Jurassic Earth

Question 1

What happens after Tr-J?

Answer 1

dinos dominate

Pangaea begins rifting

Question 2

How did Pangaea start rifting?

Answer 2

began in central Atlantic (gulf of Mexico), extended southward

Laurasia/Gondwana splits by end of Jurassic

Question 3

Early/Middle Jurassic Climate

Answer 3

spotty fossil record of climate due to vast DESERT SAND SEAS

migration of dunes shown in thick eolian deposits of sandstone (cross bedded)

Question 4

Early/Middle Vegetation

Answer 4

same as Triassic (conifers, cycads, gingkos)

the age of cycads tho

ferns not as present, seed ferns extinct

Question 5

Early/Middle Seas

Answer 5

Ichthyosaurs and plesiosaurs still dominate, but are LARGER

Question 6

Early/Middle Dinos

Answer 6

dinosaur reign began

all large meat/plant eaters were dinos

Sichuan Province of China had the most

Question 7

Late Jurassic Dinos (163-145Ma)

Answer 7

Golden Age of Dinosaurs
largest land animals ever at this time

largest sauropods appear (diplodocus, apatosaurus, camarasaurus, brachisaurus)

stegosaurids, small-med ornithopods

carnosaur and megalosaurs dominant predators

Question 8

Late Jurassic Geography

Answer 8

Laurasia and Gondwana completely separate by Gulf of Mexico and Tethys sea, caused rising sea levels

Rocky Mountains being formed by
WEST -> island arc accretions (adding materials like sediments onto it), continues into Paleogene

EAST -> crust bending downwards

Question 9

Late Jurassic Climate

Answer 9

wamer and wetter than Early/Middle

still monsoonal

Question 10

epicontinential sea

Answer 10

a shallow sea that covers central areas of continents during periods of high sea level

present in late Jurassic due to rising sea levels

Question 11

Other Late Jurassic Life

Answer 11

warmer climate lets vegetation persist in higher altitudes

oysters and sea urchins added to sea floor