Quiz 1 - New Flashcards
What type of solar system is our Solar System?
Single star solar system (most are binary)
What is the plane on which planets in our Solar System lie?
The plane of the ecliptic
What is the process that led to the formation of our universe?
Dust cloud –> Gravity accumulated and collapsed the dust in on itself –> forms a condensed rotating disc –> planetesimals
Name the rocky inner terrestrial planets in our Solar System.
- Mercury
- Venus
- Earth
- Mars
Which planet is the smallest and densest terrestrial planet in our Solar System?
Mercury
Which planet is often described as the bad twin of Earth?
Venus
What is the axial tilt of Earth?
23 degrees
Name the gas giants in our Solar System.
- Jupiter
- Saturn
- Uranus
- Neptune
What is the ‘Goldilocks Zone’?
The ‘Goldilocks Zone’ is where conditions (particularly temperature) are suitable for life to form and evolve over time.
What factors determine the habitable zone?
- Luminosity of a star
- Planet size
- Habitable zone of a star and the related planet’s orbit
What is the ‘faint young sun paradox’?
As stars evolve, their composition and size changes, and their luminosity changes, moving the habitable zone further away.
What were the objectives of the Kepler Mission?
- Determine the abundance of planets in or near the habitable zone
- Determine the distribution of sizes and shapes of the orbits of the planets
- Estimate how many planets are in multi-star systems
- Determine the variety of orbit sizes and planet properties
True or False: The early Solar System was a peaceful place.
False
What is the Nice Model?
In the first 50-100 million years of the Solar System, planets dramatically changed positions, sweeping out material.
What are the two basic entities in the universe according to Scientific Cosmology?
- Matter
- Energy
Define matter.
The substance that makes up objects.
What are the states of matter?
- Liquid
- Gas
- Solid
Define energy.
The inherent ability of a region of space and the matter within it to do ‘work’.
What is the geocentric model?
The Earth sits without moving at the center of the Universe while the moon and planets whirl around it.
What is the heliocentric model?
The sun lies at the center of the Universe with the Earth and other planets orbiting it.
What is our galaxy called?
Milky Way
What defines a planet?
An object that orbits a star, is roughly spherical, and has ‘cleared its neighborhood of other objects’.
List the eight planets in our Solar System.
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
What is a moon?
A solid object of detectable size that orbits a planet.
Which planets in our galaxy do not have moons?
Mercury and Venus
Where do most asteroids lie?
In the region between the orbits of Mars and Jupiter.
What are Kuiper Belt and Oort Cloud objects?
Bodies of ice that lie outside the orbit of Neptune.
What is a dwarf planet?
Asteroids and Kuiper Belt objects with a diameter >900 km.
What is a comet?
Planetesimals composed of ice and dust that follow elliptical orbits bringing them into the inner Solar System.
What is a contact/mechanical force?
A force that results when one mass moves and comes in contact with another.
What is a field force?
A non-contact force that applies across a distance.
Define gravity.
The pull that one mass exerts on another.
What factors affect the strength of gravity?
- Quantity of matter in the two masses
- Distance between them
What is magnetism?
The force generated by electricity flowing in a wire.
What is kinetic energy?
The energy that an object has due to its movement.
What is potential energy?
The energy stored within a material.
What is radiant energy?
The energy that a glowing object sends outward in the form of electromagnetic waves.
Fill in the blank: 1 light year = _______ kilometers.
9.5 trillion
What is the Doppler Effect?
The change in frequency that happens when a wave source moves.
What does a red shift in distant galaxies indicate?
Galaxies are moving away from the Earth at an immense velocity.
Define an atom.
The smallest piece of an element that has the property of the element.
What are the three types of atoms?
- Neutrons
- Protons
- Electrons
What is the atomic mass of an atom?
The number of neutrons and the number of protons.
Define an element.
Undividable substances.
What is a molecule?
A combination of two or more atoms.
What is a chemical bond?
The ‘glue’ that holds one atom to another.
What is a compound?
A material whose molecules contain more than one element.
What is the nucleus of an atom?
A dense ball at the center of an atom packed with protons and neutrons.
What holds the particles of a nucleus together?
Nuclear bonds.
What are electron shells?
Intervals that electrons group together into.
What is the Big Bang Theory?
All matter and energy was initially packed into a singularity that exploded, beginning the Universe.
What happened to hydrogen atoms after the Big Bang?
Hydrogen atoms formed as the temperature dropped.
