PENT Mesozoic to Now

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

W 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

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

Plants: cycads, conifers, ginkgos

                (gymnosperms) + ferns

        New Invention in Cretaceous: Angiosperms

.  Insects : ¾ of all animal species

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 Hadrosaurs –”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

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

Ornithocheirus (“bird hand”) flew 14,000 km to mate

Iguanodon

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

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

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 Manicotagan

Porphyry copper

Igneous rock with spots of copper minerals

Large tonnage low grade open pit operations

Diamonds: Adamas, means unable to scratch (name Amanda today, original was Diamantina)

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!!

“Where Terranes Collide”, the story of BC, Yukon:video

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)

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    “Shocked” quartz   Clay rich in iridium    cent

Video on Youtube : "The Day the Mesozoic Died", 33.50 minutes

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

Main 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 & eratics (large boulders)

Bering

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

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 

Laetoli footprints, 3.6 m.y.

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

June 2017 class