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Paleontology
Paleontology is the study of prehistoric life and an organism's interaction with other organisms and the environment. It is a science that attempts to explain causes, rather than to conduct experiments to observe effects, and is often based on fossil evidence. Questions here have to do with anything that pertains to paleontology.
3,044 Questions
What era covers the greatest proportion of geological time?
The Paleoproterzoic Era (2,500 - 1,600 ma) was the longest era in geological time. It lasted 900 million years. This represents 19.8% of geological time.
List from longest to shortest.
Paleoproterzoic (2,500 - 1,600 ma) - 900 million years
Mesoproterzoic (1,600 - 1,000 ma) - 600 million years
Neoproterzoic (1,000 - 542 ma) - 458 million years
Paleoarchean (3,600 - 3,200 ma) - 400 million years
Meseoarchean (3,200 - 2,800 ma) - 400 million years
Neoarcheasn (2,800 - 2,500 ma) - 300 million years
Paleozoic (542 - 251 ma) - 291 million years
Eoarchean (3,800 - 3,600 ma) - 200 million years
Mesozoic (251 - 65.5 ma) 185 million years
Cenozoic (65.5 ma - Now) 65.5 million years
There are two types of age determinations. Geologists in the late 18th and early 19th century studied rock layers and the fossils in them to determine relative age. William Smith was one of the most important scientists from this time who helped to develop knowledge of the succession of different fossils by studying their distribution through the sequence of sedimentary rocks in southern England. It wasn't until well into the 20th century that enough information had accumulated about the rate of radioactive decay that the age of rocks and fossils in number of years could be determined through radiometric age dating.
Principle of superposition: Younger sedimentary rocks are deposited on top of older sedimentary rocks.
Principle of cross-cutting relations: Any geologic feature is younger than anything else that it cuts across.
The dating of fossils was originally done by their placement in a geologic column of rock strata. Because of the Law of Superposition, the deeper the stratum, the older it is (in an undisturbed body of rock or sediment). Fossils which were evident in a particular stratum, but missing from other strata were noted as "index" fossils. The presence of these fossils indicated the age of the stratum relative to other layers. The layers of stratum were placed in a geologic column, subdivided, and assigned names based on the presence of different types of fossil organisms.This is the basis of "relative dating" of rock layers and fossils, a dating technique that was in effect until the advent of radiometric techniques in the twentieth century.
It is not possible to determine the one "first" ethnicity as there is no definitive measure of when specific ethnicities began. The concept of ethnicity has evolved over time and is influenced by various factors such as culture, history, and societal interactions.
Which trilobite characteristic did not change through time?
The exoskeleton composition did not change through time in trilobites. Trilobites maintained a calcite exoskeleton throughout their existence in the fossil record.
The presence of fins on a fossil suggests that the organism likely lived in water at some point in its life. This could indicate that the area where the dig took place was once covered by water or that the organism had adapted to an aquatic environment.
How reliable is fossil evidence?
The answer depends on how the word 'reliable' is interpreted in the question:
(1) Is the fossil evidence 'reliable' in interpreting the history of life on Earth?
Fossil evidence IS our understanding of the history of life. Fossils on which this understanding is based include skeletons, roots, leaves, bark, chemical signatures, imprints, carbon residues, burrowing and trail marks, petrified wood, footprints, eggs, gastric stones, fecal matter, and many others, found preserved mainly in stone, but sometimes in ice. There are many ways that fossils can be formed. They include freezing, carbonization, petrification, mineral replacement, unaltered preservation,
recrystallization, andauthigenicpreservation.
The fossil record of life recorded in rock is full of periods of intense diversification, appearances of new lifeforms, and extinction events that affected large percentages of the biota on a worldwide scale.
(2) Are the modern methods used to determine the age of the fossil 'reliable'?Radiometric dating of rock involves the measurement of the amount of decay in radioactive elements which are present in the rock. Radioactive elements decay at unique rates, depending on the isotope. This rate of decay is known as half-lives; it is the time necessary for ½ of the atoms to decay in a particular element. The decay follows a geometric scale, in that in the first half-life of an element, ½ of the atoms decay, yet in the second half-life, ½ of those remaining decay and so forth. By measuring this decay, and knowing the half life of an element, scientists can date a sample. Radiometric dating is particularly useful in dating igneous and metamorphic rock, but not so much for sedimentary rocks and fossils.
