MESOZOIC Trilobites, ammonites and many other species go extinct Trilobites, ammonites and many other species go extinct Dinosaurs now dominate- land, air, sea Dinosaurs now dominate- land, air, sea Drier climate Drier climate
TRIASSIC 248 mya Beginning of small dinosaurs Beginning of small dinosaurs Primitive mammals Primitive mammals All of N. America is above sea level All of N. America is above sea level Pangaea Pangaea
JURASSIC 206 mya Dinosaurs continue to dominate Dinosaurs continue to dominate Apatasaurus Brachiosaurus stegosaurus Reaching larger sizes Reaching larger sizes First birds First birds Pangaea starts to split Pangaea starts to split
Apatosaurus- goof by US postal service
ARCHAEOPTERYX
CRETACEOUS mya Intelligent dinosaurs (T- rex, raptors) Intelligent dinosaurs (T- rex, raptors) First flowering plants First flowering plants Carnivorous mammals Carnivorous mammals Pangaea splits up Pangaea splits up Rockies form Rockies form
T - REX SUE The most famous dinosaur ever! The most famous dinosaur ever!
First glimpse, with discoverer Sue Hendrickson August, 1990
All volunteers furiously dig Sue out
Every bone is incased in plaster
Finished Skull
Artist rendition
Other bones were found with Sue
Forearm; only two ever found from a T-Rex
Sue’s wishbone first one ever found in a T-Rex
Bones are seized May14, 1992
On display at the Chicago Field Museum May 17, 2000
Only bones not found, seen in black
Working paleontologist at the McDonalds Lab in the Field Museum
DINOSAUR EXTINCTION
K/T Boundary Cretaceous/Tertiary Cretaceous/Tertiary 65 mya 65 mya Separates Mesozoic from Cenozoic Separates Mesozoic from Cenozoic
What happened? Warm temps Warm temps 65% of species went extinct (most sea life) 65% of species went extinct (most sea life) Ammonites Ammonites foraminifera foraminifera Most sponges Most sponges Marine reptiles Marine reptiles On land nothing more than 25kg survived On land nothing more than 25kg survived
victims
Survivors LIZARDS, SNAKES, CROCODILES, TURTLES, MAMMALS, FROGS, SALAMANDERS LIZARDS, SNAKES, CROCODILES, TURTLES, MAMMALS, FROGS, SALAMANDERS
ASTEROID THEORY Asteroid caused climate change Asteroid caused climate change 1 st - dust blocked out sun 1 st - dust blocked out sun 2 nd - trapped in heat 2 nd - trapped in heat
Evidence Iridium Iridium Found plentifully in space rocks Found plentifully in space rocks
Evidence Shocked quartz Shocked quartz Caused by impact Caused by impact
Evidence Crater Crater Asteroid 10 km wide Asteroid 10 km wide Left 100km crater Left 100km crater
CENOZOIC 65 mya-present Mammals now dominate- Mammals now dominate- able to fill in niche left by dinosaurs able to fill in niche left by dinosaurs Epochs Epochs Further subdivided periods Further subdivided periods
North America East East Marine sedimentation Marine sedimentation West West Uplift created gorges Uplift created gorges Grand Canyon Volcanism Volcanism Sierra Nevadas created Sierra Nevadas created
Tertiary rocks
Tertiary
Tertiary 65 mya-2mya Flowering plants (angiosperms) Flowering plants (angiosperms) Mammals diversify Mammals diversify Size begins to increase Size begins to increase Brain capacity increases Brain capacity increases Specialization of teeth Specialization of teeth Specialization of limbs Specialization of limbs Birds evolve Birds evolve
Late Pliocene
QUATERNARY 2mya- present Beginning of ice ages Beginning of ice ages Caused extinction of many large mammals + Caused extinction of many large mammals + were hunted by were hunted by Homo Sapiens and Neanderthals Homo Sapiens and Neanderthals Great Lakes formed
Quaternary ice sheets
Mammoths Curved tusk Curved tusk Related to modern elephant Related to modern elephant
Mammoth fossils
Mastodons Straight tusk Straight tusk MI’s state fossil MI’s state fossil
Lucy LUCY
Oldest Hominoid Up right walking being Up right walking being 7 million years old 7 million years old
Lucy 3.5 my 3.5 my Bipedal hominoid Bipedal hominoid Oldest humans? Oldest humans?
Ardi Ardipithecus ramidus 4.4 my 4.4 my Found Oct Found Oct Ethiopia Ethiopia
resources