Earth Science/Living Creatures By: Brady Arnold
Table of Contents1. Amphibians2. Reptiles3. Mammals
What is an Amphibian?•Amphibians •Vertebrate animals (Animals with a spine) •Toads •Frogs •Salamanders. •Characterized as cold-blooded.•Most Amphibians transform from water-breathing young animals to adult air-breathing animals.•The 3 orders of amphibians •Frogs and toads •Salamanders and Newts •Limbless amphibians that resemble snakes
Amphibians Continued• Amphibians – Approximately 6,500 species. – Lay their eggs in water.• Amphibians are similar to reptiles, but reptiles are amniotes (come from an egg), along with mammals and birds.• There has been a dramatic decline in amphibians around the world. – Many species are threatened or extinct.
What is a Reptile?•Reptiles •Air-breathing •Cold-blooded vertebrates •Lay shelled eggs •Have skin covered in scales.•They are Tetrapods •Having four limbs or being descended from four-limbed ancestors.•Modern reptiles inhabit everycontinent with the exceptionof Antarctica.
Reptiles Continued• Four reptile groups that are recognized • Crocodillia: Crocodiles and alligators (23 species) • Sphenodontia: Tuataras from New Zealand (2 species) • Squamata: lizards, snakes, and worm lizards (9,150 species) • Testudines: turtles, tortoises: (300+ species)• Unlike amphibians, reptiles do not have an aquatic larval stage. • Reptiles are oviparous (egg-laying).
What is a Mammal?•Air-breathing vertebrate animals •Endothermic (Maintain own body heat) •Hair •Three middle ear bones •Mammary glands (Exists in mothers with babies). •Sweat glands •Specialized teeth •Most have a placenta (This feeds the offspring during pregnancy.)•The mammalian brain regulates theendothermic and circulatory systems (theblood in the body) •Circulatory System is operated with a four-chambered heart.•Mammals range in size from the 1.5-inchBumblebee Bat to the 108-foot Blue Whale.
Mammals Continued• All female mammals nurse their young with milk, which comes out from special glands called mammary glands.• All living mammals give birth to live young.• The 3 largest mammal groups are: – Rodentia: (mice, rats, porcupines, beavers, capybaras, and other gnawing mammals) – Chiroptera: (bats) – Soricomorpha: (shrews, and moles).• The next 3 largest mammal groups are: – Primates: (humans, Apes, Monkeys) – Cetartiodactyla: (hoofed mammals and whales) – Carnivora: (dogs, cats, weasels, bears, seals, and their relatives)