Fossils Flashcards
What are index fossils?
Fossils that are characteristically abundant and help date particular layers of rock
Index fossils are used to correlate the age of rock layers across different geographic locations.
What is the significance of index fossils in geology?
They provide a means of biostratigraphy, allowing the correlation of rock layers from different locations
Biostratigraphy is a branch of stratigraphy that uses fossil distribution to date and correlate rock layers.
Fill in the blank: Index fossils help to date particular _______ of rock.
[layers]
What do polystrate fossils represent?
Fossils that run through several sedimentary rock layers
Polystrate fossils indicate that the sediments must have formed rapidly, as they run through multiple layers that supposedly represent millions of years.
True or False: Polystrate fossils can be found in sedimentary rock layers.
True
Fill in the blank: Polystrate fossils should have decayed _______ the sedimentary layers formed.
[before]
What do polystrate fossils suggest about the time frame of sedimentary layer formation?
They suggest that the sedimentary layers represent millions of years as evolution claims
However, the existence of polystrate fossils can challenge the long time frames typically associated with sedimentary rock formation.
What are fossils used for in geology?
Fossils can be used as index fossils and to date the rocks in which they are found.
Index fossils are species that were widespread but only existed for a short period, allowing geologists to date the strata in which they are found.
What is the significance of finding living fossils?
When found living, they vary very little from their ancestral past.
Living fossils are species that have remained relatively unchanged for millions of years.
What evolutionary question arises regarding complex organisms?
Why would they evolve so complexly and then stop evolving for millions of years?
This raises questions about the mechanisms of evolution and environmental stability.
What poses a significant problem in the study of evolution?
One-celled organisms pose the biggest problem because everything is thought to have come from them, yet they have not changed much since the beginning of time.
This challenges the understanding of evolutionary processes over billions of years.
Provide examples of living fossils.
- Tuatara
- Coelacanth
These species have ancient lineages and show little change over geological time.
What is an index fossil?
A particular type of fossil found in a specific rock layer.
Index fossils are used to identify and correlate the age of rock layers.
What observation can be made about the strata of fossils?
In each strata of fossil that is abundant, there seems to be certain characteristics.
This may relate to the environmental conditions at the time the organisms lived.
What is the evolutionary progression mentioned from ape to human?
Walking on all fours to walking upright
What is a living fossil?
A living species of organism that closely resembles otherwise known only from the fossil record
What type of animals are many living fossils?
Marine animals
What is notable about the ocean in relation to living fossils?
The ocean is relatively unexplored
What has contributed to recent discoveries of living fossils?
The flood
Fill in the blank: A living fossil is a living species that closely resembles _______.
[organisms otherwise known only from the fossil record]
True or False: There is a single ancestral plant type that can be traced to all modern plants.
False
What is the significance of the term ‘living fossil’ in paleontology?
It indicates a species that has remained relatively unchanged over geological time.
What does the term ‘fossil record’ refer to?
The history of life as documented by fossils
Why is the ocean considered a key area for discovering living fossils?
Because it is relatively unexplored
What is an example of a fossil that is thought to be a transitional form?
Coelacanth
Coelacanths are ancient fish that were once thought to be extinct.
What key feature distinguishes reptiles from birds?
Different limb structure and bone structure
This includes adaptations such as wings and feathers in birds.
What is the significance of Archaeopteryx in evolution?
It is thought to be a transitional species between reptiles and birds
Archaeopteryx exhibits both avian and reptilian features.
Fill in the blank: The class that includes modern birds is classified as _______
Aves
True or False: Birds are considered to be a type of reptile.
True
Birds are classified within the clade Archosauria, which also includes reptiles.
What type of teeth did some extinct birds have?
Teeth
This feature is seen in some extinct types of birds, differentiating them from modern birds.
What is one function of feathers in birds?
Flight and insulation
Feathers play a crucial role in the ability of birds to fly and regulate their body temperature.
What does the term ‘transitional fossil’ refer to?
Fossils that exhibit traits common to both an ancestral group and its derived descendant group
Transitional fossils provide evidence for the process of evolution.
What is the primary reason there are very few human skeletons found as fossils?
They would have drowned and decomposed on the ground.
This indicates that conditions for fossilization were not met for humans, as they would not remain preserved after death.
What happens to heavier objects in water during fossilization?
Heavier objects would have sunk.
This suggests that only certain types of materials have a chance of being fossilized based on their density.
What are transition fossils?
Transitional forms or the missing link between one type of organism and another.
These fossils provide evidence for the evolutionary process.
Fill in the blank: Lighter objects would have been _______.
destroyed.
This highlights the conditions that affect fossil preservation.
What type of organisms does the explosion of complex marine organisms refer to?
The emergence of diverse life forms during a significant evolutionary event.
This event marks a critical point in the history of life on Earth.
What type of organisms are found higher in strata?
Birds and reptiles
Birds and reptiles are located higher due to their increased mobility and ability to live at higher elevations.
Which organisms appear in the fossil record when amphibians and reptiles do?
Plants
The appearance of plants is correlated with the presence of amphibians and reptiles.
True or False: Very few land-dwelling organisms are found in the lower levels of strata.
True
This suggests that the fossil record in lower strata is less diverse in terms of land-dwelling species.
Fill in the blank: Mammals are found ______ than amphibians.
higher
Mammals tend to occupy higher strata compared to amphibians.
What instincts are observed in larger animals during danger?
Gathering in herds
This behavior is a survival strategy to protect against threats.
What do we expect to find in vast fossil beds?
Many of the same type of animals
This indicates the segregation between land and aquatic habitats.
What is the significance of elevation in the fossil record?
Increased ability to avoid burial
Higher elevations may lead to fewer fossilized remains due to erosion and other geological processes.
Which two groups of organisms are mentioned as being found together due to their habitat?
Amphibians and reptiles
This indicates a close ecological relationship between these two groups.
What would happen to fossils in sedimentation?
Fossils would eventually be relocated and not be able to outrun sedimentation.
True or False: Flooding would wash away plants and sediments.
True
What would rocks undergo as they are moved by currents?
Rocks would crack and eventually be smoothed.
Fill in the blank: Vast seas would flow down ______, carrying mud and sediments.
[river routes]
What would be trapped with mud during sedimentation?
Plants and invertebrates
What changes would heat undergo during sedimentation?
Heat would undergo rapid changes.
What effect does salinity have during sedimentation?
Salinity would undergo rapid changes.
What would happen to plants during flooding?
Plants would be washed away.
Fill in the blank: Sediments would be carried away in great ______.
[masses]
What is a consequence of erosion during flooding?
Erosion would create a landscape change.
