Geo 100 Exam 1

Dinosauria

means "terrible lizard"

was first used in 1842

coined by Richard Owen

When and where did dinosaurs live?

They lived everywhere. Remains have been found on all the continents.

They originated in the late Triassic period and died at the end of the Cretaceous (225-66 million years ago)

Why are many animals mistaken for dinosaurs?

Most people think any large, extinct animal is a dinosaur like wooly mammoths, pterosaurs, etc.

Where do earth's hydrocarbons (oil and natural gas) come from?

Remains of bacteria or plants

NOT DINOSAURS!!

What do paleontologists study?

ancient life

What is phylogeny?

The evolutionary history of a species or group of related species

Central ideas behind Darwinism

Natural Selection: says that a species will change over time due to the changes in their environment.

Descent w/Modification: says that we are modified descendants of our ancestors through natural selection

Stratophentic Method (describe method and its major pitfalls)

This is a method that considered time and the overall similarity of fossils of taxa as keys to their phylogenetic relationships. This method tried to sort them by age and by that way, sorting them as descendants and ancestors.

The problem with this method is that it assumed a complete fossil record. The fossil record is missing so much that this method doesn't work.

What is the preferred method of phylogeny? How does it identify taxa?

Cladistics. It sorts taxa based on their relationships to each other and the evolutionary novelties they share

What is convergence?

2 or more distinct species share traits NOT due to a common ancestor

Birds, bats, and butterflies all have wings that allow them to fly, but they are not related to each other. Their environment perhaps allowed them to develop wings, but they aren't related.

What is divergence?

Diverse forms of species that come from a common ancestor (they don't look alike but they are related)

Dog, wolf, and fox all diverged from a common ancestor

How does convergence pose a problem for cladistics? (phylogenetic systematics)

Because an evolutionary novelties that is thought to unite taxa doesn't actually unite them (they are not related). Cladists then group them by these novelites that in reality shouldn't be grouped together.

What are the differences between homology and analogy

Homology = similar anatomy but differing functions that come from a common ancestor

Ex. Arm of human vs fin of whale

Analogy = different anatomy but similar functions that do NOT come from a common ancestor

Ex. Wing of bat vs wing of bird.

What are the differences between cladistics and the Linnaean system?

The Linnaean system created a false sense of hierarchy between species (creates a rank)

Cladistics tells you something useful about an organism (its evolutionary history) and doesn't try to use geologic age (which is almost impossible to do). These relationships are testable.

What model of organism relationships was followed by Lamarkism?

He ranked all organisms in a similar manner as the Great Chain of Being. He believed in the theory of Use/Disuse, meaning if an organism used and developed a certain attribute, that would then be passed on to its descendants (like working out would somehow make your offspring more ripped).

He also believed that organisms got more complex as they lived longer.

He didn't believe in extintion.

What are the strengths of cladistics?

It doesn't require that the fossil record be compete. It is just a way to sort them through their evolutionary traits, not by time (which can be very difficult to do)

How do you name a dinosaur?

You follow the International Code of Zoological Nomenclature which tells you how you must spell it, it must take a Latin ending, and many of them have Greek or Latin roots. Genus and species are always italicized. They are written this way so paleontologists from around the world can read it.

They can come up with creative names, as long as they follow these rules.

What is the Principle of Priority?

The oldest correctly proposed scientific name takes priority

What problems are alleviated by applying the Principle of Priority?

Alleviates people fighting over who gets to name a dinosaur

Explain how the priority issue pertaining to Apatosaurus and Brontosaurus is resolved:

Marsh thought that they were 2 different animals, so he named them both. Many years later, it was discovered that they were in fact the same. Since Apatosaurus was named first, this became the correct name for the dinosaur.

Explain the concept of Linnaean binomen:

Genus species. All organisms are made this way, creating less confusion.

Macro vs Micro evolution:

macro - study of a lot of species over a long period of time

micro - study of changes within a species over a relatively short period of time

What LInnaean levels do macro and micro evolution pertain to?

Macro = anything above the species level

Micro = at the species level

Know why the fossil record of dinosaurs is best applied to problems of macro-evolution, not micro-evolution:

Because the fossil record is so incomplete, we don't have enough detail to study dinosaurs through micro-evolution.

Strengths and weaknesses of the fossil record for studying evolution:

We have less than 1% of the fossils that once lived on Earth, so the fossil record is very incomplete.

Be able to identify clades, sister taxa, outgroups, evolutionary novelties, stems, and branches in a cladogram:

outgroup: a group that is outside of the group you are interested in (like an outlier)

Monophyletic group

A natural group that includes all its descendants (this is done correctly)

Polyphyletic group

a non-natural group that includes forms that shouldn't be there

(this is an error, cladists are always trying to fix these)

Paraphyletic group

a natural group that does NOT include all ancestors (they left some ancestor out that should also be included)

(this is an error, cladists are always trying to fix these)

How is an amniote defined within cladistics?

are a clade of tetrapod vertebrates comprising the reptiles, birds, and mammals.

