SECOND HALF OF COURSE
Ages
•Precambrian Age of bacteria
•Paleozoic = old life Age of invertebrates
•Mesozoic = middle life Age of Reptiles
•Cenozoic = recent life Age of Mammals
The PALEOZOIC : summary of main events
542 – 250 m.y.
•Lots of shallow water (snowball had melted)
•Appalachians in North America formed
•Continents drift & combine to form Pangea
•Unique environment in the Carboniferous: immense tropical forests that turned into coal
•Widespread deserts in the Permian
•Skeletons formed (there was enough oxygen)
•“Explosion” of invertebrates (Cambrian explosion)
•First fish, first amphibian, first reptile
•Land plants, insects
•Largest Mass Extinction on record (“Permian Death” or “The Great Dying” ) at ~ 250 m.y.
Environment
•Shallow water: good place for life, soft bodied animals picked up O2 & CO2, Ca 2+ from erosion to form skeletons
•Protection against predators
•Their skeletons formed limestone
•Previously plants manufactured their food from a gas (CO2) in the air
•Now animals use O2 from plants to break up their food – very convenient
•Sedimentary rocks form in shallow water from sediment transported by water/wind
•Sand is no longer pure quartz
•Shale in deeper water is rich in carbon and O2-poor. No scavengers in deep water
Reefs
•Previously reefs were constructed from bacteria. Now invertebrates added, living in symbiosis with the algae
•Reefs are barriers against waves of the ocean
•The back-reefs are tremendously rich in invertebrates
•If the sea level falls, the lagoon dries up depositing the salts dissolved in the water
Evaporite deposits
•In order of deposition:
•1. halite
•2. gypsum & anhydrite
•3. magnesium salts
•4. The last to form is potash
Continents
•N. America had combined with Europe & Greenland to form Laurentia
•Now, Laurentia + Asia = Laurasia
•S. America + Africa + Australia = Gondwana
•Finally,
•Laurasia + Gondwana = Pangea
•One detail: Florida was added to N. America, it was part of Africa
Videos on “supercontinents” on youtube
•The earth’s continents for past 4.4 billion years
(video probably by a teacher, uses today’s outline of continents, 2 minutes)
. Earth 100 million years from now (has exact shape of old continents, 3 minutes)
Mountains
•The Appalachians were prominent like the Rockies. It is the result of collision of continents. Afterwards, erosion has lowered their peaks
•3 stages:
•Subduction of Iapetus under Laurentia
•Caledonian Mts from subduction of Iapetus under N. Europe
•Result was volcanic rocks & Red sandstone
•Acadian: Baltica collided with Laurentia, uplift & deposition of red clastic rocks on land from erosion (red from iron oxides)
Carboniferous
•A unique environment: widespread forests in N. America & Europe – in tropical climate
•Forests & swamps periodically flooded
•Sea level rises & falls due to glaciation in Gondwana
•Cycles of non-marine deposits: sandstone + coal & marine shale and limestone
PALEOZOIC LIFE
•First skeletons: protection from predators, protection from UV & attachment of muscles
•In Cambrian: 50 % of fossils are trilobites – they lasted 340 m.y.; they have very advanced eyes – with 360 degree view of the sea for protection
•From Ordovician get corals, graptolites, etc
360 degrees view (one of two eyes – picture
First Fish
•530 m.y.: Jawless Agnathids later get extinct
•450 m.y.: Jawed with gills turning into jaws
Placoderms later get extinct
.Cartilaginous : primitive – sharks & rays
. Later, bony fishes appear of two types:
a. ray fins (most fishes) &
b. lobe fins with bones. These turned into amphibians
Video: Life moved onto the Land
Archeopteris, first tree
Early fish developed lungs, vital to jump onto land. Lungfish breaths air, it lives in freshwater
A 360 m.y. old tetrapod from Greenland had 8 fingers. Limbs were not for walking, but pushing logs in freshwater lakes/swamps
Earliest footsteps, 348 m.y. old, in W. Ireland
Placoderm (scary!) – picture
Devonian
The “Age of Fishes”
First time they are abundant
First Land Plants
•Vascular
•First populated along the shores. Soil now can stay on land – kept by roots. This slowed down erosion, nutrients stayed on land. Enough oxygen (O2) in the air (from plants) to form the ozone (O3) layer
•With plants on land, bacteria would stay on land to decompose them, so the insects invaded the land to feast on them. Dragonflies were 60 cm long (giants) & cockroaches 10 cm, etc
Animals
•Fish turns into amphibian to avail of abundant insects – therefore, first amphibians were meat-eaters
•Later, amphibians turn into reptiles – the first 100 % land animals
•Primitive reptiles were Dimetrodon (“sail-back”) & Theraspids, forerunners of mammals
Our babies
•One can see various stages during their development
•Embryo has eyes on the side (fish, amphibian, primitive reptiles), then they move to the front (advanced reptiles, mammals)
•When baby is born is able to float (swim) in water
•Mother’s womb is a bit of the ocean. Last stage before was the chicken egg. Mother has the egg –so to speak – inside the body. Why? For protection
Dimetrodon – picture
New invention in plants
•Gymnosperms
•Female seeds stay on plant while male seeds are spread by wind (hit-and –miss)
•Conifers survive in winter (that is why they were invented)
Manitoba in the Paleozoic
Landmark events
•Searching for the first animal: 570 m.y. South China, embryos in the earliest stage of division
•First steps on land: near Kingston, Ont. 478 m.y. Arthropod trackways in sandstone, ripple marks in a dune, 8 pairs of legs moved in unison (like oars, rather than one after the other), must be on land
•First land walker : Scotland, 345 m.y. tetrapod, amphibian, croc-like
First steps on land: Tetrapods – picture
Walking feet
•First proper walking foot, thought to be in a fish: one limb has complete foot attached with 5 digits, 1 m long
•Has a twist on its bones that allows it to bring its feet forward for walking
•Previously, feet pointed out or back for swimming
•A decapitated chicken runs for a while without the brain (spinal cord regulates the locomotion)- in a salamander diagonally opposed limbs move together
Transformations
•Ocean plants to Land plants
•Fish to Amphibian
•Amphibian to Reptile
•Reptile to Mammal
•Reptile to Bird
•Warm-blooded animals
•Cold-blooded animals
Ocean plants to Land plants
400 m.y.
•Modifications needed:
•Resistant to drying
•Get roots to obtain nutrients from soil
•Ability to transport water from roots to higher parts where photosynthesis occurred
•Respire in air
•Get strong to support against gravity
•First reproduced by spores, which had to go to water to be fertilized
Primitive fish
•No fins, no jaws
•Armor of thick plates & thick scales
•Some are 10 m long, look like armored tanks!
•With time the front gills turn into lungs
Fish into Amphibian
370 m.y.: “Not so Great a Change”
•Fins turn into limbs
•Return to water to lay eggs
•Larvae have gills that turn into lungs
•Thick, scaly skin to avoid drying out
•3-chamber heart to pump blood
•Moved eyes from side to top of head
•Early amphibians had tail fin like a fish
Amphibian to Reptile
340 m.y. “A Major Change”
•Most important: amniotic egg (leathery shell for protection, contains water, shell allows exchange of gases O2, CO2 – it was like a private pool!
•Thicker, scaly skin to protect body against drying
•Primitive had limbs on side, later limbs underneath
•Hind legs stronger
•Front legs lifted off ground later
•Tail as balance
•Cold-blooded first, some prob. Became warm-blooded
•Dinosaurs are advanced land reptiles
•Stronger lungs
Reptile to Mammal
200 m.y.
•Warm-blooded
•Produce milk from sweat glands + suckle young
•Live young (“egg” inside mother)
•Hairy skin to keep temperature
•Complex teeth
•Highly active (high metabolism)
•Separate passages for air & food (so young could suckle from mother)
•Breathing assisted by chest diaphragm
•4-chamber heart
•Typical mammalian string of sound-conducting bone (originally a reptilian jaw joint)
•Large brain / body mass ratio
•The marsupials were primitive mammals – the embryo stays in pouch & suckles
Reptiles to Bird
175 m.y.
•Hollow bones (hard to fossilize)
•Powerful arm muscles to flap wings
•Rigid breastbone + vertebrae
•Keen vision
•Sense of balance
•Landing requires retractable feet
•Flight requires enormous energy (warm-blooded)
•Insulated cover (fur, feathers) to keep body warm
•Wings tucked away (Pterosaurs could not do that)
Warm blood?
