Turtles! Ma ayan Dagan

Transcription

1 Turtles! Ma ayan Dagan

2 Table of Contents 1: Taxonomy: What kind of animal is a turtle? 2: Turtle or tortoise? 2: Anatomy: The Parts of a Turtle 3: The Shell of a Turtle 4: Evolution from Ancient Reptiles 5: Habitat 6: To the Ocean!: Life Cycle of the Sea Turtle 7: Turtles of Worcester: Museum Dwellers Glossary Image Credits About the Author

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4 Taxonomy What kind of animal is a turtle? What is taxonomy? Testudines Means Turtle Common Names As you may know, all living organisms are categorized in a system made up of many groups. Animals are in one group, plants in another, and fungi, protists, and bacteria make up the other groups. Within these large groups, called kingdoms, there are smaller groups, and within those are smaller groups. If you follow a specific animal or species through the classification system, you will find that it belongs to seven groups in total. All turtles that live today belong to the kingdom Animalia (animals), phylum Chordata, class Sauropsida, and order Testudines. (3) The order has in it several types of turtles: Land turtles Marine, or sea turtles Freshwater turtles Turtles have scientific names like Chelonia mydas, but most people know them by their common names. For example, Chelonia mydas is just the scientific name for the Hawaiian green sea turtle.

5 Turtle Tortoise Lives most of its life in the water Lives most of its life on the land Has webbed feet that help it swim Turtle or tortoise? Has strong legs for burrow-digging Burrows in the mud when the weather gets cold Climbs out onto rocks to sunbathe There really is no difference between turtles and tortoises! They both belong to the Testudines group. Sometimes the word tortoise is used to describe turtles that are more adapted to living on the land. They can have higher domed shells. The word turtle is used to describe turtles that spend most of their lives in the water. But for those who call them by different names, here is how they define the difference. Eats foods like shrubs, grasses, and cacti (spiny desert plants) Digs into the ground when the weather gets hot Green turtle Aldabra giant tortoise

6 Anatomy: The Parts of a Turtle Beak Respiratory System Skin Limbs Turtles mouths are actually called beaks. They don t have teeth, but turtles instead use their jaws to cut up their food. Herbivores, plant eaters, have jaw edges that help them chew up plants. Omnivores, plant and animal eaters, have sharper jaws that let the turtles cut through meat. Turtles have a very unique method of respiration, or breathing. A turtle can hold its breath under the water for more than an hour before it must come up for air. Some turtles have even developed special techniques for taking in more oxygen while under water. The Fitzroy River Turtle can literally breathe through its hindquarters, more scientifically called the cloaca sac. Like many reptiles, turtles shed their skins. This process is called molting. However, turtles do not molt like snakes, who shed their skin all at once. Turtles shed scale by scale. Turtles have short sturdy feet that help them swim but not walk quickly. Aquatic turtles have long claws on the ends of their feet that let them grab onto shorelines or riverbanks and crawl up into the sun.

7 The Shell of a Turtle Upper shell The upper part of the shell is called the carapace. The bony scales that make it up are called scutes. Compared with tortoises, turtles have more flat carapaces, which help them move smoothly through the water. This is the carapace of a red-eared turtle. Why can t turtles crawl out of their shells? The shell is connected to the backbone of a turtle, which contains the spine and the spinal cord, as well as its ribs and legs. Without its shell, the animal could not live! Turtle Geometry Turtle shells have a dome with a shape which is called a gomboc. It is the world s first self-righting object. This shape has only one stable position, which allows a turtle to flip back over if it is turned on its back. Take a look at some turtle-flipping in action! Lower shell The lower part of the shell is called the plastron. It is joined by a bridge to the carapace. Uses The shell is helpful to the turtle in many ways, including: Keeping in moisture Gliding through the water Protection from predators

8 Evolution from Ancient Reptiles A Very Old Turtle The oldest turtle on earth lived 220 million years ago! It was called Proganochelys quenstedi, and it had no teeth. But scientists still say that it is the ancient ancestor some turtle that lives today.

9 Marine Marine turtles spend their entire lives on the beach and in the ocean. Habitat Freshwater Freshwater turtles live in ponds or other bodies of water which do not have salt in them. Land Land turtles often live in wooded areas.

10 5. Feeding The turtles spend the next part of their lives (about 5 to 10 years) feeding on small sea animals until they are mature enough to migrate and breed. To the Ocean! Life Cycle of the Sea Turtle 1. Breeding Sea turtles migrate to their original birth sites. 4. Hatching and Swimming The eggs hatch after 7 to 12 weeks. The baby hatchlings swim out to sea as a group, using signals like ocean currents and wave direction to find the way. 3. Nesting 1 to 2 months later, the female lays 3 to 7 clutches (groups) of eggs at the nesting beach inside a 30 to 60 centimeter deep hole in the sand. Each clutch contains around 120 eggs. 2. Mating There the males and females breed. Each turtle may have a few mating partners.

11 Wood Turtle Blanding s Turtle Wood turtles, a protected species, are a good indicator of clean and unpolluted water. They are endangered by pet collection, habitat loss, and road construction. Blanding s turtle is semi-aquatic: it lives and eats both in and out of the water. Turtles of Worcester Museum Dwellers Spiny Softshell Turtle Spotted Turtle The spiny softshell turtle is named that way because unlike most turtles, it has no scutes on its shell. The spotted turtle eats only underwater plants and insects; one common food is lily pad seeds.

12 Glossary taxonomy- system of classifying or naming animals kingdom- largest group in taxonomy species- smallest group in taxonomy marine- of the sea aquatic- of water tortoise- land based turtle turtle- water based turtle herbivore- eats only plants omnivore- eats plants and animals respiration- breathing molt- shed skin carapace- top of a turtle shell plastron- bottom of a turtle shell bridge- connector of a turtle shell scutes- scales of a turtle shell gomboc- self-righting shape clutch- group of eggs hatchling- newly hatched anima

13 Image Credits (1) Microsoft Clip Art (2) Microsoft Clip Art (background) (3) Microsoft Clip Art (background) (4) Microsoft Clip Art (background) (green turtle) (Aldabra tortoise) (5) Microsoft Clip Art (background) (6) Microsoft Clip Art (background) (skeleton) (carapace and plastron) (flipping turtle) (7) Microsoft Clip Art (background) (Collecting Fossils in California) (8) Microsoft Clip Art (background) (beach) (9) data/assets/image/0017/7280/image002.gif (10) Microsoft Clip Art (background) All other photographs by the author

14 About the Author Ma ayan Dagan is an eleventh grade student at the Massachusetts Academy of Math and Science. She lives in Worcester, Massachusetts where she attends school. She hopes that this book will interest young students in the fascinating world of animals.