National Geographic - UK (2022-05)

Strobilus

Megaspores

Actual size shown

(1/25 inch

in diameter)

Guangdedendron era (372-359 MYA)

Major volcanic activity

Atmospheric CO 2 (parts per million)

Current

level

413 ppm

1,969 ppm

420 MYA

(million years ago)

250 MYA Present

Juvenile

tree

Mature

Guangdedendron

3.6-25.3 feet

Clam shrimp

Jiangxilepis

Crinoid

CHANGING THE CLIMATE

During the Devonian period,

primitive mossy plants evolved

into trees, which gradually grew

bigger and more abundant.

They collectively removed ever

greater amounts of CO 2 from the

air, causing an “anti-greenhouse”

effect that cooled the planet

and expanded the polar ice caps.

A clam shrimp and other

possible invertebrate and fish

fragments were also found.

SEEDLESS SPREAD

Guangdedendron repro-

duced by dispersing

snowman-shaped mega-

spores, held in its crown’s

arched branches.

Beijing

CHINA

TAIWAN

THE FIRST FORESTS GuangdeCounty

BY MONICA SERRANO

AND SCOTT ELDER

Researchers in China have

discovered fossils of the

oldest forest ever found in Asia,

a 62-acre stand dating back

some 365 million years. The

newly unearthed genus, named

Guangdedendron, lived when

trees were starting to put down

roots around the world. The rise

of forests permanently altered

Earth’s atmosphere and climate.

EXPLORE | DECODER

ILLUSTRATION: RAÚL MARTÍN

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