned to record their thoughts

the Earth's volumes remained inscrutable to humans.

unaware of the antiquity of our own planet

It wasn't until the turn of the 19th century

first, with the publication of James Hutton's "Theory of the Earth,"

in which he told us that the Earth reveals no vestige of a beginning

and then, with the printing of William Smith's map of Britain,

predictive insight into where certain types of rocks might occur.

"If we go over there, we should be in the Jurassic,"

or, "If we go up over that hill, we should find the Cretaceous."

Now of course, you can only make a fossil in a sedimentary rock,

in an igneous rock formed by magma, like a granite,

or in a metamorphic rock that's been heated and squeezed.

And you have to get yourself in a desert.

It's not that dinosaurs particularly lived in deserts;

It's that you need to go to a place that's a desert today,

a place that doesn't have too many plants covering up the rocks,

and a place where erosion is always exposing new bones at the surface.

【TED】Kenneth Lacovara: Hunting for dinosaurs showed me our place in the universe (Hunting for dinosaurs showed me our place in the universe | Kenneth Lacovara)

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【TED】Kenneth Lacovara: Hunting for dinosaurs showed me our place in the universe (Hunting for dinosaurs showed me our place in the universe | Kenneth Lacovara)

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