•To protect life during the Ice Ages – must have suffered a lot, so decided to make changes
•First it was the dinosaurs who changed
•Later was passed on to mammals & birds
Warm-blooded animals: mammals, birds
•Temperature at 36.6’ C
•Walk upright
•Food intake & rate of metabolism is 2 – 10 X that of cold-blooded
•Production of heat more efficient
•Temperature is maintained by ‘waste’ heat of metabolism
•Bones have blood passages
•Heat retained by insulation (fat, fur, feathers)
•Less difficulty coping with cold weather (shivering produces heat)
•Poor radiators (few degrees higher than 36.6’ C is lethal
Cold – blooded animals:
fish, amphibians, modern reptiles
•Temperature same as the environment
•Legs on the side
•Low food intake & low metabolism
•½ of energy in food is released
•Uses devices like “sail-back” & hibernations
•Low blood pressure
Late Paleozoic plants: - HANDOUT
Group name, features, examples, method of reproduction, height, today
•Psilophytes: most primitive, spores, 0.5 m
•Lycopsids: “scale trees” leaves directly from trunk, Lepidodendron, spores, 30 m club moss
•Pteridosperms: seed ferns, Glossopteris (tongue-leaf), seeds, 12 m, Lowly ferns
•Sphenopsids: Jointed stems, Calamites (reed-like), 12 m, spores, Horsetail, Scouring rush
•Pteropsids, True ferns, spores, 20 m, ferns
•Gymnosperms (means naked seeds): cycads, conifers, Ginkgo, seeds, 30 m, pine, spruce. This was an invention to protect from cold during Ice Ages
Lepidodendron – picture
Glossopteris – picture
Calamites – picture and sample
Formation of coal & oil/gas
•Plants
•Get buried
•Peat, Lignite shallow
•Coal deeper
•Anthracite much deeper
•Below 9 km turn into graphite
•At 150 km turn into diamonds
•Animals
•Get buried & become
•Tar (asphalt) shallow
•Petroleum below 2 km
•Natural gas (methane)
•Below 9 km all are destroyed
Coelacanth: Fish with legs
•A “living fossil”
•Spotted in fishing market by Mrs. Latimer, 1938 in South Africa. No fridges then, soft parts decayed. Expert came 2 months later
•No backbone, empty spine filled with oil under pressure, can swim very deep, low metabolism, needs little food
•Gives birth to live young (200 m.y. before mammals appeared!)
•Observe lobe fins in motion: like walking
•Blue color with blue eyes
•At depth lots of oxygen, can’t survive in swallow water
•The tail is very distinctive, belongs to the primitive fish
•Appeared 350 m.y., closest living relative of the first fish that came ashore to live on land, 360 m.y.
•Rarely found in water less that 200 m deep
•Still air-breathing, 3-lobe tail, 1.5 m long 45 kg
•Covered with white splotches & looks like a sponge (camouflage)
•Several rows of pointed teeth
•Eyes are lined with reflecting cells that enhance vision, sensory system detects weak electric signals emitted by other life forms
•Live young, 5 – 25 babies
Fossil forest underground in Illinois – 4 pictures
Primitive fish: Dunkleosteus – picture
Sturgeon: primitive fish in Manitoba
•No backbone, but a notochord
•First of the ray-finned fishes to appear
•No scales, tail like a shark, lives long & produces few offsprings
•Commercial fishing in Manitoba stopped in 1992
Salt lakes in Saskatchewan
•Manitou Beach, Watrous lake (name from “Waters Work Wonders”, or “doctors” lake)
•You float in the water
•Cures fever, clears up skin eruptions, eases pain for arthritis
•Slightly oily water puts an end to constipation
•From the cured: lumps on skin, then in the lake a burning sensation & they are gone!
Watrous lake, Sask. – picture of a swimmer floating
•A bad paper cut: an hour later could not find it!
•Eczema: stings a bit, but went away
World’s Largest trilobite found in Manitoba – picture
Tyndall Stone – picture
•Quarry north of Winnipeg
•Discovered along CN line
•Building stone for Legislature & the Parliament in Ottawa, then all buildings in Manitoba
Fossils of corals and spiral cephalopods – picture
Paleozoic Metal deposits
Permian Death: mother of mass extinctions
•96 % of marine life gone
•75 % of land life
•Destruction caused by heat?
•Extinct: trilobites, most sea urchins, gorgonopsid reptiles, almost all insects
•Fluid inclusion evidence: too much oxygen in the air
Possible explanation
•Siberian Traps: largest volcanic eruption in earth’s history. Lasted 1 million years. Not violent eruption. Lavas cover an area as large as the USA, 4 km thick, can cover entire planet 3 m deep
•The release of sulfur could bring about an ice age with a 5 degrees drop in temp.
Other evidence
•Traces of complex organic molecules called fullerines or buckyballs. Have a soccer ball structure with 60 atoms of carbon
•Such atoms found in Carbon stars. Could have come with an asteroid collision. Crater invisible today, covered up by lava.
•Life bounced up 80 m. y later & it was more diverse than ever before
THE MESOZOIC: Main events
250 my to 65 my
•Starts after the “Permian Death”
Pangea broke up
•Rise & Fall of Reptiles (Dinosaurs are the land reptiles, also marine, flying)
•Cordilleran Mountains formed
•K-T Extinction at the very end (comet hit?)
Manitoba
•SW part under the sea (part of Williston Basin)
•Mostly shales (deep water) – made of soft clay
•Marine reptiles near Morden
•Crocodile-like reptiles near The Pas (in Sask.)
•Oil/gas deposits from organic remains of marine animals (protozoa, etc)
•Gypsumville meteorite crater formed
3 subdivisions- periods
•Cretaceous: hot climate, shallow water, chalk (microscopic plants) + chert (microscopic sponges), some coal, colder near the end
•Jurassic: shallow water restored from glaciers melting, rifts & volcanoes
•Manicouagan / Gypsumville craters formed from fragments of same asteroid (unique event)
•Triassic: Deserts, Red beds, volcanoes
World maps of the Triassic, Jurassic & Cretaceous – pictures
Mountains
•Cordillera, Andes (thrusting, folding, intrusions, subduction, accretion)
•Other mountains in NE Asia & Antarctica
Mesozoic Life
•Reptiles : Primitive & abundant in the Triassic
Flourish in Jurassic
Slow decline in Cretaceous
. Mammals & Birds: mammal-like reptiles turn
into mammals
small, fossils mostly teeth & jaw
nocturnal, hunt by night, eat insects
feathered reptiles (with teeth) turn
into birds (without teeth)
bird fossils are very rare
Archeopteryx is the first fossil bird
.Invertebrates: cephalopods (ammonites) very
common: best index fossil ever
belemnites also common
modern corals, pelecypods (clams)
replace brachiopods
Archeopteryx – picture
•Plants: cycads, conifers, ginkgos
(gymnosperms) + ferns
New Invention in Cretaceous: Angiosperms
. Insects : ¾ of all animal species
Cycads – picture
Gingko - picture
Gingko leaf – picture
Angiosperms (flowering plants)
100 m.y ago
•New invention in plants
•Have protected seed, need a pollinator
•Before they could start, they signed a treaty with the insects: “I give you food, nectar, you pollinate me” by carrying pollen to a female plant. The insects agreed!
•Later, the insects were joined by the birds
•To attract the insects, they painted themselves & added perfumes. Big competition is on
Later on, the humans
•Copied the plants
•Females paint themselves as well as perfume themselves to extremes to attract the insects, I am sorry, the males
•If you get a bee buzzing at you, it is because you are dressed in bright colors and/or added too much perfume, therefore, you pretend to be an angiosperm plant
So don’t blame the bee
•It is doing its 100 m.y old business activity
•So, be nice to the bee!
•It is not interested in you, you have no nectar
Dinosaurs
•250 – 65 m.y. : Lasted for 185 m.y.!
