self-guided tour of the fossil discovery center
TRANSCRIPT
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: 12-14 ft.
: 11,00022,000 lbs.*
*Body weight is difficult to gauge because fateaves no impression on the skeleton.
Columbian Mammoth (Mammuthus Columbi)
Asian ElephantClosest modern day
Relative
*This mammoth was named after the location of the
first discovery - the Columbia Plateau.
Steppe MammothMost recent ancestor
Woolly MammothCousin
About the exhibit
Adult Columbian Mammoths were only preyed upon
humans; however, the younger mammoths were preye
upon by Sabertooth Cats. How we know: 441 milk tee
(the teeth below your gums when you are born) of
Columbian Mammoth calves were found in Freisenhahn
Cave, Texas, alongside Sabertooth Cat remains.
The most common causes of death in adult mammoth
were accidents, human hunters, and starvation.
Predators Columbian Mammoths lived in North America as far back as
1.1 million years ago and occupied southern Canada to
central Mexico, but never made it into South America.
The Columbian Mammoth is believed to be a greatswimmer. We find their remains on the Channel Islands
and there has never existed a way to get there by land.
Also, the Mammoths that made it to the Channel Islands
underwent extreme genetic dwarfing, we call them Pygmy
Mammoths.
Columbian
Mammoth
Fossil
Locations
The Columbian Mammothskeleton in front of you is
replica. A replica is an exactcopy of the original bone
(there is a diagram explaining how they are made on th
7th stop of your tour the lab!). Replicas are importan
because otherwise you wouldnt be able to see the enti
animal skeleton. The original bone is too fragile, too he
and much too valuable to try and assemble.
Also, we needed to get this replica because we never
find an entire skeleton. The Fairmead bones were
scattered by predators and scavengers before they wer
covered in sediment by local flood water. The mammo
before you is from Florida.
Next Exhibit: Mammoth
Teeth and Tusk
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Columbian MammothTeeth
Characteristics: 5-8 enamel plates per 3.9 in.*Weight: The molar is approx. 8 lbs.*All mammoths are identified primarily by features oftheir teeth!
Lower jaw of a Columbian Mammoth
About theExhibits The specimens on the table are real fossils. On the left side of the table, marked with a 1, the
are two remnants ofColumbian Mammoth molars
and a partial rib. They are encased in a Plaster of
Paris and burlap jacket.
In the center of the table, marked with a 2, you casee a tusk fragment. Notice the growth rings inside
of the tusk? Unfortunately we cannot tell the age o
the mammoth by counting the rings but
paleontologists can extract data from them such as
the season of death, age at sexual maturation,
calving, and migration. On the right side of the table, marked with a 3, yo
see a Columbian Mammoth molar that has been
partially damaged by the heavy equipment at the
landfill.
Beside the table stands a tusk that was discovered 2006 and took 3 days to excavate. It is still encased
in the silty clay in which it was buried.
Tusks
Both males and females had tusksbut male tusks were longer and
heavier.
The tusks were used to dig forfood, fight during mating season,
and to defend against predators.
Mammoth tusks growcontinuously.
They are actually the mammothstwo front teeth (incisors)!
Molars
Columbian Mammoths gothrough 6 sets of molars in their
life time.
New molars grew in from the backof the jaw rather than under the
old tooth. It would push the old
ground down tooth out of the
mouth like a conveyor belt.
The old ground down tooth thatgets ejected is called a spit
tooth.Next Exhibit: The Dig Diorama
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Basic tools used: Chisel tip hammers, screw
drivers, brushes, tin foil, toilet paper, and
anything that can dig through hard soil.
The Excavation Process First, paleo-monitors will follow behind the heavy equipment
carrying orange flags that they use to mark off an area thatthey think a bone occupies. Afterwards they will go back to the
flags and begin excavation(Which means to dig out).
The paleontologist will dig a trench around the bone (shown intop right of page) so that it is elevated on a dirt pedestal.
The dirt and bone is then covered in toilet paper to protect itfrom the wet plaster cast that will shortly be wrapped around
it.