What is the Nebular Theory?
Molecules began sticking together to form specs of ice, leading to star formation.
What happens when the gravitational pull of a nebula increases?
It sucks in surrounding ice and gas, growing in mass and density.
What is a protostar?
A central ball of a disk that becomes hot enough to glow due to gravitational collapse.
What is the Giant-Impact Hypothesis?
The moon formed from a collision disintegrating a comet and a large part of the Earth’s mantle.
What is the Canup Model?
ProtoEarth collided with a Mars-sized planet (Theia), resulting in a molten moon.
What defines first generation stars?
They tend to be massive and burn hotter, running out of fuel faster.
What is stellar nucleosynthesis?
Elements formed during the life cycle of stars that create new, heavier elements when stars die.
What is the Nebular Theory also known as?
Condensation theory
What do tiny ice and dust particles do in a nebula?
Condense
What happens to atoms and molecules in relation to the particles in a nebula?
Attach to these particles
What builds large enough structures in the Nebular Theory?
Particles that attract one another by gravity
What force is responsible for attracting particles together in the Nebular Theory?
Gravity
What is the geological time scale that includes the last 539 million years?
Phanerozoic Eon
Divided into Cenozoic, Mesozoic, and Paleozoic eras.
What are the three main eras within the Phanerozoic Eon?
- Cenozoic
- Mesozoic
- Paleozoic
What period precedes the Phanerozoic Eon?
Precambrian
Encompasses Proterozoic, Archean, and Hadean eons.
What is the age range of the Hadean Eon?
45 to 40 Ma
What key event marks the beginning of the Hadean Eon?
Planetary formation, ending with known intact rock formation
What is the significance of the oldest zircon?
It is the oldest piece of the Earth.
At approximately what time did single-celled organisms first appear?
~2.5 million years
How long did it take for complex life to develop?
Almost 2 billion years
What is the importance of a ‘goldilocks zone’ for life development?
Life requires a very stable environment for a very long time to develop
What 4 major events likely occurred during the Hadean period?
*Late Heavy Bombardment (LHB)
*Earth’s core formed
* Moon-forming event occured
* first continents emerged
What percentage of Earth’s surface is land?
30%
What makes Earth different from other planets?
- Plate tectonics
- Oxygen-rich atmosphere
- Liquid-water ocean
- Abundant life
What is the composition of Earth’s atmosphere?
Mostly nitrogen and oxygen
What are the two main layers of Earth’s atmosphere?
- Troposphere
- Stratosphere
What is an earthquake?
Sudden movement generating vibrations
What are seismic waves?
Waves that move through rock or along the Earth’s surface during an earthquake
What drives internal processes in Earth’s geology?
Internal energy (heat from inside the Earth) (e.g. plate movement)
What drives external processes in Earth’s geology?
External energy from the sun
What are the concentric layers of the Earth?
- Crust
- Mantle
- Core
What is the difference between oceanic and continental crust?
- Oceanic crust: Thinner (7-10 km), underlies seafloor
- Continental crust: Varies in thickness (25-70 km), underlies continents
What is the lithosphere composed of?
Crust and uppermost part of the mantle
What is the asthenosphere?
Softer/plastic part of the mantle that can flow and undergoes convection
What does the theory of plate tectonics describe?
Movement of plates and consequences like earthquakes, volcanoes, mountains
What are the three types of plate boundaries?
- Divergent
- Convergent
- Transform
The Earth’s magnetic field is primarily described as a _______.
Dipole
What is the significance of Earth’s magnetic field?
It interacts with solar wind, distorting into a teardrop shape
What is the Earth’s core primarily composed of?
Iron alloy
What is the outer core’s state of matter?
Liquid iron alloy
What is the inner core’s state of matter?
Solid iron alloy
What are the main components of the Earth System?
- Atmosphere
- Hydrosphere
- Cryosphere
- Biosphere
- Solid Earth
How do we have any facts about the Hadean era?
From isotopes
Why are there no primary rock records during the Hadean period?
Likely due to the Late Heavy Bombardment, thought to be during this period.
What was the Late Heavy Bombardment (LHB)?
A period of time when Earth was intensively bombarded by proto-planets/meteorites (clearing out of the inner solar system) - 4-3.2 Ga
When was the Earth formed?
4.5 Ga
What is the Earth System?
The interconnected web of interacting materials and process of the Earth.