•Were advanced reptiles
•Modern reptiles: crocodiles, turtles, snakes
•Prob. some were cold-blooded, others definitely warm-blooded (meat-eaters, flyers, those with massive bodies)
•Some were mammal-like
•Early were lizard-hipped (meat-eaters, or plant eaters). Later, bird-hipped (plant eaters)
Facts about Dinosaurs
•Land-only animals
•Reptiles
•Mesozoic only
•Walk upright with pillar-like legs
•Variable size
•Skulls had large holes (muscles)
•Eyes either in front or sides
•No ears (some making sound with hollow beaks)
•Large nasal openings (breath+ eat same time)
•Large heart / lungs (4-chamber heart)
•Long tail (3rd leg) for balance
•Bones had blood vessels (like mammals), but growth rings (unlike mammals)
•Skin has scales (overlapping, waterproof) + color (color does not fossilize)
•In herds, hunted in packs
•Nesting sites, parents brought food to young
•Babies cute (large eyes, small noses)
•Reptiles can’t chew, but later chewing teeth
•Some spike tail or club tail for protection
•Bipeds were active predators & had claws
•Either meat eaters or plant eaters –NOT both
Other data on dinosaurs
•Gigantism during Jurassic: to store food for hard times, defense, heavy bodies generate lots of heat, elongated necks/tails as radiators of heat. Maybe turned into warm-blooded in this way
•Species: about 400. It can take 25 years to dig up a complete skeleton of a large animal
•Sizes: Sauropods, long neck & long tail
Seismosaurus 43 m long 100 tons
Diplodocus 30 m ‘ 100 tons
Brachiosaurus 22 m ‘ 100 tons
………………………………………………………..
Compsognathus 1 m
Plant eaters: 7 – 10 m
Large meat-eaters: T. Rex 14 m tall 7 tons
Social habits
•Small meat eaters: in herds or packs
•Large meat eaters: 1 or 2, scavengers
•Large plant eaters: in herds up to 30 (young in the middle, like buffalo)
•Medium plant eaters: large herds, 100’s or 1000’s. Examples: 80 centrosaurs caught in flood, 400 centrosaurs, 10,000 maiasaurs perished from a volcanic eruption
Nurseries
•Nesting sites used repeatedly with spirally arranged eggs in a pile of rotting vegetation to feed young, Food was brought to the nest. Guarded by adults (baby-seaters)
•In Gobi, Oviraptor died with arms around 20 eggs tucked beneath body to protect against advancing dunes
Evolution
•When dinosaurs emerged (Triassic) Pangea was still there. Dinosaurs looked alike everywhere. By the Cretaceous, each continent has separated & had its own, unique forms, slightly different from other continents.
•Argentina had the largest predator, also the most bird-like dinosaur
Posture
•Not the same as in movies, things change with new finds. For example,
•The tail does not touch the ground (not found with tracks)
•Sauropods could not raise neck much above body
•Sauropods were not submerged in water (to make it easy to carry their massive bodies). The water pressure could make lungs collapse
Feathers
•First used for insulation or courtship
•Later to help fly
•Archeopteryx, the first dinosaur with feathers – he was only a glider
Brains
•Small meat eaters relatively large brains – need to organize hunting strategies
•Velociraptor had almost human intelligence & was about human size (largest brain relative to body weight)
•Next in brain the large meat eaters (T.Rex)
•The plant eaters the smallest brains by comparison
Teeth – chewing
•Reptiles can’t chew
•First plant eaters (sauropods) cut food with meat-eating teeth, swallowed & needed large ‘grinding mills’ to break down tough plants (gymnosperms)
•When angiosperms appeared with softer leaves, chewing dinos developed
Claws
•Raptors had claws on forelimbs to cut flesh
•Speed:
Large sauropods were slow walkers
Medium plant eaters ambled most time
Medium-size predators were capable of
40 – 50 km/h
Notes on specific types
•Stegosaurus: plates on back for heat regulation & spikes on its tail for protection
•Armored Ankylosaurs: only ones with bone separation between air / food passages (like mammals)
•Triceratops: beak like shears would cut bark of tree. Massive grinders at back of mouth reduced plants to pulp!→ the Most powerful chewing device ever!
•Duck-billed Hydrosaurs –”sheep of the Mesozoic”: most successful herbivores, up to 2000 teeth in the back, colorful crests up to 1m high, bigger nasal bones, acute smell, air passages producing sounds, like bellows, grunts & honks
•Bone Heads: separate air & food passages (like mammals), muscular cheeks
•Therapods (large meat eaters): not active hunters, speed about 7 km /hr, teeth like steak knives, ideal for inert meat, not living flesh, small hands to pull flesh from between teeth & help animal get up
Fight – to – death
•In Mongolia: Velociraptor’s right arm caught in the mouth of Protoceratops. The raptor’s slashing claw is stuck in its prey’s neck at the carotid artery
•In Antarctica: crested carnivore, in its mouth 2 long, thin rib bones of unknown species. Choked to death on its last meal
Marine Reptiles – breath air
•Plesiosaurs: carnivorous giraffe of the sea, long neck –up to 7m- can lead to losing its head, could not twist around. Senses so far away from tail, didn’t know who is behind. Paddles have frequent shark bites, exposed to attacks from below & behind, jaws designed for tearing, not chewing
•Frequently, fossils don’t have heads
•70 vertebrae
Ichthyosaurs: the porpoises of the day
•Looked like fish
•Started to die off mid-Cretaceous
•Biggest in BC (Fort St. John), 22m, size of blue whale
•Some had live young – tail comes out first to avoid drowning
Mosasaurs (Morden, Man.)
•130 vertebrae, up to 16m long
•Really long water snakes
•Deep divers, push their limits of their abilities
•Swallowed stones to sink
•Plates to protect eyes from water pressure
•Long jaws with short stubby, razor-sharp teeth
•Had live young
•Ate whatever they wanted & swallowed whole
•A joint in the lower jaw allowed them to grab prey by the head & ratchet it, snake-like into the throat
•Last meal of S.Dakota fossil: small mosasaur, fish, birds
•A famous ammonite shell with many circular holes – was bitten 16 times by an inexperienced mosasaur
•Mosasaurs survived to end of Cretaceous
•Modern monitor lizard & snakes either descended from mosasaurs or had a common ancestor
Videos
•Attenboro
•BBC: Walking with Dinosaurs
•Baby Dinos
Walking with Dinosaurs: BBC - videos
•1. Triassic, New Blood. Deserts, primitive reptiles, Placerias with largest carnivore on Earth, Postosuchus. Coelophysis’s advanced features shows the dawn of dinosaurs is approaching.
•A new type appears near the end, the plant-eater Plateosaurus in great numbers
•2. Jurassic, Time of the Titans. Wet climate
Sauropods, the largest animals to walk on the planet. Meet the 25-ton Diplodocus mother laying eggs in the forest. Babies hatch & hide in deep forest. Stegosaurus has 2 rows of plates on its back for display & lethal spikes at its end. Allosaurus is the top predator. Diplodocus has a huge stomach with stones to grind tough leaves. Brachiosaurus, the largest land animal, grazes the tops of trees
•Life won’t be that large again
•3. A Cruel Sea The Ichthyosaur, Ophthalmosaurus, giving birth to live young. The mosasaur, Liopleurodon, 25 m long weighing 150 tons, the largest & most powerful carnivore ever, scares the sharks to make a surprise attack. It eats stones to keep itself down & counterbalance the air in its lungs. Sea full of ammonites
•4. Giants of the Skies in the Cretaceous Pterosaus have become huge, largest is 12 m long Ornithocheirus. It travels from Brazil to Europe to mate, the most outstanding journey in the animal kingdom. It meets the “sheep of the Mesozoic”, the Iguanodons, on the way. They are the first to have back teeth to chew
Cadborosaurus (Caddy), B.C.
•Looks like a marine reptile
•Archie Wills saw it in 1933
•1937: a 3.2m specimen (reptilian) was found in stomach of a sperm whale. It has features of a dog, horse, & camel. Many pictures taken & disappeared on the way to a lab!
•Has been seen over 1,000 years from Alaska to Oregon (native legends & sketches on rock)
•Feb.1953: 10 people watched for over an hour its performance at Qualicum Bay
•1954: 30 people watched one performing near Nanaimo
•The female is smaller, 18m
•1968: infant captured, was 16” long. After frantic efforts to escape, was let loose
•Several babies shot by frightened fishermen
•1996: 12 sightings
•1997: 3 sightings, one was much publicized near Desolation Bay
•Features: 5 -20 m long, snake-like, head like a horse, camel, sheep or giraffe, pair of anterior flippers, tail is spiky, moves very fast, up to 40 knots
Caddy video
Morden Fossils
•Cretaceous period
•Mosasaurs, plesiosaurs, great sea turtles, squids, shark, fish
•Mosasaurs up to 15 m long, dominant predator, fish-eater with razor-sharp teeth with inner teeth to hold prey. Backbone with 130 vertebrae, tail was ½ its length, flippers were webbed, bore live young
•Plesiosaurs: not quick as mosasaurs, swallowed gastroliths, long necks, 70 vertebrae, not as plentiful
•Fish: up to 4.5m long & 300 kg
•Sharks: only teeth preserved as they had no bones
•Turtles: some large (3m), capable of sudden turns to catch fish, similar to today
•Squids: among the largest known, up to 18 m long
•Birds: Hesperonis has small wings, large feet & could not fly. Could swim & catch fish. Looked like an oversized loon
Morden museum – ppt
Flying Reptiles: 245-66 m.y.
