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213 Cards in this Set

  • Front
  • Back

Relative dating

Getting geological events in the right order. Looking at strata

Superposition

Oldest strata will be at bottom, youngest on top

Law of horizontality

Strata is deposited in layers that are parallel

Law of original continuity

Law of horizontality continues over lateral distance, if not disturbed

Boundary

Between geological units

Unconformity

When a "time period is missing" between strata in a geological section.



Disconformity

Type of unconformity. Erosion between sedimentary strata

Non-conformity

Type of unconformity. Sedimentary rocks deposited on eroded metamorphic/igneous rock.

Angular unconformity

Type of unconformity. Sedimentary strata is deposited on tilted and eroded layers



Absolute dating

Measuring radiometric data. You measure radioisotopes in fossils to get an exact date.




Compare radioisotopes with amount of gatherd decay.




Volcanic ash beds are important, contains zircoins.

Continental drift

How the continent moves. proposed by Alfred Wegener 1912

Alfred Wegener

Proposed continental drift on following "evidence" 1912


1. The fit - continents visually fit together


2. Distribution of fossils - Gondwana contains Mesosauros and Glossopteris


3. Ice flow FROM center of gondwana


4. Continuation of mountain belts across present oceans




Rejected because he couldn't think of a mechanism.

Mesosaurus & Glossopteris

Evidence for continental drift. Fossils found on different continents of animals that couldn't have moved over oceans

Geophysical evidence for continental drift

Mid ocean ridges, paleomagnetics, No ocean crust older than 200 ma - older further away from mid ocean ridge

Mid ocean ridge

Underwater mountain ridge, ocean spreading center, seafloor spreading, plate spread + mantle upwelling




No ocean crust older than 200 ma - older further away from mid ocean ridge

Paleomagnetics

How continental plates move

Continent - continent collision

Continents collide and that produces mountains, ex south asia and india collided and formed himalayas

Subduction zone

Where one plate is forced under another, ex pacific plate subducting western south america to form Andes

Nuna

Supercontinent (all continents) 1800 MA to 1500 MA. Proterozoic

Rodinia

Supercontinent (all continents) 1250 MA to 750 MA. Proterozoic.

Pangea

Supercontinent (all continents) 300 MA - 200 MA. Between Paleozoic and Mesoic.

Gondwana

Megacontinent (not all continents) 540 MA - 142 MA. Paleozoic and almost whole Mesozoic

Rift valley

Low land between mountains, begins breakup of continent

Wilson Cycle

How oceans are formed:


Transitory features created when a mega/super continent breaks up. Dissapears when continents collide.




Takes 100 ma years. Continents collide, then break a part forming oceans



Nucleotide

Organic molecule, subunit in a nucleic acid

Nucleic acid

"Biopolymers" essential for all life - RNA, DNA

DNA

Molecule dontaining genetic instructions on Growth, development, functioning, reproduction

RNA

Polymeric molecule essential for coding, decoding, redulation, expression of genes

Gene pool

Total amount of genetic info coded on all individuals in a group. Species who reproduces sexually reshuffles gene pool - this is what keeps evolution going

Mutation

Change in one or more nucleotides in DNA. Innovation: Most likely small and harmful. If beneficial -> enhanced by natural selection

Natural selection

Survival of the fittest, individual best suited for hunt for food, living space, mating, avoidance of predators will survive and pass down their genes




Pepper moth: speckled, 1880 industrial revolution, black, 1960 clean air act, 50/5




Darwin's finchers: one species to galapagos, evolved into 14 different ones




DIRECTIONAL - eliminates bad genes and enhances beneficial

Anagenesis

Mutation, Continued evolution until the species unconsciously becomes a new one, replacing the other

Cladogenesis/divergence

Splitting of on species in to two

Convergence

Opposite of cladogenesis/divergence: Similar life, similar environment will evolve similar morphology even though they are not related

Analogous convergence

Opposite of cladogenesis/divergence: Similar life, similar environment will evolve similar morphology even though they are not related




Functionally similar traits,


sabre tooth: for cutting chunks of flesh from prey leaving them to bleed to death. evolved separately 5 times.

