week 9

Question 1

what is the principle of superposition?

Answer 1

Chronological organisation of rock layers; the oldest rocks are at the bottom, and the layers
become increasingly younger towards the top

Question 2

define stratigraphy

Answer 2

using arrangements of rocks to interpret geological history

Question 3

OKAY LADIES NOW LETS GET IN FORMATION (what is a formation)

Answer 3

an uninterrupted series of rocks that is made of multiple layers that all share similar properties, and all formed under similar conditions

Question 4

what is radiometric dating?

Answer 4

The use of isotopic ratios to calculate age of a rock

isotopes are variations of an element that differ in the number of neutrons; has a specific half-life or rate of decay, which can be used for dating

Question 5

what is the cambrian explosion?

Answer 5

Dramatic diversification of aquatic animal life that occurred approximately 541 million years ago.

Question 6

what are trilobites? when did they live/die?

Answer 6

marine arthropods that were successful during the cambrian, but died during the permian ME

Question 7

what are pterosaurs? when did they live/die?

Answer 7

group of flying archosaurs that lived during the late triassic all the way to the cretaceous (first verte to fly)

Question 8

what are plesiosaurs? when did they live/die?

Answer 8

diapsids adapted for marine life

lived in early jurassic to late cretaceous

Question 9

what is pikaia? when did they live/die?

Answer 9

thought to be the oldest known animal with a notochord, dating back to the cambrian

Question 10

which was the largest extinction event we ever experienced? when was it?

Answer 10

permian ME, occurring at the end of the permian and beginning of triassic

estimated to have wiped out 96% of all marine life and 70% of all terre life

Question 11

what are mosasaurs? when did they live/die?

Answer 11

group of lepidosaur that evo’d for marine life in the late cret

Question 12

what are ammonites? when did they live/die?

Answer 12

marine cephalopod w spiral shells

born in the devonian and survived until the cret

Question 13

what is the significance of the burgess shale?

Answer 13

fossil rich deposit in BC of CAMBRIAN ERA marine organisms

Question 14

what are ichthyosaurs? when did they live/die?

Answer 14

marine reptiles that evo’d in the late triassic and survived until the cret

looked superficially like dolphins

named ‘fish lizard’ despite being neither fish nor lizard

Question 15

what are rhamphorynchoids? when did they live/die?

Answer 15

flying reptiles w longer tails and soft tissue head crests, similar to later flying reptiles

earlier suborder of pterosaurs, living in late triassic up til the cret

Question 16

what are pterodactyloids? when did they live/die?

Answer 16

flying reptiles that differed from earlier relatives
- shorter tails
- elongated wrist carpels, contributing to bigger wings
- large, bony head crests

later suborder of pterosaurs, living in late jurassic and cret

Question 17

what is are two problems with the principle of superposition?

Answer 17

igneous rocks can vertically cut through already established horizontal layers of rock

mountains can flip, fold, and fuck when tectonics get fucked

Question 18

which is better for radiometric dating: igneous or sedimentary rocks? what does this mean for paleo?

Answer 18

igneous, as the date they are formed is when radioactive decay begins

often, sedimentary rocks are the broken down remains of other rocks

problem! dinos are usually found in sedimentary, not igneous, so we need to take into consideration both radiometric dating and the law of superpositi

Question 19

describe the hadean eon

Answer 19

• magma oceans + volcanic activity
• moon was formed when a planetoid hit earth and a chunk flew off
• by the end, the planet cooled and oceans covered the surface

Question 20

describe the archean eon

Answer 20

• earliest known single cell organisms show up which would eventually become archaea
• cyanobacteria make the atmosphere
• stromatolites date back to this time

Question 21

describe the proterozoic eon

Answer 21

• first multicell organisms evo
• life is still microscopic
• during the edicarian period, animals w ‘hard parts’ evolved (he just like me fr)

Question 21

describe the paleozoic era’s periods (6)

Answer 21

cambrian period: cambrian explosion!

ordovician period: sea levels rose and ocean life diversified

silurian period: fish got jaws, first plants are recorded on land

devonian period: first forest appeared; Dunkleosteus and sharks first appeared; Tiktaalik got onto land

carboniferous period: swamps! amphibians! eventually would be the source of most of our coal!

permian period: pangaea + mass extinction
also during the permian the reptiles separated into anapsids, synapsids, and diapsids

Question 21

what eras were within the Phanerozoic eon

Answer 21

paleozoic era, mesozoic era (what we’re looking at), and cenozoic era

Question 22

when did the first flowers appear? the first grasses?

Answer 22

flowers: towards the end of the mesozoic

grasses: cenozoic

Question 23

describe the cenozoic era’s periods

Answer 23

paleogene period: mammals diversified

neogene period: homonids spotted in africa!!

quaternary period: ice ages and modern humans

Question 24

what did the world look like at the start of the triassic? what was the state of plate tectonics like?

Answer 24

we just came off the permian extinction, so there wasnt much around… but that means room for diversification

pangaea was around at this time, so dinos from this period are found around the world

Question 25

what did the jurassic look like in terms of herbivores?

Answer 25

sauropods were dominant (diplodocids > macronarians)

stegosaurs were around, and they were around exclusively for the jurassic

first ankylosaurs, ornithopods, and ceratopsians evo at this point

Question 26

what did the jurassic look like in terms of carnivores?

Answer 26

non-coelosurian theropods such as Allosaurus were dominant

coelurosaurians were around, but they were twinks still

first birds, incl Archaeopteryx evo at this time

Question 27

what did the early cret look like in terms of herbivores?

Answer 27

diplodocid sauropods were getting phased out, iguanodonts were getting larger and diversifying. ankylosaurs and ceratopsians were first evolving

macronarian Titanosaurus was fucking on bitches at this time

Question 28

to what age do the yixian formation in china, wealdean supergroup in england, and the cedar mountain formation in utah date back to?

Answer 28

the early cretaceous

Question 29

what did the early cret look like in terms of carniv?

Answer 29

as pangaea was mostly broken up, we got regional differences

in africa, dominant theropods were spinosaurs and carcharodontids (allosaurids).

meanwhile, coelurosurian theropods were getting larger and diversifying (come back to them later)

Question 30

what did the late cret look like in terms of herbiv

Answer 30

ceratopsians and hadrosaurs are dominant in north hemisphere, w pachycephalosaurs and anyklosaurs also found

titanosaurid sauropods are dominant in south hemisphere

pachycephalosaurs are only found in the late cretaceous

ankylosaurs split into ankylosaurids and nodosaurids

Question 31

what did the late cret look like in terms of carniv

Answer 31

in laurasia the coelurosurian theropods was FUCKIN (tyrannosaurus, ornithomimids, therizinosaurs, oviraptorosaurs, dromaeosaurs, troodontids, etc)

in gondwana, where the Titanosaurus was still fuckin, Carcharodontosaurus, Spinosaurus were eating. smaller Abelisaurs such as Carnotaurus were all that remained of the ceratosaurid lineage, and they were relatively smaller

Question 32

when did we get first evidence of vascular plants?

Answer 32

silurian period of the paleozoic

Question 33

order the bearpaw formation, dino park formation, and old man formation in terms of relative age. what period do they correspond to?

Answer 33

bearpaw: youngest
dino park: middle
old man: oldest

all date back to cret period

Question 34

order centrosaurus, coronosaurus, and styracosaurus in terms of age. how do we know?

Answer 34

styracosaurus is found in upper dino park formation

centrosaurus found in lower dino park formation

coronosaurus found in old man formation

Question 35

when did insects evolve flight?

Answer 35

carboniferous period of paleozoic