•Rules the skies for 150 m.y. ! 120 species
•Long before birds flew
•Evolution’s success story
•Conquered all continents
•From as small as a sparrow to 15m wingspan
•Early forms had membranes joining elbows & knees (like flying squirrels). Must have started as gliders
•Hairs like fur
•As variable as modern birds, exploit all environments
•Elongated fourth finger transformed into a wing
•Awkward to walk on land, some had no tail
•Pterosaurs: warm-blooded, with fur
•Pteranodon: no teeth, crest-like like a rudder, no tail
•Quetzelcoatlus: 15m wingspan, vulture-like, a “feathered serpent”. The largest animal ever to fly, like a 2-seater plane, or a fighter plane
•Pterodactyl: famous from movies
•Dwindled near end of Cretaceous, too windy?
•Fossils: hollow, thin bones filled with air, rare to fossilize, only if they lived near the ocean
•Relationship to birds: feathers don’t make a bird! Reptiles first used feathers as insulation or courtship, Later used them to glide & fly
Feathered or furry Dinosaurs: a puzzle
•Feathers existed long before birds appeared
•Baby dinos had fur & feathers to keep them warm
•A larger animal can generate more heat, so it does not need them
•Liaoning province, China: dinos with arms of a primitive bird & a tail of a dinosaur, mixed features (a missing link?)
Pterosaurs, Brazil
•>1000 specimens world-wide
•Exquisitely fossilized in quiet sediments of a lagoon
•Upper arm bone produced flapping motion, looks like a hatchet
•Light-weight, eggshell-thin bones filled the air
•Arms had 3 small fingers & a 4th finger that extend 10X the length of others
•Bony crests: some extraordinary, rudder-like, steering aid
•In the wing were fibers for added strength (something like metal frame in an umbrella)
•Wings had a curve-aeronautical engineers use same cambered-wing principle to design planes
•Needed elevated metabolic rate
•The biggest fliers were also the last
Flowering plants: we could not survive without them
•235,000 species
•First appeared 130 m.y. with no petals
•Defining feature of all angiosperms: Carpels enclosing seeds that grow into fruits
•Like mammal, develop their young inside the mother
•(Casting pollen into the wind is a hit-or-miss method of reproduction)
•Took 30-40 m.y. before plants grabbed the attention of insect pollinators by showing flashy petals, that was about 100 .m.y. ago
•Petal: was a spark that ignited an explosion of numbers of flowering plants. It has variety of colors & smells
•Benefits for insects: nectar in exchange for pollen disposal
Mary Anning’s contribution
•Survived a lightning strike that killed 4
•Her father was a part-time fossil collector, but died early from TB
•She continued fossil hunting to support her younger sisters
•“She sells sea shells sitting on the sea shore”
•She discovered the 1st ichthyosaur
•People who purchased her fossils claimed that they discovered them
•She also discovered the 1st skeleton of a plesiosaur, a pterosaur, etc etc
•Doctors & others who bought fossils from her sold them to museums
•Died at age 48 from cancer
•Her contribution was commemorated by geological society recently
Mesozoic Resources
•Oil/gas & the oilsands of Alberta
•Lead-zinc deposits in limestone
•Tin in granite intrusions (mountains)
•Silica sand (Manitoba) & bentonite (Manitoba)
•Porphyry copper deposits along the Andes mountains, Cordilleran mountains & Central American mountains
Tin
•Used to make bronze
•In tin cans (due to its low toxicity)
•In tin plating to cover other metals so they will not corrode
Silica sand
•Very common substance
•Used to make glass, casts & moulds
•Thousands of other uses
•But silicosis is a problem
•Old mine near Manikotagan
Porphyry copper
•Igneous rock with spots of copper minerals
•Large tonnage low grade open pit operations
Mountain of copper….
will be reduced to a hole in the ground – picture of a porphyry copper mine
Diamonds: Adamas, means unable to scratch (name Amanda today, original Diamandina)
•In volcanic rocks ~ 100 m.y old & older (?)
•Magma came from the mantle as a result of plate tectonics or asteroid / comet collisions
•Have unique physical properties
•Extremely hard (10, Mohs scale of hardness)
•Heavy – ~ twice as heavy as glass
•So dense that it slows speed of light by 2/3rds, therefore it looks very bright, “it is the closest you come to a star”
•Has superb thermal conductivity, absorbs heat from the flesh, so it feels coool!
•Used in circuit TV, heat-seeking missiles
•Rhodes Scholars: financed by Mr. Rhodes, the founder of DeBeers (South African diamond mines)
•Usually clear, rare with colors
•Average $ 2,000 for engagement ring
•Private company, no competition, so prices are set by company. Immense profits
•Now, there are many producers, all continue the DeBeers prices, because no one is objecting !
•In India, worth only $ 120
•Used in eye surgery
•Largest is 3,100 carats (1 carat = 0.2 gram)
•Host rock is kimberlite pipe, shape of a carrot
•Richest country from diamonds is Botswana, yet Canada finances aid to that country!
•The quest for diamonds causes misery in Africa, gangs, mafia
•The gem grade is low, for one engagement ring need to process 200 – 400 million times its volume of rock
Strange facts
•Diamonds come from a depth of ~ 150 km
•To ensure they are not converted to graphite, they erupt at speeds of ~ 20 km/hour, in the last few km, probably go supersonic!!
Cullinan: largest found on Earth, 3,100 carats - picture
Lesotho Promise, 603 carats – picture
Star of Africa, 503 carats – picture
The Ekati Spirit (NWT), 78 carats – picture
Mining the “carrot” – picture of a n open pit
NWT mine: Diavik – picture
Where Terranes Collide - The Rockies
•The story of the formation of the Rockies, British Columbia & Yukon
•Starts 750 m.y. ago when N. America broke away from Australia & Antarctica
•Western edge of N. America was the west border of Alberta
•Terranes (piece of crust, some land some ocean) formed far away in the south Pacific
•200 terranes amalgamated & collided with N. America thus were welded to the continent
•160 – 100 m.y. ago: another collision against N. America formed the Coast Mountains
•Thrust Faults resulted from this eastward push of the ground. This makes mountains rising at an angle ( as seen from the bedding of sedimentary rocks)
Thrust fault (red line) – picture
Diatoms
•Start in Mesozoic, more info in Cenozoic
•Algae in all environments, mostly ocean
K – T Extinction
•Animals that disappeared: microscopic animals
•Plants
•Ammonites
•Dinosaurs, Marine reptiles, Flying reptiles
•Primitive mammals
•All animals bigger than 25 kg
Not affected
•Birds
•Lizards
•Turtles
•Crocodiles
•Flowering plants
•Fish, squid, cuttlefish
•Insectivore & herbivorous animals
Other events
•Dinosaurs had declined towards the end of Cretaceous, only 12 species were left
•Climate got colder, it would be harder for cold-blooded animals to survive
•Mantle plumes were reaching the surface creating huge eruptions in India (Deccan Traps). Dust & ash would block sunlight for a long time
Evidence of an asteroid collision
•Discoverer gained a Nobel prize for the evidence (Mr. Alvarez)
•Crater 180 km large in Yucatan, buried 10 km below surface
•A clay-rich layer, black or reddish with soot + iridium (a metal not found on earth, came with an asteroid)
•Presence of shocked (shattered under extreme pressures) quartz grains
•Tektites are small glassy fragments made up of quartz found in sediments of that age. The result of a huge explosion that melted sand and sent it flying in the air
•Presence of huge blocks of rock in sediments of that age- only tsunamis could move them ( too far south for glaciers)
•Global photosynthesis shut-off (nuclear winter)
Asteroid & volcanoes linked?
•The energy from the asteroid collision could propagate through the earth and cause it to reach the surface on the opposite side of the earth
•Yucatan and India (at that time) were pretty close to opposite sides of the earth
Crater in Yucatan, Mexico – picture
“Shocked” quartz – picture
Clay rich in iridium –picture
Tektites – picture
New Data
•Gas Bubble: may have wiped out Jurassic life ~ 183 m.y. ago. Methane hydrate trapped beneath ocean floor when algae die heated out of sea bed → 80% of deep sea species died, bivalves, ostracods, belemnites
•Methane hydrate is locked in ice-like state
•Extinction associated with lack of oxygen
•Release was about 20% of the 12 trillion tonnes of gas hydrate on the ocean floor
Some dinosaurs
•Willo, S.Dakota: 66 m.y., 4-chamber heart with a single aorta (reptiles have 2 aortas), more like a bird or a mammal, high metabolic rate
•Eastend Fossil Research Station, Sask., “Scotty”, the world’s 13th T.Rex, droppings with bone fragments of duck-billed dinos, mammals, birds, frogs
•Argentina has the oldest dino at 230 m.y..Also, has the largest T.Rex-type at 12 m, 100 m.y ) 30 m.y. older than T.Rex)
CENOZOIC
•in events: Rise of mammals to fill the gap created by reptile extinction.
