FOSSILS LESSON 1

CHAPTER 4

http://www.kids-dinosaurs.com/giganotosaurus.html

• What are Fossils?Fossils form when living things die and are buried by sediment. The sediment hardens into rock and preserves the shapes of the organism

What happens next?The sediment becomes rock preserving the remains.

What are the kinds of fossils?1.Molds - A hollow area in sediment in the shape of an organism or part of an organism. A mold forms when the organism is buried in sediment.

earthgauge.net

CastA solid copy of the shape of an organism. Molds and casts can preserve fine details.

external mold of the shell of Eumorphoceras girtyi Elias 1956

http://www.ammonoid.com/Manning.html

Petrified fossilsFossils in which minerals replace all of an organism, or a part such as a dinosaur bone. This can also happen to wood such as tree trunks.

http://www.statesymbolsusa.org/Arizona/fossil_petrified www.hoobly.com

Carbon filmAn extremely thin coating of carbon on rock. When sediment buries an organism, some gases escape from the sediment, leaving carbon behind.

http://1.bp.blogspot.com/-sn-UGDNBR-A/TaTsRVnIZcI/AAAAAAAAAA4/otG4Hwi38kc/s1600/flower-fossil-_39205_1.jpg

Trace fossilsProvides evidence of the activities of ancient organisms. A fossilized footprint is one example. A print is buried by sediment, which slowly becomes solid rock. Below is a trilobite trace fossil.

http://www.trilobites.info/trace.htm

Preserved RemainsOrganisms trapped in sticky tar or tree resin. When the resin hardens, it becomes a substance called amber. Freezing can also preserve remains.

http://naturalselection.0catch.com/Files/fossilizeddna.html

http://pediaview.com/openpedia/Bog_body

Bog bodyTollund Man lived in the 4th century BCE. Bog bodies, which are also known as bog people, are the naturally preserved human corpses found in the sphagnum bogs in Northern Europe. Unlike most ancient human remains, bog bodies have retained their skin and internal organs due to the unusual conditions of the surrounding area. These conditions include highly acidic water, low temperature, and a lack of oxygen, combining to preserve but severely tan their skin. Despite the fact that their skin is preserved, their bones are generally not, as the acid in the peat dissolves the calcium phosphate of bone.

CAST

MOLD

TRACE FOSSIL

CARBON FILM

PRESERVED REMAINS

PETRIFIED FOSSIL

What Do Fossils Show?The fossil record provides evidence about the history of life and past environments on Earth. The fossil record also shows how different groups of organisms have changed over time.

PaleontologistsScientist who study fossils!

So.. You want to be a paleontologist

http://formontana.net/malta.html

PALEONTOLOGIST10:00

Fossils and past environments

http://thestonescryout.com/flood_geology_challenges/turks_and_caicos_islands

DINOSAURS AND FOSSILS (5:37)

Change and the fossil record

EvolutionThe change in living things over time.

ExtinctA type of organism that no longer exists and will never live on earth.

Evolution of the Horse

http://www.biology-online.org/2/11_natural_selection.htmTheir beaks have evolved over time to be best suited to their function. For example, the finches who eat grubs have a thin extended beak to poke into holes in the ground and extract the grubs. Finches who eat buds and fruit would be less successful at doing this, while their claw like beaks can grind down their food and thus give them a selective advantage in circumstances where buds are the only real food source for finches.

http://virtuallaboratory.colorado.edu/Biofundamentals/lectureNotes/Topic1I_Evo.htm

As organisms adapt to a specific environment and life style, traits once useful can become irrelevant and may be lost. A classic example is the reduction of hind limbs during the evolution of whales.

extinct

http://virtuallaboratory.colorado.edu/Biofundamentals/lectureNotes/Topic1E_Evo.htm

http://www.zimbio.com/Cloning/articles/78O6qWOHanj/Woolly+Mammoth+Extinct+Animals+PicturesEARTH’S CHANGINH ENVIRONMENT (9:05)

http://www.ypte.org.uk/environmental/extinction/27 Desmostylus hesperus, an amphibious

mammal from the Miocene that lived in North America and Eastern Asia

http://www.eoearth.org/article/Miocene

REVIEW AND REINFORCEType of Fossil Description

  1. Petrified fossil Fossils in which _____________ replace all or part of

an organism

  2. _____________ A hollow area in sediment in the shape of an organism

  3. _____________ A solid copy of the shape of the organism

  4. Carbon film An extremely thin coating of _____________ on rock

  5. Trace fossils Evidence of the _____________ of ancient organisms

  6. _____________ Remains of organisms in tar, amber, or ice

7. Describe how a mold is related to a cast.  8. What can a paleontologist tell from fossil footprints of a dinosaur?  9. What does the fossil record reveal about the evolution of life on Earth?

10.___ no longer and never again existing as an organismon Earth

11. ___ the preserved remains or traces of living things

12.___ the process by which all the different kinds ofliving things have changed over long periods of time

13.___ the type of rock that is made of hardened sediment

14.___ an extremely thin coating of carbon on rock

15.___ a scientist who studies fossils

a. evolution

b. sedimentary rock

c. extinct

d. paleontologist

e. fossils

f. carbon film

  1. minerals   2. Mold

  3. Cast   4. carbon

  5. activities   6. Preserved remains

  7. A mold is an empty space in rock in theshape of an organism or part of an organism.If water carrying dissolved minerals andsediment seeps and deposits those mineralsand sediments into the mold, the result is acast in the shape of the organism.

10. c 11. e

12. a 13. b

14. f 15. d

  8. Fossil footprints can provide clues about thedinosaur’s size and behavior.

  9. The fossil record provides evidence that manydifferent organisms have existed at differenttimes. The fossil record also shows that groupsof organisms have changed over time.

ANSWER KEY