* atmosphere
* hydrosphere
* cryosphere
* biosphere
* solid earth
What is the atmosphere?
a layer of gases surrounding a planet or other celestial body, held in place by gravity
What is the hydrosphere?
encompasses all the water on Earth
What is the cryosphere?
Earth’s ice in all its forms
What is the biosphere?
the global ecosystem encompassing all life on Earth, including living organisms and the non-living parts of the environment that support life
Describe Earth’s magnetic field
Dipule - has 2 poles (north and south)
What layer of Earth is the most dense?
The core
Describe Earth’s mantle.
*The shell that surrounds the core
* Almost all is solid rock h/e some parts are so hot that they are soft/plastic enough to change shape (extremely slowly)
* warmer regions upwell, cooler regions downwell
What are the 2 sublayers of the mantle?
*Upper mantle
*Lower mantle
What are the 2 parts of Earth’s core?
*Outer core
*Inner core
Describe the differences between the outer and inner core of Earth.
- Outer core: consists of liquid iron alloy that can flow (and creates Earth’s magnetic field)
- Inner core: consists of solid iron alloy
Describe the lithosphere.
Composed of rigid rock and separated into plates which move very slowly
What is the first evidence of a dinosaur?
Scrotum humanum (Robert Plot 1677)
The end of a femur looked like a scrotum, leading to misidentification.
Who discovered footprints that were later identified as dinosaur tracks?
Pliny Moody (1802) in Massachusetts
This discovery was significant in dinosaur research.
What did Indigenous interpretations of dinosaur fossils include?
- North America: Grandfather of the buffalo
- Europe: Giant mule carrying Virgin Mary, Dragons
- China: Heavenly chickens, divine eagle, dragons
- Australia: Marala, the Emu Man
Which dinosaur was first described in 1825?
Iguanodon (Mantell 1825)
This marked the beginning of the dinosaur craze.
What is the significance of the Crystal Palace in relation to dinosaurs?
It revealed fossils and interpretations to the world, featuring statues of early dinosaurs
Megalosaurus was among those presented.
What was the first ‘good’ dinosaur skeleton discovered?
Hadrosaurus foulkii
This discovery helped fill gaps in the understanding of dinosaur morphology.
What major discovery occurred in 1878?
Coal miners in Belgium discovered 31 skeletons which were used to update the hypothesised look of dinosaurs
This discovery led to a better understanding of the true appearance of dinosaurs.
What anatomical feature is unique to dinosaurs within Archosauria?
Antorbital fenestra
A hole in front of the orbital socket that may have lightened the skull.
Current working hypothesis states that _____ are dinosaurs.
Birds
Some dinosaurs did not evolve into birds, but all birds are considered dinosaurs.
What are the main characteristics of birds?
- Highly pneumatic skeletons
- Endothermic
- Covered in feathers
- Have a wishbone (furcula)
*Fused caudal
(long arms
*beak
*capable of vocalisation (syrinx)
*can fly
What significant fossil exhibited feather-like structures and when was it discovered?
Sinosauropteryx (1996, China)
It showed early evolution of feathers.
What are the two first groups of dinosaurs that appeared instantaneously in the Late Triassic?
Ornithischia & Saurischia
They appeared ‘instantaneously’ around 230 Ma.
What is Eoraptor known for?
The earliest ancestor of giant sauropods
It was a small, bipedal dinosaur that occupied both herbivorous and carnivorous niches.
What distinguishes Saurischia from Ornithischia?
Saurischia have a pubis that faces forward, while Ornithischia have a backwards pointing pubis.
What characterizes the Thyreophora group of dinosaurs?
Armoured dinosaurs with bony armour (osteoderms) plates and spines.
What does the science of paleobiology encompass?
- Individual and group behavior
- Growth/ontogeny
- Reproductive strategy
- Macroevolution
What are Lagerstätten?
Places with exceptional fossil preservation (rare chance discovery)
They provide detailed insights into ancient ecosystems.
What can trace fossils tell us?
- Footprints
- Burrows
- Feeding traces
- coprolite
True or False: Marine reptiles are considered dinosaurs.
False
Birds are the closest living relatives to dinosaurs.
What factors increase the chances of fossil formation?
- Fast burial
- Energy of the depositional setting
- Presence of hard parts
- Oxygen content of the environment
Name 5events that can lead to mass extinctions.
- Global climate change
- Asteroid or comet impacts
- Tectonic activity
- voluminous volcanic eruptions
- the appearance of a new predator or competitor
What organisms are classed under Archosauria?
