Books published by publisher Core Learning Library

Pelycosaurs were lizardlike creatures that inhabited Earth long before dinosaurs first appeared. From sail-backed Dimetrodon to tiny Archaeothyris, pelycosaurs shared characteristics of both mammals and reptiles. Learn about the prehistoric animals that preceded dinosaurs by several million years.

Sharp teeth and excellent hunting and swimming skills made plesiosaurs dangerous additions to prehistoric oceans. Young readers will get a glimpse of what life was like for these fierce predators as they scoured the waves in search of their next meal.

Babysitting can be a fun way for kids to earn money, but it also involves a lot of responsibility. Young readers will learn how to prepare for a babysitting job, what kinds of questions to ask the parents, what to do in emergencies, and much more that will help them become confident and responsible sitters.

Looking for adventure? Take a trip down the Amazon with this book! From its start as an icy stream high in the Andes all the way to the Atlantic Ocean, each turn of this mysterious river reveals new and wonderful secrets.

Roar! Swordlike teeth made this prehistoric cat a formidable predator long after dinosaurs had ceased to roam Earth. Kids will enjoy reading about this infamous carnivore and how it used it hunting skills and terrifying teeth to wreak havoc until about 10,000 years ago.

These now-extinct cephalods were the predecessors of modern-day squid, octopus, and nautilus and survived for nearly 335 million years! Young readers will discover how these shelled creatures came in myriad shapes, sizes, and designs, and how they managed to outlast several mass extinctions until about 65 million years ago.

Neither fish nor lizards, ichthyosaurs swam ancient seas for nearly 150 million years. This title reveals how more than 80 species of these dolphinlike reptiles commanded Earth's prehistoric waters at the same time dinosaurs walked on land.

Megatherium was one of the biggest ground sloths that ever existed. This 'great beast' weighed between 3 and 4 tons and was enormous compared to its modern-day relatives, the tree sloths. Read Megatherium to find out more about this huge creature, as well as to learn interesting facts about other ancient ground sloths.

The earliest known bird, Archaeopteryx first appeared about 150 million years ago. Kids will be introduced to a creature that was no larger than a crow, but that proved remarkably important to scientists searching for answers about the ancient relatives of modern-day birds.

Imagine walking down the street and running into an Ankylosaurus. Its heavy, plated body and thick spines would surprise anybody! But despite its size and armor, this 'stiff lizard' could move pretty quickly when it needed to. Discover how Ankylosaurus continues to surprise scientists--and unsuspecting readers--to this day.

Life was often difficult for the Iguanodon. It couldn't fight larger dinosaurs with sharp teeth or pointy spikes. Even thunderstorms could pose a danger. Learn how Iguanodon survived on Earth for nearly twenty million years and why its fossils have been discovered all over the planet.

Mammoths and Mastodons gives young readers a glimpse at the furry, elephantlike mammals that roamed Earth until about 10,000 years ago. Learn more about how and where these animals spent their time during the Ice Age.