Homologous convergence

Opposite of cladogenesis/divergence: Similar life, similar environment will evolve similar morphology even though they are not related




Common origin but not similar function

Co-evolution

Evolution as a response to change in environment. arms race and mutualism

Arms-race

Co-evolution: Race between predator and prey. Faster, hunting strategies, powerful, camouflage, poison and so on

Mutualism

Co-evolution: Mutually beneficial, nectar - insects. berries/nuts - birds = polination and seeding

Red Queen Effect

The world is changing around you, evolve or go extinct

Court jester effect

Factors outside of the animals control also shape evolution

Species

2 million species described.


Animals 1 1 600 (insects 80%)


Plants 270 000


Fungi 72 000


Algae 40 000


Bacteria/archae 4 000


Viruses 1500

Phylogeny

Mapping of organisms according to evolutionary relationsships. Shown in a Phylogeny Tree. Based on similariteis/differences in physical or genetic characters

Phylogeny tree

Diagram that show a species phylogeny

Organelle

Subunit in cell that has a specific funtion, tiny organ. Ex: Nucleus (cointains DNA)

Nucleus

Organelle, contains DNA

Eukaryote

Unicellular or multicellular. DNA in Nucleus, contains organelles

Prokaryote

Unicellular, no nucleus or organelle, bacteria and Archaea

Linnean classification

Carl Von Linne 1700, Organized organisms.


Domain/Superkingdom


Kingdom


Phyla


Classes


Orders


Families


Genera


Species

The three superkingdoms/domains

A) Bacteria - normal prokaryotes


B) Achae - extremophile prokaryote


C) Eukaryotes - All eukaryotes

Eukaryote 4 kingdoms

1. Protoctista - unicellular


2. Fungi - multicellular, non-motile


3. Plantae - nutrients, multicellural, non-motile, photosynthesis


4. Animalia - Multicellular, motile

Motile

Organism moves and consumes energy in process

Cladistics

How we know which animals to put where. Method in which you divide organisms into brances (clades) depending on evolutionary connections.

Will Henning

First cladistics guy, 1950

Clade

Group of organisms who share same characters (morphological and molecular). Ancestor and all species descendant from that ancestor

The three sets or morphological characters

1. Primitive - from ancestor


2. Derived - first appear in the clade


3. Convergent - similar features in unrelated organisms

Cladogram

Tree that shows evolutionary appearance of derived characters

Strengths of cladistics

1. Rigorous and testable


2. Can be used at any level of taxonomy


3. Can include fossil and living species in same cladogram


4. Shows sibling (not ancestor-decendant) relationships

Molecular phylogeny

Measures genetic differences. Francis Crick.




Measures degree of substitution in DNA, RNA and Protein

Molecular clocks

Technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. Timing of these are controversial

Strengths and weaknesses of molecular phylogeny

Str:


1. Rigorous and testable


2. Can be used at any level of taxonomy


3. Directly measure genetic differences




Weakness:


1. Can only be used in modern fossils. except if fossil is preserved in amber

Molecular Phylogeny and Cladistics

Poweful tool to unravel history of life

Fossils

Remains of ancient organism. More than 5000 years old.




Organisms remains or traces



5 categories of fossils

1. Bones - phosphate much mor resiliant than soft bodies.


2. Shells - invertabrates, carbonate and silica


3. cellulose - plants, wood can become pertrified by silica (quartz). carbonized into coal


4. Trace - tacks, burrows


5. Soft tissue - harder to find coz bodies disapear easier than bones. lagerstätten fossil collections. Amber also

Fossilization

Taphonomy. Quicker burial the better.

