History of The Discovery of Dinosaurs 11/6/2013 10:31:00 PM
Paleontology: Is the study of ancient life
Became a field at about 1800
First discovery was in the 1600s. It was a thigh bone of a carnivorous
animal in London, and the people who found it thought it was the
fossilized scrotum of a biblical giant, but it was not. It was dubbed
“Sctrotum Humanum” highly likely that it was from a Megalosaurus
About 100 years laster, in Holland a Mesasaurus fossil was found. They
inferred it was a marine mamal.
Later, Gideon and Mary Ann Mantell found fossilized teeth from a
reptile called Iguanodon.
As time passed, more and more began to be found. People began to
realize there were animals that were no longer around.
Richard Owen recognized that there was a group of large “new”
animals, and named them in a class: Dinosauria meaning “terrible
Dinosauria must have these characteristics
o More than 5 vertebrae fused to the pelvis
o Had erect posture
Dunosaurs were very popular during the victorian era
North America later became a fossil hunting ground and in around 1970,
many large dinosaur fossils were found in America
Cooper/Marsh: Rival Hunters whose rivalry caused many discoveries, but
in the rush of things misnamed them.
In the 60’s and 70’s there were a lot of discoveries in Australia and South
In the last 20 years, Arctic fossils, South America and “and explosion of
John Olstrom suggested that birds were dinosaurs. We are now able to
study fossils in a new light due to the discoveries in technology
Paleobiology: The study of how ancient life forms lived.
Reading Pages 306-333 Reconstructing Dinosaurs 11/6/2013 10:31:00 PM
Finding pieces what they looked like learning about them.
We are ALWAYS missing information, but we want to know!
Understanding the animal and how it lived gives us a greater mage of the
ancient world, so the only way to know this is by learning how they
Dinosaurs have Bilateral Symmetry, meaning they are symmetrical
between the right and the left sides if they were to be divided thru the
Comparative Anatomy looks at bones of living animals to find
Phylogeny is the evolutionary development and history of a group of
Animals. It tells us about relatives and about itself by looking at relatives.
Was there a trunk? Nasal opening on the head-top are then followed by a
hole in the skull, with muscle scars. With this, we can conclude that its an
animal with a trunk
Most of the time, body opening are hard to identify because they are not
fossilized since they are soft tissue.
Pages 57-59, 61-62
How do we reconstruct Animals?
We do this by using bilateral symmetry and comparative anatomy
Why do we reconstruct Animals?
What features can be reliably rebuilt? Which can we only
speculate? Skeleton Formations 11/6/2013 10:31:00 PM
Vertebrates have from 200-400 bones
The skeletal system is a very compromised system.
It needs to balance support (bones) and mobility (joints)
The skeleton starts with bone, which is a living tissue, and isn’t the same
as dead bone
Bones have 3 forces acting upon them:
Compression: Bones being pushed together (blue)
Tension: Bones being pulled apart (pink)
Shearing: Bones being pushed by offset forces, pushed and
Bone is made of collagen fibers and hydroxyapatite
Collagen helps resist tension and compression
Hydroxyapatite is calcium, phosphates, etc…, and gives the bone
Compression of bone strength is 4x that of the compression strength of
Tension is ½
Shear is the least
Bones break because we do things with them that they were not designed
for (ex. sports)
Cartilage is good at resisting tension and is good for where shape and
structure are needed. Also, it can be a bone precursor. At birth, we at
first have cartilage until we reach adulthood does most turn to bone. It
goes away when we are done growing.
Muscle comes in different sized, and almost all movement happens due
to it. With some exceptions such boners.
Tendons attach muscle to bone
Ligaments attach bone to bone, usually found in joints
Bones react to internal and external things Exercise is good for them. It strengthens and gives growth
Minerals also affect them in various ways
Bones also respond to gravity. Gravity helps bones grow stronger.
Ossification is when a bone is d-one turning into bone, usually
from cartilage to bone.
Vertebral Column: AKA Spine. Oldest part of the skeleton. Everything
attaches to it. You can tell a lot about an animal by its spine. (A)
Cervical Vertebrae: Neck
Dorsal Vertebrae: Back to the hips (B)
Sacral Vertebrae: Fused in hips (c)
Caudal Vertebrae: Tail (D)
o A: Neural Spine
o B: Transverse Process
o C: Neural Arch
o D: Centrum
o E: Haemal Arch
Pectoral Girdle: not fused to the rest of the skeleton unlike the pelvic
Scapula: Shoulder blades, big fat slates of bone.
Coracoid: Attaches to scapula
Pelvic Girdle: Made of up 3 bones
Front Limb: contains
Humerus: Large bone from shoulder blade to elbow.
