A stegosaurus dinosaur weighed about 1,600 kg
but had a brain that weighed only about 70 grams (0.07 kg). Therefore, the brain
was only 0.004% of its total body weight. In contrast, an adult human weighs
about 70 kg and has a brain that weighs about 1.4 kg. Therefore, the human brain
is about 2% of the total body weight. That makes the brain to body ratio of the
human 500 times greater than that of the stegosaurus.
Buzzard: Retina has
1 million photoreceptors
per sq. mm. can see small rodents from a height of 15,000 ft.
Earthworm:
Entire body covered with
chemoreceptors (taste receptors).