Thursday, 1/12 Homework

• ELA
• Spelling contract is due/study for test - remember all in cursive!
• Re-read story for comprehension test prep and review questions from class
• Math:  everyone has a multidigit multiplication worksheet according to his/her specific mastered/practicing skill level.  Unless it is 3x1 digit problems, no one is to do more than 15 problems unless parents want it.  20 minutes is the amount of time I would like the kids to spend on it.  :)
• Science:  study fossils vocabulary.  The kids will complete their Fossils study guide for Test on Wednesday (not Tuesday - I forgot about MLK!!) and the study guide tomorrow for morning work (no need to print it out) but we will start learning about Eleanor Roosevelt on Tuesday.

Vocab:

fossil                           is something that has lasted from a living thing that died long ago

mold                           is the shape of a plant or animal left in sediments when the rock formed

imprints                      are molds of leaves or other thin objects (an imprint is a lot like a stamp)

cast                             forms when mud or minerals fill a mold and hardens

decay                          to rot or decompose

extinct                        when a plant or animal is no longer living on earth

sedimentary

rocks                                 layers of materials that   

                                         are squeezed together  

                                         and turn into rock

petrified                           when wood turns to  

                                         stone

paleontologists                  a person who studies fossils

Fossils of Georgia

By Travis Eby, eHow Contributor

The bones of ancient animals can be fascinating and mysterious. Fossils appear all over the world. Many of the fossils in Georgia are found along the Coastal Plain Province.

1.   Shark Teeth

Shark teeth are common fossils in Georgia and are the official state fossil. From the Cretaceous to the Miocene periods (approximately 10 to 70 million years ago) sharks hunted and stalked the coastal areas of Georgia. It is very rare to find a fossil of an actual carcass of these prehistoric sharks, but their teeth are found in sizable numbers due to the fact that sharks constantly lose and replace their teeth.

2.   Invertebrate

o    An abundance of invertebrate marine fossils appear along the coastal plain of Georgia. The most common of these are bivalved mollusks, a shelled marine animal. Another invertebrate fossil of Georgia is the sponge. They first emerged in the Precambrian period (over 500 million years ago), and are animals that feed through tiny holes in their bodies that absorb water and food. Some invertebrate fossils appear similar to modern invertebrate animals.

Whales

o    Whale fossils of Georgia are quite famous, and represent early whales of the Eocene Epoch (54.8 to 33.7 million years ago). These fossils represent a key period of evolution for whales. The fossils have shown that these whales had only partly adapted for underwater hearing and had serrated teeth and vestigial hind limbs. Recently, an almost complete skeleton of an even more primitive whale was discovered in Burke County.

Dinosaurs

o    Three main dinosaurs have been identified within the fossils of Georgia. These include a smaller relative of the tyrannosaur, an ostrich-like animal and duck-billed dinosaurs. Since Georgia was mostly covered in water in the ancient past, many large animal fossils are actually ocean creatures. A common dinosaur fossil of Georgia is the giant crocodile, which reached a length of 9 meters and could weigh as much as 2.8 tons.

HOW FOSSILS FORM

Fossils of hard mineral parts (like bones and teeth) were formed as follows:

• Some animals were quickly buried after their death (by sinking in mud, being buried in a sand storm, etc.).
• Over time, more and more sediment covered the remains.
• The parts of the animals that didn't rot (usually the harder parts likes bones and teeth) were encased in the newly-formed sediment.
• In the right circumstances (no scavengers, quick burial, not much weathering), parts of the animal turned into fossils over time.
• After a long time, the chemicals in the buried animals' bodies underwent a series of changes. As the bone slowly decayed, water infused with minerals seeped into the bone and replaced the chemicals in the bone with rock-like minerals. The process of fossilization involves the dissolving and replacement of the original minerals in the object with other minerals (and/or permineralization, the filling up of spaces in fossils with minerals, and/or recrystallization in which a mineral crystal changes its form).
• This process results in a heavy, rock-like copy of the original object - a fossil. The fossil has the same shape as the original object, but is chemically more like a rock! Some of the original hydroxy-apatite (a major bone consitiuent) remains, although it is saturated with silica (rock).

