Chapter 34 Notes:

The Mesozoic Era:

Pangaea breaks:

Dinosaurs:

Group of large terrestrial reptiles
Lived on all continents (US and Canada seem to be a particular hot spot for life!)
Major dino remains have come from Montana, Utah, Wyoming, Colorado, Kansas, Texas, Oklahoma, and New Mexico.
First were very small (rabbit size!)
Largest lived during the last period (Cretaceous)
Averaged 25-30 meters in length
Tallest found could see over a 5-story building!
The largest carnivore known was Tyrannosaurs Rex - about 20 feet tall with banana-size teeth!
Plant eaters (herbivore) are divided into 4 groups:

Other Land Animals of the Mesozoic:

Archeopteryx - probably could not fly, but did have wings and feathers
Protoavis - even older bird; had wings but was even more dinosaur-like; about the size of a modern crow

Marine Life:

Ichthyosaurs - looked like swordfish
Plesiosaurs - snake-like marine animal with four leg-like flippers and long body (Loch Ness Monster!)
Corals thrive well again during the Mesozoic
Clams and plankton thrive during this time

Land Plants:

Tree ferns, spore-bearing ferns, rushes, and conifers continue to thrive into the Mesozoic
Pines, yews, and cypress are new to this time
Flowering plants appear!
Magnolia, sassafras, fig, willow, laurel, and tulip trees develop.
Later came oak, maple, beech, birch, walnut, chestnut, and other modern trees.
Evergreens continue to thrive.
Giant Sequoia (early redwoods) first appear

Mesozoic Era Closes:

All dinosaurs vanish with almost all flying and swimming reptiles
Maybe 50% of all life is wiped off earth!
Reasons include change of climate, rise of mammals, drop of sea level, uplift of mountain, massive volcanic eruptions, or world-wide disease.
OR giant asteroid hits earth 65 million years ago and creates such a cloud of debris, that it blocks light into our atmosphere and all plant life die, thus causing death of ALL large animal life. (The meek shall inherit the earth???)
They have found a large buried crater off the Yucatan Peninsula of Mexico supporting this theory…the rock samples have been aged to be similar to the time of extinction?????

The Cenozoic Era:

Rise of the Mammals:

Creodonts – first mammals on record (resembled cats and dogs; early carnivores)
Oreodons – resembled modern deer
Mastodon – early elephant
Brontotherium – head like a rhino and body of an elephant???
Baluchitherium – early rhinoceros (largest land mammal of all time!)
In most cases, early ancestors of all animals today have been found to be much smaller than their current descendant.
Example: Early horses were no larger than a large cat!

Other Cenozoic Animals:

Plant life:

Palm, fern, and fig trees grew all over the humid, warm earth
Cypress, laurel, and sequoia grew as well
As temp. cooled, only the sequoia remained in the hardy climates…rest only grew in the central regions of earth
Grasses first appear!
Grasses are thought to be the reason for so many grazing animals on earth today
Wheat, corn, barley, rye, oats, and rice thrive to today

The Rise of the Human:

We have found nearly 3000 remains of early humans dating back 2.5–7 million years ago
Apes and Man are different by BRAIN size and WALK (bipedal)
Hominids – humanlike, bipedal primates
Australopithecus – oldest accepted hominid!

Last 300000 years
1300 cm3 brain size
Neanderthal – early "modern" human, short and robust
Cro-Magnon – "more modern" human, our closest ancestor. Migrated around the world about 100000 years ago.

The Past 11,000 Years:

Causes include hunting and civilization expansion

We must build habitat, control hunting, fishing, and whaling, and help preserve the endangered animals….they are not replaceable!!!