Archean World

1. No continents, volcanic islands


2. Faint new sun - 80 % power


3. Volcanic atmosphere - No oxygen. co2 500x todays level


4. Stromatolites

Synthesesis of life

1. Formation of simple organic compunds. Miller urey experiment


2. Simple organic compounds to complex. NOT SOLVED


3. Initiation of replication. Spiegelman Monster

Miller-Urey experiment

chemical experiment that simulated the conditions thought at the time to be present on the early Earth - solved issue 1 in synthesesis of life

Spiegelman Monster

is the name given to an RNA chain of only 218 nucleotides that is able to be reproduced by the RNA replication enzyme RNA-dependent RNA polymerase, also called RNA replicase. Solved issue 3 in synthesesis of life - initiation of reproduction

Where did life evolve

Theory: Hydrothermal vents.


1. Not affected by bombardment of meteorites 3,8 ga


2. Wide range of temperatures needed(-1 to 100) for chemical reactions


3. Extremeophiles root of universal tree of life

Oldest life

Pilbara Craton Western austrailia. more than 3 ga old


Barberton south australia more than 3,4 ga




1. Stromatolites, greatest abundance proterozoic


Oldest from Warrawoona in pilbara craton




2. Organic microfossils - unicellular organisms


Pilbara craton microfossils formred in submarine hot water springs

Great oxidation event

Oxygen increased 100x to 5% of todays levels




ca 2300 ma - between 2400 and 1800 ma - Nuna around same time




Why: Cyanobacteria produced o2 through photosynthesis




Effect:


1. BIF dissapeared


2. Red soils appeared


3. co2 decreased - led to first ice ages


4. Ozone layer formed (o3)


5. First fully aerobic metabolism

Gunflint chert

North shore of lake superior. Most important and famous early proterozoic fossil locality



BIF

Banded Iron Formation. Units of sedimantary rock that indicates that iron was in a reduced form in the oceans (stage 1, 4600-2400 ma)

faint new sun paradox

Archean world: sun at 80 % but temperatures still high. Explanation: co2 levels 500x todays levels - green house effect kept earth warm.

Early prokakryotes used what to "breath"?

Nitrate, sulphate, carbon dioxide - did not utilize oxygen

Anaerobic

cannot tolerate oxygen

Amphiaerobic

Used o2 if avalible, otherwise anaerobic

Aerobic

Uses oxygen for metabolism, 18x more effective than anaerobic

Stages of oxygenation of earth

1. 4,6-2,4 Iron ocean. reduced iron in oceans


2. 1,8-0,6 Canfield ocean. some free oxygen in shallow oceans, deep oceans still no oxygen.


3. 0,6 -> modern oceans. Atmosphere, shallow and deep oceans are all oxygenated

Endosymbiosis

Theory of evolution of eukaryotes and prokaryotes. Eukaryotes evolved by prokaryotes joining together in symbiosis. Containing:


1. Fermenter cell - host


2. Purple bacterium - ancestral mithocondrium


3. cyanobacterium - ancestral plastids

Steranes

Eukaryote biomarkers, signs of eukaryotes. Early 2,7 - controversial evidence of life:


1. Acritarcs 1600 ma eukaryote microfossil


2. Carbonaceous compressions: 2,1 ga MAYBE. 1,6 ga definitely.


3. Fossil red algae 1200 ma. green algae


4. testate Amoebans (first heterotrophic - predator/scavanger)

Greenville mountains

Records the collision that produced Rodinia - Set up for Ediacaran Biota


Biota

The plant/animal life of a region

When life got big

Neoproterozoic. around around 580 ma. After gaskiers glaciation

What happens when glacials melt

Increased biological complexity

Oxygen events are connected to what

ice ages

Describe end of proterozoic

Tumultuous


rodinia breaks up


Severe global ice ages


major change in sealevel and isotopes in water

The three massive episodes of Neoproterozoic glaciations:

1. Sturtian Glaciation - 715 ma. Sponge biomarkers, simple, first to evolve


2. Marionoan Glaciaiton - 635 ma. Microscopic animals.


3. Gaskiers glaciation - 580 ma. Ediacara biota - first large eukaryotes - when life got big.

Mistaken point

In newfoundland. Contains oldest ediacaran fossils. 580 ma old. 2 ma after gaskiers.



Rangeomorphs

Fractal formed creatures. extinct clade - the ediacaran experiment.