•Glaciation (2my – 10,000 BC). Earth’s surface depressed by weight of ice (example: Hudson Bay)
•India collided with Asia to form the Himalayas, world’s tallest
•Rockies still going up, also Alps, Atlas, Andes
Environment
•Angle of subduction decreased, magmatism shifted inland.
•N. America moved over a mantle plume (Yellowstone)
•Columbia River basalts
Fallaron Plate
•N. America moved over it
•Boundary moved from the ocean to California (San Andreas Fault used to be under the sea)
Mt. Everest
•Rocks at the peak contain excrements of crabs & shrimp, used to be underwater
•Peak is 15 km high, but top slid off 70 km to the north some 20 m.y. ago
Badlands
•Cretaceous landscape: river deltas, flood plains swamps with mud, silt, sand
•Floodwaters from melting glaciers carved out modern valleys 10,000 – 15,000 years ago depositing gravels & erratics (large boulders)
Beringia
•Ice-free between 90,000 – 10,000, because of its arid climate
•Land bridge became submerged 11,000 years ago
•Migration of mastodons from Asia to America 15 m.y. ago
•Migration of horses & camels from America to Asia
•People occupied 20,000 – 25,000 coming from Asia
“Big Bang” in Antarctica
•25 m.y. ago
•Immense eruption as big as Krakatau
•Pumice layer 1.2 m thick
•Caused cooling
Mediterranean Sea
•Dried up 5 m.y. ago
•Salt desert led to extinctions & Ice Age
•“Messinian Salinity Crisis”
•At the bottom of the Med. Sea immense deposits of salts
•18,000 years ago: maximum extent of glaciation
•12,000 years ago: mega-floods at the end of Ice Age. N. America & Europe, scablands in Wash. state, with house-size boulders in glacial deposits
CENOZOIC LIFE
•Invertebrates: modern corals, clams, plankton
•Arthropods: 1 million + species
6 legs, chitin skeleton, body in 3
parts, often winged
. Amphibians, reptiles: mostly primitive forms
. Birds: abundant, but rare as fossils
. Plants: 95% angiosperms, rest gymnosperms, some primitive from Carboniferous. Diatoms with 70,000 species
Prehistoric beasts: video
•Primitive marsupials (Leptictidium)
•Ambulocetus : ancestor of whales
•Miniature horses
•Big Bird (top predator at the time) eats horses, but its egg is eaten by ants!
•Andrewsharcus, 1-ton predator is the largest mammal carnivore ever, 5 – 6 m long
•Basilosaurus, 20 m long predator in the oceans
•Largest land mammal, Indricotherium, 15-ton giant, 5.5 m tall
•Entelodon, ancestor of pigs
•Saber-tooth cat, Smilodon only in N. America
•Sloth – bigger than an elephant
Mammals
•4,000 species
•Earliest shrew-like from Madagascar 167 m.y.
•Early egg-laying platypus arose in southern hemisphere from 100 m.y. : furry, with lizard-like gait, produces milk from sweat glands all over body, male has venom-secreting spur on its ankle –can cause severe pain & swelling to humans
•Pouched marsupials & placental arose in Asia & spread to N. America
•Marsupials evolved in S. America, migrated to Australia through Antarctica. Survived in Austr. only because it separated from other continents – 50 m.y. ago
•Remaining marsupials in S. America are anteater, sloth & armadillo (not as big as they used to be)
Insectivores (eat insects)
•Developed next. They branched out into 4 forms:
•1.Rodents: rats, mice, squirrels, beavers, gophers, hamsters, porcupines
•2. Ungulates (hooved, plant-eaters) subdivided into odd-toed (horse, rhino) & even-toed with horn (deer, cattle)
•3. Carnivores (cats & dogs)
•4.Proboscidians (elephant & mammoth=means animal that lives underground, because it was found under the ice)
Trunks evolved from nose + upper lip, while their tusk from an overgrown tooth, 4m tall, up to 5m tusk
Where & How
•North America: horse, dog, deer
•Europe: bear (from dogs)
•Whales, dolphins, seal: from dogs that went into the sea
Evolution of the Horse
•Classic document in evolution
•Started as dog size
•Gradual increase in size, reduction in number of toes, ending up with 1 that curved into a hoof (from running at the tips of their toes to avoid predators)
•Evolution sped up by the invention of grass – 25 m.y. ago –grass is made up of silica, so it’s tough on teeth
Evolution of Whale
•On land ~ 50 m.y. ago
•Early webbed hind legs, part-time in water ~ 47 m.y.
•From ungulates, so hippo is the closest living relative !
•Basilosaurus stomach had sharks up to 1m long
•Breathing: with each breath, exchange 90% of air in the lungs (humans exchange only 15%)
The Intelligent Hunters
•Had to get smarter to catch fast-moving prey in vast prairies
•Developed hunting strategies
•Cats stalk victims, then either bite neck to choke or stab with saber-teeth, like steak knives (extinct)
•Running dogs became specialized for running on their toes. The bones of their forelimbs were fused so that they could rotate (contrary to cats’ flexible forelimbs)
Before the Ice Age
•Ancestors of cattle, sheep & ox crossed into America over Beringia
•Bison became dominant on the plains & pushed sheep up the mountains, ox & moose to colder climates, & horses into extinction
Peculiarities brought about by the Ice Age
•Giantism: beginning of Ice Age, larger size is more efficient in conserving heat & less vulnerable to flesh-eaters
•Giant beavers, 2.75 m long
•Giant Hyenas, 2.5 m long
•Rhinos 6.5 m long (double weight of Diplodocus)
•Exception: mammoth became smaller
•Dwarfism: end of Ice Age, animals became stranded as large lakes were created & animals grew smaller, less to eat
•Deer 1.5 m tall
•Sloth, cat-size
•Elephant 1 m tall – island of Tilos
•Exception: rodents the size of goats
Cenozoic extinctions
•Between 40,000 & 1000 years ago were the biggest extinctions since 65 m.y.
•Almost all animals > 100 kg in the Americas, Australia & New Zealand
•America: sloths the size of dump trucks, teratorn birds with 8m wingspan, lions, tigers disappeared 10,500 – 11,000 (La Brea Tar Pit)
•Australia: giant kangaroos, rhino-size marsupials 30,000 – 15,000
•New Zealand: giant flightless birds – Moas
•Last extinction at 11,000 years ago : Possible reasons are humans, climate, viruses or an asteroid ?? All animals > 40 kg perished
•As yet, no explanation
Did something happened 13,000 years ago?
•Extinction of many large animals
•Many theories
•Lots of support for comet collisions
Diatoms: 70,000 + species
•“The plants with a touch of glass”
•Single cell, multiply either by cell division, or sexually
•Their shapes are amazing!
•Used for gas purification, filtering liquids, such as molasses, fruit juices, water, sewage, etc
•Insect dust, insect killer
“Living fossils” today
•Tuatara: lizard-like, skull similar to Triassic reptiles. In islands near New Zealand
•Ginkgo: abundant in Triassic, now in China. Good for cities, not bothered by pollution
•Komodo : reptile in Indonesia
•Sturgeon
•Coelacanth
•Cadborosaurus (Pacific coast) & Ogopogo?