The paleontologist then soaks burlap in water (damp burlapabsorbs the plaster more efficiently) and mixes the Plaster of
Paris. After ringing out the wet burlap it is dipped into the
plaster and wrapped around the specimen in a crisscross
pattern.
Once the jacket dries the specimen is flipped over, examinedfor exposed bone, and removed from the site.
A Paleontologist digs the trench aroun
mammoth tusk.
A paleontologist dips burlap
into the Plaster of Paris.
Fun Facts This low-tech method has been used for over 100
years and we are yet to find a better way to remov
fossils!
For fossils that are 1cm or smaller in size (Microfoswe use a screen washer to find them. The two wat
troughs seen in the back of the Fossil Discovery Ce
building are used for that process.
The Dig Diorama An Excavation Model
Next Exhibit: Display Cabinets
A casted fossil dries!
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ate of the Fairmead site: 550,000 780,000 yr. B.P.
Fossil Display Cabinets and Signage
Paleomagnetism: Two samples from the site were taken to thePaleomagnetism Laboratory of UC Davis and run through a
cryogenic magnetometer. The results showed that the fossils
were deposited during the Brunhes normal polarity epoch
(around 780,000 the present).
We discovered Tetrameryx (Antelope) bones that were onlyknown to exist in the bay area during the Irvingtonian time
period.
When you find large herbivore bones that are from theRancholabrean time period you usually find bison along with
them. We dont find any bison at the Fairmead Site.
About the exhibit Fossils are exceptionally rare because it takes very
specific circumstances to allow for fossilization. The
animal needs to be covered in sediment as soon as
possible unless it is frozen or dies in an anoxic (oxyg
free) environment.
The display cases show a variety of fossils frompetrified wood and amber (fossilized tree sap), to
trilobites and coprolites (fossilized dung).
Trace fossils, such as burrows, carvings, footprints, afeeding marks, give us clues to what the organism d
while it was alive!
The first two glass cases contain fossils that are notfrom our site. The third glass case contains bones th
were found at our site. On the top shelf you might
able to find a bone that has a hole in it. This is the h
bone of a horse and that hole just might have been
made by the strong jaws of a Dire Wolf.
The fourth case illustrates some of the tools that areused to preserve the fossils.
t the Fairmead site? The Fairmead Landfill is situated on what used to be the alluvial
fan of the Chowchilla River. An alluvial fan is where a fast
flowing river or stream flattens, slows, and spreads.
The seasonal flooding of the river would have left behindtemporary watering holes that would attract many animals and
predators. The next season of flooding would then cover the
bones with sediment.
An alluvial fan
Geologic Time Scale
Next Exhibit: The Evolution of the Horse
erms you might want to know:
r. B.P.: Years before present
vingtonian: A time period specific to North America from 1.8 million 240,000 yr. B.P.
ancholabrean: A time period specific to North America from 240,000 11,000 yr. B.P.
Dinos
First H
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Fun Fact: Horses share common ancestry with Rhinoceroses
Terms you might want to know:
*mya: Million years ago
Browser: An herbivore that feeds on high growing plants, such as shrubs.
Grazer: An herbivore that feeds on grass or other low vegetation.
Evolution of the Horse Display
What does vestigial(Ves-ti-jee-ul) mean? If you look at the bones that are on the ground on the ri
side of the horse display you should see a modern horse
foot (The only light colored bone). The two bones on th
back of the foot are actually remnants of the outer toe
of its ancestors!
These toe bones are considered vestigial because theyhave lost most if not all of their ancestral function as toe
More examples of vestigiality:
The blind mole rat has eyes that are covered by skin Whales and other cetaceans (mammals adapted to aqua
life) have leg bones!
Humans have underdeveloped ear muscles that dontallow us the mobility of other animals.
Human goose bumps are vestigial. Their originalfunction was to raise the hair to make us larger so we
could scare off predators.
Flightless birds like emus, penguins, and ostriches still hawings.
During the late Eocene the climate in North America becamemuch drier and grass began to evolve! This would mean that
the forests were giving way to flatlands and prairies. Because
of thhis environmental change the horse (now Mesohippus)
evolved to have only 3 toes. It walked predominantly on its
middle toe. This horse still had soft feet.
