Mexican beaded lizard generic name "Heloderma" means "studded skin", from the Ancient Greek words "hêlos" (ἧλος)—the head of a nail or stud—and "dérma" (δέρμα), meaning skin. Its specific name, "horrĭdum", is the Latin word meaning rough or rude. The four subspecies of beaded lizard, elevated to full species in 2013, are: Adult beaded lizards range from in length. They are substantially larger than the Gila monster, which only reaches lengths of . The snout-to-vent length of a beaded lizard averages . The average body mass of an adult beaded lizard is , about 45% heavier than the average mass of a gila monster,
Viviparous lizard Viviparous lizard 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 most populations are viviparous (giving birth to live young), rather than laying eggs as most other lizards do. It is the only species in the monotypic genus Zootoca. Both ""Zootoca"" and ""vivipara"" mean "live birth," in Greek and Latin respectively. It was called "Lacerta vivipara" until the genus "Lacerta" was split into nine genera in 2007 by , Arribas & Carranza. "Zootoca vivipara" can be seen in a variety of different