Proterozoic
Compare and contrast eukaryotes and prokaryotes.
Prokaryotes are simple single celled organisms without any internal structures or organelles. Eukaryotes are more complex, single or multi-celled, with distinct organelles and a nucleus.
What are the three largest categories of geologic time in order?
Eon, Era, Period
What is taxonomy? Give an example of a taxonomy category.
Its the study of how we classify organisms based on shared characteristics. Categories include kingdom, domain, phylum, etc.
Compare and contrast brachiopods and bivalves.
Both are two part shells with a hinge. Brachiopods have symmetry along the center line (left/right symmetry) while bivalves have top/bottom symmetry. Bivalves are mollusks.
What are ichnofossils? Give an example.
Trace fossils, they don't have any of the original organism. Footprints, burrow marks, etc.
What is Snowball Earth and how did it happen?
A period where nearly the entire earth was covered in ice. Typically a result of changes in oxygen and CO2 levels, natural climate variations, and positive feedback loops.
What is the Precambrian?
It is a supereon which combines the Hadean, Archean, and Proterozoic Eons into one (aka everything before the Cambrian).
What would the shorthand be for the species Treptichnus pedum? Write it on your whiteboard.
T. pedum
What are the three segments of a trilobite called? (not the lobes!)
Cephalon, thorax, pygidium
What is permineralization and what materials does it typically preserve?
It is fossilization where minerals form in the gaps of the hard material, typically bones and wood.
What are the important events of the Cryogenian?
Snowball Earth! Evolution of multicellular life.
Compare and contrast absolute and relative age. How do we determine each?
Relative age puts rock units and events in order relative to one another using Steno's Law. Absolute age gives a number age, often by using half-life for radiometric age dating.
What are evolutionary traits? How do they form? Give an example.
They are traits that develop as adaptations that help an organism survive or reproduce better which leads to it being passed down to future generations. Things like eyes, spines, a shell, etc.
What is glide symmetry? Explain and draw it. When was this common?
Its an offset bilateral symmetry common during the Ediacaran.
What are replacement/recrystallization? How are they different and what type of material do they usually preserve?
Both are common for shells. Replacement completely replaces the original material with a chemically different mineral. Recrystallization take the original material and changes the structure while keeping it chemically the same.
What are the important events of the Ediacaran?
Very diverse and abundant multicellular life with distinct symmetry and body plans, allowing us to start using taxonomy. Extinction event at the end marks the end of the Precambrian.
List three of the Principles of Steno's Law and explain them.
Superposition, Cross-Cutting Features, Inclusions, Unconformities, Original Horizontality, Lateral Continuity, etc.
Compare and contrast scavengers and predators.
Both are carnivorous, but predators hunt and kill their prey which uses lots of energy. Scavengers eat already dead and decaying animals and use their energy mainly to find carrion rather than needing to hunt.
What is an echinoderm and how do we identify them?
They are an organism with 5-point radial symmetry like a crinoid, seastar, etc.
What is carbonization? What does it usually preserve?
It preserves softer tissues by turning the carbon in the organic matter into a black carbon film on the surface. Common for plants especially.
Why was multicellular life able to diversify and increase in abundance towards the end of the Proterozoic?
Snowball Earth wiped out previous organisms leaving behind a "space" for new organisms, they developed sexual reproduction which created more diverse organisms.
What do the prefixes Meso-, Ceno/Neo-, and Paleo- tell us about the time? Put them in order from oldest to youngest.
Paleo is oldest, then Meso means middle, Ceno/Neo means the newest or most recent time.
Discuss the pros and cons of the feeding types of herbivores, carnivores, and omnivores.
Herbivores require less energy, get less energy from food. Carnivores require high energy to get food, but get high energy from food. Omnivores require high energy but have many sources which can make it easier overall.
Compare and contrast two examples of Cambrian fossils (other than trilobites). Include names, appearances, as much taxonomy as we discussed (might be phylum, might be genus species, etc.)
Lots of options.
What is that special word for a location with lots of very well preserved soft tissue fossils?
Konservat Lagerstatten