5 What is a fossil?The preserved or mineralized remains (bone, tooth, or shell) or traces (footprints, burrow, or imprint) of an organism that lived long ago.Dinosaur fossil - (bone)Ammonite fossil (shell)
6 Fossils come in many forms Shark teethDinosaurfootprintImprint of fish
7 Fossils are very old Trilobite fossils Stingray fossil 445 million years agoStingray fossil95 million year oldBird egg fossil1 million years oldBeetle fossil50 million years old
8 How do We Know How Old things Are? Carbon dating half –life of carbon 14 is 5730 years.
9 How do fossils form?Most fossils are laid down in sedimentary rock -(particles carried by streams and rivers that eventually settle to the bottom in layers)Many fossils in theGrand Canyon
10 The oldest particles, and therefore the oldest fossils will be at the bottom, with new layers being added.The deeper down you go, the simpler the life forms are.This leads some to believe that life began as simple prokaryotic cells and gradually became more complex because…
12 What is the “fossil record” Over the years, paleontologists (scientists that study fossils) have collected millions of fossils. This groups of fossils is called the Fossil RecordThe fossil record represents the preserved collective history of the the Earth’s organisms.
13 The fossil record shows that some organisms that once lived are now extinct triceratopsstegosaurousarcheopterous
14 The fossil record can show that organisms changed gradually over time Fossil record of the whale60 millionyears agoToday
15 Fossil record of the modern horse Today55 millionyears ago
16 Fossil record of the camel Today40 millionyears ago