Merriam-Webster's Talk Like an Expert: Dinosaurs

CONTENTs

Foreword

Meet the Dinosaurs

Earth on the Move

Dawn of the Dinosaurs 10

Dinosaurs Take Over 12

When Dinosaurs Ruled 14

Strong Skeletons 16

Head to Tail 18

On the Menu 20

Baby Dinosaurs 22

Dinosaur Life 24

On the Hunt 26

Powerful Protection 28

Taking Flight 30

RecorD–Breakers

Dinosaur Neighbors 34

Going Extinct 36

From Bone to Stone 38

Amazing Evidence 40

In the Field 42

In the Lab

In the Museum 46 Digging Up the past

Dinosaurs Are Still Alive!

Dictionary

Featured Creatures

Dinosaur Definitions

Throughout this book, you’ll see hundreds of awesome words to help you understand the language of dinosaurs. Some words are so important to dinosaur science that they’re featured in a special box on the page. Other key words are also in bold. You can find the official Merriam-Webster definitions of all these words and many more in the Paleontology Dictionary on page 52.

FOREWORD

Millions of years ago, dinosaurs lived across our planet. Some dinosaurs were powerful and plated while others were fast and feathered. Some ate plants— and some ate each other! For about 165 million years, dinosaurs were the most successful animals on Earth. But then, about 66 million years ago, nearly all of these fantastic beasts went away forever.

Have you ever wondered how we know about these long-dead creatures? It is because they left behind clues about their lives: fossils. Today, experts called paleontologists study these remains. They examine all kinds of life forms that emerged long ago, from plants and microbes to beetles and butterflies, from swimming sea creatures to flying reptiles all the way to Coelophysis (my favorite dinosaur, which you can meet on page 11).

Some experts study fossilized dinosaur bones. Others study teeth, skin, or even dinosaur poop! Still others, like me, use microscopes to look at the insides of fossils. The evidence all paleontologists gather helps answer questions about the lives of dinosaurs. Find out more about amazing paleontology careers on pages 48–49.

We paleontologists use special words to talk about our work. Using these words allows us to communicate, work together, and even debate about discoveries. These words also help dinosaur fans understand our work so they can learn more about these fascinating animals. This book will introduce you to the language of dinosaur science, so when it is your turn, you can talk like an expert!

Ellen-Thérèse Lamm Paleohistologist Museum of the Rockies, Montana State University

DINOSAUR

DYE-noh-sor

(noun) any of a group of mostly land-dwelling reptiles that lived millions of years ago

FOSSIL FAH-sul (noun) a trace or print or the remains of a plant or animal of a past age preserved in earth or rock

PALEONTOLOGIST pay-lee-ahn-TAH-luh-jist (noun) a person who studies life from the past using fossil remains

DINOSAURS TAKE OVER

Jurassic Period

During the Jurassic, it finally happened: The supercontinent of Pangea fractured into two separate continents, Laurasia and Gondwana. The climate became warmer and wetter—conditions perfect for lush plant life. With all this food to eat, many kinds of plant-eating dinosaurs thrived. Some of them grew to enormous sizes, like the long-necked sauropods. Predators capable of attacking these giants also appeared during the Jurassic. One of the mightiest was Allosaurus, a hunter with eight-inch (20-cm)-long claws and dozens of tearing teeth.

Reaching New Heights

Sauropods such as Diplodocus and Apatosaurus were some of the mightiest plant eaters that have ever lived on Earth. They used their extremely long necks to browse on leaves from the tops of trees or to mow down vegetation without having to move their massive bodies.

avian dinosaur

AY-vee-un-DYE-noh-sor (noun) any of a group of theropod dinosaurs that survived the Cretaceous mass extinction event and are known today as birds

sauropod

SOR-uh-pahd (noun) any of a group of planteating dinosaurs that mostly walked on four legs and had long necks and tails and small heads

201–145 mya

200 mYA: Early butterflies and moths evolve Jurassic timeline*

The 56-million-year Jurassic Period saw lots of new animals and a changing landscape:

*All dates are approximate

190 MYA: First frogS evolve

180 MYA: First modern ocean begins to form

190 MYA

180 MYA200 MYA

rhamphorhynchus

ApatosaurusDiplodocus

Flocks of Feathers

During the Jurassic Period, some smaller theropod dinosaurs developed feathers and began to use their forelimbs to take flight. This group of flying dinosaurs, or avian dinosaurs, would go on to survive the extinction of the rest of the dinosaurs. Today, we call them birds.

