palaeontology

Question 1

trace fossils

Answer 1

fossil records of biological activities

Question 2

ethologic classification

trace fossils

Answer 2

traces of…

• resting
• locomotion
• grazing
• feeding
• dwelling etc.

-> representing evidence of animal behaviour

Question 3

2 type of body fossil

Answer 3

• mould -> mineralised impression of organism left in sediment
• cast -> mineralised sediment that fills mould recreates shape of remains

Question 4

micropalaeontology divided into 4 areas…

Answer 4

1. Calcareous -> eg. coccoliths
2. Phosphatic -> eg. conodonts
3. Siliceous -> eg. diatoms, radiolarians
4. Organic -> eg. pollens, spores

Question 5

what are fossils?

Answer 5

• physical evidence of prehistoric life
• may be preserved remains / other traces

Question 6

palaeontology

Answer 6

study of fossils and evolution of life on Earth

Question 7

main characteristics of trace fossils

Answer 7

• same organism may produce >1 ichnotaxon & same ichnotaxon may be produced by >1 organism
• trace fossils commonly preserved in rock units that are otherwise unfossiliferous & rarely transported

Question 8

type of trace fossil:

bioturbation

Answer 8

• bioturbation structures are biogenic sedimentary structures reflecting disruption of sedimentary layers…
• by activity of an organism, inc tracks, trails & burrows

Question 9

coprolites

trace fossils

Answer 9

fossilised faeces -> giving evidence of animal’s diet

Question 10

stromatolites

Answer 10

• layered sedimentary formations that are created by photosynthetic cyanobacteria
• are trace fossils that record interaction between microbial communities & sediments

Question 11

sedimentary rocks

Answer 11

• layered rocks formed by the accumulation / deposition of mineral / organic particles…
• that are transported to place of deposition by water, wind, ice & mass movement

Question 12

taphonomy

Answer 12

study of how organisms decay & become fossilised

Question 13

Konservat-Lagertätten (conservation Lagerstätten)

Answer 13

• deposits known for exceptional preservation of fossilised organisms / traces…
• which are crucial in providing answers to important moments in history & evolution of life.

Question 14

exceptional preservation examples

Answer 14

• Burgess Shale- type fossils
• amber fossils
  -> when animal was alive, quickly trapped in tree sap -> stops scavengers/bacteria decomposing body
  -> only small animals trapped in tree sap, bigger can get away so not often seen
• frozen fossils
  -> eg. baby mammoths
  -> in cold temps, specific mud burial env keeps baby mammoths flesh

Question 15

palaeontological kit

Answer 15

• hard helmet -> broken rock in quarries might fall
• geological hammer
• geological notebook
• boots
• hand lens -> helps you identify rocks & fossils
• binocular microscope

Question 16

palaeontological techniques

Answer 16

• essential kit
• field collection
• fossil preparation-> use needles to remove sediment covering fossil to reveal fossil details
• acid preparation -> to dissolve sediment
  -> takes 1-2 yrs!!! limited damage to fossil
  -> also used to separate microfossils from matrix
• microfossil picking -> looks like sand so use microscope & small paint brush to find valuable fossils for study
• advanced technology -> eg. SEM to show high magnification image of fossil
  -> eg. synchrotron -> have a particle accelerator which reveals 3D image of microfossils
• reconstruct fossils (everything else has lead to this!!)
  -> use computer reconstruction & drawings of what we thought animals looked like

Question 17

example of fossil that synchrotron helped us identify

Answer 17

Markuelia
(from early Cambrian->early Ordovician)

• fossil embryos -> each fossil like a grain of sand
• when you put them under SEM, each grain is actually tiny worms
• using synchrotron facilites, can see internal structures

Question 18

(in)vertebrate palaeontology

Answer 18

concentrates on (in)vertebrate fossils

Question 19

Palaeobotany

Answer 19

studies fossil plants

Question 20

Micropalaeontology

Answer 20

focuses on microfossils of all kinds

Question 21

Ichnology

Answer 21

interprets trace fossils

Question 22

Palaeoecology

Answer 22

examines interactions between…

• diff ancient organisms
• organisms & their env

Question 23

Biostratigraphy

Answer 23

uses fossils to work out chronological order in which rocks were formed

aka…

focuses on correlating & assigning relative ages of rock strata by using fossil assemblages contained within them

Question 24

Palaeoclimatology

Answer 24

focuses on history of Earth’s climate

Question 25

5 classic subdivisions of palaeontology

Answer 25

- **Vert.** Palaeontology - **Invert.** Palaeontology - Palaeo**botany** - **Micro**palaeontology - **Ichno**logy -> largely focused on **individ. fossils/organisms**

Question 26

principle of **faunal succession**

Answer 26

- sedimentary rock strata contains **fossilised flora & fauna**... - & these fossils **succeed each other vertically** in **specific, reliable order** that can be identified over **wide horizontal distances**

Question 27

radiometric dating

Answer 27

- technique used to date rocks ... - based on comparison between **abundance of naturally occurring radioactive isotope** & its **decay products**

Question 28

examples of radiometric dating

Answer 28

- **radiocarbon** dating -> for recent fossils - **potassium argon** dating - **uranium lead** dating -> for ancient fossils -> often find uranium in volcanic ash

Question 29

evidence of evolutionary history

Answer 29

1. ***providing time scale of evolution*** -> faunal succession -> radiometric dating -> biostratigraphy 2. ***revealing evolutionary pathways*** -> fossils unique morphological combos reveal **links** between **extant taxa** -> eg. *Archaeopteryx*: oldest bird BUT recently suggested non-avialan dinosaur instead 3. ***reconstructing macroevolution*** -> Sepkoski Curve

Question 30

macroevolution

Answer 30

- encompasses **biggest trends & transitions in evolution**... - especially with regard to evolution of **whole taxonomic groups**... - over **long periods of time**

Question 31

classical "Sepkoski" Curve

Answer 31

- Jack Sepkoski plotted **no. of marine invert. fossil taxa in each interval of Phanerozoic...** - which revealed no. of interesting patterns inc. **Cambrian, Paleozoic & Modern "Evolutionary Faunas"...** - as well as **identified " Big Five " mass extinctions** of marine inverts.

Question 32

evidence of **palaeoecology**

Answer 32

1. ***interaction between sp*** -> eg. fighting dinosaurs preserved (Velociraptor vs Protoceratops) 2. ***organisms & env*** -> **trace fossils** can reveal interaction between organism & env.

Question 33

continental drift theory proposed in 1912

Answer 33

- earth's outer shell divided into several plates & they move around over geological time - **fossils** are evidence of this: -> **similar plant & animal fossils** found around shores of **diff continents** (S.America, Africa, India, Antarctica, Australia) -> suggests continents were once joined together

Question 34

palaeoclimatology

Answer 34

- new field of study focusing on **past climates** - fossils with **continuous stratigraphic ranges** can be exploited for climate proxies to reconstruct climate change, such as diatoms, foraminifera, corals, shells & pollens - most widely used method based on **variations in oxygen isotope composition of biogenic marine carbonate**, from which the broad pattern of change in marine temps has been reconstructed

Question 35

evidence of env changes

Answer 35

1. ***plate tectonics*** -> similar fossils found around shores of continents suggest they were once joined 2. ***palaeoclimatology***