Tarsier
A photograph of the tarsier showing its big eyes
© Getty
With each eye as big as its brain, the tarsier has the largest eyes in relation to the body size of any mammal. But with such huge eyes, they can’t move them like we can, instead swivelling their whole head 180° like an owl. This helps them silently look for prey, and they’re the only completely carnivorous primate – no plants at all.
And this strategy has proved successful, tarsiers are some of the oldest living primates on the planet, dating back at least 55 million years. This potentially dates them to the Paleocene-Eocene Thermal Maximum (PETM), a time when Earth experienced a sudden, and extreme warming, widely linked to the rise of mammals on Earth.