Describe the diversity of organisms today. About how many species live on earth today? What % of earth's species are preserved in the fossil record?

10 to 30 million species on Earth today

Less than 1% of organisms in Earth's past are fossilized

What is the definition of a fossil?

Over 10,000 years old

Evidence of ancient life

Body Fossils

mineralized bone, skin if dead

Trace Fossils

tracks, eggs, skin impressions, tooth marks, stomach stones, fossilized feces

What are the 5 different types of fossilization?

Permineralization

Replacement

Carbonization

Amber

Freezing

What are examples of each type of fossilization?

Permineralization: minerals added to open spaces around the bone

Replacement: wood replaced by silica, shells replaced by quartz

Carbonization: this is like a stamp kind of. It preserves leaves, feathers, skin, etc.

Amber: is like a natrual resin, this would be like a bug getting stuck inside an amber stone

Freezing: wooly mammoths have been found frozen in ice

Which type of fossilization is predominant in dinosaurs?

Permineralization

What is the composition of dinosaur bones?

50% organic material (collagen fibers)

50% mineral (hydroxl-apatite)

What is the composition of dinosaur teeth?

5% organic material (collagen fibers)

95% mineral (hydroxyl-apatite)

What are the advantages of composite structures?

They are flexible and strong!!

Explain why/how cellular details are preserved in fossil bone/wood:

When a creature dies, if it is buried, before or after decay, it can eventually become a fossil. This is because after being buried, if the conditions are right, it'll be mineralized. The minerals will over the years seep into the bones and tiny spaces around the inorganic material, and fill it in. So, when it is dug up much later, it can be used/studied to be understood better. After 10,000 or so years of this process, it'd become a fossil. Wood is replaced by silica. Petrification does not preserve detail very well.

What is uniformitarianism?

The belief that the Earth's past geological changes can be fully explained by current processes.

What type of rock are dinosaurs most usually preserved in?

Sedimentary!

What type of rock are dinosaurs least likely to be preserved in?

Igneous or metamorphic

Fluvial

pertaining to a river

typically has more energy and is thus able to move larger grains or particles

has floodplains

Lacustrine

pertaining to lakes

is slowly moving, stagnant, so it cannot move very large particles

Eolian

pertaining to wind

it cannot move large particles

Deltaic

pertaining to or like a delta (where the river meets the ocean)

is similar to a fluvial environment

What type of rocks result when sediments of mud, sand, gravel, and organic matter are lithified?

mud: makes mudstone, is very silty, if bones in there, they will most likely be crushed

sand: fairly fine sediments, although not as fine as mudstone

gravel:

What environment contains most dinosaur fossils?

Fluvial because it allows for dinosaurs to be buried quickly and also there is enough water there to allow for preservation (?)

What is paleosol and what can it reveal about the environments in which the dinosaurs lived?

It is a buried soil/strata of soil. It can reveal about the environments that were previously there. For example, what is today a desert, may have once been a river or a swamp. By looking at the soil, they can figure out what the area used to be like, and it's likely role in that environment.

What is the relative geologic time scale?

It just says "thing A is older than thing B"

doesn't try to put an exact age to anything, just compares relationships between things

What is the absolute geologic time scale?

attempts to put an absolute age ( a number ) on the ages of dinosaurs

What is superposition?

the rock strata at the bottom is the oldest, the rock strata on top is the youngest

What is biostratigraphic correlation?

using comparable fossils in separate rocks to determine the age of the rocks

Why was the relative time scale useful in spite of the lack of absolute ages?

It is so difficult to put an absolute age on dinosaur fossils because you can't test them directly. For this reason, it is helpful to compare two types of dinosaur fossils and say "This one is older than the other"

When did dinosaurs live (in terms of relative time scale and absolute time scale)?

They lived in the Late Triassic period to the Cretaceous

About 225 million years ago to 66 million years ago

Which type of rocks can be directly dated?

Crystals from igneous rocks (uranium)

What is carbon 14 dating?

The amount of

radioactive carbon in an object is measured

to determine the age of it.

What is Carbon 14 dating used for?

to date relatively young stuff.

Why can't carbon 14 dating be used to date fossils?

The half life is too short (only 5700 years, so you can't go back far enough)

Why are mineral crystals in igneous rocks used to determine absolute ages?

because they have the most uranium in them?

Anapsids

no temporal fenestrae

these are amniotes (reptiles)

ex: turtle

Synapsids

Have one temporal fenestra

they are mammals

ex: humans

Euryapsids

have a single temporal fenestra but its placement is different than that of synapsids.

they are marine reptiles, plesiosuars, and ichtyosaurs

Diapsids

two temporal fenestrae

(mandibular fenestra and antorbital fenestra)

they are dinosaurs, birds, crocodiles, lizards, pterosaurs

What are the temporal fenestrae that dinosaurs had?

Mandibular fenestra

Antorbital fenestra

This connected their jaw muscles

What is the relationship between Dinosauria, Archosauria, and Diapsida?

