BBC Knowledge Asia Edition 3

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PHOTOS: SCIENCE PHOTO LIBRARY, GETTY X5 ILLUSTRATION: DANIEL BRIGHT

Eyes, by at least 40 million years. The only

invertebrates with ears are land arthropods

and they didn’t emerge until about 480

million years ago. Older invertebrates had

antennae that would have been able to

sense vibrations in the water, but that’s not

quite the same thing as hearing. Trilobites

already had complex compound eyes 521

million years ago, and simple eyespots

without a lens probably date back to 570

million years ago, when the first multicellular

animals appeared. LV

What evolved first: eyes or ears?

TOP 10

Top 10 largest birds

of prey (by weight)

6. Steller’s sea eagle
   Weight: 9kg
   Distribution: Russia and Japan
   6. Harpy eagle
   Weight: 9kg
   Distribution: Mexico, Central
   and South America


7. Lammergeier
   Weight: 8kg
   Distribution: Southern Europe,
   Middle East,
   China and Africa


8. Philippine eagle
   Weight: 8kg
   Distribution: Philippines


9. Golden eagle
   Weight: 7kg
   Distribution: North America,
   Eurasia and North Africa

The eyes can clearly

be seen on this

fossilised trilobite

ring.

ound

e ey

bac

first

. Trilobites
d eyes 521
yespots
ck to 570
multicellular