*pterosaurs
* birds
* crocodiles
* dinosaurs
When was the first bird?
160 Ma
Where are fossils found?
In sedimentary rocks, some in volcanic tuffs
How long did dinosaurs survive for?
180 Ma
What are 2 examples of Saurischia dinosurs?
- Therapods (ceratosaurs, ceolurasaurs)
- Ornithischia (diplodocid, macronaria)
What are some examples of Ornithischia dinosaurs?
*Cerapoda
*Pachycephalosauria
*Ornithopoda
* Ceratopsia
What are some key differences between Hadrosaurids and Ceratopsians?
*Hadrosaurids: powerful back legs, slender arms.
* Ceratopsian: Obligate quadrupedal, rhino like bodies
What are 2 examples of Thyreophora?
*Stegosauria
*Ankylosuria
What is the traditional approach for learning about dinosaurs?
Science of discovery, description, and interpretation.
What does palaeoecology investigate?
- Diet and predator-prey relationships
*Ancient ecosystems - Foodwebs
- Response to changing environments
What are 3 main ways to study fossils?
- Extraordinary fossils
- Large samples
- Digital methods
Where do scientists find large fossil samples?
Mass death accumulations
What can digital methods for analysing fossils tell us?
*can see inside the skull
*take measurments
*analyse ariflow through nasal cavity
*identify landmarks on bones
What experiment did Miller conduct in 1953?
Simulated conditions on early Earth to prove favoured chemical reactions that may have synthesised complex organic compounds
This experiment is often cited as a foundational study in the origins of life research.
What complex organic compounds did Miller’s experiment synthesize?
Amino acids, adenine, cytosine, uracil, hydrogn cyanide, etc.
These compounds are essential building blocks for life.
What role did hydrogen cyanide (HCN) play in early Earth conditions?
Facilitated chemical reactions important for early Earth life
HCN is believed to have contributed to the formation of organic compounds.
What are the two key processes involved in early life development?
Self-replication and self-regulation (metabolism)
These processes create a cycle essential for the survival and evolution of life.
What is necessary for DNA/RNA to function?
A microenvironment, specifically a phospholipid membrane
This structure is crucial for the stability and functionality of genetic material.
Approximately when did life originate on Earth?
~4 billion years ago
This estimation is based on molecular dating techniques.
What evidence suggests life was present around 3.86 billion years ago?
Light isotopic carbon found in rocks from Greenland
This finding is considered indirect evidence of early life.
What are cyanobacteria-like microfossils and where have they been found?
Microfossils found in 3.46 billion year old Apex Chert from Western Australia
Their existence is still debated among scientists.
What is subduction in the context of plate tectonics?
One tectonic plate slides beneath another, recycling carbonate and H2O
This process is vital for geological and ecological dynamics on Earth.
How does the formation of mountains influence ocean chemistry?
Leads to huge erosion that sheds materials into the ocean, changing its chemistry and providing nutrients for organisms
This nutrient influx is essential for the development of life.
Why is it difficult to test hypotheses about the origins of life?
We only have one data point (Earth)
This limitation makes it challenging to draw definitive conclusions about life’s origins.
What are the time ranges for the Archaen Eon?
3.8? - 2.5 Ga
Ga stands for billion years ago.
What was the atmosphere like in the Archaen?
Low oxygen
Prokaryotic life includes bacteria and archaea.
What was the Great Oxygenation Event (GOE)?
Increase in atmospheric oxygen around 2.4-2.3 Ga due to biotic and abiotic drivers
Biotic drivers include photosynthesis, while abiotic drivers refer to early atmospheric conditions.
During which Eon did the Cambrian Explosion occur?
Phanerozoic Eon
The Cambrian Explosion marks a significant diversification of life forms.
What are some key features of the Paleozoic Era?
- Ediacaran biota die out
- Great Ordovician Biodiversification Event (GOBE)
- Evolution of amniotes
- Radiation of fishes and jawed vertebrates
- First appearance of reptiles
- Evolution and radiation of grasses
The Paleozoic Era includes significant events leading to the diversification of life.
What is the time range for the Cenozoic Era?
65 - 0 Ma
Ma stands for million years ago.
What life forms dominated during the Precambrian?
Essentially all prokaryotic (bacteria and archaea)
Prokaryotic life was the predominant form of life before the evolution of more complex organisms.