Diapsids are at the bottom of the clade (2 temporal fenestra)

Archosaurs are Diapsids (so they still have 2 temp. fenestra) but they also have 2 additional fenestra (mandible/anotrbital)

Dinosaurs are Archosaurs, meaning they are also Diapsids. Their evolutionary novelty is the deltopectoral crest on their humerus

How are the ankle structures of archosaurs a key to their phylogenetic relationships?

Archosaurs are broken up into Crocodilians and Avemetatarsalia, which are differentiated by their ankle bones.

Crocodilians have an ankle that supports their sprawling posture

Avemetatarsalia (which then goes to dinosauria) has a hinge like ankle structure. This allows for their upright posture.

What is the relationship between silesaurs and dinosaurs?

Silesaurs are the closest relatives to dinosaurs

they are dinosaur like archosaurs that probably shared a common ancestor with dinosaurs

What is the evolutionary novelty of the clade Dinosauria?

upright posture

deltopectoral crest on humerus

What is the definition of dinosaur?

Triceratops + Birds

Which clade has a unidirectional lung?

Archosaur

Why do cladists prefer to use the term Archosauria in discussing dinosaurs and avoid using the terms reptiles and thecodonts?

Designating these groups as such necessitates paraphyletic clades, because, for example, to say reptile would then have to exclude birds and mammals. Thus, amniote is preferable to reptile. Thecodonts means reptiles with teeth set in sockets, but that is not ideal because that would include iguanas, which are non-archosaurian diapsids. Archosaur is a better term

What are the distinguishing characteristics of Archosaurs?

Mandibular fenestra and antorbital fenestra

Unidirectional air flow through lungs

teeth set in sockets

What are the 2 clades of archosaurs?

Crocodilian and Birds (avemetatarsalia)

What are the 2 clades of dinosauria?

Saurichia and Ornithicia

Compare and contrast saurischian and ornithischian dinosaurs:

Saurischian: The pubis is simple, down and forward

Ornithischian: 2 branches of pubis (forward and backward), predentary

Were dinosaurs rare, common, or abundant in the Late Triassic period?

They were very sparce.

Crocodilian related species dominated the land

Describe the nature of non-dinosaurian fauna such as dicynodonts, aetosaurs, and phytosaurs:

Dicynodonts: they were cow like herbivores

Aetosaurs: they were an armored herbivore

Phytosaurs: a predator similar to crocodiles, but their nostrils near the eyes

What other clades of non-dinosauria had their origins in the late Triassic?

Crocodilians?

How and when did dinosaurs become the dominant terrestrial vertebrates? What event may have enabled dinosaur dominance?

The Triassic-Jurassic Extinction

This extinction killed off all the archosaurs, except the dinosaurs and some crocodilians

What was the arrangement of Earth's tectonic plates when dinosaurs lived here How did this influence diversity of dinosaurs through time?

Pangaea.

What was the dominant climate during the Triassic period?

very dry and hot

how did climate change through the mesozoic era?

generally warm

What were the first 3 dinosaurs described? What was their nature?

Megalosaurus, Iguanadon, Hylaeosaurus

When and where did the study of dinosaurs begin?

Began in England in the 1820s.

What were the contributions of Richard Owens, William Buckland, and Benjamin Waterhouse?

Richard Owens: the man who made up the term Dinosaur

William Buckland: in 1824, he found the Megalosaurus

Benjamin Waterhouse: was the artist who made the statues on Iguanadon in England

What is the significance of the discovery of the Hadrosaurus?

It was found in New Jersey and was the first relatively complete dinosaur skeleton found. It made Leidy realize that dinosaurs had an upright posture.

Why was the Iguanadon named that?

It had teeth similar to the teeth of the living iguana.

What was the Owens-Hawkins portrayal of the dinosaurs?

They were portrayed like slow, brute reptiles.

What was the "Great Dinosaur Rush"?

1870s

Between Edward Cope and Othniel Charles Marsh

They went to the western US and found tons of dinosaurs

What happened in the 1970s in regards to dinosaurs?

Robert Bakker made John Ostrom's ideas famous. He started to teach his ideas about them being "turbo charged." They were active, agile, and dynamic!

Which paleontologists began the Dinosaur Renaissance and the dinosaur-bird hypothesis?

John Ostrom, he is known for putting dinosaurs back on the map. He taught that they were very fast, warm-blooded, feathered, dynamic

What major discoveries happened in the 20th century?

They were discovered to be agile, fast, feathered, warm-blooded

the misconception of them being brutes, slow, was disproved

What is the age of the Morrison formation? Where is it and why is it world renowned?

between 148 million and 155 million years old

colorado, utah, they have found tons of dinosaurs there

What is the significance of the Megalosaurus?

It was the first dinosaur to be named.

What was the principal purpose of the Central Asiatic Expeditions of the American Museum of Natural History?

Roy chapman andrews wanted to find early man!!

Instead they found many nests, eggs, and the oviraraptor, velociraptor, etc.

Which part of the world is currently popular in dinosaur excavation?

Western North America

What are the rules of science?

Reproducibility

Predictive Power

Prospect for Improvement

Naturalism

Uniformitarianism

Simplicity

Harmony