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Glossary of Terms Extreme Mammals Natural History Museum of Utah EXTREME MAMMALS THE BIGGEST, SMALLEST, AND MOST AMAZING MAMMALS OF ALL TIME EDUCATOR’S GUIDE Extreme Mammals is organized by the American Museum of Natural History ! e z i s l a u t ac INSIDE: • Suggestions to Help You Come Prepared • Essential Questions for Student Inquiry • Strategies for Teaching in the Exhibition • Map of the Exhibition • Online Resources for the Classroom • Correlation to Standards • Student Worksheets to Use in the Exhibition ESSENTIAL QUESTIONS This exhibition uses both living and extinct mammals to trace the ancestry and evolution of this remarkable group of animals. It’s a story full of surprises, with quite a cast of characters. What is a mammal? How have mammals evolved in You might have grown up thinking that all mammals response to changing environments? share certain traits, like fur and giving birth to live young As environments change over time, living things — and most living mammals do. But some are hair- must adapt or go extinct. Different traits are favored in less, like the river dolphin, while a few others, like the different habitats and are passed on to future genera- echidna, or spiny anteater, lay eggs. So what defines this tions. For example, when various groups of mammals diverse group of animals? They all are descended from invaded the sea, adaptations like blubber and flippers — a common ancestor shared with no other living animals. which are modified limbs — helped them survive. Mammals can look radically different from each other, Gargantuan blue whales can grow far larger than any but the underlying body plan is still strikingly similar. land animal because water helps support their bulk. Their ancestors lost their teeth but evolved baleen in What’s “normal” for mammals? the upper jaw: rows of flexible plates made of keratin The terms “extreme” and “normal” are relative, of that help them capture vast amounts of small crustaceans. course. In mammals, one way to define normal is in Tails also evolved a wide array of forms to help mammals terms of traits that are inherited from ancestors, such swim, balance, grasp tree limbs, or keep warm. as producing milk, warm-bloodedness, and four limbs for walking, or quadrupedalism. Another way to think How have extreme or specialized traits about “normal” is what is typically observed in the helped mammals adapt and survive? group. For example, today the typical mammal weighs Over millions of years, every part of the mammalian about one pound, although for most of their history they body was shaped and reshaped through evolution, were generally even smaller. All mammals have both from snout to tail. Sometimes remarkable in form, normal and extreme, sometimes unique, features. these adaptations conferred evolutionary advantages, like the extremely long premolars of the extinct How and why are some mammals marsupial Thylacoleo carnifex or rodents’ sharp “extreme”? incisors, which never stop growing. Echolocation As species evolve over time, “extreme” traits can arise: evolved independently in a few specialized groups, characteristics that differ widely from those found in including bats, cetaceans (dolphins and whales), and ancestors or from the most common condition. subterranean shrews. Evolving big brains relative to Examples include the tiny brain of the extinct, two-ton body size distinguishes mammals from other verte- Uintatherium; the bipedal hopping of kangaroos; or brates, and humans from all other mammals. Much of the venom of species of Solenodon, large shrew-like the increase occurs in the cerebrum, the part of the mammals. Humans also have a mix of both normal traits brain largely associated with thought, memory, most inherited from early ancestors (we’re warm blooded senses, and information processing. Some of the most and have differentiated teeth and five fingers and toes) remarkable adaptations occurred when mammals and specialized extreme features (upright bipedalism, evolved in isolated areas. and big brains relative to our body size). How do scientists study mammals? Scientists observe mammals in their environments, and analyze modern and fossil specimens back in the laboratory. Combining physical and genetic data helps The six-banded scientists recognize the relationships between species. armadillo is almost completely Today, nearly 25 percent of living mammal species are covered by bony, threatened with extinction, even as new species are still keratin-capped armor plates. being discovered. Scientists find them by exploring — and helping to protect — remote ecosystems in the ongoing quest to learn more about life on Earth. USEFUL CONCEPTS Come Prepared Before your visit, review the Essential Questions to see Natural Selection and how the exhibition’s educational themes connect to your Adaptation curriculum. Identify what you’d like your students to learn from Extreme Mammals, and how they could continue Individuals inherit traits, or features, from learning back in the classroom. Visit the Extreme Mammals their parents. Those members of