Fill in the blank: The first appearance of most extant phyla occurred during the _______.
Cambrian Explosion
What are some causes of the Cambrian Explosion?
- Rise in atmospheric O2
- Global marine transgression
- Methane ‘burps’
- Accelerated erosion from Transgondwanan ‘supermountain’
- Phyto- and zooplankton radiation
- Predation leading to an ‘arms race’
- Evolution of eyes and color perception
These factors contributed to the rapid diversification of life forms.
What types of organisms first appeared during the Cambrian period?
Macroscopic organisms with no hard parts
The Cambrian period saw the emergence of larger, more complex life forms.
What is the significance of trace fossils?
They provide important information about behavior, movement, and directionality of ancient organisms
Trace fossils are indirect evidence of life, such as footprints or burrows.
What characterizes the end-Permian mass extinction?
Greatest mass extinction event, impacting over 80-96% of species
This event is often referred to as ‘The Great Dying.’
What were the ecosystem impacts of the end-Cretaceous mass extinction?
- Oxygen-depleted environment
- Poorly diverse environment
- Major restructuring of ecosystems
The end-Cretaceous extinction is commonly attributed to an asteroid impact and volcanism.
What is the time range for the Ordovician period?
485 - 444 Ma
This period is marked by significant diversification of life in marine environments.
True or False: The Paleozoic Era includes the development of flowering plants.
False
Flowering plants appeared in the Cretaceous period, which is part of the Mesozoic Era.
What type of tectonic activity characterized the Hadean Eon?
Not much going on: ‘stagnant lid’
Tectonic activity was minimal during the Hadean Eon.
Fill in the blank: The last glacial maximum occurred approximately _______ years ago.
~26,500
What major evolutionary step occurred in the late Devonian?
Evolution of amphibian-like tetrapods from lobe-finned fish
This transition marks a significant step in the colonization of land by vertebrates.
What was the significant outcome of the Great Ordovician Biodiversification Event?
Huge number and increase in diversity of fauna
This event is characterized by the rapid expansion of marine life.
What types of life forms are included in the synapsids?
- Mammals
- Mammalian-like reptiles (therapsids)
Synapsids are a group of animals that include modern mammals and their ancestors.
What are the key features of the Mesozoic eon?
- Evolution of reptiles (including dinosaurs)
- First appearance of birds
- Diversification of mammals
- Appearance of flowering plants (Angiosperms)
The Mesozoic Era is often referred to as the age of reptiles.
What lifeforms are found in the Archean eon?
- Essentially all prokaryotic (bacteria & archaea) - photosynthetic
- Possible eukaryotes
What were the key features of plate tectonics during Archaea eon?
*Not much happening - stagnent lid
* Basaltic continents
What time was the proterozoic eon?
2.5 Ga - 541 Ma
What did higher oxygen levels in the Proterozoic eon allow?
- aerobic organism
- more complex life
- terrestrial life (eventually)
1.2 - 1 Ga
What were the first eukaryotes?
- Oldest: Grypania Spiralis (2.1 Ga)
- red algae
- green algae
Describe plate tectonics during the Proterozoic eon.
*plate tectonics and subductions initiated
* increased felsic volcanism
* less mantle-derived reductants at surface (=02 accumulates)
What is the time frame for the Ediacacaran eon?
635 - 542 Ma
What were the 2 main glacier periods during the Ediacaran eon?
*Mannoan Snowball Earth
* Gaskiers Glaciation
What is the significance of the glacier periods during the Ediacaran eon?
They were huge events that separate the simple microbial world from the more complex life that comes after
What type of life forms were found in the Ediacaran eon?
- macroscopic organisms (squishy, nothing hard)
*organisms with emerging bilateral symmetry
*sea mats
What is the time frame for the Cambrian Explosion?
541 - 510 Ma
Describe the atmosphere during the Cambrian explosion?
Rise in atmospheric 02 (major algal bloom)
What died out during the Cambrian explosion?
Ediacaran biota
What was the Cambrian explosion?
*Abrupt appearance of rapid diversification of metazoans (bilaterians)
*First appearance of most extant phyla
* Evolution of the first complex ecosystems
What are the 4 key features of the Cambrian explosion?
*Colonisation of the water column
*Colonisation of of the sea floor
*Evolution of biomineralised skeletons
*Diversification of feeding strategies and trophic interactions
What is the environmental explanation for the Cambrian explosion?