Suspension fed - filtering chemicals from seawater (osmoptrophy)

Ediacara Australia

younger assemblages of fossils 560-550 ma ediacara biota

Namibia and British columbia

550 - 541 ma - first shelly fossils found



Ediacara biota - what was it?

First animal eco-system! Major extinction at the end of proterozoic - led to beginning of cambrian explosion of animals






Older theories


"dawn of animal life" - the ediacaran animals had similarities with later life




Dolf seilacher - proposed that ediacaran clades died out - failed experiment




New:


"Both right


Extinct clades, most ediacaran fossils cannot be related to any modern animal


Stem group - some may have been ancestral taxa that evolved into ex arthropods

Big bang of evolution

Early cambiran, most profound & rapid diversification event

Crown - group

Clade

Sponge

Appeared early cambrian, Easy simple animals, just cells that attach to eachother

Sclerites

Spines that armour body

Cambrian skeletons

Sponges, small shelly fossils, Brachiopods, Trilobites, Echinoredmata and chordata

Cambrian brains

Ediacaran burrows were simple horizontal


Cambrian burrows shows evidence of complex patterns:


- Comlpex patterns


- Vertical dwelling burrows


Systematic meandering burrows

Burgess shale

Field British COlumbia


One of the most important lagerstätten of all time


Info: soft bodied and soft parts of skeletal animals preserved


Stem group arthropods


Predators! Opabina and anomalocaris

Anomalocaris

Top cambrian carnivore.




Misidentified as seperate fossils first, shrimp, jellyfish, some kind of teeth looking thing




Was in fact one animal. Big compund eyes, brain

Cause of cambrian explosion

1. Higher oxygen levels allows formation of collagen, exoskeleton, high oxygen, favours predatord




2. Ecological feedback - arms race

Agronomic revolution

Part of cambrian explosion. From only on bottom to swimming, on bottom, under bottom. form 2d to 3d

First life: Collagen

Protein molecules holding cells together. Sticky tape of life. Most comon protein in our body. Oxygen needed to produce.


Oxygen event -> ability to produce

First life: Rangeomorphs

Protoanimal - body built up by fractals.


did not evolve


Mistaken point

First life: What attributes does the 550 ma australian fossils have that the rangeomorphs didn't?

They could move

First life: Sex, what evidence, why important?

Colonies of animals were found. one colony one size, other colony other size. suggest that they reproduced and spread the same genes among them.



To evolve with changing environment you need to reshuffle the gene pool


First life: What caused carboniferous oxygen event? Effect?

Forest with many plants - photosynthesis




Enabled animals to grow very big

Supercontinent cycles and climate

Supercontinent cycles coincide with glaciations


Cycles seem to control climate


BReaking up 0 ice age

Greenhouse - ice house - cycles

HUndreds of millions of years, CO2 as driver




Greenhouse: Warm conditions over much of earth, high sea




Icehouse: Cold conditions, low sea levels, ice sheets, ice-covered poles

Three main ways of measuring global temperature change



1. leaf analysis


2. Oxygen isotope analysis


3. Community analysis (look at animals/plants living at that time/area)

Al Fischer

Greenhouse/icehouse cycles guy



Fossil Forest

Axel heiberg island canadian arctic


Mummified forests with trees and leaves perfectly preserved


Aligators, turtles etc - indicates warm climat



Milankovits Cyclicity

relates to changes in obliquity (tilting) precession (wobble, and eccentricity of earths orbit



Sepkoski

Divided all Phanerozoic marine animals into three overlapping evolutionary faunas



Three Evolutionary Faunas

1. Cambrian fauna


no hard bodies, trilobites, archaic molluscs, echinoderms, brachiopods


armoured mudgrubbers




2. Palleozoic fauna


Armoured filter-feeders and pelagic predators (ordvician)


ecological tiering


Cephalopod top carnivore




3. Modern fauna


Gastropods, bivalves, crustaceans, echinoids, bony fish.


