0
Fossils
This category is for questions about the bones, fragments, imprints, and other remainders from a different time. The questions and answer you will find here are history set in stone -- our past, immortalized in solid rock. You will also be able to find questions pertaining to the locations of these fossils, how you might identify them, and how they were formed.
3,454 Questions
Why are fossils most likely to be found in sedimentary rock samples?
Most fossils are found in sedimentary rock, because igneous and metamorphic rock undergo great heat and pressure when forming, where as sedimentary rocks undergo much less pressure and heat to form, better preserving the fossil
Where is the world's richest area of dinosaur fossils?
Traditionally the earliest dinosaur was considered Eorapter. Examples have been found in the Ischigualasto Basin in Argentina dating from 230 million years ago.
A recent discovery of a pro-sauropod was found possibly predating this discovery in Madagascar.
Why the fossil record contains an incomplete record of the history of life on earth?
We have an incomplete fossil record because the earth is continually re-cycling its' crust.
The oldest oceanic crust is less than 200 million years old and as most fossils are found in sediments deposited at the bottom of seas and oceans, this means that only the small amounts pushed up onto the edge of continents, when oceanic crust is subducted, are preserved.
Fossilization is only a very rare occurrence so many species of animals and plants never get the chance to become fossils.
There are other reasons; when an earthquake pushes up a part of the crust it disturbs the cycle of deposition of sediment. A drop in sea level would also do something similar. This means that if organisms were previously buried, a change of deposition could mean whole sections of sediment being washed away, along with the potential fossils.
Does the igneous rock and sedimentary rock form a new rock?
== == They are both composed of minerals. They both occur from natural processes. They are both solid. Both types have rocks that have varied chemical compositions. Either would tend to cause damage when thrown at an object with some energy.
They are dissimilar in their method of formation. Sedimentary rocks are formed by processes that usually involve the compaction and cementation of sediment particles over geologic time spans. Igneous rocks are those that have solidified from magma, either below, at, or above the surface.
To determine the absolute age of rocks and fossils geologists use?
They would look for evidence of index fossils, those of certain rapidly evolving creatures that lived during a specific time period. This method is called relative dating. For a closer estimation they would be able to date the rock using radiometric techniques that base its age on the degree of isotope decay . This method would reveal the much more specific absolute age.
What are traces or remains of organisms that lived in the past?
Fossils are proof of organisms that lived long ago
How can fossils help geologists match rock layers?
If the fossils that the scientists find are very evolutionarily similar, for example, if they are the same species or genus, then that means that the sedimentary rock layers have some correlation to each other since the two extinct animals that turned into the fossils most likely lived during the same time period. This hints that the two rock layers were both exposed to the atmosphere during the same time period.
Are scientists creating DNA recreate dinosaurs?
Why was the 3.2 million year old hominid fossil in Hadar called Lucy?
The name "Lucy" is supposedly inspired by the Beatles song "Lucy in the Sky with Diamonds" a track which the team who found the fossil were listening to on the evening of the discovery.
Using methods such as radioactive dating, scientists can determine the approximate age of a fossil or the rock in which it was found. Utilizing this knowledge of approximate age, scientists can compare progressive fossils, and identify changes. Changes are often minimal, and sometimes organisms do not change at all for large amounts of time, making comparative analysis of fossils a tedious task.
Some eras produced better fossils than others. This can have several causes, such as particularly prolific habitation of environments that more easily produce fossils, general population booms, certain mass extinction events, and even happenstance. Because some eras produce better or more fossils, and some produce few to almost none, the fossil record can sometimes falter. In such cases, scientific investigations may be forced to fill in blanks between species using genetic analysis of preceding and proceeding species or groups within species, if the fossil(s) contain(s) any remaining genetic material. In other cases, computers will be used to recreate images of the species based on fossils, and identify progression between species. In any case, the fossil record is often used as a base off of which to obtain or recreate further information about an organism's evolutionary history.
Define fossils and explain how fossil are made?
Fossils are depositions of dead animal imprints and/or bones. When an animal or plant dies, its skin rots away, leaving behind the bone or imprint.
What layers of sedimentary rock can be found in fossils?
Think of the layers like leaves of a book. The further you go back in the book is farther back in time. The layers show drought, floods, fires, and other things that happened in time. They are piled on top of each other. So, the further back you go the more apt you are to find fossils. Location also has a great deal to do with it.
What igneous rock or magma has the lowest silica content?
Peridotite, a type of ultramafic rock composed largely of the mineral olivine, has the least silica.
Read more: Which_igneous_rock_out_of_granite_basalt_andesite_and_peridotite_has_the_lowest_silica_SiO2_content
How is the law of super position used to determine relative age of strata?
They are used to determine the relative ages of rocks by stating that younger rocks lie above older rocks, and that rocks that cut through a layer are younger than the existing layer.
Why can you not find every type of organism that ever existed as a fossil?
because it is hard to solve the fossil and the organism it is
What type of dating would be used to determine the age of rocks by using the fossil?
By using the geologic time scale. Certain organisms are only found during certain times and if a fossil of one of these organisms is found then you can determine the relative age of the fossil.
Which of the following is true about species whose evidence is preserved in the fossil record?
Most of the species have become extinct.
Which part of an animal is least likely to be preserved as a fossil?
Among the possible environments that might hold fossils:
- There are fewer fossils from land creatures than marine creatures.
- There is no evidence of life living in lava or igneous rocks because we know for certain that a) Organisms cannot live in lava (plant matter burns, lack of oxygen deprives animals of life) b) fossil evidence is destroyed due to the melting and recrystallization of the lava.
- Most fossils are found in rocks from marine environments. Famously, graptolites are best preserved in black shale.
You cannot say for certain that there were no land creatures, but because land fossils would be exposed to erosion and weathering. Most fossils are formed as a result of a tranquil marine environment allowing the dead organism to sink to the bottom of the water body, and are covered. In the absence of oxygen, the form is preserved and is fossilised.
What battery goes in a fossil blue am-3920 watch?
Not all Fossil watches carry the same battery, so you'll need to verify the make of your watch and see what battery type is compatible. Replacing batteries yourself can be tricky and could harm the watch internally. Your best bet is to send the watch into Fossil for a replacement. It will cost you $18.50, which includes return shipping and handling fee.