Ulna: Pinky to elbow
Radius: Thumb to elbow
Carpals: Wrist bones. Varying degrees of rotability and mobility
Metacarpals: Wrist to beginning of fingers.
Femur: From thigh to knee
Tibia: Shin bone. Most weight-bearing
Fibula: Long, skinny bone Tarsals
Dermal Scutes: Small plates of bone imbedded in the skin of the animal,
usually in the back.
Fenestras are holes.
Pages 57-59, 61-62
Study the skeleton over again Evolution 11/6/2013 10:31:00 PM
Aristotle was the founder of zoolgy
They believed observation and experimentation as a way to find
more about animals
The word came up first in the 1200s
When the church came along, it said that the earth is “de novo” in 7 days
Cornelius Laneius: Wanted to describe all the plants and animals,
and created the way we name and classify animals.
o Believed species were fixed as made by gods.
Francis Bacon: Scientific Method. Believed animals could change
Jean LeMark: French biologist and zoologist who believed species
from pre-existing species, organisms and their parts grow thru
o Size Increase: not always
o New need gives rise to new organs/structures: if the genetics
aren’t there, then no.
o Disuse does leads to degeneration.
o Inheritance of acquired traits (giraffe) (false)
Wallace: Friend of Darwin that got the same thing as him. Then
Darwin was encouraged to publish because of him.
Nature is prodigal: Organisms reproduce too much, but there is no
zero population growth
All else being equal, adult population numbers tend to remain
constant, therefore there is a struggle to survive
All species vary: some variants are more advantageous in the long
struggle for survival
Natural Selection acts to preserve advantageous variation and to
extinguish disadvantageous variation.
Mendel: worked on genetics w/ peapods and produced the theory of
Recognized ¾ but worked independently.
Ernst Haeckel: Von Baer’s law: “Ontogeny re-copulates phylogeny”
meaning that by looking at the development of embryos we can see the
process of our evolution, but it is not 100% true. Evolution synthesis threw a lot of new information out there, such as
ecology, anatomy, etc…, it became a multilayered picture.
Evolution is both, a fact and a theory
It is of fact because we can observe it through time (beak of finch)
It is a theory because we don’t know it all entirely, and we have
been wrong before. We don’t know for sure how it happened.
There is common ground between faith and science, but supernaturalism
How evolution works:
New genetic material enters the population via mutation but are
usually more disadvantageous
Natural selection does its thing.
Because variation is good for the species as a whole
Recombination maintains the variation and protects the species as a
Fitness: A measure of how likely you are to reproduce compared to
others of your kind. There are 3 components:
1. Viability: ability to survive
2. Developmental rate: the rate at which you’re able to reproduce
3. Fecundity: The ability of your offspring to reproduce
Genotype: Your genetic make up
Phenotype: The physical expression of your genotype. Acted on by the
Species: Only one to have biological meaning.
A species is a group of actually or potentially interbreeding
populations reproductively isolated from other such groups. Can’t
mate with it? It’s not your species.
Speciation: The rise of new species
Allopatric: Geographic isolation that causes speciation
Simpatric: Species arising from other species Evolution performs at different levels.
What’s missing from Darwin’s theories?
Heredity, but Darwin didn’t know anything about genetics because he didn’
know Mendel’s work.
What is a theory?
1. Domesticated animals and plants show a wide variation
2. A similarly wide range of variation exist among wild animals as
3. All living creatures are engaged in a “struggle” to survive and
ultimately reproduce, and that struggle is most severe among those
individuals that are most closely related
4. The struggle to survive in combination with the variation that
exist among individuals leads to the survival and, most importantly,
successful reproduction of some variants as opposed to some
others, a process Darwin called Natural Selection 5. The reproductive success of some variants as opposed to others
ensures that the characteristics of the successfully reproducing
variants make it to the next generation
6. This process, repeated over hundreds or even thousands of
generations, is evolution by natural selection, sometimes called
Darwanian evolution. Classification 11/6/2013 10:31:00 PM
Without classification, all is chaos and disorganized
How we classify things depends on how we’re looking at it.
Results of all classification are shaped by the criteria and the criteria
We use a hierarchical way of classification
Our classification is based upon Binomial Nomenclature. Which is a
two-name mix of the genus and the species.
Ex. Tyrannosaurus (genus) Rex (species)
Since we use Morphology, it’s more difficult for us to recognize these
dinosaurs, yet time is also a barrier
Classification does not mean its all accurate.
Systematics is the study of the relationships between organisms. Its
goal is to explain phylogeny (by using Cladograms)
Shark Lizard Cat S.T. Cat Monkey
The monkey and the cat are more closely related than either of them are
to the shark.
Nodes give rise to two branches
There are multiple ways to arrange Cladograms.
Synapomorphy: New feature that a group of animals share together.
We get info on synapomorphies from as much biological information
as we can gather.