*Rise in atmospheric 02
*global marine transgression
*methane ‘burps’ resulting in global warming
*accelerated erosion from a Transgonwanan ‘supermountain’
What are the ecological explanations for the Cambrian explosion?
*phyto- and zooplankton radiation
*predation resulting in an ‘arms race’
* ecological niche saturation
*evolution of eyes and colour perception
What is the developmental explanation of the Cambrian explosion?
*evolution of development genes
What is the time period for the Ordovician eon?
485 - 444 Ma
What is the Great Ordovician Biodiversification Event (GOBE)?
Huge number and increase in diversity of fauna
When was the End-Ordovician Mass Extinction?
~445 Ma (in 2 pulses separated by 3.5 My
What was affected by the End-Ordovician Mass Exctinction?
> 25% families
60% genera
85% of species
What were the impacts to the ecosystem following the End-Ordovician Mass Extinction?
*No collapse of ecosystem structure
*No extinctions of major groups, although graptolites and conodonts were hard hit
What time was the Silurian - Devonian eons?
444 - 359 Ma
What 2 radiations were featured during the Silurian - Devonian eons?
*fishes (+evolution of jawed vertebrae)
*amphibian-like tetrapods (linked to the colonisation of land)
*land plants (+first vascular plants- mosses, ferns)
How many extinctions were there in the Deonian eon?
2x mass extinctions in late Devonian (13 Mt in between)
What time was the Carboniferous - Permian eon?
359-252 Ma
Describe the atmosphere during the Carboniferous - Permian eons?
High oxygen levels (promoted the development of vegetation)
What were the key changes to fauna during the Carboniferous - Permian eons?
*evolution of amniotes
*diversification of seedless and seed plants (coal-swamp forests)
*diversification of insects
*Terrestrialisation of molluscs
What was impacted following the End-Permian mass extinction?
> 50% families
80% genera
80-96% species
What became extinct following the End-Permian mass extinction?
*Trilobites
*Eurypterids
*Some corals
*2/3 of tetrapod families
*8 orders of insects
What were the ecosystem impacts of the End-Permian mass extinction?
*oxygen depleted environment
*poorly diverse environment
*major restructuring (bony fish thrive)
*forests virtually disappeared
What was the likely cause of the End-Permian mass extinction?
- increased volcanism
*formation of Siberian Traps
*formation of Pangea
What thrived following the End-Permian mass extinction?
*microbes
*ferns
What time was the Mesozoic eon?
252 - 65 Ma
What radiations were seen in the Mesozoic eon?
*reptiles (including dinos, pterosaurs, large marine reptiles
* true ammonites
What became extinct during the Mesozoic eon?
Mammalian-like reptiles (therapsids)
What first appeared during the Triassic eon?
Modern corals
What first appeared during the Jurassic eon?
*Modern mammals
*Birds
When was the End-Triassic Mass Extinction?
201 Ma
What was impacted following the End-Triassic Mass Extinction?
> 20% families
50% genera
76-84% species
What became extinct following the End-Triassic Mass Extinction?
*Non-dinosaur archosaurs
*Conodonts
What was the likely cause of the End-Triassic Mass Extinction?
Volcanism
What first appeared during the Cretaceous period?
Flowering plants (Angiosperms)
When was the End Cretaceous mass extinction?
65 Ma
What was impacted during the End Cretaceous Mass Extinction?
> 15% families
45% genera
71-81% species
What became extinct following the End Cretaceous Mass Extinction?
*Non-avian dinosaurs
*Flying and marine reptiles
*Ammonites
What was the cause of the End Cretaceous Mass Extinction?
An asteroid impact + volcanism (may have weakened ecosystems prior to asteroid hitting, make it harder to recover)
What evidence do we have for the cause of the End Cretaceous Mass Extinction?
*The Iridium Anomaly
*Shocked quartz
*Glassy spherules
*Evidence of wildfires
*Both plants and animals affected
*Impact crater (Mexico)
What time is the Cenozoic eon?
65 - 0 Ma
When did the glacial and interglacials begin?
2.58 Ma (ongoing)
When was the ice age during the Cenozoic eon?
125,00 - 14,500 yrs ago
When was the last glacial max?
~26,500 yrs ago
What radiation was noted during the Cenozoic eon?
Grasses
What key fauna changes were noted during the Cenozoic eon?
*Diversification of mammals
*Birds
*Flowering plants
*Pleistocene megafauna (adult body size over 45kg)
