Why Do Reptiles Have Scales?: And Other Questions About Evolution and Classification
WILDLIFE WONDERS Why Do Reptiles Have Scales And Other Questions About Evolution and Classification PAT JACOBS PowerKiDS press
What is a reptile Reptiles were the first vertebrates to become fully adapted to life on dry land They are cold-blooded animals which means that their body temperature changes according to their surroundings A reptile’s skin is covered with scales made of keratin the same material as our hair and nails Reptiles cannot control their body temperature They bask in the Sun to warm up and move into the shade when they get too hot Ruling reptiles Reptiles evolved more than 300 million years ago from reptile-like amphibians Amphibians have moist skin and breed in water Reptiles developed tough scaly skin and eggs with tough shells so they could move away from the water and spread throughout the world They became so successful that giant reptiles including dinosaurs and pterosaurs ruled the Earth during the Mesozoic era Dinosaurs see box text included the largest animals ever to have walked the Earth 4
Winged lizards Pterosaurs were flying reptiles that lived alongside the dinosaurs They were the earliest vertebrates to develop powered flight Their wings were made up of skin and muscle and stretched from their ankles to their extra-long fourth finger With a wingspan of about 36 feet 11 m the pterosaur Quetzalcoatlus was one of the largest flying animals of all time Marine giants While dinosaurs ruled the land during the Mesozoic era other reptiles took to the water During the Cretaceous period marine monsters including the fearsome mosasaurs preyed on fish birds and other reptiles Mosasaurs stalked their prey until it was within striking distance of their massive jaws 5
