Lecture 6

Question 1

Fossils

Answer 1

Are the preserved remains or trances of animals, plants and other organisms from the past

Question 2

Fossil types

Answer 2

• Miniralized bones (endoskeleton)
• Shells (exoskeleton)
• Teeth
• Mineralized tissues ( very seldom)
• Animal prints
• Places of residences
• Casts

Question 3

The best-preserved fossils

Answer 3

• In deep frozen ground = permafrost
• In dry desert caves - mummification
• In resin (amber)
• Sunken in cold swamps
  
  • Anaerobic environment
  • Natural antibiotics of plants (destroy bacteria)
• In deep sea
  
  • Small amounts of oxygen
• In volcanic ash

Question 4

Rare locations of fossils

Answer 4

• tropical raindorests: quick decay
• Mountain areas: strong erosion
• They are not well-preserved
  
  • Light bones with large surface area - their dilapidation is very fast
  • Small bones - they break into pieces quickly and are easily carried away

Question 5

Typical creation of a fossil

Answer 5

• After death of an organism, bacteria destroy organic components of bones
• Anorganic part with microscopic pores remains
• Water which trickles through higher placed strata, melts mineral material
• Mineral materials are left on porous parts
• Bones are becoming more and more similar to the surrounding stones

Question 6

Fossils give us information about

Answer 6

• Processes of evolution and trends
• Sex
• Patterns of growth
• Expected life period
• Patologies, specific diseases and injuries
• Form of body
• Form and largeness of muscles
• Physical efficiency
• Importance of some sensory organs
• Largeness of brain
• The age at death
• The way of eating

Question 7

Datation of fossils

Answer 7

1. Relative datation
   
   • It tells us what was before, and what after
2. Absolute, chronometric datation
   
   • Event is placed in the sequence of events
   • Gregorian calendar
   • Chronometric date is usually represented as: average