Less armored adn more mobile than their eqvuvalents in Paleozic fauna

Why was the modern Fauna mor mobile and amored compared to the Paleozic Fauna?

a) Predation - mobile svimmers, enhanced ability to drill, crush, break shells




b) Biological bulldozing


Depth and amount of burrowing increased, burrowed up to 1 m depth


Not good for filter feeders

Classification of extinctions

1. Major: More than 50 % familiy extinction; permian




2. Intermediate: 10-50 % familiy extinction; ordvician, Devonian, Triassic, cretaceous




3. Lesser: 3-10% family extinction; several

What followes a mass extinction?

Burst of evolution (RADIATION) into unfilled niches


Mass extinctions is probably equal to natural selection in controlling the evolution of life on earth

Paleobiography

Biographic provinces are areas with distinct biotas.




High temperature area = more species




Low temperature area = less species




Larger are = more speceis

Simpson Similarity Index

Measures degree of similarity between two biographical provinces - increases as continental plates gets closer and decreases as they move a part.

Kingston in ordvician, 3 steps

1. Tidal environment (oldest)

Lower part of rock section


Broad supratidal and intratidal flats


few modern organisms can stand these conditions


abundant stromatolites




2. Tetradium Thicket


Fringinf reef attached to shoreline


Coral Tetradium


filter feeders




3. Subtidal sea-floor


Ideal environment for animal and algal life





Sea level in ordvician + warm shallow seas

Extremely high. almost all north america covered in warm shallow seas - Epeiric seas


From what "sea plant" was land plants probably derived from?

Green Algea

Which plant dominates terrestrial life?

Empryophytes (bryophytes + vascular plants)

Bryophytes

Mosssa, thin walled, water dconduction cells - no xylem. Needs a lot of water. Waxy cuticle

Vascular plants

more advanced than Bryophytes


Xylem


Phloem


Intercellular gas transport tubes

Xylem

elongate dead cells taht form upwardly-directed pipes for water flow

Phloem

Elongate cells that transport sugars made in photosyntesesis to roots and stem

Intercellular gas transport tubes

brings o2 to roots and co2 to leaves

When did first plants on earth?

ordvician

Early paleophytic floras (devonian and earlier)

1. Rhynophytes




2. Trimerophytes




3. Lycopods and PRogymnosperms

Rhyniphytes - where?

Rhynie Chert in Scotland

Type of trimerophyte?

Psilophyton

Lycopod

Leaves present, small and narrow


first appear in Devonian, dominate carboniferous


trees up to 50 m, good roots

Progymnosperms

Fern liek leaves, secondary xylem = wood)


10 m tall trees

Early Paleophytic forests - were?

Gilboa in the Catskills of New York state


Proymnosperms, lycopods, fern, horestail


poor root system - floodplains with semi-permnantn water

Late Paleophytic floras


Upper paleozoic and Triassic AGE O PLANTS


Lycopods and fern

Fern

spore bearing, feathery leaves

Seed fern

First gymnosperm - plants bearing a naked seed


Glossopteris

Effects of evolution of land plants:

1. Binding loose sediment by plant roots permanentely changed pattersn of erosion and sedimentation on the continents

2. Firt appearance of a new type of river - meandering


3. First appearence of a new rock typ - coal


4. Altered carbon cycling - MASSIVE DRAWDOWN OF CO2 = end of greenhouse cycle


5. PErmanent rise in oxygen in atmosphere


6. Permitted origin of terrestrial animals


Osteichthyes

bony fish, 95% of 19,500 living species of fish

Agnatha - origin of fish

Jawless fish - earliest type of fish


Early cambrian Craniated from Chengjian lagerstätten - imply that boneless fish arose early cambrian explosion


Fish was uncomon throughout ordvician - major radiaiton in Silurian


Slow, bottom grubbing fish - definitely not top carnivore YET





ORIGIN OF TETRAPOD

four limbed vertabrates - descendants are amphibians, birds, reptiles, mammals




COllision of europe and NA in devonian produces mountain belts, complec mountains, lowlands, rivers etc


Earliest evolution of terrestrial vertabrated occured in this interface bewtween fresh water, the land and the sea




