Cryptolacerta and the rise of the worm-lizards

This animal is not an earthworm. It is long and sinuous, it lives underground, and its flanks look like they’re lined with rings. But it is not an earthworm - after all, it has a skeleton, jaws, scales, and two stubby legs. It is a “worm lizard” or amphisbaenian. Amphisbaenians are a group of burrowing lizards, and one of the most mysterious groups of reptiles. They’re named after Amphisbaena, a Greek serpent with a second head on its tail – indeed, amphisbaeneans do have tails that look a bit like their heads. They are meat-eaters, and they search for their prey underground, burrowing through the soil with strong, reinforced skulls. Most species are completely legless, but four of them – the ajolotes (including the one in the photo above) – have bizarre, stunted arms. Their origins are mysterious. Their bones suggest that they are close relatives of snakes and obviously, ...