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Dinosaurs
Minicourse
32
Geology
Undergraduate 2
04/19/2010

Additional Geology Flashcards

 


 

Cards

Term
Why is paleontology called a 'four-dimensional' science?
Definition
Paleontology is called a 4 dimensional science because it adds a time dimension to the three dimensions of space we live in. That is, paleontology adds time to studies of biology.
Term
What did the word 'fossil' originally mean?
Definition
Something dug up
Term
What is the difference between a body fossil and a trace fossil?
Definition

a body fossil is the preserve of some portion of the once living organism-most complete body fossil

a trace fossil is a preserve of trace left behind by the organism and doesn't include part of the organism itself- shows what organism could do and more dynamic than body fossil

Term
What is a fact? A hypothesis? A theory?
Definition

Fact: objective and verifiable observation made about the natural world

Hypothesis: general explanation of facts; makes predictions that can be tested

Theory: hypothesis that has withstood repeated testing

Term
What is the tree of life? What is at the tips of the twigs and what is at the branchpoints?
Definition
The tree of life is used to discuss the four dimensions/deeper history. The tips of twigs are existing species and the trunk is the common ancestor of all life. The branchpoints represent ancestors of particular regions of the tree. For example, if you gather many twig tips representing mammals, birds, lizards, snakes, and turtles, the branch point that unites them is the ancestor of all those animals together. Make sense? 
Term
How does Natural Selection Work?
Definition

reproduction->variation-> excess->selection-> divergence (separation and time result in ADAPTION and SPECIFICATION)

*types of competition either biotic(intraspecific competition, prediation) or abiotic (environmental factors)

Term
Are few/some/many animals that one existed now extinct?
Definition

Most species are extinct (>98% of organisms have gone extinct)

*to prove something is extinct you must prove that the fossil is distinct from living forms or that the fossil is no longer in existence*

Term
What is the difference between relative and absolute dating?
Definition

relative: places fossils on a time scale via ordering strata (super position, original horizontality, lateral continuity, faunal succession, cross-cutting relationships)

absolute: determine the specific date; linear change (constant overtime) and geometric change (rate decreases overtime)

Term
What is superposition?
Definition
sedimentary layers are deposited with oldest on bottom and youngest on top
Term
How do cross-cutting relationships help us to order events?
Definition
The geologic feature which cuts another is the younger of the two features (can get a relative sequence of events)
Term
How old is the earth?
Definition
4.5-4.6 billion years old and this is determined by radiometric dating of 1)rocks from the earth 2)extraterrestrial rocks 3)oldest moon rocks
Term
What is plate tectonics?
Definition
Describes the large scale motions of Earth's Lithosphere- which is broken up into 1-8 major and many minor tectonic plates which are able to move because the lithosphere has higher strength and lower density than underlying aesthenosphere
Term
What is DNA and where is it stored in your body?
Definition
DNA is stored on chromosomes (each body cell contains 2 copies of 23 chromosomes(diploid) and sex cells contain 1 copy of your 23 chromosomes (haploid))
Term
What are sex cells?
Definition
Sex cells contain 1 copy of your 23 chromosomes
Term
What happens during fertilization? Cleavage? Gastrulation?
Definition

fertilization: fusion of gametes (sex cells)

cleavage: rapid cell division (prophase->metaphase->early anaphase->late anaphase produces blastula

gastrulation: making layers

Term
What do homeobox (Hox) genes control?
Definition

'Master Control Genes' or genes whose protein products control the expression of other genes

DETERMINE CELL FATE

Term
How did the configuration of continents change during the dinosaur era?
Definition
originally one supercontinent which then split apart; mid-jurassic there was a northern and southern landmass
Term
What is Pangea? Gondwana? Laurasia?
Definition

Pangea: supercontinent that existed during the paleozoic and mesozoic eras

Laurasia: northern land mass during the mid-jurassic

Gondwana: southern land mass during mid-jurassic

Term
Which of the major groups of living tetrapods (limbed, backboned animals) were around during the Mesozoic?
Definition
Mammals were present during this era but weren't predominant (mostly teeth and jaws. Mesozoic snakes had legs
Term
When was the term "dinosaur" coined?
Definition
1842 Sir Richard Owen coined the word Dinosaurs
Term
What was the original intent of the name?
Definition
"fearfully great reptile"
Term
What are the two major groups of dinosaurs? Which group do birds fit into?
Definition
Ornithischia and Saurischia. Birds fit into Theropoda
Term
What is the 'Dinosaur Renaissance'?
Definition

1969-Present

The idea that birds are dinosaurs->deinonychus -> proof looked at physiology, biomechanics/functional morphology and development 

Term
What was the Cope-Marsh feud and why was it important?
Definition
Rivalry between two paleontologists during the "Dinosaur Rush." Cope described the first dinosaur, Laelaps, and Marsh criticized his findings. This time of back and forth continued until they both died. The two's best legacy wereThe techniques of prospecting, recording, excavating, and shipping large fossils are perhaps the two scientists' greatest legacy.
Term
When was the dinosaur-bird connection first hypothesized?
Definition
During the Heroic Periodic (1868) by Huxley
Term
What did the discovery of many Iguanodon skeletons in a Belgian coal mine tell us?
Definition
It was the first population of dinosaurs found - it gave us a sense for the natural variation within populations. 
Term
When did the first dinosaurs appear?
Definition
228 million years ago (mid-Triassic period) and they were small and rare
Term
Where are the best sedimentary rocks for finding early dinosaurs?
Definition
Los Rastros Fm, Argentina
Term
What characteristics did the ancestral dinosaur have?
Definition
small, bipedal and carnivorous
Term
What are two competing hypotheses explaining dinosaurs' rise to prominence? Which has more evidence supporting it?
Definition

Competitive Replacement:Dinosaurs outcompeting the other species

Opportunistic:An event occurred that caused an extinction of the previous animals which then allowed dinosaurs to thrive (THIS IS SUPPORTED because the Mesozoic era is defined by two extinctions)

Term
What is the role of mass extinction in the origin of dinosaurs?
Definition
It allowed dinosaurs to become predominant
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