Motivated by the new hard ground and the need to outrunpredators (cant hide in the prairies) the horses foot began to
change into a hoof. The hoof is made out of keratin, the same
protein that makes up our hair and nails.
Many other changes were taking place as well. The legs of thehorse were getting longer enabling it to run faster, their neck
was getting longer to make it easier to reach the grass, and the
Next Exhibit: Fossil Display Cabinets and Skulls
The first horse, Hyracotherium (52 32 mya)
Horse foot evolution
The Hyracotherium (52 32 mya) is the earliest animal to showhorse-like anatomy and is shown in the upper right hand
corner of the exhibit. Hyracotherium bones are found mainly
in Wyoming, and as you can see it did not have a hoof yet and
his teeth were small and rigid. The environment at the time
was like that of a tropical rainforest.
The early Hyracotherium was a browser because grass did notexist yet!
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1. Astragalus2. Atlas3. Axis Vertebra4. Calcaneum Caniniform Shaped like a
canine tooth
5. Carpals6. Cervical Vertebra7. Cranium8. Cuboid9. Dentary/Mandible
Dentitian Arrangement of
Developing Teeth in the mouth
10.Fibula11.Humerus12.Incisors13.Lumbar Vertebra14.Maxilla15.Metacarpal16.Metatarsal Metapodial Referring to
either the metatarsals or the
metacarpals
Molariforms Having the formof a molar tooth
Neurocranium The part ofthe skull that houses the brain
17.Occiptal Condyle18.Pelvis19.Philanges20.Radius21.Scapula22.Tarsals23.ThoracicVertebra24.Tibia25.UlnaThe radius/ulna (forearm) and
tibia/fibula (shin) bones of a horse
fused together. The wolf compari
shows the difference.
You may find the following diagram helpful when viewing the bones
displayed in the cases.
The names of the bones are listed alphabetically and the numberscorrespond to their location on the horse.
*The bones are still located in similar places on the other mammals (#4 is
the horses heel bone and #5 is the horses wrist).
Fossil Display Cabinets
Wolfs Shin
Wolfs
Forearm
Refer to the next page for Information on the
replica skulls on top of the cabinets
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Fossil Display Cabinets (cont.)
Why do the horse and the Camelops skull look sosimilar? Interestingly enough, the horse and the camel
arent very closely related. A rhinoceros is more
closely related to a horse than a camel is!
The similarities in the skull that you see are duewhat is called convergent evolution. This means
that two organisms (i.e. the horse and the came
developed similar traits even though they are fr
different lineages. They developed these traits
because they both shared similar environmenta
challenges.
Pill Bug Pill Millipede
Duck Platypus
Mammal
Bird
Woodlou
se
Lizard
Snake
Brown SnakeGlass Lizard
More examples of convergent evolution:
Predator Skulls
Dire Wolf
Carnivore
The highlighted area onthe back of the dire
wolfs skull is called the
sagittal crest. This is
where the jaw muscles
will attach giving them amore powerful bite!
Smilodon
Carnivore
The saber-toothed cat(nottiger) could open its
mouth at a 120 degree
angle.
The inside edge of theirlarge teeth (highlighted
yellow) is serrated, like a
steak-knife.
Defense
Beak
Legless
Browser
Modern-day Camel
The skull on the top leftof the cabinets is a
Camelops (Western
Camel) skull. The picture
on the left is modern day
camel. You can see how
much the camel has
changed!
Grazer
Horse
Sitting to the right of theCamelops skull is the
skull of a Pleistocene
horse.
Next Exhibit:
The Lab
-The skulls located on the top of the shelves are all
replicas but the bones inside the display cases are real.
-A replica is an exactcopy of the original.
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The Laboratory
Fun Fact: Most of the lab work is done by volunteers! If you share our
interest in past life feel free to fill out a volunteer application at the front
desk.
Fossils that come in from the dig sight are cleaned and prepared for
exhibit here at the lab.
Common tools used to work on specimens
Once the fossils are removed from the dig sight they are
moved to a safe location and eventually end up here at the
laboratory.
