Week 9

Question 1

Hadean Eon

Answer 1

First eon, 4.6-4 BYA.
-Earth forming and moon forms.
-Could have some very early examples of life.
-oceans cover by end

Question 2

Archean Eon

Answer 2

4-2.5 BYA,
-Contains the oldest fossils from single cell organisms (cyanobacteria) which produced oxygen. they form large clumps called stromatolites when fossilized.

Question 3

Proterozoic Eon

Answer 3

2.5 BYA-541MYA:
-First multicellular organisms but didn’t have many bones so fossils are poor
Contains: Ediacaran period

Question 4

Ediacarn period

Answer 4

630-542 MYA within the Proterozoic Eon, has some of the first large animals with hard tissues that could fossilize.

Question 5

Phanerozoic Eon

Answer 5

541-0 MYA,
-Rapid animal differentiation and growth including dinosaurs
-basically everything happens here
Contains: 3 Eras (Paleozoic, Mesozoic and Cenozoic) which each contain many periods

Question 6

Paleozoic Era

Answer 6

541-252 MYA, start of paleozoic eon, had small primitive invertebrates in oceans, but by the end had reptiles, amphibians and insects
contains: Cambrian, Ordovician, Silurian, Devonian, carboniferous and permian periods

Question 7

Cambrian period

Answer 7

541-485 MYA:
-Start of the paleozoic Era and is the Cambrian explosion with many aquatic species like sponge, molluscs and worms (many invertebrates)
-Contains Pikaia an ancestor of vertebrates

Question 8

Ordovician period

Answer 8

485-443 MYA: Second period of paleozoic Era,
-Still only in ocean, this is when fish started to become dominant

Question 9

Silurian period

Answer 9

443-419 MYA: third period of paleozoic era
-Evolution of jaws and large predatory fish, as well and primitive plant life on land

Question 10

Devonian period

Answer 10

419-359 MYA: fourth period of paleozoic era,
-Large forests on land, as well as larger predatory fish (dunkleosteus) and some lobe fined fish like tiktaalik making their way onto land

Question 11

Carboniferous period

Answer 11

359-299 MYA: fifth period of paleozoic era,
-Many amphibians and first amniotes.
-Plant life from this period makes up most of the coal we now have

Question 12

Permain Period

Answer 12

299-252 MYA: sixth and last period of paleozoic era,
-Pangaea was formed
-Reptiles made three lineages (anapsid (turtles), diapsids (further reptiles) and synapsids (mammals)).
-Desert enviro
-Mass extinction event to finish it off

Question 13

Mesozoic Era

Answer 13

252-66 MYA. Age of dinosaurs
contains: Triassic, Jurassic, Early cretaceous and late cretaceous

Question 14

Triassic period

Answer 14

252-201 MYA: first period of Mesozoic Era
-Starts slow in recovery from mass at end of Permian extinction
-After lots of evolution and start of the dinosaur groups we went over.
-pterosaurs evolved (group, rhamphorhynchoids)
-pangaea starts to come apart
-ornithischains and saurischians start to show up
-ichtyosaurs (fish lizard), reptiles that returned to water, joined later by plesiosaurs

Question 15

Jurassic Period

Answer 15

201-145 MYA: second period of Mesozoic Era
-dinosaur diversity with lots of sauropods.
-had the stegosaurs only in this period
-from the rhamphorhynchoid group in the triassic they evolve to the Pterodactyloids
- the first ankylosaurs, ornithopods and ceratopsians appear

Question 16

Early Cretaceous period

Answer 16

146-100 MYA: third period of mesozoic Era:
-Theropods evolve (spinosaurs) and others
-mosasaurs in the oceans joining plesiosaurs and ichthyosaurs
-main fossils found in yixian formation (china) and cedar mountain formation in Utah

Question 17

Late Cretaceous period

Answer 17

100-65 MYA: fourth and last period of mesozoic era:
-apex of non-avian dinosaurs till the meteror came and killed them all
-coelurosaurian theropods are abundant (tyrannosaurs, ornithomimids, therizinosaurs, oviraptorsaurs, dromeaeosaurs, troodontids
-ceratopsians and hadrosaurs are dominant
-this is the only place that pachycephalosaurs are found
-the first flowering plants also evolve

Question 18

Cenozoic Era

Answer 18

66-0 MYA: age of mammals,
-Even though they have been around since the triassic after the metetor came they became dominant
-Grasses become dominant for the first time.
contains Paleogene, neogene and quaternary periods

Question 19

Paleogene Period

Answer 19

66-23 MYA: first period of Cenozoic Era:
-cooler temps and mammals have lots of diversity more as well as birds

Question 20

Neogene period

Answer 20

23-2.6 MYA: second period of cenozoic Era:
-hominids in Africa and cooler temps still

Question 21

Quaternary Period

Answer 21

Current period and third period of the Cenozoic Era:
-several ice ages happened and now humans are doing our thing