Earleist tetrapods were primitive amphibians

Age of fishes

Devonian

Vertabrate origins

Chordate closely related to echinoderms


2 chordate like phyla on the way to fish: Urochordata and Cephalochordata



Gnathostomes - jawed fish four main groups

Achanthodians - first jawed fish, agile filter feeders, few predators



Chondrithyes - sharks, first appear devonian




Placoderms, heavy external armor, devonian, some gigantic (6m)




Osteichytehs jawed bony fish, devonian, dominant of modern seas, lakes , rivers


Lobefins very important in devonian


Rhipidistians an extinct griup that evolved into tetrapods



Paleozoic amphibians (leaving the water)

Earliest tetrapods primitive amphibians


late devonian


Carniverous

Early reptiles - one important change that made colonizing land possible

Development of cleidoic egg (closed) permitted true colonization of land

Amniotes

Reptile, mammals and birds

Threemain groupings of amniotes based on number and position of fenestrae (holesother than orbits and nostrils) temporal fenestrae (fenestrae means window)

Anapsid: No fenestrae (earliest reptiles)




Synapsid - one fenestrae (mammal like reptiles and mammals)




Diapsid - 2 fenestrae (most modern reptiles, dinosaurs, birds)

How was synapsid and diapsid conditions derived?

from anapsid reptiles in the late carboniferous

earliest stem group repitiles, what and where?

350 ma from sctoland, "Lizzie" - anapsid


Earliest true reptile from joggings Nova Scotia


Hylanomus

"Sail" on pelycosaurids

Dimetrodon, early Permian Reptile used sai for heat regulation by facing it into or against the sun - sail filled ith blood vessels



Pelycosaurs replaces by what?

Therapdis, mammal like



What are therapdids thought to had evolved?

Thermoregulation (ability to produce their own hear and control their body temperature)




Evidence suggest that they atleast were partial endotherms (creating own heat - ex when we eat)


1. Pits for insertion of bristles whow that they had hair


2. Therapdids lived in cold places - no modern cold blodded reptiels are able to live in these climates



The great dying what, when and why

Late Permian MAJOR mass extinction


End of Paleozoic Eon


57 % families


95 % Species


Filter feeders got hit the worst


Corals extinct for 20 million years


Trilobites, several bryozans, cephalopods extinct




Terrestrial vertebrates - 75 % families




Less effect on terrestrial vegetation




WHY?


Extreme oceanic anoxia followed by sudden release of CO2


Same age as SIberian Traps (big volcanic deposit)





How did the ecosystem recover after the Permian Extinction_


1. Lower Triassic Lag phase (9 ma)


low biomass, low numbers, low diversity


Distaster biotas (abundant marine stromatolites and terrestrial weeds common)


Simple community structure




2. Middle Triassic Rebound Phase 15 ma years


Increas biomass and dieversity


Lazarus taxa (taxa same as pre-extinction)


Elvis taxa (convergent with pre-extinction)




3. Upper Triassic Expansion phase


New evolutionary innovation on land - dinosaurs and mammals, sea and air

The Triassic Takeover


1. Amphibians, Paleozoic amphibians extinct, replaced by modern amphibians, frogs.




2. Marine Reptiles


turtles, pleisiosaurs, ichthyosaurs




3. Terrestrial Diapsid Reptiels


Archosaurus in middle-late Triassic


SPRAWLING POSTURE

Carrier's Constraint


All amphibians, Paleosoic diapsids and living lizards had a sprawling posture. They cannot run ant breath at the same time, every step constricts the works of one lung, next step constricts the works of the other side and so on




Short burts of speed, ambush tactics


What freed the archosaurs form carriers constraint?

evolution of semi-erect and erect posture
Theodonts and posture


Archosaurs that utilized all three postures (sprawl, semi-erect, erect)




Parasuchids


Crocodiles




Other bramch led to 3 groups woth erect posuter INCLUDING DINOSAURS

Oldest dinosaurs, when?
early, late Triassic EORAPTOR - chicken to osrich size, theropods

End Triassic extinction

Massive volcanism, elimitad ornitosuchian diapdis and most synapids




marks the beginning of age of dinosaurs

Dinosaur


First appeared beginning of late Triassic. Dominant land animal of Jurassic and Ctetaceous


Largest land animals ever lived



How do we investigate how dinosaurs were so big yet could still move? and how fast?

