Leptictidium

Leptictidium is a small prehistoric bipedal mammal from the Eocene Epoch, 50 to 35 million years ago, when the world was covered in tropical rainforests. Some scientists say it hopped on its hind legs like a miniature kangaroo while others say it ran alternatively like a modern flightless bird or a theorpod dinosaur. Its size varied from 24 to 35 inches long (60 to 90 centimeters), and weighted at a couple of kilograms. It was a carnivore that fed on frogs and lizards in the rainforests. But it also fed on bugs and insects while steering clear of bigger apex predators.