Lacerta vivipara

The viviparous lizard, or common lizard, (Zootoca vivipara, formerly Lacerta vivipara) is a Eurasian lizard. It lives farther north than any other species of non-marine reptile, and is named for the fact that it is viviparous, meaning it gives birth to live young (although they will sometimes lay eggs normally). Both "Zootoca" and "vivipara" mean "live birth", in (Latinized) Greek and Latin respectively. It was called Lacerta vivipara until the genus Lacerta was split into nine genera in 2007 by Arnold, Arribas & Carranza. Male and female Zootoca vivipara are equally likely to contract blood parasites. Additionally, larger males have been shown to reproduce more times in a given reproductive season than smaller ones. The lizard is also unique as it is exclusively carnivorous, eating only flies, spiders, and insects. Studies show that the more carnivorous an individual is (the more insects they eat), the less diverse the population of parasitic helminths that infest the lizards. Zootoca vivipara lives in very cold climates, yet participates in normal thermoregulation instead of thermoconformity. They have the largest range of all terrestrial lizards which even include subarctic regions. It is able to survive these harsh climates as individuals will freeze in especially cold seasons and thaw two months later. They also live closer to geological phenomena that provide a warmer environment for them.