Fossils

1
Fossils

• Pgs. 106G 112G
• 8-2.2 Summarize how scientists study Earths
  past environment diverse life-forms by
  examining different types of fossils (molds,
  cast, petrified, preserved fossils carbonized
  remains of plants animals and trace fossils.)

2
(No Transcript)
3
Fossils

• Fossils are preserved remains or traces of living
  things.
• Most fossils form when living things
• 1. die
• 2. buried by sediments quickly.
• 3. bones are replaced by minerals.
• 4. sediments slowly harden into rock and
  preserve the shapes of the organisms.
• Can all dead things become a fossil?

4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
Types of Fossils

• Mold
• Cast
• Petrified
• Preserved
• Carbonized
• Trace

11
(No Transcript)
12
Mold Fossil

• A mold is a hollow area in sediment in the shape
  of an organism or part of the organism.
• Forms when sediments bury an organism and the
  sediments change into rock.
• The organism then decays leaving a cavity in the
  shape of the organism

13
Cast Fossil

• Cast is a copy of the shape of an organism.
• Forms when a mold is filled with sand or mud that
  hardens into the shape of the organism.

14
Website

• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es2901/es2901page01.cfm?cha
  pter_novisualization

15
Petrified Fossils

• Forms when minerals soak into the buried remains,
  replacing the remains and changing them into
  rock.
• Petrified fossils are fossils in which minerals
  replace all or part of the organism.
• Petrified means turning into stone.

16
(No Transcript)
17
Preserved Fossils

• Forms when entire organisms or parts of organisms
  are trapped in ice, tar, or amber and are
  prevented from decaying.
• Iceman found in ice
• Amber insects stuck in the sap
• Tar animals get stuck in tar and die.

18
ICE MAN preserved in ice
19
Ötzi the Iceman (pronounced 'œtsi (helpinfo)),
and Similaun Man are modern names of a
well-preserved natural mummy of a man from about
3300 BC (53 centuries ago).1 The mummy was
found in 1991 in the Schnalstal glacier in the
Ötztal Alps, near Hauslabjoch on the border
between Austria and Italy. The nickname comes
from Ötztal (Ötz valley), the region in which he
was discovered. He is Europe's oldest natural
human mummy, and has offered an unprecedented
view of Chalcolithic (Copper Age) Europeans.
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
AMBER insects preserved in sap from a tree.
24
(No Transcript)
25
(No Transcript)
26
TAR animals fall into tar pits and are buried
like saber-toothed cats and mammoths.
27
(No Transcript)
28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
http//blackhills360.com/bhgalleries/mammogallery.
html
32
Carbonized Fossils

• Forms when organisms or parts, like leaves,
  stems, flowers, fish, are pressed between layers
  or soft mud or clay that hardens squeezing almost
  all of the decaying organism away leaving the
  carbon imprint in the rock.
• Carbon fossils are a thin coating of carbon on
  rock.

33
Undetermined Leaf Henefer Formation, Cretaceous,
Coalville, Summit Co., Utah
Crossopteris utahensis Fern Leaf, Manning Canyon
Formation, Pennsylvanian, Lake Mountains, Utah
Co., Utah
34
Ginko Leaf Paleocene, Morton Co., North Dakota
Macginetea Sycamore leaf, Green River Formation,
Eocene, Douglas Pass, Colorado
35
Rhodea Fern Leaf, Manning Canyon Formation,
Pennsylvanian, Lake Mountains, Utah Co., Utah
36
Trace Fossils

• Form when the mud or sand hardens to stone where
  a footprint, trail, or burrow of an organism was
  left behind.
• Provides evidence of the activities of ancient
  organisms.
• Size and behavior
• Did it walk on two or four legs?
• Did it travel alone or with others?
• ..

37
(No Transcript)
38
Megalosaurus footprint - A meat eating predator
from the Jurassic
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)