Anthropology :Rise of humans
•Primates: evolved ~ 36 m.y., characteristics:
•Complex nervous system, high activity, alertness
•Binocular vision with depth & color perception
•Highly mobile joints, mobility in several directions, so ability to dance, etc
•Thumbs opposable to other fingers
•Tail as 5th hand
•Developed in Africa & spread elsewhere later
•15 m.y. ago: orangutans split, later gorillas split
•Main branch have only chimps
•Hominids split from chimps ~ 5 m.y. ago
•Hominids stand upright, right from the beginning
Events around 6 m.y. ago
•Panama bridge forms that link N, America to S. America
•Atlantic gets colder, cool currents pile up snow on Greenland
•Sahara desert forms, forests in Afar region dry up
•Some primates are forced to look for food on the plains
First finds of human fossils
•1856: Neanderthal in Europe
•1890’s : in Java – “Java-man”, also “Peking-man” were puzzles for a very long time
•Nothing was found until Leakey’s find of Lucy in 1959 along the East African Rift
Stage 1
•Australopithecus (=southern ape): ONLY found in Africa
•Lucy, 3.2 m.y., 4ft tall, walked with slightly bent knees, heavy brow jutting, chimp-like face, brain 1/3 of ours, still vegetarian, skeleton 40% complete. But she had stiff wrists: walked on her knuckles. Based on hip & leg bones, walked upright. Did not have flexible wrists that allowed later humans to throw spears & make tools
Laetoli footprints, 3.6 m.y.- pictures
•This way, retained long fingers that allowed her to climb trees. From 2.5 m.y. wrists become mobile, like in modern humans
•3.3 m.y. : arm, hand find: rare – usually the first carnivores eat, tasty & easy to eat. Elbow joint similar to modern humans
•Toeing-off: method to propel forward by leaving front part of foot on the ground & lifting the heel. Causes the bones in the middle of the foot to take a distinctive shape
Features of stage 1
•Spine: straight up & chest above pelvis
•Thigh bone at an angle, so don’t walk from side to side (apes)
•Pelvis is broader & hip joint has muscles to stabilize the pelvis
•Knee joint: bones are larger at ends
•Foot has an arch, which is shock absorber. Big toe is aligned with other toes
•“Millenium Man”: 6.0 m.y. strong back legs, key find was his teeth, small canines & robust molars, diet of fruits-veg. + occassional meat
Stage 2: Homo erectus
•Left Africa ~ 2. m.y.
•Earliest fossil in Africa = 1.8 m.y.
•Earliest in Asia = 1.7 m.y.
•Became meat-eater by necessity
•Smaller jaw, keen sight, same brain as a 1 year old, narrow pelvis, more efficient on 2 legs, larger spinal cord hole, therefore able to make simple sounds
•1.75 m.y.: Dmanisi, Georgia, 3 skulls, biggest collection of well-preserved early human fossils, 1000 stone tools, brain was 800 cc (2/3 of modern)
•1.36 m.y.: China, stone tools, surprise to find them so far north, too cold
•1 m.y.: Eritrea, stone tools during transition from erectus to modern
•800,000, Indonesia: “erectus afloat”, stone tools, flakes & tools to work wood & animals, therefore, able to make boats & travel between islands
•700,000, Petralona, Greece: skull with brain of 1,200 cc, fire, tools, 1.2m tall, lived for 30-35 years
Inventions of erectus
•2.6 m.y.: Sharp flakes as tools
•1.7 m.y.: Oldest ax
•1.4 m.y.: first fire
•Probably returned to Africa by 120,000 years ago
BIGFOOT, Saskquatch
•China: 2.5 m tall, red hair, 40 cm footprint, chewed corn cobs
•Reported from many places, even Norway House
•Is he a remnant of H. erectus?
Stage 3: Homo sapiens
with symbolic thinking
Bigger face, protruding browridge above eyes at first, would bury the dead, migrated to all continents
.Inventions: 125,000 to 80,000: used red ochre crayons for painting
60,000-40,000: made boats to cross to Australia
37,000-10,000: made art in caves (200 caves worldwide)
25,000: could fish
•Out-of-Africa: all leaving Africa before 100,000 were dead ends. Modern humans left Africa ~ 50,000 years ago
•“Out-of-Africa” theory or replacement theory: moderns replaced earlier hominids everywhere by inter-breeding, assimilation
•Europe 20,000 years ago: DNA evidence that only as few as 50 survived in northern Europe. The rest moved south
South Africa
•70,000: a find of 28 spears & harpoons from bone
•Modern human behavior in Africa was 35,000 years before in Europe
•Cape Town: oldest footprint 117,000 in wet sand dune identical to modern
•Modern humans from 120,000 with advanced tools & red ochre pigment
Neanderthals in Europe during Ice Age
230,000 – 20,000
•Trapped in Europe. Intelligent meat-eaters (scarce food), grew more massive bones & stocky bodies to conserve heat, also broad noses, skulls slope back low over their brains. Beneath eyes face jutted forward making cheekbones angle to the side rather than to front (like Inuit)
•Some buried their dead, capable of making speech. Larynx was high up like in babies
•Commonly wounded with broken bones, painful arthritis. Injured by thrusting rather than throwing spears at animals (no brain yet to throw)
•Pushed to extinction by moderns through some assimilation, inter-breeding. Skeleton in Portugal with mixed features, 24,500 with pronounced chin & teeth
Extra-ordinary meeting
•Poland, 40,000 between N. with primitive tools & no art with moderns with advanced tools & art
•Eventually, moderns pushed N. westwards & down to Spain
•Last N. skeleton in Spain is 24,000
Neanderthal fossil sites
•Krapina cave, Croatia: more fossils than any other site at the time. X-rays of 874 bones belonging to 75 individuals: Healthy, but one had benign bone tumor, one had surgical amputation of his hand, several had osteoarthritis & healed fractures
•As recent as 28,000, bones heavier, more robust than moderns with more primitive-looking face & head
•Cave in France: cannibal feast where N. were eaten, sucked marrow & brains, tongue cut out, 2 adults, two 15-year olds, two 6-year olds were systematically defleshed. Flesh eaten raw
“Most spectacularly injured N.”
•40-year old had lesions from head to toe, bone around eye & cheek had crushed & healed over. Had double vision permanently. One arm broken in 2 places above elbow & did not heal. Severe arthritis in right ankle & big toe & healed fracture on outside of his foot
DNA mitochondria evidence
•Ancestors of modern humans are women in Nigeria about 170,000 years ago
•Left Africa ~ 50,000
King Midas, 700 BC
•Midas mound, Gordion, Asia Minor (Turkey)
•A body of a 60 -65 year old male, rich burial, wooden furniture, cups, plates, remains of spicy meal of sheep & goat. Meat first barbecued, then cut-off & seasoned with herbs & spices. Fermented beverage of grape wine, barley beer & honey mead, bronze vessels & 100 bowls. Apple & cranberry drink
First Americans
•“Out-of-Iberia” theory: crossed Atlantic 18,000 years ago from Iberia to S. America. Theory based on blades & artifacts
•Ice-free highway through Alaska ~ 13,500 - Clovis culture
•3 puzzle sites: Pennsylvania, Monte Verde, Chile, Virginia & S. Carolina” settled 12,000 – 16,000 BC
Mythology in “Greece” tells of exploration journeys
•By the Argonauts & Ulysses, Hercules (to west), Orpheus & Dionysos (to east)
•Names match with South American names of places & others worldwide (Spain, Scotland, Ireland, Denmark, N. America, China, Japan, Indonesia, Philippines, Pacific islands all the way to Easter Island)
The Minoans of Crete
•Called “Sea Peoples” by the ancient Egyptians
•Explorers, traders & metallurgists – the words “mine” and “mining” prob. from them
•Worked tin mines in the UK, mines in Brazil (Minas Gerais), Nova Scotia (Minas Basin), Pacific Islands
•Civilization collapsed ~ 1,600 BC by the volcano / tsunamis. Ruins have no skeletons or gold, therefore people left by boat
•First New Americans (the Olmecs) arrived in Mexico ~ 1,300 BC, but from where? No one knows, but the dates match
Ice Age
•Ice Ages of the past: 3 in Precambrian, the Snowball the longest
•4 in Paleozoic (south pole)
•None in Mesozoic (relatively warm)
•1 in Cenozoic ( lasted from 2 m.y. to 10,000 BC, up to 7 separate Glacial episodes with warming in-between)
•A “Little Ice Age” in Europe 1500 -1800AD
•Now, maybe an Inter-glacial
Reason for Ice Age
•Many theories, prob. changes in amount of gases in the air –we know from global warming
•We know that CO2 & CH3 (methane) make temp rise, so less CO2 /CH3 may lead to colder climate
•Too much sulfur in the air –from volcanoes/asteroid collision- blocks the sun & lowers the temp
•Too many clouds in the air from volcanoes or humidity in the air also can cause cooling
Last Ice Age
•Antarctica iced up ~ 30 m.y.
