Vertebrates- Animals with Backbones
See these animals giving one another a back rub? They are all vertebrates. Vertebrates are animals with backbones (vertebrae). The 5 classes of vertebrates are: Fish, Amphibians, Reptiles, Mammals, and Birds.
Fish (Gills, Fins, Scales, Cold Blooded)
Fish are the only group of vertebrates that live entirely in water. All of them have gills, which is special breathing tissue that allows fish to breathe oxygen underwater. Fish have fins which help them paddle and maneuver through water. They also have scales that protect their bodies like armor. You can actually determine the age of fish by counting the rings on their scales! Fish are cold blooded animals which means their blood becomes cooler or hotter depending on the temperature of the water. Fish will swim slowly below the ice during winter, or even sleep in icy waters. Some fish actually produce antifreeze molecules called glycoprotein that keep their bodies from freezing in really cold temperatures!
Amphibians (Slimy skin, Metamorphosis, Four Legs, Cold Blooded)
Amphibians like frogs, toads, and salamanders are born in water and develop the ability to live on land. This means almost all amphibians will go through metamorphosis. (Think of how tadpoles become frogs.) Most are born with gills and then develop lungs and four legs, though caecilians do not have legs. They have permeable, wet, slimy skin that absorbs water and oxygen, and usually have webbed feet. Amphibian eggs have no shell, but are covered in a jelly-like substance. Amphibians are also cold blooded, so they are quick and active when it is warm, but slow and sluggish when it is cold.
Reptiles (Scales, Eggs, Four Legs, Cold blooded)
Reptiles like turtles, snakes, crocodilians, and lizards are covered with scales, and usually have claws. Reptiles are cold blooded creatures and lay eggs. They are tetrapods, meaning they have four legs, or in the case of snakes, “descended” from creatures with four legs. Interestingly there are a number of snake fossils with legs, and some pythons have vestiges of legs.
Mammals (Hair, Milk, Live Birth, Warm blooded)
Mammals can be bears, bunnies, or even whales. Mammals give birth to live young. Mammals get their names from mammary glands that produce milk to feed their newborn babies. All mammals have hair or fur that helps them maintain their warm blooded bodies. All mammals have lungs and breathe air, so most mammals live on land, but some live in the sea. These marine animals include pinnipeds (seals, sea lions), cetaceans (whales, porpoises), sea otters, sirenians (manatees), and polar bears.
Birds (Feathers, Beak, Eggs)
Birds can be as tiny as a hummingbird or as large as an ostrich. All birds have feathers, though not all of them fly. Penguins have feathers, but they swim. Ostriches and emus have large feathers, but their sternum is not attached to their pectoral muscles, making them too weak to fly. All birds have a beak. Beaks come in many shapes and sizes, and are used for different purposes, including tearing meat, breaking seeds, sipping nectar, fishing, or finding and eating insects.
Enjoy the FREE printable vertebrate packet more fun illustrations, a poster, study guide, and short quiz!
For more fun consider studying:
Different types of feathers
Four types of fish scales (Placoid, Cosmoid, Ganoid, Cycloid)
Explore reptiles!
Go find some frogs at your local pond! Be sure to wash your hands…
Try making a list of the mammals that live in your neighborhood. Or try one of these cool ideas!
Visit the local pet shop and see if you can identify what creatures belong in which vertebrate class!
Browse by category:
- Book Reviews 1
-
Buddy Blog
7
- Apr 4, 2019 Buddy Blog Epidsode 5: Counting!
- Nov 22, 2018 Buddy Blog, Episode 4: Happy Thanksgiving!
- Nov 13, 2018 Buddy Blog Episode 3: Fall Leaves
- Oct 30, 2018 Here’s your guide to Pumpkin Everything— Recipes, Crafts, and Carving
- Oct 30, 2018 Buddy Blog, Episode 1: Exercise
- Jul 18, 2018 Fish Fashion 2018
- Jul 13, 2018 Orange You Tired?
-
Cooking with Kids
3
- Jun 3, 2019 Guiltless Peanut Butter Cookies
- Oct 26, 2018 Love Pumpkin Spice? Try this New Fall Favorite
- Aug 9, 2018 Goodness Granola
-
Earth & Space
2
- Nov 9, 2019 Astronomy: Comets, Oids, and Shooting Stars!
- Oct 9, 2019 Astronomy: Parts of the Sun FREE PDF
-
For Parents
15
- Aug 28, 2025 How a Little Engine Could, and You Can Too
- Jun 4, 2021 What Kids Learn From Reading At Every Age
- Apr 27, 2021 7 Powerful Picture Books to Make Your Child Feel Loved
- Feb 24, 2021 Words of Healing
- Oct 20, 2020 Words: Sticks and Stones
- Oct 20, 2020 You are Wonderful! Marzette- A Parable of Redemption
- May 4, 2020 "My house is a disaster!" Cleaning hacks so you can embrace the fun
- Apr 7, 2020 Help, My Kid Is Bored! How to Stop Whining and Cure Boredom Fast
- Nov 9, 2019 Homeschool Styles 101: Your Quick Easy Guide to Find What Fits Your Family
- Jun 3, 2019 5 Quick Ways to Invent Stories Your Kids Will Love
- May 27, 2019 Today is for Eternity
- Nov 10, 2018 Know nothing except... a lesson in teaching my kids
- Oct 30, 2018 Why Stranger Danger Doesn’t Work (And What To Do Instead)
- Jun 14, 2018 "Did you have fun?" Asking better questions
- Jun 12, 2018 Another day at the superstore
-
Life Science
8
- Apr 1, 2025 Botany Basics: Parts of a Flower
- Jun 5, 2021 Flightless birds? Swimming Mammals? How awkward vertebrates fit
- Apr 28, 2021 Biology: Animal and Plant Cells
- Nov 9, 2018 Botany Basics: Plant Systems
- Oct 16, 2018 Biology Basics: How Animals Reproduce
- Oct 8, 2018 Vertebrates- Animals with Backbones
- Sep 25, 2018 Biology Basics: Invertebrates
- Sep 7, 2018 Biology Basics: Kingdoms
-
Physical Science
4
- Jul 22, 2022 Astrophysics for Kids! 25 Easy Experiments to Do at Home
- Feb 24, 2021 Chemistry: The Atomic World
- Apr 8, 2020 Thermodynamics ...for Kids!
- Jan 24, 2020 Newtonʻs 3 Laws of Motion
-
Poetry
2
- Oct 20, 2018 Be Someone's Rainbow
- Jul 18, 2018 Bugs
- Science 3
-
Teaching Aids
3
- Nov 8, 2025 Explore the Nervous System: Cool Facts & Games for Kids!
- Jul 8, 2020 Phonics Fun for FREE
- Oct 21, 2018 How to draw a dog named Buddy