Term
| During which period did the emergence of the first simple plants in terrestrial (land) environments occur? |
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Definition
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Term
| Factors related to spread of early land plants were what? |
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Definition
- The increased levels of oxygen in the atmosphere (photosynthesis)
- Protectic atmosphere shield from UV radiation
- Evolution of protective waxy surface cover (cuticle) on leaves
- More temperate (less extreme) climatic conditions
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Term
| How long ago was the Silurian scene? |
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Definition
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Term
| How long ago was the Devonian? |
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Definition
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Term
| What were some characteristics of the more complex plants of the Devonian? |
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Definition
| They were the first vascular plants, first seed producing plants, and the frist large tree size plants in the early forests. |
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Term
| What were some examples of the more complex plants found during the Devonian? |
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Definition
| Ferns, horsetails, and club mosses. |
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Term
| What terrestrial arthropods first appeared as part of the landscape during the Devonian? |
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Definition
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Term
| Which type of fish found within the Devonian is characterized by paired fins with fleshy muscular lobes at base of fin, and a limb-like internal skeleton? |
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Definition
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Term
| Compare the fin structure in lobe-fins with limb structure in tetrapods. |
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Definition
Lobe-fin
Shoulder attached to skull
Bones covering gill region
Fins with fin-rays
Dorsal and anal fins present
Strong tail fin
Tetrapod
Shoulder separate from skull
Loss of bones from back of skull
Gills present
Limbs with toes
Loss of dorsal and anal fins
Tail fin still ~ fish-like |
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Term
| Why was the Canadian Arctic a good place to look for a "transitional" lobe-fin fish? |
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Definition
There were many fossil fishes already known from the Devonian of the Canadian Arctic prior to discovery of Tiktaalik, from deposits around 380-390Ma; and, early tetrapods were known from slightly younger deposits on Greenland, dating back to approximately 365Ma.
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Term
| What thought process led to the discovery of Tiktaalik? |
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Definition
| If scientists looked at geologic deposits in-between the age of earlier lobe-fin fishes (380-390Ma), and the first true tetrapods (365Ma), and in the same general geographic area, they would have a chance of finding a transitional form that linked lobe-fin fishes and tetrapods. |
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Term
| What are the fish like features of Tiktaalik? |
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Definition
Body scales
Fin rays
Lower jaws |
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Term
| What are the tetrapod features of Tiktaalik? |
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Definition
Flat, croc-like head,
short skull
Mobile neck joint
Modified ear
Shoulder separate from skull
Flexible wrist joint
Ribs associated with air-breathing |
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Term
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Definition
| Hiccups reslut from nerve spasms in the neck, throat, body wall, and diaphragm, triggered by nerve impulses that rapidly close a flap of tissue, the epiglottis in our throat. |
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Term
| How can the nerve spasm involved in hiccups be traced back to fish and sharks? |
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Definition
| Shark and fish brains control the rhythmic, sequential 'firing' of muscles that control the opening and closing of the gills using the same nerves that are invloved in controlling breathing movement of the diaphragm in mammals. The longer distance and complex path these nerve impulses have to travle in mammals results in problems related to hiccups. |
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Term
| How does the actual 'hiccup' relate to the amphibian part of our history? |
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Definition
| Tadpoles breath using gills, but they don't want the water they bring in to pass over their gills to also get down their lungs so they abruptly close off the flap protecting the airway into the lungs which we have inherited in the form of hiccups that happen when there is a nerve spasm in the associated muscles. |
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Term
| How do hernias occur and how are they related to sharks and fish? |
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Definition
| Hernias are the result of moving the gonads from a position inside the ody cavity, as in sharks and fish, to (in males) outside. The problem is that now the gonads aren't protected and are now external creating a 'weak spit' in the body wall, which is the site of many hernias. |
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Term
| How do backaches come from our "Inner Fish"? |
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Definition
| Backaches result in large part from the complete transformation of the skeleton that happens going from a quadraped to bipedal. |
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Term
| When did the transition to Carboniferous begin? |
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Definition
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Term
| What were the first amniotes? |
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Definition
| small, lizaed-like reptiles, living in coal swamp environments |
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Term
| What did the amniotic egg allow early reptiles to do? |
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Definition
| Start expanding into more fully terrestrial niches |
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Term
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Definition
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Term
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Definition
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Term
| How did the environment transition to Permian Period? |
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Definition
| With cooler, drier, more pine dominated environments |
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Term
| When did the End-Permian Mass Extinction occur? |
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Definition
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Term
| What percent of marine species were wiped out during the End-Permian Mass Extinction? |
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Definition
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Term
| What percent of terrestrial species were wiped out during the End-Permian Mass Extinction? |
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Definition
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Term
| What are the two possible causes of mass extinction? |
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Definition
| Catastrophic events or a gradula environmental change |
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Term
| What are some possible catastrophic events that may have caused the mas extinction? |
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Definition
- Volcanoes, causing temp. changes
- Bolide (extraterrestrial object) Impact
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Term
| What are some possible events that may have caused an environmental change resulting in the mass extinction? |
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Definition
- Increasing Aridity (drier)
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Term
| What are some factors that helped some species survive the mass extinction? |
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Definition
- Relatively small body size
- Wide geographic distribution
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Term
| When was the Triassic Period? |
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Definition
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Term
| What kind of dinosaurs were grouped under the category of Ornithischians? |
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Definition
- Armored plate-backed
- Duck billed
- Horned
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Term
| What kind of dinosaurs were grouped under the category of Saurischians? |
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Definition
- Herbivores
- Carnivores
- (including birds)
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Term
| What were the two possible reasons for the dinosaurs' success? |
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Definition
| The oppurtunity to fill unoccupied niches or just simply outcompeting other reptiles. |
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Term
| How do we know that dinosaurs were warm blooded? |
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Definition
| Dinosaur bone had a system of small canals for blood vessels, many had erect stance, were fast, agile, some found in polar regions, some had rapid growth rates. |
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Term
| How has the perception of dinosaurs changed over the past 200 years? |
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Definition
For many years, virtually all Mesozoic mammals were thought to be small, inconspicuous, not very diverse, and living in the “shadow of the dinosaurs." According to recent discoveries, there is a much greater diversity of early mammals than previously thought such as;
-aquatic “beaver like” mammal
-large carnivores
-burrowing diggers
-tree-climbers
-gliders |
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Term
| How was the Archaeopteryx first discovered? |
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Definition
| On the basis of a single, asymmetrical flight feather |
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Term
When and where were more complete skeletons of Archaeopteryx discovered?
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Definition
| Not long after 1861 a nearly complete specimen is found-the 'Ancient Wing'- in London. |
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Term
| Describe the retained reptillian features of Archaeopteryx |
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Definition
| Teeth, seperate clawed fingers, long bony tail |
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Term
| Describe the retained bird features of the Archaeopteryx |
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Definition
| Wings, flight feather, reversed hallux, furculum |
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Term
| Describe the features that show a close relationship between birds and "raptor" theropod dinosaurs |
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Definition
| Lightly built skull, hollow limb bones, strap-like shoulder blades, reduction to 3 clawed fingers, theropod-like pelvis, semilunate carpal bone |
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Term
| Describe the recent discovery of a feathered theropod dinosaur |
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Definition
Recent discoveries in China show that the Theropod dinosaurs thought to be closest to Archaeopteryx (and later birds) had feathers. A
- Anchiornis huxley:Jurassic of China~160Ma
- 10 million years older than Archaeopteryx
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Term
| What were Archaeopteryx's flying capabilities? |
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Definition
| Capable of power flying, but likely relatively weak flyer |
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