•Arctic ocean froze up ~ 4 m.y. ago, a result of Panama bridge forming
•Wind blowing from the Arctic over Hudson Bay & Ungava piled up snow over N. America
•Weight of snow/ice over Hudson Bay depressed it– lowest about 200 m. It is expected to rise & become land again
Major landscape development
•From continental & mountain glaciers
•Active zone is at the bottom of the ice pile where repeated melting & freezing cycles break up bedrock below & incorporates it as fragments into the glacier
•Variety of scenery in Canada a result of glacial cover
•Periglacial features from permafrost conditions in the north
Boulder can only be transported by ice - picture
•in events: Rise of mammals to fill the gap created by reptile extinction.
•Glaciation (2my – 10,000 BC). Earth’s surface depressed by weight of ice (example: Hudson Bay)
•India collided with Asia to form the Himalayas, world’s tallest
•Rockies still going up, also Alps, Atlas, Andes
Environment
•Angle of subduction decreased, magmatism shifted inland.
•N. America moved over a mantle plume (Yellowstone)
•Columbia River basalts
Fallaron Plate
•N. America moved over it
•Boundary moved from the ocean to California (San Andreas Fault used to be under the sea)
Mt. Everest
•Rocks at the peak contain excrements of crabs & shrimp, used to be underwater
•Peak is 15 km high, but top slid off 70 km to the north some 20 m.y. ago
Badlands
•Cretaceous landscape: river deltas, flood plains swamps with mud, silt, sand
•Floodwaters from melting glaciers carved out modern valleys 10,000 – 15,000 years ago depositing gravels & erratics (large boulders)
Beringia
•Ice-free between 90,000 – 10,000, because of its arid climate
•Land bridge became submerged 11,000 years ago
•Migration of mastodons from Asia to America 15 m.y. ago
•Migration of horses & camels from America to Asia
•People occupied 20,000 – 25,000 coming from Asia
“Big Bang” in Antarctica
•25 m.y. ago
•Immense eruption as big as Krakatau
•Pumice layer 1.2 m thick
•Caused cooling
Mediterranean Sea
•Dried up 5 m.y. ago
•Salt desert led to extinctions & Ice Age
•“Messinian Salinity Crisis”
•At the bottom of the Med. Sea immense deposits of salts
•18,000 years ago: maximum extent of glaciation
•12,000 years ago: mega-floods at the end of Ice Age. N. America & Europe, scablands in Wash. state, with house-size boulders in glacial deposits
CENOZOIC LIFE
•Invertebrates: modern corals, clams, plankton
•Arthropods: 1 million + species
6 legs, chitin skeleton, body in 3
parts, often winged
. Amphibians, reptiles: mostly primitive forms
. Birds: abundant, but rare as fossils
. Plants: 95% angiosperms, rest gymnosperms, some primitive from Carboniferous. Diatoms with 70,000 species
Prehistoric beasts: video
•Primitive marsupials (Leptictidium)
•Ambulocetus : ancestor of whales
•Miniature horses
•Big Bird (top predator at the time) eats horses, but its egg is eaten by ants!
•Andrewsharcus, 1-ton predator is the largest mammal carnivore ever, 5 – 6 m long
•Basilosaurus, 20 m long predator in the oceans
•Largest land mammal, Indricotherium, 15-ton giant, 5.5 m tall
•Entelodon, ancestor of pigs
•Saber-tooth cat, Smilodon only in N. America
•Sloth – bigger than an elephant
Mammals
•4,000 species
•Earliest shrew-like from Madagascar 167 m.y.
•Early egg-laying platypus arose in southern hemisphere from 100 m.y. : furry, with lizard-like gait, produces milk from sweat glands all over body, male has venom-secreting spur on its ankle –can cause severe pain & swelling to humans
•Pouched marsupials & placental arose in Asia & spread to N. America
•Marsupials evolved in S. America, migrated to Australia through Antarctica. Survived in Austr. only because it separated from other continents – 50 m.y. ago
•Remaining marsupials in S. America are anteater, sloth & armadillo (not as big as they used to be)
Insectivores (eat insects)
•Developed next. They branched out into 4 forms:
•1.Rodents: rats, mice, squirrels, beavers, gophers, hamsters, porcupines
•2. Ungulates (hooved, plant-eaters) subdivided into odd-toed (horse, rhino) & even-toed with horn (deer, cattle)
•3. Carnivores (cats & dogs)
•4.Proboscidians (elephant & mammoth=means animal that lives underground, because it was found under the ice)
Trunks evolved from nose + upper lip, while their tusk from an overgrown tooth, 4m tall, up to 5m tusk
Where & How
•North America: horse, dog, deer
•Europe: bear (from dogs)
•Whales, dolphins, seal: from dogs that went into the sea
Evolution of the Horse
•Classic document in evolution
•Started as dog size
•Gradual increase in size, reduction in number of toes, ending up with 1 that curved into a hoof (from running at the tips of their toes to avoid predators)
•Evolution sped up by the invention of grass – 25 m.y. ago –grass is made up of silica, so it’s tough on teeth
Evolution of Whale
•On land ~ 50 m.y. ago
•Early webbed hind legs, part-time in water ~ 47 m.y.
•From ungulates, so hippo is the closest living relative !
•Basilosaurus stomach had sharks up to 1m long
•Breathing: with each breath, exchange 90% of air in the lungs (humans exchange only 15%)
The Intelligent Hunters
•Had to get smarter to catch fast-moving prey in vast prairies
•Developed hunting strategies
•Cats stalk victims, then either bite neck to choke or stab with saber-teeth, like steak knives (extinct)
•Running dogs became specialized for running on their toes. The bones of their forelimbs were fused so that they could rotate (contrary to cats’ flexible forelimbs)
Before the Ice Age
•Ancestors of cattle, sheep & ox crossed into America over Beringia
•Bison became dominant on the plains & pushed sheep up the mountains, ox & moose to colder climates, & horses into extinction
Peculiarities brought about by the Ice Age
•Giantism: beginning of Ice Age, larger size is more efficient in conserving heat & less vulnerable to flesh-eaters
•Giant beavers, 2.75 m long
•Giant Hyenas, 2.5 m long
•Rhinos 6.5 m long (double weight of Diplodocus)
•Exception: mammoth became smaller
•Dwarfism: end of Ice Age, animals became stranded as large lakes were created & animals grew smaller, less to eat
•Deer 1.5 m tall
•Sloth, cat-size
•Elephant 1 m tall – island of Tilos
•Exception: rodents the size of goats
Cenozoic extinctions
•Between 40,000 & 1000 years ago were the biggest extinctions since 65 m.y.
•Almost all animals > 100 kg in the Americas, Australia & New Zealand
•America: sloths the size of dump trucks, teratorn birds with 8m wingspan, lions, tigers disappeared 10,500 – 11,000 (La Brea Tar Pit)
•Australia: giant kangaroos, rhino-size marsupials 30,000 – 15,000
•New Zealand: giant flightless birds – Moas
•Last extinction at 11,000 years ago : Possible reasons are humans, climate, viruses or an asteroid ?? All animals > 40 kg perished
•As yet, no explanation
Did something happened 13,000 years ago?
•Extinction of many large animals
•Many theories
•Lots of support for comet collisions
Diatoms: 70,000 + species
•“The plants with a touch of glass”
•Single cell, multiply either by cell division, or sexually
•Their shapes are amazing!
•Used for gas purification, filtering liquids, such as molasses, fruit juices, water, sewage, etc
•Insect dust, insect killer
“Living fossils” today
•Tuatara: lizard-like, skull similar to Triassic reptiles. In islands near New Zealand
•Ginkgo: abundant in Triassic, now in China. Good for cities, not bothered by pollution
•Komodo : reptile in Indonesia
•Sturgeon
•Coelacanth
•Cadborosaurus (Pacific coast) & Ogopogo?
