Past Life and Past Climate Flashcards
What are three purposes of fossils?
To determine the relative age of rock, To determine the paleoenvironment conditions at the time of deposition, To study the process of evolution
What are the eight ways organisms can be classified?
Kingdom, Phylum, Class, Subclass, Order, Family, Genus, Species
Define Lagerstätten
Fossiliferous deposits that are rich in palaeontological information
What are the three types of conservation trap?
Resin, Stagnation, Obrution
What are three reasons Lagerstätten are important to the geological record?
Exceptionally well preserved showing detail including soft parts, Provide a more complete view of the fossil record
Define Evolution
The progressive development of new life forms
What are the two interpretations of evolutionary patterns?
Gradual Evolution and Punctuated Equilibrium
Define Gradual Evolution
Implies slow genetic change as one species replaces another by the process of natural selection
Define Punctuated Equilibrium
Implies long periods of stability where the characteristics of animals stay the same for a long time followed by rapid change in the characteristics
Define Missing Link
A missing intermediate species from the fossil record
Define Sepkoski Curves
Illustrates when we think organisms underwent diversification (radiation) and declines (extinctions)
What are the two groups of dinosaur?
Saurischian (reptile hipped) and Ornithischian (bird hipped)
Are saurischian dinosaurs herbivores or carnivores?
Both
Are ornithischian dinosaurs herbivores or carnivores?
Herbivore only
Define Therapod
Two legged carnivore
Define Sauropod
Four legged herbivore
What are four causes of mass extinctions?
Sea level variation, Glaciation, Volcanicity, Asteroid impact
Which oxygen isotope is “heavier”?
18O
Define Proxy Indicator
An indirect measurement of temperature
What three pollens are an indicator of warmer interglacial periods?
Oak, Elm, Hazel
What two pollens are an indicator of colder interglacial periods?
Pine and Birch
What are five advantageous characteristics of pollen?
Abundant, Small, Easily preserved, Distinctive shape, Not easily destroyed through erosion
What are two disadvantageous characteristics of pollen?
Affected by altitude, Plant height
What are four processes adding CO2 to the atmosphere?
Combustion, Respiration, Diffusion, Volcanic activity
What are two processes removing CO2 from the atmosphere?
Photosynthesis, Weathering of silicate rocks
What are three things ice cores can be used to infer?
Temperature, Chemistry of the atmosphere, Ocean productivity
What are three places methane hydrates naturally occur at?
Major river deltas, Frozen methane hydrate in Arctic Ocean, Trapped by permafrost layers that overlay decaying vegetation
How can flood basalts can affect climate and potentially cause mass extinctions?
Ash and dust rise to the atmosphere, lowering global temperatures by 4-5 degrees C. Animals and plants are not used to this temperature so sudden decrease coud cause extinction
When continents are apart…
There is more shallow shelf sea so less competition and more diverse life
When continents are together…
There is less shallow shelf sea so more competition and less diverse life
