Midterm 1 Flashcards
Where and when were dinosaurs first found, and how were they perceived?
- during the Victorian and Georgian eras
- in the UK
- surprising because they were like both reptiles and humans
What were the first three dinosaurs, and who found them?
Megalosaurus- Buckland
Iguanodon- Mantell
Hylaeosaurus- Mantell
Who named Dinosauria, when, and why?
- Richard Owen
- 1842
- organisms that had at least 5 vertebrae fused in the pelvis
- means “terrible lizard”
Who were the early American dinosaur workers?
Joseph Leidy, Edward Drinker Cope, and Charles Othniel Marsh
When was the turning point of dinosaur research?
1961- John Ostrom found a hand that could grip, which meant the group had to be more intelligent than they originally thought
-also found a straight tail, which means they had good balance and motor control
How long is the geologic time axis?
4600 million years or 4.6 billion years
What is the relative age?
The approximate age of the dinosaur using the rocks around the dinosaur (biostratigraphy)
What are fossils?
a part or all of a body of an organism, preserved in whatever way
How are typical fossils made?
- carbonization- just leaves carbon (not informative for dinosaurs)
- permineralization- solidified from the outside (fossil gains)
- dissolution and replacement- recycling of original elements into new elements
Will the fox I saw the other day become a fossil?
It is unlikely because
- usually bodies are consumed by other organisms
- needs to be buried in the sand or water without easy access to oxygen, without being broken, without changing too much, without erosion
- it has to be in a discoverable area
How do we find, collect, and prepare fossils?
- look around where fossils would be
- find impressions of what used to be there
- dig away cliff to find more
- lay down a grid system
- preparation
a. transport in plaster
b. chip away rock (ex. with air chisel, used to use acid)
What is the tree of life?
A branching diagram that depicts the ‘family’ relationships of species
How do you read relationships from a tree?
ancestor- determines the closeness of the relationship
plesiomorphy- basal character
apomorphy- derived character
sister- two groups that share the same ancestor
What is Linnean classification?
kingdom- phylum- class- order- family- genus- species
What is the timeline of vertebrate history in the Paleozoic?
Early Cambrian- 1st vertebrate (some controversy) Ordovician- 1st fish Devonian- tetrapod Permian- reptile Permian/Triassic- archosauromorph
What reptiles are archosaurs and lepidosaurs?
lepidosaurs- scaly reptiles (snakes, lizards, tuatara)
archosaurs- birds and crocodiles, dinosaurs
What are Archosauromorpha and Ornithodira?
Archosauromorpha- close to dinosaurs
Ornithodira- dinosaurs and Pterosauria
Where are fossils found?
In sedimentary rock, mostly on the coasts where they have been exposed through erosion
How do we place absolute ages on relative ages?
using half-lives, mass spectrometers, and isotopes yields an actual age, using the stratum of sedimentary rock surrounding a fossil yields relative ages
Root (tree of life)
usually unnamed, leads to the common ancestor of that family
nodes (tree of life)
common ancestors
basal (tree of life)
closer to root than terminal, in relation to a specific species
derived (tree of life)
closer to terminal than root, in relation to a specific species
stem (tree of life)
leads to its descendants
