older than the rock layer above it and can provide information about the time period in which it lived and the environmental conditions at that time. This helps scientists estimate the age of the rock layers and understand the history of the area where the fossil was found.
The trilobite species Eldredgeops rana is a common New York State index fossil found in Devonian rock layers. If a rock layer containing this index fossil is missing due to unconformity, it suggests a gap in the rock record where deposition ceased, erosion occurred, and then new sediment layers were deposited on top.
Fossils are typically found in sedimentary rock layers, which are formed from the accumulation of sediments over time. Fossils are most commonly found in the mid to lower layers of sedimentary rock formations. The specific layer in which a fossil is found depends on the age of the fossil and the geological history of the area.
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It is usually older than the rock layer it is found under.
It is usually older than the rock layer it is found under.
First, a thin layer of sediment hardens and forms a mold. Then, what is known as a cast is when a new layer of sediment fills in the mold breaking down the creature/ animal/fossil.
A mold and cast fossil is and exact stone replica of an organism but it is formed like this. The first layer of sediment hardens and forms a mold. then a new layer of sediment fills in the mold and hardens. That is the cast.
There are layers of earth that are deposited over time and based on where a fossil is in the layers a scientist can understand what the age of the fossil is relevant to another fossil in a different layer of earth. The law of superposition says that new sediment is deposited on top of old sediment so, the sediment in the bottom layer is the oldest and the sediment at the top is the youngest. Because of this the fossils in the bottom layer are the oldest and the fossils near the top are the youngest. Say you have 10 layers of rock, and the top layer is number 1 (the youngest) and the bottom layer is number 10 (the oldest). Even if a scientist can't tell exactly how old a fossil is if they know it is in a layer deeper than another fossil they know it is older than that fossil so, a fossil from layer 9 is older than a fossil from layer 5 which is also older than a fossil from layer 3. This is relative age. If we take it a step further... If a scientist knows that the fossil in layer 4 is 65 million years old than we not only know the fossils in layer 5-10 are older than the one in layer 4, but that they are all older than 65 million years old. So, the fossils in layer 1-3 would be less than 65 million years old. Scientists can know how old a specific fossil is sometimes based on whether or not it is an index fossil (a fossil that only occurred during a very small, specific interval of time), or if it is possible to carbon date it or something in the same layer.
By using relative age. Over a long period of time, sediment will, layer by layer, coat and cover the fossil, making it difficult for paleontologists and scientists to figure out how old the fossil really is.
It's when the rock dies and is attacked by decomposers. This is why it has a small chance of becoming a fossil, but if it does, it gets covered by sediment where it slowly starts to decay. The rock then starts to be preserved where the first layer of sediment is compressed by the weight.
Fossil fuel is made out of, decomposed plants and animal matter that had been buried upon layer under sediment over millions of years.
older than the rock layer above it and can provide information about the time period in which it lived and the environmental conditions at that time. This helps scientists estimate the age of the rock layers and understand the history of the area where the fossil was found.
Sedimentary rock is formed by the settling down of bits of sediment material on the surface of the Earth and within bodies of water. The deeper down the layers of sediment are, the older the layer is. If a layer of sedimentary rock is nearer to the surface, then that layer was formed much more recently. The different layers can show different sorts of records. For example, a fossil found in a deeper layer of sediment is very probably a predecessor of a later fossil found closer to the surface of the Earth. With the help of such dating methods as the layer in which the fossil was found and radiocarbon dating, the numerous finds that have been discovered have revealed a reliable timeline of events related to life on Earth such as evolution, periods of great dyings-out, and periods of new life forms emerging i.e. the Cambrian Explosion. Sedimentary rocks also reveal a record of geologic activities like great floods and ancient rivers - like the powerful waters that carved out the Grand Canyon.
A mold and cast fossil is and exact stone replica of an organism but it is formed like this. The first layer of sediment hardens and forms a mold. then a new layer of sediment fills in the mold and hardens. That is the cast.
The trilobite species Eldredgeops rana is a common New York State index fossil found in Devonian rock layers. If a rock layer containing this index fossil is missing due to unconformity, it suggests a gap in the rock record where deposition ceased, erosion occurred, and then new sediment layers were deposited on top.