a species with website at amnh.org/extrememammals to learn more about traits that help them survive in a particular environment — like the sharp, piercing canines the exhibition. and slicing molars of carnivores versus the This Guide includes Activities for Before You Visit, flat grinding teeth of mammals that eat tough During Your Visit, and Back in the Classroom, and Student grasses — pass on these characteristics. Worksheets for grade levels K–2, 3–5, 6–8, and 9–12. These Generation after generation, individuals with activities are designed to be used together to focus your visit the advantageous trait, or adaptation, will survive longer and produce more offspring, around one or two themes. Here are some other ways to until most or even all members of the species explore the Extreme Mammals exhibition: possess it. Called natural selection, this is • You (and your class chaperones) can use the Teaching in an important mechanism of evolution. the Exhibition section of this guide as you move through the gallery with students. Convergent Evolution • You can create student worksheets using the Teaching in This refers to situations in which different the Exhibition section. groups evolve similar adaptations because they live in similar environments. These species • You can distribute copies of the Map of the Exhibition may even live on different continents and be to chaperones and/or students, and let them choose their far apart on their family trees. For example, own paths. high-crowned grinding teeth for chewing tough grasses have evolved independently in a diverse Visit nhmu.utah.edu for: suite of mammals, including bison, horses, elephants, some rodents, and many extinct • information on field trips, reservations, lunchroom, and mammal groups. other useful tips to help plan your visit • free resources, including activities and references Mammal Reproduction The ancestor of all mammals almost certainly laid eggs, as do most vertebrates and a tiny mi- Correlation to Standards nority of living mammals, the monotremes — Your visit to the Extreme Mammals exhibition can be like the platypus and echidnas of Australia and correlated to the standards listed below. New Guinea. But the vast majority of modern mammals are placentals. They’ve evolved to Utah Science Education Standards give live birth to babies that are nourished for a long time inside the mother’s body, using an K–2 organ called a placenta. A few hundred other Standard 1, The processes of Science, Communication of Science, living species (and many more fossil forms), and the Nature of Science; Standard 4, Life Science: the study of like koalas and kangaroos, are marsupials; changes in organisms over time and the nature of living things. their young are born very immature and much Grade 4 of their development occurs while Standard 4, Fossils can be compared to one another, to living drinking milk, typically inside organisms, and to organisms that lived long ago. a pouch on their mother’s Grade 5 belly. The group Mammalia Standard 5, Students will understand that traits are passed from the is named for mammary parent organisms to their offspring, and that sometimes the offspring glands, which produce may possess variations of these traits that may help or hinder survival milk — as all mammal in a given enviroment. species do. Koala, a marsupial TEACHING IN THE EXHIBITION The Extreme Mammals exhibition uses fossils, models, live animals, interactives, videos, and more to engage individuals with all learning styles. This guide divides the exhibition into ten areas, which are indicated on the map and described below. 1. Introduction Exploration: Overview: Living and fossil mammals exhibit a huge • Human, Uintatherium, and opossum skeletons: range of shapes and sizes. Ask students to distinguish between normal and extreme characteristics in each of these species. Exploration: • Animal models: Have students compare and contrast Guiding Questions: these life-size models of the largest land mammal and • What are some examples of extreme and normal the smallest mammal that have ever lived. Point out characteristics in these three mammals? that despite all the differences, we’re all mammals. • Are humans extreme or normal? Why? Guiding Questions: 4. Head to Tail: Heads • What do the largest and the smallest mammals have Overview: Mammalian bodies have been modified by in common with each other? With humans? evolution. Some of these changes are found in the head. 2. What is a Mammal? Exploration: Overview: Mammals are defined by common ancestry, • “Headgear” and skulls of living and extinct not by physical characteristics — although inherited traits mammals: Point out to students that headgear can do help us recognize relationships between mammals. be formed from teeth, bones, and even hair. Ask them how horns and antlers are similar, and different. Exploration: • Skulls with teeth: Invite students to compare and • Video: Encourage your students to watch the video, contrast the different types of mammal teeth, and to focusing on the traits shared by living mammals.
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