Shrinking Insects

Before birds evolved, enormous insects ruled the skies. The largest dragonfly had a wingspan the same size as a hawk’s today! However, during the Jurassic, birds began to take flight and prey on this banquet of bugs. Smaller, more nimble insects evolved that could evade these flying predators.

archaeopteryx

Stegosaurus

Allosaurus

Puzzle

When Dinosaurs Ruled

Cretaceous Period

It was a good time to be a dinosaur. In the Cretaceous, the planet’s land separated into more distinct continents and different dinosaurs reigned on each. History’s most iconic species lived during this time period. Titanosaurs as big as jumbo jets stomped their way across South America and Africa. In Asia, Velociraptor sprinted on swift legs. And North America was terrorized by one of the biggest, mightiest land predators that ever lived: Tyrannosaurus rex.

A seabird and the first known species to have a beak similar to modern birds.

angiosperm AN-jee-uh-sperm (noun) a flowering plant

TITANOSAUR

tye-TAN-uh-sor (noun) any of a group of approximately 40 species of sauropod dinosaurs, some of which were the largest animals ever known to walk the planet

In Bloom

The first flowering plants, or angiosperms, appeared in the early Cretaceous. They would provide a food source for more than a million species of insects, including pollinators such as bees and butterflies.

Coniophis

145–66 mya

Cretaceous timeline*

The Cretaceous Period lasted 79 million years and ended the reign of the dinosaurs:

*All dates are approximate

140 MYA

130 MYA: Early bees emerge

128 MYA: First snakes appear

130 MYA

MYA

MagnoliaParasaurolophus

140 MYA: First flowering plants appear

Ichthyornis

Dinosaur Superstar

Tyrannosaurus rex is history’s most famous dinosaur for a reason. It was the size of a bus, with 60 banana-sized teeth and jaws so big they could have fit a full-grown human inside. This hunter stomped across the Cretaceous landscape for millions of years.

Small and Furry

Lush Cretaceous forests were home not only to dinosaurs, but also to early mammals that scurried at their feet. The behavior of these small creatures was diverse. There were gliders, swimmers, burrowers, climbers, and more.

Tyrannosaurus

Alphadon

STRONG SKELETONS

Amazing Dinosaur Anatomy

To learn about what dinosaurs were like, paleontologists start with their bones! Even though finding a complete skeleton is rare, just one fossilized bone can tell scientists a lot about what a dinosaur looked like, how it lived, and much more.

Anatomy uh-NAT-uh-mee (noun) the structural makeup of the body and parts of a living thing

Vertebrate VER-tuh-brut (noun) an animal with a backbone

Caudal Vertebrae (tail bones)

FEMUR (thigh bone)

Metatarsals (foot bones) Sternum (breastbone)

All in the Hips

Scientists divide dinosaurs into two main groups, the saurischians (sor-IH-skee-unz) and ornithischians (or-nuh-THIH-skee-unz). The most important difference is in the arrangement of their hip bones. The saurischians—which includes theropods such as T. rex and sauropods such as Diplodocus—had hips arranged more like those of lizards. The ornithischians—such as Stegosaurus and Triceratops—had hip bones positioned more like those of birds.

Bonus Bones

Some dinosaurs, including Allosaurus and T. rex, had an extra set of riblike bones that stretched across their belly. T. rex had around 60 of these bones, called gastralia (gass-TRAY-lee-uh). Experts think these belly bones would have helped huge dinosaurs push air in and out of their lungs.

On the Move

The shape of a dinosaur’s skeleton can tell scientists how it moved. The earliest dinosaurs were all bipeds that walked on two legs. Later, some dinosaurs became quadrupeds that walked on all four legs. Details of a dinosaur’s skeleton tell which type of mover it was. For example, bipeds had front limbs with slimmer bones than quadrupeds.