The larger fossils are usually still encased in the burlap and
plaster cast which is carefully removed.
Once the cast has been removed the lab worker will use
dental picks to slowly expose the bone and a paint brush is
Loose dirt form the landfill is run through a screen washer
and the remaining sediment is closely inspected for
microfossils like small rodent, reptile, and amphibian bones.
Microfossils are very important because small burrowing
rodents, snakes, and frogs do not migrate making them a
good environmental indicator.
How are replicas made?A clay bed is built around the
fossil
Liquid Rubber
is painted atop
the bone
The rubber iscovered with
hard plastic
Once dry it is
removed and steps
1-4 are done for the
other half.
Next Exhibit: Mammoth
Skull
1
2
3
4
The two halves are then put
together and filled with a resin.5
A microfossil claw
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The Columbian Mammoth Skull
In 1914 A Paleontologist named Othenio Abel theorized
that dwarf elephant skulls found in Cyprus and Sicily
might have been the influence for the Cyclops myth. If a
Greek farmer were to stumble upon one of these skulls it
would be very easy to confuse the sinus cavity for a
single, large eye.
Incorrect
Correct
Dwarf elephant skull interpretations
Shark Tooth Fossils
Europe: Known as Glossopetrae
(Petrified snakes tongue), and they
grew naturally in the ground.
Malta: In 1768 they arelisted as an
available medicine in the pharmacy of
Santo Spirito to cure poisoning.Japan: Believed to be the thumbnails of
Tengu Man, a mountain goblin.
llr
Ammonite Fossils
Folklore
Northern England: Known as the
petrified remains of snakes that were
turned to stone and beheaded so an
abbey could be built in their stead.
Southern England: A British virgin who
lived in the woods turned the snakes to
stone. In other areas they were
thought to be fairies first turned to
snakes, then stone.(Extinct Mollusk)
About the Exhibit Just like humans, elephants and mammoths can be ri
or left handed. The tusk that the elephant or mamm
used more often is called the Master Tusk.
See if you can figure out what tusk the mammoth in fof you might have preferred.
In most humans the left side of the brain controls finmotor skills like hand movement, and because eachbrain hemisphere controls opposite sides of the body
have more right-handed than left-handed people.
Handedness TheoryElephant brain location
Next Exhibit: Mosasau
Woolly Mammoth head preserved in permafros
Fun Fact: This replica skull used to hang from the ceiling.
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Mosasaur Exhibit
A hunting Mosasaur
We find very fewdinosaurs in California because almost all
of the state was covered in ocean water when they were
alive! The rare exception is probably because a dinosaur
was washed out to sea after drowning in a river.
We do find Mosasaur bones in California because this
reptile was adapted to life at sea.
Mosais Latin for Meuse Riverand
Saurosis Greek for Lizard
erms you might want to know:
inosaurs: Potentially warm blooded and walked with their legs directly
eneath them
eptiles: Cold blooded and have splayed out legs.Vs.
California During the time of the Dinosaurs
Shark Tooth Hill: A spectacular amount of Miocene shark
teeth and marine mammals are buried in the hills of
Bakersfield, including Megalodon teeth!
Fossil Reef Park: The remnant of an 18,000,000 year old
tropical shell reef is located in Orange County.
There was widespread volcanism in California because the
Sierra Nevada was beginning to form during the time of
the dinosaurs. Two huge plates crashed into each other
and one went below the other.
About the Exhibit The Mosasaur breathed air and had a double-hinged
that allowed it to eat prey that was larger than its hea
This is one reason why it is considered to be the snak
closest ancestor.
Ammonites were the Mosasaurs favorite prey.
A Mosasaur (Tylosaurus Proriger) and a School Bus
In 1918 a Mosasaur was found with the remains of aPlesiosaur in its stomach!
The largest of the Mosasaur family is the TylosaurusProriger, shown in the image above.
The first Mosasaur found was in the Netherlands in1764. During the French Revolutionary war the Frenc
occupied the Netherlands and supposedlybought the
fossil for 600 bottles of wine and took it back to Paris
Fun Facts
Next Exhibit: The Pond
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