Lecture 19: Dinosaurs and paleogeography

Question 1

Are vertebraes or intervertebraes more rare

Answer 1

vertebraes

Question 2

What is Endemism?

Answer 2

Restriction to one area, migration routes may be shut down because of continental separation

Question 3

What was the temporal distribution?

Answer 3

A new dinosaur genus occurred every 4-8 million years, could be longer if a mass extinction occurs

Question 4

Ceratopsian Dinosaurs

Answer 4

Relatively complete fossil record, a new species every 1.9 million years, Stegosaurs produced 1 new species every 5.6 million yrs.

Question 5

What is Minimum Divergence time?

Answer 5

Used as an estimation (based on earliest fossil finds) for fossil completeness, Minimum divergence time used with ceratopsian dinosaurs

Question 6

Late triassic (231-208)

Answer 6

Time of pangea, a time of heat and aridity and strong seasons and low endemism. Small amount of dinosaurs in comparison to the jurassic and cretaceous

Question 7

Who was around in the triassic?

Answer 7

therapsids
Archosaurs
Pterosaurs
Early mammals
Earliest dinosaurs (231-223ma) e.g., eoraptor

Question 8

Fossil Localities of the triassic

Answer 8

China and India
South Africa- Stromberg series (ancient fluvial system, beautifully preserved therapsids Prosauropod melanorosaurus)
Several Localities in Europe
South America (argentina)
North American 
-Chinle formation
-new mexico, utah and Arizona
-Ghost ranch- Coelophysis

Question 9

Early jurassic (208-178 Ma)

Answer 9

Dinosaurs become more dominant, slow break up of Pangea, no endemism yet

Question 10

What was around during the jurassic?

Answer 10

Ornithischia (cerapoda, thyreophora) Prosauropods remained, true sauropods developed

Question 11

Fossil localities of the early jurassic

Answer 11

Asia (china and India)
Africa (south Africa, Zimbabwe, morocco) (footprints and body fossils)
Europe, strata not well preserved
South america (trackways of theropods)
North america (fossils in lake sediments filling rift valleys, in the west fluvial)
Antartica (remains of theropods and large prosauropod)

Question 12

Middle Jurassic (178-157 ma)

Answer 12

Few sediment sections are preserved, sea level lowstand in early to middle jurassic, time of erosion, gap in dinosaur record, no reflection of abundance

Question 13

Fossil localities of middle jurassic

Answer 13

Asia (china has most diverse fauna, monolophosaurus and sinraptor)
Africa
Europe (england has footprints and megalosaurus)
South America (chile and argentina)
North America (footprints, ornithischian and theropod teeth, pterosaurs, crocodiles and mammals
Australia (footprints and one sauropod)

Question 14

Late jurassic (157-145)

Answer 14

Climate warming, sea level rose, tethyan sea continued to widen, North and South America split, endemism, this was the age of dinosaurs. (sauropods became abundant, theropods, turtles, pterosaurs, archaeopteryx and crocodiles)

Question 15

Fossil localities of the late jurassic

Answer 15

Theropods: 
-china 
-india and thailand
African tendaguru beds
-spectacular sauropods, small ornithopod,primitve stegosaurs and theropods
Europe
-Solnhofen (compsognathus and archaeopteryx)
South america
-trackways from chile and argentia

Question 16

North american (fossil locality) of the late jurassic

Answer 16

Morrison formation
Extensive sedimentary package that was shed from the rocky mountains
rivers, lakes and coastal barrier bars

Question 17

Fossils from Morrison Formation

Answer 17

Allosaurus
Ceratosaurus
Diplodocus
Apatosaurus 
ultrasaurus
supersaurus
seismosaurus
eggshells and trackways

Question 18

Early cretaceous (145-97 ma)

Answer 18

Enhanced tectonic activity, increased greenhouse effect, warmer climate, increased endemism due to increased continental separation

Question 19

Who Became dominant in the early cretaceous?

Answer 19

Ornithopoda replaced sauropods and stegosaurs as major herbivores
Ankylosaurs

Question 20

Fossil localities of early cretaceous

Answer 20

Asia: wide distribution
-Earliest ceratopsian psittacosaurus
Africa (north)
-important primitive ornithopods
Europe
-Wealden fossil beds in southern England
South america
North america (deinonychus)
Australia- fossils indicate connection at the time with gondwana, separation from Antarctica during early tertiary

Question 21

Late cretaceous (97-65ma)

Answer 21

High sea levels, advanced continental separation, increased endemism, warm climates, cooling trend over the last 30 million years

Question 22

The late cretaceous had the greatest _____ of dinosaurs

Answer 22

Diversity; tyrannosaurids, duck billed dinosaurs, ceratopsian dinosaurs, pachycephalosauria

Question 23

Evolution (late cretaceous)

Answer 23

Older taxa remained in south america, new taxa developed in north america, Stegosaurs left before extinction event

Question 24

Similarities between North america and China

Answer 24

Cladisitc analysis indicates;
North american Fauna developed from china (mongolia)
Land bridge over bering strait
During pleistocene called beringia

Question 25

Changing food sources of the late cretaceous

Answer 25

Development of angiosperms, connection to radiation fo dinosaurs, co evolution

Question 26

Robert Bakkers view

Answer 26

Before angiosperms: conifers, cycads and ginkgoes
Low, indiscriminate feeding
destruction by trampling feet
Plant counteracted by production of vast quantities of off-springs (seeds)

Question 27

Dominance of Dinosaurs

Answer 27

Dominance in Northern hemisphere but there is a bias due to better funding

Question 28

Which dinosaurs lived together, Southern central Fauna

Answer 28

Alamosaurus- dominant
Hadrosaurids, ankylosaurs, ceratopsian, and theropodss.
Series of intermontane basins with seasonal wet and and dry climates

Question 29

Which dinosaurs lived together: Central Fauna

Answer 29

Dominated by triceratops and leptoceratops
Theropods, ankylosaurs and hypsilophodontids
Close to uplifting rocky mountains with cooler temperatures

Question 30

Which dinosaurs lived together: Northern Fauna

Answer 30

Dominated by triceratops
Theropod, ankylosaurs, duckbills, pachycephalosaurs, hypsilophondontids.
Low, broad, humid coastal plain setting adjacent to the western interior sea

Question 31

China’s Paleoenvironments

Answer 31

Semiarid and arid basins
No abundant water
only playa lakes

Question 32

North america vs. China

Answer 32

NA: gradual change towards advanced taxa
C: mixed taxa
NA: good predator to prey dominance
C: no direct dominance, dominance of ceratopsian dinos not matched

Question 33

Dinosaurs Migrated from _____ to _____ _______ over the bering strait

Answer 33

Asia; North America

Question 34

Tertiary

Answer 34

160 million years of successful evolution comes to an end, Mammals take over, in 1987 tertiary dinos were discovered in Montana