Hips

(Hip bone)

TIBIA AND FIBulA (shin bones)

Phalanges (toe bones)

Scapula (Shoulder blade) Coracoid (Shoulder bone)

Reading Rings

Many animals—including dinosaurs—have bones that grow in layers. Scientists can cut into a dinosaur bone to see growth rings that look like the rings of a tree. They can count the rings to see how old a dinosaur was when it died. Experts have learned that T. rex went through a major growth spurt during its teenage years—just like humans do!

inside a bone

A “Frilling” Transformation

The brow horns of Triceratops changed over its lifetime from backward-facing to forward-facing. Scientists believe these changes could have indicated how old the dinosaur was. Other dinosaurs also had features that changed over time. For instance, as a Protoceratops grew up, its frill got much larger, showing off the dinosaur’s health and strength. That feature may have helped it attract a mate.

Ulna (Front Limb)

Humerus (upper arm)

bones)

Brow Horns

Nasal Horn

Rostraldentary

Predentary

FRILL

Osteon close-up

Marrow cavity Growth ring Blood vessels

Perfect Protection

Skeletons provided protection inside and out. Some bones, like the rib cage, kept a dinosaur’s heart and lungs safe inside its body. Other bones, like the enormous frill of a Triceratops, protected the dinosaur’s vulnerable neck from attack.

Triceratops

Triceratops

TALK LIKE AN EXPERT

DINOSAURS

400 Words for Budding Paleontologists

For ages 6-9. Do you know what pieces of fossilized dinosaur poop are called? (Answer: Coprolites.) How about the large collar at the back of a Triceratops’s skull? (Answer: Frill.) Take a deep dive into the science behind these creatures with this impressive book from Merriam-Webster and learn over 400 words you need to talk like a dinosaur expert! Travel back in time millions of years to discover how these extraordinary creatures lived, breathed, ate, fought, raised babies, and survived in the wild.

With full color illustrations and up-to-date scientific research, meet hundreds of dinosaurs and learn how they evolved on a changing planet. Behind-thescenes information on paleontology and scientists, plus an A-Z glossary, will leave readers talking like the experts and thinking like them, too!

Expert Consultant

Ellen-Thérèse Lamm is currently the Paleontology Histology Lab Manager at the Museum of the Rockies. She works with institutions worldwide to catalog thousands of slides of fossil tissue structure. Blending discovery, art, and science, Ellen-T. also produces award-winning photomicrographs, some featured on the covers of technical publications.

Illustrator

Daniel Long graduated from Norwich University of the Arts in Norwich, United Kingdom, in 2014 and has been working as an illustrator since then. He recently illustrated DK’s Dinosaurs and other Prehistoric Life His work is heavily influenced by mid-century design, architecture and fashion which can be easily seen in his use of color palettes and choice of subject matter.

Merriam-Webster

For over 180 years, Merriam-Webster has been America’s leading provider of language information. Each month, our award-winning websites, apps, and social media channels offer guidance to tens of millions of visitors. All Merriam-Webster products and services are backed by the largest team of professional dictionary editors and writers in America.

Selling points

• This book contains 64 pages of dinosaur science and terminology created using the most up-to-date research from the Museum of the Rockies in Bozeman, Montana, and other international institutions. Includes the names of hundreds of dinosaurs, plus definitions and explanations of how each body part or system functioned.

• Full color illustrations from artist Daniel Long and high-resolution photographs of fossils bring these extinct creatures vividly to life.

• Each section in the book takes a close look at a different aspect of dinosaur science: Evolution, Anatomy & Physiology, Life Cycles, Fossilization, and Curation/ Exhibition.

• This book explains each aspect of a dinosaur’s existence, from birth to death and fossilization, so that children can imagine these creatures as they lived and breathed.

• Includes an A-Z Glossary of Paleontology Terms with over 400 words and definitions for kids to reference when they want to talk like dinosaur experts.

• Expert consultant Ellen-Thérèse Lamm, Paleontology Histology Lab Manager at the Museum of the Rockies, provides cutting-edge research from the field.

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