THE FOSSIL RECORD Ecology and Paleoecology

1. THE FOSSIL RECORD Ecology and Paleoecology • Fundamental Concepts of Ecology and Paleoecology • Paleoecologists are particularly interested in the marine (ocean) • ecosystem because the fossil record is dominated by • marine life.

2. THE FOSSIL RECORD Ecology and Paleoecology Fundamental Concepts of Ecology and Paleoecology • Ecology is the interrelationship between organisms and their environment. • Paleoecology is ancient ecology. • The study of the interaction of ancient organisms with their environment. • In large part, paleoecology depends on comparisons of ancient organisms with living organisms. • We use modern analogs to help us interpret something about the way in which the fossils lived and related to their environment.

3. THE FOSSIL RECORD Ecology and Paleoecology Fundamental Concepts of Ecology and Paleoecology • Ecosystem = the organisms and their environment - the entire system of physical, chemical, and biological factors influencing organisms • Habitat = the environment in which the organism lives • Niche = the way in which the organism lives - its role or lifestyle. • Community = the association of several species of organisms in a particular habitat (the living part of the ecosystem) • Paleocommunity = an ancient community

4. THE FOSSIL RECORD Trophic Levels • The organisms living in the ocean ecosystem are • commonly grouped according to their method of • obtaining nutrients, or their trophic level. • Primary Producers or autotrophs - produce their own • food through photosynthesis, and supply food • and energy for other organisms. • In the marine ecosystem, many of the autotrophs • are plankton, including tiny diatoms and other • photosynthetic organisms.

5. THE FOSSIL RECORD Trophic Levels Primary Producers or autotrophs

6. THE FOSSIL RECORD Trophic Levels • Consumers or heterotrophs - cannot produce their • own food and must eat. • Herbivores - heterotrophs that eat plants

7. THE FOSSIL RECORD Trophic Levels • Carnivores - heterotrophs that eat herbivores and • other carnivores

8. THE FOSSIL RECORD Trophic Levels

9. THE FOSSIL RECORD Trophic Levels • Decomposers and Transformers - bacteria and fungi • which break down organic matter converting • it into a form which can be utilized by other • organisms (nutrients)

10. THE FOSSIL RECORD Trophic Levels • Parasites - derive nutrition from other organisms • without killing them

11. THE FOSSIL RECORD Trophic Levels Scavengers - derive nutrition from dead organisms

12. THE FOSSIL RECORD The Marine Ecosystem Pelagic Realm Zones: Neritic Oceanic

13. THE FOSSIL RECORD The Marine Ecosystem Benthic Realm Zones: Supralittoral Littoral Sublittoral Bathyal Abyssal Hadal

14. THE FOSSIL RECORD Marine Organisms Planktonic - small plants and animals that float, drift, or swim weakly (plankton)

15. THE FOSSIL RECORD Marine Organisms • Phytoplankton - plants and plant-like plankton, such as • diatoms and coccolithophores silica carbonate

16. THE FOSSIL RECORD Marine Organisms • Zooplankton - animals and animal-like plankton, such as • foraminifera and radiolaria Radiolarians silica Foraminifera carbonate

17. THE FOSSIL RECORD Marine Organisms • Nektonic - swimming animals that live within the water • column (nekton)

18. THE FOSSIL RECORD Marine Organisms • Benthonic or benthic - bottom dwellers • Infaunal - living beneath the sediment surface; • they burrow and churn and mix the sediment, a • process called bioturbation

19. THE FOSSIL RECORD Marine Organisms • Benthonic or benthic - bottom dwellers • Epifaunal - living on top of the sediment surface

20. THE FOSSIL RECORD Ocean Chemistry Nearly all water contains dissolved chemicals.

21. THE FOSSIL RECORD Ocean Chemistry These dissolved chemicals are called “salts” Salinity is a measure of the total dissolved solids in water. Salinity is measured in parts per thousand (ppt or o/oo) by weight.

22. THE FOSSIL RECORD Ocean Chemistry • Salinity terms for various types of water: • Normal ocean water = 35 ppt or 35 o/oo or 3.5% • A salinity of 35 ppt means that there are 35 pounds • of salt per 1000 pounds of sea water • Freshwater = about 5 ppt to less than 1 ppt • Brackish water = sea water with less than about 30 ppt • Hypersaline water = more than 250 ppt • (typically in lakes in arid areas, or in enclosed areas • like lagoons or isolated seas in arid areas)

23. THE FOSSIL RECORD Ocean Chemistry

24. THE FOSSIL RECORD Ocean Chemistry • Many of the chemicals in sea water are essential to life • Carbon dioxide (listed as part of HCO3) • used by marine plants; amount varies with • photosynthesis • Nitrogen - used in proteins and nucleic acids • Phosphorus - a component of DNA and RNA • and molecules used in metabolism • Sulfur - used in proteins and other molecules • an energy source for Bacteria and Archaea

25. THE FOSSIL RECORD Movement of Ocean Water Waves

26. THE FOSSIL RECORD Movement of Ocean Water Waves

27. THE FOSSIL RECORD Movement of Ocean Water Surface currents

28. THE FOSSIL RECORD Movement of Ocean Water Surface currents Currents are the unidirectional flow of water. Surface currents are slow drifts of water set in motion by prevailing winds. Global current patterns are related to the pattern of atmospheric circulation and prevailing winds. Land masses cause currents to be deflected. Surface currents have an affect on the climate – transporting warm waters to northern latitudes, for example.

29. THE FOSSIL RECORD Movement of Ocean Water Surface currents

30. THE FOSSIL RECORD Movement of Ocean Water Surface currents Coriolis Effect

31. THE FOSSIL RECORD Movement of Ocean Water Surface currents Currents are also affected by the Earth's rotation through the Coriolis Effect. Currents in the northern hemisphere tend to be deflected toward the right (or clockwise), and currents in the southern hemisphere tend to be deflected to the left (or counter clockwise) as a result of the Coriolis Effect.