Palaeogeography and Plate Tectonics Flashcards
What was the supercontinent called?
Pangaea
Who was the German researcher who first proposed that the continents used to be connected into one?
Alfred Wagner
What evidence did alfred wagner use to form his hypothesis?
The east coast of South America and West coast of Africa seemed to share a similar shape; there were also overlaps in fossilized specimens in these two regions that would not have been able to swim.
What was Wegener missing when he first suggested that there used to be a supercontinent?
He was able to show by which mechanism the Continents moved?
What is the outermost layer of the earth that consists of continents and ocean basins?
The crust
How deep is the crust?
Between 5 and 25 km deep
What is the layer of the earth that is below the crust?
The mantle
How deep is the mantle?
The mantle layer is over 2,500 km deep.
What is the uppermost portion of the mantle + the crust called?
The lithosphere
What is the layer below the lithsphere of the mantle called?
The Asthenosphere
What are the differences between the asthenosphere and the lithosphere?
The lithosphere is rigid and solid, the asthenosphere is viscous and flows
What is below the mantel in the earth? What is it made of?
The core that is made of iron and nickel
What are the two layers of the core?
The outer core which is made of molten liquid, and the inner core that is a solid ball, the inner core is estimated to be as hot as the surface of the sun
What causes currents in the asthenoshpere?
The high internal temperatures of the earth
What do the asthenosphere currents do?
They move plates/pieces of the lithosphere around causing them to move
How does the lithosphere move?
The viscous asthenosphere and currents that it experiences move the lithosphere plates, slowly overtime the lithosphere also sinks into the asthenosphere and gets heated while part of the asthenosphere gets exposed to the colder outer temperatures and solidifies
What is the movement of the Lithosphere called?
Plate Tectonics
What are the three natural events/formations that can come of two tectonic plates colliding?
Earthquakes, Volcanoes, or Mountains
What did the earth look like at the start of the triassic?
It was still a single supercontinent - Pangea
What was the name of the super ocean that coincided with pangaea?
Panthalassa
Why were dinosaurs quite similar all over the planet throughout the late Triassic and early Jurassic?
There were no major sea barriers preventing the same dinosaurs form moving and occupying all the land.
What formations porvide evidence for dinosaurs being similar in different parts of the world during the jurassic?
The Morrison Formation, The Tendaguru Formation (Tanzania) and the Lourinha Formation (Portugal)
When did the first true sauropods appear?
Late Triassic
When did sauropods surpass prosauropods in abundance and body size?
The early Jurassic
Which linneages of Sauropods evolved during the Jurassic?
The Diplodocids and the Macronarians
What was a characteristic feature of Diplodocids?
They had long necks even for sauropods, having short front legs and a horse-like face - peg like teeth
What were characteristic features of the macronarians?
More robust bodies, no shorter front legs, some had much longer front legs, filled the ecological niche of high browsers
What is an ecological niche?
An animals way of life - An animals role in an ecosystem
Why did Diplodicus and macronarians not face high levels of competition when they coexisted?
Macronarians and Diplodicus were both hgh browsers however Macronarians have mouths adapted to eat much harder even woody vegetation, meanwhile the Diplodocids would generally only eat leaves, thus the diplodocids could eat the leaves and leave the stems for the nacronarianes.
What is niche partitioning?
A situation where animals adapt to change their niche slightly when they come into competition in the same niche.
What were the small herbivorous ornithiscians that coexisted with the macronarians and diplocidus?
The Thyreophorans - The stegosaurus
What did ornithopods look like during the Jurassic?
Small with long legs and fast, nickname Jurassic gazelle
What were the major early Jurassic theropod carnivorous branches?
megalosaurids and ceratosaurids
Which theropod Carnivore took over in the late Jurassic period?
The allosaurids
What was different about the allosaurids?
Their vertebrae interlocked more rigidly, and their legs were longer.
What were the smaller and equally rigid spined dinosaurs that evolved alongside the allosaurids called?
Coelurosaurs
What were characteristics of coelurosaurs?
long series of sacral vertebrae, narrow hands, lightweight tails
From which major branch of theropods did birds evolve?
Coelurosaurs
What two major continents did pangaea split into?