Only the evolutionary group is an ancestor and all of its descendants. This
is termed monophyletic groups.
Defining primitive animals is very difficult. The more they resemble
their ancestors makes it hard to distinguish them.
Data is always missing Convergence: when animals come to look alike not because theyre
related but because they’ve adapted to the same environment (ex.
penguins, sharks, fish all have torpedo bodies)
The loss of feature is also possible in synapomorphy
How is the classification hierarchy laid out?
Hypothesis make testable predctions Adaptation 11/6/2013 10:31:00 PM
Process of continuing to be/getting better at being suited to the
Noun: features that increase/maintain fitness in a set of circumstances
Not everything is optimal.
Specialists are easier to identify because they have prescribed anatomy.
Good at one thing, options narrowed
Generalists are harder, and are more common. Good at many things,
The reason we have cheeks is to prevent food from falling out of our
Chewing helps with a lot of things such as enzyme coating and facilitated
Jaw opens on a hinge and don’t use a lot of side to side chewing
More cusps on teeth
No need to chew food
Need to catch food so they waste energy while doing so.
Food not ensured
Recurved teeth Killing methods include strangulation, ripping Achilles to hinder, etc.
o Sharp pointed short teeth
Good: lunch does run away! Plants don’t move.
Bad: Plants are nutrition-poor and need to eat a lot of them to live.
Chew a lot
Teeth subjective to a lot of wear
Tooth structure of all is enamel dentin cement.
Jaw is 2 units: long, specialized cropping teeth followed by a gap
and then chewing @ back of the mouth
Eat more than 1 category, but not all
Are opportunistic eaters. Can eat plants and meat
Teeth used to chew a lot! Why are animals adapted to their environments? Locomotion 11/6/2013 10:31:00 PM
Locomotion is based on hind-leg foot position
Plantigrades walk with heel on the ground (slow)
Digitigrades run with all fingers on the ground but the rest of the foot
lifted off the ground (faster than plantigrades)
Anguligrades run on last phalanx with the rest of the foot lifted off the
Usually hooved animals
Ex. Horses, deers
Ambulatory: Walk most of the time but can do other things too, they are
the generalists of locomotion
Specialized for running
Increase distance and speed
Tend to have long legs
Increase tarsal and metatarsal segments
Tibia longer than femur
Long skinny legs with small feet
o It’s easy for them to get stuck and break their bones
Bipedals: two-legged animals
Gliding/parachuting: when animals control descent. Usually up on a
tree, but gliding allows them to jump
Expand body surfaces
Examples: Dracos, gliding squirrels
Animals that glide have some sort of adaptation. Small, light-
Gliding: Can go much further
Parachuting: 45 degree, steep
Flying: Needs power, flapping and flight
Bats, ducks, ptosaurs
Long fingers to support wings so they don’t rip
Flying is very energy expensive, thus, they have light bones that
are occasionally hollow, were endothermic, and had no extra weight
if not needed
Have locking joints on wings
Have depth perception Climbers:
More rotation on elbow, the better climber you are.
Claws, scales, etc… can be devices to climb
Really, really big dinos
Leg bones kneed up in columns to bear weight
Femur longer than tibia
Look digitigrade but are plantigrade
Most animals can swim
Fur layers or fat to store heat
Fur is very light and oil diminishes drag
Most have a torpedo tape
Tails flattened to function as propeller
o Manatee, otters
Some sort of insulation must keep you from losing heat to the
Runners have long skinny legs with a lot of muscle
What is scansorial? IB Review 10/02 11/6/2013 10:31:00 PM
What will the midterm be like?
50 Minutes to take it
Matching/Multiple Choice/ Short answer
o Fine to just list, spelling doesn’t count.
What was missing from Darwin’s studies?
Heredity, but Darwin didn’t know anything about genetics because
he didn’t know Mendel’s work.
Von Bear’s Law
Ontogeny repeats phylogeny, meaning that the embryos repeat the
evolution of the organism (ex. we have gills and slowly develop)
Omnivores: Low, rounded cusps
Insectivore: Low, its more of a slurping than chewing. Little spaced
teeth, where as in carnivores, they’re more steak-knife.
Herbivores: Cropping teeth, then a gap, then flat teeth
Groups of animals change thru time and you can track that, and you can
find where fauna fits in using this.
Disuse DOES not always lead to degeneration.
Wallace = Discoverer of evolution, independently of Darwin, discovered
the basic principles of evolution. Pushed Darwin to publish Origin of
Species in a way.
Broad sternum on birds so there is more muscle to attach.
How and why we reconstruct animals.
Bilateral symmetry helps us build them then we study them and see
muscle ridges, then we look at the colors that they might have.
We look if we can reconstruct behavior
5-point question, giver 5-point answer.