Here's a flow chart of fossil formation:


There are six ways that organisms can turn into fossils, including:

• unaltered preservation (like insects or plant parts trapped in amber, a hardened form of tree sap)
• permineralization=petrification (in which rock-like minerals seep in slowly and replace the original organic tissues with silica, calcite or pyrite, forming a rock-like fossil - can preserve hard and soft parts - most bone and wood fossils are permineralized)
• replacement (An organism's hard parts dissolve and are replaced by other minerals, like calcite, silica, pyrite, or iron)
• carbonization=coalification (in which only the carbon remains in the specimen - other elements, like hydrogen, oxygen, and nitrogen are removed)
• recrystallization (hard parts either revert to more stable minerals or small crystals turn into larger crystals)
• authigenic preservation (molds and casts of organisms that have been destroyed or dissolved).

Most animals did not fossilize; they simply decayed and were lost from the fossil record. Paleontologists estimate that only a small percentage of the dinosaur genera that ever lived have been or will be found as fossils.

Most of the dinosaur skeletons that are shown in museums are not actually fossils! Exhibits are often lightweight fiberglass or resin replicas of the original fossils.

Why are Fossils Rock-Colored?
Because they ARE rocks! A fossilized object is just a rocky model of an ancient object. A fossil is composed of different materials than the original object was. During the fossilization process, the original atoms are replaced by new minerals, so a fossil doesn't have the same color (or chemical composition) as the original object. Fossils come in many colors and are made of many different types of minerals, depending on what the surrounding rock matrix was composed of; one dinosaur bone (Minmi) is an opal.

Also, some fossils of skin (and other soft body parts) have been found. Again, the color of the skin is not retained during the fossilization process, all that remains today is a rocky model of the original

Name:  _____________________  Test is WEDNESDAY, Jan. 18^th

Science: Fossils:  Study Guide

1.     How can the shape of a tooth tell us what an animal might eat?

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2.    What does a carnivore eat? What will its teeth look like?

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3.    What does an herbivore eat?  What will its teeth look like?

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4.    What does an omnivore eat?  What will its teeth look like?

5.    What is a Trace Fossil?__________________________________________________

6.    How do scientists use fossils?

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7.    What do fossils tell us?

_______________________________________________________________________

_______________________________________________________________________

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8.    What do Trace Fossils do?

__________________________________________________________________________________________________________________________________________

9.    How do we know animals have changed over time?

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10. What type of fossil is most common?

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11.  Dinosaurs are an example of an animal that is now extinct. What does extinct mean?  __________________________________________________________________

12. What are some other examples of extinct animals?  __________________________________________________________________

13. What is a cast?  ______________________________________________________

14. How is a mold made?  __________________________________________________

15. For a fossil to form, what must first happen to the animal?  ______________________

16. A triceratops dinosaur is very similar to what animal today?  _____________________

17. How did scientists figure #15 out?  __________________________________________________________________

And what you all love.....................  the answers  :)

Name:  _______________________________

Science: Fossils  Study Guide

·         Sharp teeth, like shark and alligator teeth belong to animals who eat meat. (carnivores)

·         Rounded teeth, like hippos and horses, belong to plant eating animals. (herbivores)

·         Animals that have rounded and sharp teeth, like humans, eat plants AND animals. (omnivores)

·         Trace fossils are things left behind that are imbedded in the ground, like foot prints.

·         Scientist use fossils to learn about animals that used to live on Earth.

·         Fossils that are found help tell us what USED to be somewhere. Animals that have fins probably once lived where there was a lake, river or ocean.

·         Trace fossils, like footprints, help tell us the size an animal used to be.

·         Scientist know animals change over time because there are animals today that are similar to the ones that used to be around. They compare these two things.

·         Animal fossils are the most common.

·         Dinosaurs are an example of an animal that is now extinct. Extinct means they don’t live any more.

·         Casts are made when something fills up a mold. (i.e. the glue in our fossil making activity)

·         When a fossil forms, this means the living thing it once was, must die.

·         A triceratops dinosaur is very similar to a Rhino today. Scientists compare these two animals to each other to see how times have changed.