Comparative anatonomy and dinosaur footprints
Undertracks

impressions of footprint preserved some distance below actual track
Relative stride length

length of stride / length of leg
How fast were dinosaurs travelling?


most ambling speeds at 2-5 km




Faste speeds are shown in dinosaur stampede at Winton Queensland




small dinos race at 11-20 kmh




Some show speeds up to 43 kmh

Homeotherms

are able to maintain a constant body temperature. Most homeotherms area endotherms and/or gigantotherms

Heterotherms

allow their body temperature to vary widely depending on external factors. Heterotherms are ectothermic

Ectotherms

invertabrates, fish, amphibians, reptiles. recive their body heat from an external source. Hiding in the shade or basking in the sun are their main methods of decreasing or increasing their internal temperature. Ectorherms are favoured in warm climates

Endothersm
placental mamals, birds - produce heat to regulate their internal temperature. endothermy has a high energy cost but permits sustained exterion and function even in cold conditions. Favoured in temperate and especiall cold climates

Partial endotherms

monoremes, produce their own body heat. but are not able to fully overcome the effects of external temperature changes

Internal homeotherms (= gigantotherms)

large animals who maintain a constant high body temperature simply by the virtue of teir large size. Note that mass (=heat production) rises as the cube diameter, but the surface area (=heat loss) only rise as the square. therefore any animal in excess of one tonne will experience giganothermy (eg adult tuna, great white, some turtles)
Dinos warm or cold blooded: Bakkers evidence

Says dinos were endotherms because:


1 Predator/prey footprints


2. Gigantotherms and partia lendotherms requires far less energy - t rex 5 good feees/year


3. Upright posture


4. Running speeds


5. Polar dinosaurs




Dinos warm or cold blooded: Modern evidence

1. plates and frills


2. Oxygen isotopes


3. Bone microstructure


4 Nasal rubinates


5 feathers -


almostcertain that the origin of feathers was for insulation, implying that thesedinosaurs were at least partly endothermic



which three vertabrate groups evolved powered flight?

Pterosaurus, Birds, Bats

What flora dominated carboniferous and Permian landscapes?

Paleophytic flora, ferns lycopods



What flora dominated triassic and rest of mesozoic

Mesophytic flora

The mesophytic flora

DOminated by gymnosperms, trees 60m high


early conifers (pine osv)


Cycads (palm like leaves)


Ginkgo important gymnosperm



What flora dominated middle cretaceous to present?

Cenophytic flora

The Cenophytic flora

Dominated by angiosperms


strong reliance on vector pollination and seed dispersal - attract insets to carry pollen


COEVOLUTION ANGIOSPERMS AND ANIMAL VECTORS



Angiosperm

Dominant plant group today, floweringplants, seeed enclosed in tough outer coat, changed dinosaurs story, grass, magnolia

Traits of the Mesozoic marine life

Filter feeders replaced by modern fauna: gastropods, bivalves, corals, bony fish


Rudist reef builders


Ammonites - coiled cephalopod


Belemnites




OCEANS DOMINATEd BY LARGE MARINE REPTILES

Sauropterigians

Jurassic and Cretaceous, large marine reptiles that solved carriers constraing in water


1. Ichtysaurs


2. mososaurs


3. pleidosaurs

Cynodont

Most advanced therapsid


mammal ancestor

Evolving mammalian characters in the skeleton included MAMMALIAN INNOVATIONS:

1. increasingly complex teeth and tooth replacement


2. reduction in the bumber of bones in lower jaw


3. simultaneous increase in the number of bones in the inner ear


4.fully uppright stance


5. increase brain size


6. full thermoregulation


7. live birth


8. milk production



Morganucodontids

early stem-grou of mammaliformes, late triassic


shrew to mouse sized

Monotremes

"protherians" fur covered partial endotherms, originated from Gondwana and has been restriceed to gondwana ever since