Laurasia (Northern) and Gondwana (Southern)
In which period did Pangaea split into two halves?
The Jurassic
What were the major dinosaurs in the north during the early cretaceous?
Iguanodontians, ankylosaurs, brachiosaurid sauropods and the first Ceratopsians ; coelurosaurian theropods
Who were the dominant Theropods in Africa during the early cretaceous?
Spinosaurs and carchardontosaurids
When did Sauropods go extinct in Laurasia?
The Late Cretaceous, continued to live in Gondwana
Which branch of Sauropods dominated during the late Cretaceous?
After Diplodocids and Brachiosaurids went extinct, the major Sauropod was the Titanosaurs
What are titanosaurs?
The most robust of all sauropods, broad chests and wide hips, many had osteoderms some had spiky armour
What is a major example of the Titanosaur line?
Argentinosaurus, largest creature to ever walk the earth
What were the major predators of the Titanosaurs?
The carcharodontasours - bigger heads with longer jaws
What was the biggest carcharodontosaur?
Giganotosaurus
Other than carcharodontosaurs what were the other large predator of the late cretaceous in South America?
Abelisaurs
What did niche partitioning cause in abelisaurs to look like?
short muzzles, tiny teeth, short stubby arms, smaller prey
What suggests that there was a land bridge between North and South America during the late cretaceous?
The appearance of Hadrosaurs and Ankylosaurs in south America from that period
What was a major difference between the herbivore niches of the north and south in the late cretaceous?
Titanosaurs played a much smaller role in the northern ecosystems.
What are the two major groups of ankylosaurs during the late cretaceous and what differentiates them?
Ankyosaurids - tail clubs large backward pointing horns; Nodosaurids - no tail club, outward projecting osteoderm spikes.
What were the most successful herbivores in the north during the late Cretaceous?
Hadrosaurs
What were the two advanced groups of hadrosaurs during the late cretaceous?
The lambeosaurine hadrosaurs - crested sound amplifying hadrosaurs; hadrosaurines - no sound amplifying crests, but still have fleshy crests
What were the second most prevalent herbivores in the north during the late cretaceous?
The marginocephalians - pachycephalosaurs and ceratopsians
What did early ceratopsians look like?
They were bipedal, small, large beaks and small cheek-horns
Where did more derived ceratopsians live?
The north
Who was dominating the carnivorous niche in the north at the end of the cretacious?
The tyrannosaurids
What advantages did tyrannosaurids have?
Even stiffer vertebral columns and even longer legs with massive skulls and jaw muscles
How did Tyrannosaurs compensate for the largeness of their heads?
Reduced their arms and hands
What other groups besides tyrannosaurs evolved from coelurosaurs in the late cretaceous?
Ornithomimids - similar to modern ostriches and emus; Maniraptorans - ancestors of birds evolution of semilunate carpal
What is the semilunate carpal?
Crescent shaped carpal bones that allow the hand to fold backwards at a sharp angle
What are the noteworthy lineages of the maniraptorans?
Birds, Dromaeosaurs and Oviraptosaurs
What group did scientists believe that therizinosaurs belonged to?
Turtles
What group are Therizinosaurs actually part of?
Maniraptoran Theropods
What is faunal interchange?
A phenomenon where plate tectonics bring previous separated regions together so that their fauna intermingle
What caused the climate to be much hotter during the mesozoic?
Volcanic activity releasing carbon dioxide and changes in air and water currents
Did dinosaurs thrive in polar regoins?
Yes
What is there debate about concerning periods of low light in the polar regions?
Whether dinosaurs in these regions migrated south or overwintered in the polar regions
Why was there a much higher sea level during the Mesozoic?
There were no icecaps or glaciers, and the warmer temperatures caused thermal expansion in the oceans.
What were the consequences of a higher sea level during the mesozoic?
Flooding of vast regions of the earth, limiting the amount of exposed land and splitting areas that are currently connected.
What was the vast waterway of North America called from the mesozoic?
Western Interior seaway
Why can marine fossils be found in albertan fossil records?
Because they were covered by the western interior seaway
What is a southern formation in Alberta that has marine specimens?
The Bearpaw formation