Scrotum Humanum is the first scientifically named dinosaur.
Linneaus: what to know.
Classification system creator. Pre-Darwininan so classification system wasn’t Darwininian
Cladogram Practice on notebook
Test Corrections and stuff:
LaMark’s thing: Changes in phenotype can be inherited. This is false b/c
genotype gets inherited not phenotype Fossils 11/6/2013 10:31:00 PM
It takes a lot of planning to star excavating or to even start to think of
There are three basic criteria to find fossils:
1. Right Rocks: The rocks must be sedimentary
2. Right Time: The rocks must be of the right age. Between late
Triassic and late Cretaceous.
3.Living on the land: The rocks must be terrestrial, occasionally
there are fossils in lakes and waterbeds due to sinking.
Fossils are any trace of past life.
Paleontology is the study of ancient life
Types of rocks:
Igneous: Form when rocks have been heated enough to melt
(magma), then all of the minerals in the magma crystalize when
o Slower cooling = larger crystals
o Most dates of fossils derived from Igneous
o Form deep in the earth under high pressure
o Some rock under other rocks transforms
o Formed at/near the surface
o Formed at a normal temperature and pressure
o This is where we find most fossils
o Formed from particles eroding from existing rocks
Process of breaking rocks down to particles
Water erodes chemically as well as physically
Process by which rocks are destroyed
Helps erosion particles get to deposition environment
Sometimes the erosion agents are the transportation agents
Places where rock accumulates
Deltas of rivers (because river slows it down)
An erosional environment is never a depositional environment Lithification:
Process of forming sedimentary rock
More likely to preserve fossils without destroying them, unlike
igneous or metamorphic rocks
Any of the three types of rocks can be turned into any other type
Earth isn’t static, it is always changing
Water running through loose sediment leave “ripple marks”
Tells us about the environment’s formation
“Mud Racks” are sediment filling inbetween cracks. Tells us about
climate change, etc.
Preserved imprints of rain
Principle of superposition: In any undisturbed sequence of sediment,
the oldest is on the bottom
Principle of Uniformitarianism: “The present is the key to the past.”
Understanding geological processes today can help us explain rock
record. Some geological process today happened in the past (lava flows,
river erosions, etc) but only works if earth is really old.
Faunal Succession: Any time we find new fauna to help see where new
faunas are in time because of similarities toward other faunas.
Animals living together at the same time. Fossilization 11/6/2013 10:31:00 PM
The biosphere is the three-dimensional layer of life that encircles the
earth, which is 3.8 billion years old.
Fossils are the buried remains of organic life in rock, but most of their
soft tissues are all gone
The most common part is the skeleton, and enamel is the hardest part of
your body which is why we often find teeth and bones.
o Can be destroyed by several factors such as weathering
o The minerals are replaced since calcium-sodium
hydroxyapatite weathers and dissolves rather quickly. It is
not common to see many bones with their original organic
Once dead, an animal is susceptible to decomposition, other animals
eating it, bugs breaking it down and nature’s wear and tear.
Other animals may eat them, gnaw them, or drag them elsewhere,
causing the skeleton to often be incomplete.
To be fossilized, you must die in a depositional environment not in a
transport environment nor a erosional environment.
The Fossil Record: History of life preserved in the rocks. The sum total
of all the fossils we have.
It’s biased towards hard parts
Favors animals that lived in depositional environments
Not a lot of subtropical environments.
o It’s hard for archeologists to get to the rocks
o It’s moist so its acidic
Small fragile animals do not show up often
Birds are under-represented because of the hollow bones and the
lack of teeth.
We only know about the fossils we find because we cant just dig
Fossils are non-renewable sources
Selling fossils and collecting them is bad because unless museums can
take it off their hands, we will not get any information from the fossil. If you want to find fossils:
Look in sedimentary rocks
Look in sedimentary rocks of the right age
Look in the land; there were not any aquatic dinosaurs
Only a small fraction of animals that have ever lived have been found.
Types of Fossils:
Bones: Bone undergoes varying degrees of alteration. Lithification
changes the bone a lot.
o Permineralization: Happens when sediment and ground
water fill the holes in the bone.
o Petrifaction/Replacement: The bone can be replaced
molecularly by other elements because the structure is there
but the organic material might not necessarily be there.
The degree of these depends on how old the fossil is.
Tar would get things stuck and kill them. Doesn’t really alter the
o Freezing keeps soft tissues.
o Environments have changed, which also affects things.
o Desiccation: When there is no moisture and its extremely
dry, animals might dry out completely.
o Tanning: Tannic acid tends to preserve things well.
Amber: Fossilized tree sap. If you find something trapped in tree
sap, it will be pristinely kept in. When the amber fossilizes, it keeps
whatever is inside completely intact.
Trace (ichno) Fossils: Fossils