(1797-1875): Principles of Geology (three volumes, published 1830-1833); established the doctrine of uniformitarianism.

 Two methods for finding dinosaur fossils ?

• Prospecting-walking around looking at the ground 

• Quarrying- opening a big pit and breaking open rocks 

 1.Both methods involve finding a place to look: 

Criteria include?

• Geologic strata of the right age-- (use geologic principles like those you learned about : original horizontality, lateral continuity, superposition as well as the dating methods- radioactive decay etc.) 

• Usually little ground cover (trees, plants) or some commercial enterprise has cleared area 

• Nobody else has looked there! 

 2.Tools for finding a place to look: 

 Geologic Maps and Satellite images/aerial photographs 

Geologic maps show mapped distribution of strata of different ages 

Satellite images/Aerial photographs 

• Can recognize strata by color/ spectral signature in areas that have not been mapped 

• Very important in most areas dinosaur hunters want to look- which are places that are no one has looked before 

Mesozoic rocks (strata) are a great place to look for?

non-avian dinosaurs 

Most non-avian dinosaurs are known from what age?

Cretaceous age strata 

T or F

• We have great Triassic in Texas. 

Triassic 

 3.5 Other factors effecting where we look for a dinosaur ?

• The kind of environment where the dinosaur lived and died -in a desert or tropical forest 

• The environment in that region now. Climate- how fast dinosaur bones are coming to the surface (via rain or wind) 

• Whether or not the area is now heavily forested - how many rocks exposed to look at 

• These factors are largely unpredictable… so practically speaking they aren’t considered much… 

 Other tools for finding a place to look: 

• Previous papers by other geologists/ paleontologists 

• Locals - reports of bones, eggs etc. 

• Researching the most isolated areas to visit 

After prospecting and evaluating find (deciding to collect it), further clean off bones on surface, add more special glue 

• Cleaning away some rock to see if we can see a synapomorphy identifying the fossil as an important find- maybe new species or part of a poorly known group 

• Dig a moat around fossil using pickax, shovels, rock hammer, knives- sometimes a cobra hammer or rock saws 

• Cover top of fossil with toilet paper such that the plaster you will use doesn’t stick to the exposed bone. 

• Cover in splattered plaster, plaster-soaked burlap strips and more plaster. Then let dry. 

• Tunnel under block so that dino is on a pedestal of rock and capped with plaster. Pry loose. 

• Flip block over and cover other side in plaster. 

• Prying loose a jacket (plaster covered fossil+rock matrix) 

• Trimming excess rock -lightening the jacket so that it is easier to transport 

• Transportation + Cataloging 

• Preparation of fossil in lab plaster jackets with fossil embedded in rock are carefully opened in a lab with a saw and the rock is slowly removed with dental tools and compressed air “scribes” 

13. Second of the two methods for finding dinosaur fossils 

Gansu Province, 

in northwest China 

Quarrying Example 

Looking for new feathered dinosaur beds 

• as an undifferentiated mass whose composition reflected the meteorites that accreted to form it.

• Impacts were frequent at first, and have tapered off as the primordial matter of the solar system has clustered into the planets and other bodies.

1. located at the center of the Earth; the densest region of the Earth; composed largely of iron and other dense metals; its radius is about 3500 km.

   
   

compositional layers (5) 

remember 

Adorable 
Hairs 
Curl 
Moms
Chin 

physical properties (5)

Long 
Adjectives 
Mangle 
Over
Ice 

• the plate margins are deformed, often producing mountains and deep oceanic trenches that are associated with volcanoes and earthquakes.

  
  

 a series of semi-rigid tectonic plates.

 continuous evolution of the Earth and change in the structure and composition of its layers is caused by 

is the study of the formation of Earth's major structural features by thermal convection in the asthenosphere and subsequent deformation of the lithosphere.

formed by the cooling and

             crystallization of molten magma originating deep in the

             crust or in the mantle.

               a. includes volcanic rocks, which cool and crystallize at

                   the surface of the crust

               b. includes plutonic rocks which cool and crystallize deep

                  in the crust

which form as a result of the

              transport and deposition of particles eroded from pre-

              existing rocks, or from organic activity, or from chemical

              precipitation of minerals.

which form as pre-existing rocks are

              transformed by great heat and pressure

sedimentary rocks

(1. In rare cases, fossils have been recovered from volcanic

              deposits.

          2. Metamorphosis of sedimentary rocks usually destroys

              useful information about fossils.)

T or F

Volcanic deposits can carry fossils.

1. Mineralization (=petrification)

          2. Carbonization (mostly affects plants)

          3. Trace fossils (e.g. tracks, skin impression)

 dinosaurs are widely recognized to have ruled the continents for over 

 150 million years 

In essence, to obtain an age for when the volcanic rock formed, 

one must measure the proportion between the parent atoms and daughter atoms in the volcanic rock 

What are the ages of the dinosaurs?

Creta is on the 

Jury for a 

Trial 

the Age of Dinosaurs, 

the Mesozoic Era 

the Mesozoic Era happened when?

250 million years ago up to about 65 million years ago 

(35 times longer than the entire evolutionary history of humans to this point. If a human generation is assumed to average 20 years, then 9,150,000 generations of parents and children could be fit into the Age of Dinosaurs )

Triassic Period

about 228 million years ago. The Triassic was the earliest period of the Mesozoic Era. 

Jurassic, 

extends from about 205 million years ago to about 144 million years ago 

Cretaceous. 

144 million years ago  to 65 million years ago 

(This period saw the evolution of the most fearsome terrestrial predator the world has ever seen, Tyrannosaurus, as well as the evolutionary bursts that produced a dazzling diversity of duckbills and horned dinosaur )

antartica below africa, 

india touching antartica