THerian mammals

Marsupials(pouch) and placentals (delivers fully operational offspring)

Most common mesozoic mammals

Multituberculates


similar to modern rodents, extinct early tertiary

THerians

marsupial and placentals originated in northern continents in the Jurassic or Cretaceous

Where was the largest mammal of the Mesozoic found? how big was it?

inside dinosaurs stomach, racoon sized

Cynodonts - traits

poor offaction and vision


insensitive hearing


lack of fine motor coordination

Stem-group mammals - traits

brain 50-100% larger than cynodonts


larger olfactory bulbs and vertebral hemispheres


better smell and feel because burrowing

Crown group mammals - traits

further brains size than stemgroup



The terminal cretaceous event:

End of mesosoic 65 ma


17 % familiy extinction (fifth largest)


DInosaurs, Pterosaurs and marine reptiles went extinct




1. Volcanism - Deccan Traps shows huge volcanic movement at same time


2. bolide impact - meteor: crater 80 km, dust cloud bloc ksunlight, heatblast then cold winter


Walter Alvarez reported iridium anomaly




Yucatan in mecixo crater

Factors that control susceptibility (mottaglighet) to mass exinctions

1. size no animal över 25 kg has sruvived


2. Climate tropical and reef highly vulnerable, polar biotas less affected


3. Evolutionary niche - specialized = vulnerable. generalists and burrowers are less effected

Dinosaur reign

Appeared in late Triassic, dominated through rest of mesozoic and went extinct in cretaceous 165 ma years.





What dominated the permian world

Synapsids, especially therapids - first animal to achieve partial thermoregulation



When did mammals increase in size and by how much

1000 fold in early cenozoic when dinosaurs went extinct

Eocene life - which fossil forrest exemplifies?

sea mammals evolved, and most modern orders of mammals MESSEL fossil forest in germany

Mammalian top carnivores

1. Mesonychids bizarre ungulates (andrewsaurchus) - largestcarnivours land mammal ever analogous to grizzly


2. Creodonts, small ferret-cat-dog sized


3. true carnivore evovle in eocene

The Miocene Savannah

Kept in check by grazing and browsing organisms


eat top parts of foliage


encourages sideways growth




Grazers:Thesize and diversity of the grazers were both similar to those of today, but inthe Miocene consisted almost entirely of early horses (modern grazers areantelope and zeras)- Browsers:most ecological roles filled by similar but mostly unrelated species (eglong-necked camel filled the role of modern giraffe as top browser)-


MixedFeeders: A similar array of different sized mixedfeeders, but dominanted by camels rather than antelope in the Miocene.-


Carnivores: Asimilar array of stabbing (sabre-tooth “cats” vs lions, leopards, and othertrue cats) and bone-crunching (bear-dogs vs hyenas) predators. Onlyswift-running pack hunters (wild dogs) seem to have been absent from theMiocene Svanna.

Evolution of horses

To orders of hoofed mammals (ungulate) in eocen 1. Artiodactyls (sheep, deer, cows) 2. Perissodactyls (horses, rhinos, tapirs)




Miocene age of horses

Ungulate

hoofed mammal

Afrotheria

early clde of mammals, evolved in africa and includes all modern elephants ,sea cows, hyraxed and aardvarks

Xenarthra

Early clade of mammals, evolved in south america includes sloth, armadillos, anteaters

Early hominins

In africa,






1. Sahelantropus 6,5ma


single skull that exhibits chimplike and human like features




2. Ardipithecus


Complete female skeleton "ardi"


was a faculative biped, who was equally adept on the ground or in thetrees


palmigrade climbing was later modified into "knuckle walking" and "tree swining"

EARLY HUMANS Australopithecines

Taung Child found by Raymond Dart south africa


2,5 ma old subdivide into gracile and robust


G:

EARLY HUMANS HOMO and their tools

1. homo habilis 2.3-1.6 ma Oldowan tools


2. Homo erectus 1.8-0.3 ma Acheulean tools


3. Neanderthal 150.000 - 30.000 bp Mousterian tools


4. early homo sapiens 140-100.00 bp. Aurignacian tools