Anthropology :Rise of humans
•Primates: evolved ~ 36 m.y., characteristics:
•Complex nervous system, high activity, alertness
•Binocular vision with depth & color perception
•Highly mobile joints, mobility in several directions, so ability to dance, etc
•Thumbs opposable to other fingers
•Tail as 5th hand
•Developed in Africa & spread elsewhere later
•15 m.y. ago: orangutans split, later gorillas split
•Main branch have only chimps
•Hominids split from chimps ~ 5 m.y. ago
•Hominids stand upright, right from the beginning
Events around 6 m.y. ago
•Panama bridge forms that link N, America to S. America
•Atlantic gets colder, cool currents pile up snow on Greenland
•Sahara desert forms, forests in Afar region dry up
•Some primates are forced to look for food on the plains
First finds of human fossils
•1856: Neanderthal in Europe
•1890’s : in Java – “Java-man”, also “Peking-man” were puzzles for a very long time
•Nothing was found until Leakey’s find of Lucy in 1959 along the East African Rift
Stage 1
•Australopithecus (=southern ape): ONLY found in Africa
•Lucy, 3.2 m.y., 4ft tall, walked with slightly bent knees, heavy brow jutting, chimp-like face, brain 1/3 of ours, still vegetarian, skeleton 40% complete. But she had stiff wrists: walked on her knuckles. Based on hip & leg bones, walked upright. Did not have flexible wrists that allowed later humans to throw spears & make tools
Laetoli footprints, 3.6 m.y.- pictures
•This way, retained long fingers that allowed her to climb trees. From 2.5 m.y. wrists become mobile, like in modern humans
•3.3 m.y. : arm, hand find: rare – usually the first carnivores eat, tasty & easy to eat. Elbow joint similar to modern humans
•Toeing-off: method to propel forward by leaving front part of foot on the ground & lifting the heel. Causes the bones in the middle of the foot to take a distinctive shape
Features of stage 1
•Spine: straight up & chest above pelvis
•Thigh bone at an angle, so don’t walk from side to side (apes)
•Pelvis is broader & hip joint has muscles to stabilize the pelvis
•Knee joint: bones are larger at ends
•Foot has an arch, which is shock absorber. Big toe is aligned with other toes
•“Millenium Man”: 6.0 m.y. strong back legs, key find was his teeth, small canines & robust molars, diet of fruits-veg. + occassional meat
Stage 2: Homo erectus
•Left Africa ~ 2. m.y.
•Earliest fossil in Africa = 1.8 m.y.
•Earliest in Asia = 1.7 m.y.
•Became meat-eater by necessity
•Smaller jaw, keen sight, same brain as a 1 year old, narrow pelvis, more efficient on 2 legs, larger spinal cord hole, therefore able to make simple sounds
•1.75 m.y.: Dmanisi, Georgia, 3 skulls, biggest collection of well-preserved early human fossils, 1000 stone tools, brain was 800 cc (2/3 of modern)
•1.36 m.y.: China, stone tools, surprise to find them so far north, too cold
•1 m.y.: Eritrea, stone tools during transition from erectus to modern
•800,000, Indonesia: “erectus afloat”, stone tools, flakes & tools to work wood & animals, therefore, able to make boats & travel between islands
•700,000, Petralona, Greece: skull with brain of 1,200 cc, fire, tools, 1.2m tall, lived for 30-35 years
Inventions of erectus
•2.6 m.y.: Sharp flakes as tools
•1.7 m.y.: Oldest ax
•1.4 m.y.: first fire
•Probably returned to Africa by 120,000 years ago
BIGFOOT, Saskquatch
•China: 2.5 m tall, red hair, 40 cm footprint, chewed corn cobs
•Reported from many places, even Norway House
•Is he a remnant of H. erectus?
Stage 3: Homo sapiens
with symbolic thinking
Bigger face, protruding browridge above eyes at first, would bury the dead, migrated to all continents
.Inventions: 125,000 to 80,000: used red ochre crayons for painting
60,000-40,000: made boats to cross to Australia
37,000-10,000: made art in caves (200 caves worldwide)
25,000: could fish
•Out-of-Africa: all leaving Africa before 100,000 were dead ends. Modern humans left Africa ~ 50,000 years ago
•“Out-of-Africa” theory or replacement theory: moderns replaced earlier hominids everywhere by inter-breeding, assimilation
•Europe 20,000 years ago: DNA evidence that only as few as 50 survived in northern Europe. The rest moved south
South Africa
•70,000: a find of 28 spears & harpoons from bone
•Modern human behavior in Africa was 35,000 years before in Europe
•Cape Town: oldest footprint 117,000 in wet sand dune identical to modern
•Modern humans from 120,000 with advanced tools & red ochre pigment
Neanderthals in Europe during Ice Age
230,000 – 20,000
•Trapped in Europe. Intelligent meat-eaters (scarce food), grew more massive bones & stocky bodies to conserve heat, also broad noses, skulls slope back low over their brains. Beneath eyes face jutted forward making cheekbones angle to the side rather than to front (like Inuit)
•Some buried their dead, capable of making speech. Larynx was high up like in babies
•Commonly wounded with broken bones, painful arthritis. Injured by thrusting rather than throwing spears at animals (no brain yet to throw)
•Pushed to extinction by moderns through some assimilation, inter-breeding. Skeleton in Portugal with mixed features, 24,500 with pronounced chin & teeth
Extra-ordinary meeting
•Poland, 40,000 between N. with primitive tools & no art with moderns with advanced tools & art
•Eventually, moderns pushed N. westwards & down to Spain
•Last N. skeleton in Spain is 24,000
Neanderthal fossil sites
•Krapina cave, Croatia: more fossils than any other site at the time. X-rays of 874 bones belonging to 75 individuals: Healthy, but one had benign bone tumor, one had surgical amputation of his hand, several had osteoarthritis & healed fractures
•As recent as 28,000, bones heavier, more robust than moderns with more primitive-looking face & head
•Cave in France: cannibal feast where N. were eaten, sucked marrow & brains, tongue cut out, 2 adults, two 15-year olds, two 6-year olds were systematically defleshed. Flesh eaten raw
“Most spectacularly injured N.”
•40-year old had lesions from head to toe, bone around eye & cheek had crushed & healed over. Had double vision permanently. One arm broken in 2 places above elbow & did not heal. Severe arthritis in right ankle & big toe & healed fracture on outside of his foot
DNA mitochondria evidence
•Ancestors of modern humans are women in Nigeria about 170,000 years ago
•Left Africa ~ 50,000
King Midas, 700 BC
•Midas mound, Gordion, Asia Minor (Turkey)
•A body of a 60 -65 year old male, rich burial, wooden furniture, cups, plates, remains of spicy meal of sheep & goat. Meat first barbecued, then cut-off & seasoned with herbs & spices. Fermented beverage of grape wine, barley beer & honey mead, bronze vessels & 100 bowls. Apple & cranberry drink
First Americans
•“Out-of-Iberia” theory: crossed Atlantic 18,000 years ago from Iberia to S. America. Theory based on blades & artifacts
•Ice-free highway through Alaska ~ 13,500 - Clovis culture
•3 puzzle sites: Pennsylvania, Monte Verde, Chile, Virginia & S. Carolina” settled 12,000 – 16,000 BC
Mythology in “Greece” tells of exploration journeys
•By the Argonauts & Ulysses, Hercules (to west), Orpheus & Dionysos (to east)
•Names match with South American names of places & others worldwide (Spain, Scotland, Ireland, Denmark, N. America, China, Japan, Indonesia, Philippines, Pacific islands all the way to Easter Island)
The Minoans of Crete
•Called “Sea Peoples” by the ancient Egyptians
•Explorers, traders & metallurgists – the words “mine” and “mining” prob. from them
•Worked tin mines in the UK, mines in Brazil (Minas Gerais), Nova Scotia (Minas Basin), Pacific Islands
•Civilization collapsed ~ 1,600 BC by the volcano / tsunamis. Ruins have no skeletons or gold, therefore people left by boat
•First New Americans (the Olmecs) arrived in Mexico ~ 1,300 BC, but from where? No one knows, but the dates match
Ice Age
•Ice Ages of the past: 3 in Precambrian, the Snowball the longest
•4 in Paleozoic (south pole)
•None in Mesozoic (relatively warm)
•1 in Cenozoic ( lasted from 2 m.y. to 10,000 BC, up to 7 separate Glacial episodes with warming in-between)
•A “Little Ice Age” in Europe 1500 -1800AD
•Now, maybe an Inter-glacial
Reason for Ice Age
•Many theories, prob. changes in amount of gases in the air –we know from global warming
•We know that CO2 & CH3 (methane) make temp rise, so less CO2 /CH3 may lead to colder climate
•Too much sulfur in the air –from volcanoes/asteroid collision- blocks the sun & lowers the temp
•Too many clouds in the air from volcanoes or humidity in the air also can cause cooling
Last Ice Age
•Antarctica iced up ~ 30 m.y.
•Arctic ocean froze up ~ 4 m.y. ago, a result of Panama bridge forming
•Wind blowing from the Arctic over Hudson Bay & Ungava piled up snow over N. America
•Weight of snow/ice over Hudson Bay depressed it– lowest about 200 m. It is expected to rise & become land again
Major landscape development
•From continental & mountain glaciers
•Active zone is at the bottom of the ice pile where repeated melting & freezing cycles break up bedrock below & incorporates it as fragments into the glacier
•Variety of scenery in Canada a result of glacial cover
•Periglacial features from permafrost conditions in the north
Boulder can only be transported by ice - picture