Because of geologic events such as plate tectonics and volcanism, suitable material for radiometric dating, such as volcanic tuff, solidified lava, and igneous intrusions have been found as layers on, in, and cut through layers of sedimentary rock and fossils. Intrusions are always younger than the rock body they penetrate, meaning that the sedimentary rock in which intrusions are found will be older than a radiometrically dated sample of the intrusion. Lava flows and volcanic ash which form layers in rock will be younger than the rock below and older than the rock above. The solidified intrusions and lava flows can be dated with radiometric techniques.
The radiometric dating of suitable rocks (i.e. igneous or metamorphic) in proximity to their sedimentary counterparts, therefore allows the sedimentary rock to be dated as well. Radiometric dating techniques are constantly being refined and improved with a resulting increase in accuracy and date range.
Scientific inquiry and the scientific method have contributed greatly to our lives in the fields of electronics, physics, engineering, chemistry, manufacturing, and medicine. This same scientific method is being used in genetics and Earth sciences to broaden our knowledge and understanding of Earth's history, including the origin and evolution of life.
What are preserved remains of a living thing called?
Preserved remains of a living thing are called fossils. Fossils can be bones, shells, imprints, or traces of ancient organisms that have been preserved in rocks. They provide valuable information about past life forms and environments.
As weathering eats away pockets of limestone underground what are likely to form?
As weathering erodes limestone underground, it can form caves, sinkholes, and underground rivers. Over time, the chemical reactions between water and limestone can result in the dissolution and reshaping of the rock into unique structures and landscapes.
What is a common Devonian fossil?
A common Devonian fossil is the trilobite, which was an ancient marine arthropod with a hard exoskeleton. Trilobites were diverse and abundant during the Devonian period, with many different species found in rocks from this time period. Their distinctive appearance and widespread distribution make them one of the most well-known fossils from the Devonian period.
Fossil beds are geological formations where a concentration of fossils is preserved. These beds often result from the deposition of sediments over a long period of time, which helps protect and preserve the fossils within them. Scientists study fossil beds to understand past ecosystems and the evolution of organisms over time.
To calculate her angular momentum, you would need to know her moment of inertia (which depends on both her mass and how this mass is distributed relative to the axis of rotation), her velocity (speed at which she travels in a circular path), and the radius of the circle she is skating. You would use the formula for angular momentum, which is given by the equation: L = I * ω, where L is angular momentum, I is moment of inertia, and ω is angular velocity.
Mummified animals found in dry caves can be examples of fossils with?
i'm not sure but i think it's original preservation.
What are facts about the devonian period?
The Devonian Period is a part of the Paleozoic Era, which covers the time from 541 to 252.17 million years ago. It began with the Cambrian explosion, in which most phyla of life began, and ended with the mass extinction called the Permian-Triassic extinction event.
Is a mammoth in frozen ice a trace fossil?
No. A mammoth trapped in ice is a body fossil.
Trace fossils are evidence of life but not part of the animal itself. Examples of trace fossils are footprints, nests, worm burrows, teeth marks etc. Coprolites (fossilized Dung) in the strictest sense are also trace fossils.
Eggs, teeth, bones, skin, hair, feathers etc are all body fossils.
What envolved to become the dominant land plant during the Cenozoic era?
During the Cenozoic era, angiosperms (flowering plants) evolved to become the dominant land plant group. Their efficient reproductive structures (flowers) and ability to co-evolve with pollinators and seed dispersers allowed them to outcompete other plant groups. This dominance was further bolstered by their ability to adapt to a wide range of environments and climates.
This is a pagan symbol of the rebirth of the earth in celebrations of spring and was adopted by early Christians as a symbol of the ressurection of Jesus.
i hope it helps..
Were there bugs during the cretaceous period?
Yes, there were bugs during the Cretaceous period, which lasted from around 145 to 66 million years ago. Insects were diverse and abundant during this time, with many different species thriving in various ecosystems around the world.
Are fossils examples of organic matter and why?
Yes, fossils are examples of organic matter because they are the preserved remains or traces of once-living organisms. Fossils can include bones, shells, teeth, and other organic materials that have undergone a process of mineralization or replacement with inorganic materials to become stone-like structures.
What did eath's surface look like in the Permian period?
During the Permian period, Earth's surface was largely covered by the supercontinent Pangaea. The interior of Pangaea was dominated by vast desert regions, while the coastlines were characterized by shallow seas and coal swamps. The climate was generally hot and dry, with significant fluctuations in temperature and sea levels.
When did abundant fossil evidence first appear in the geologic record?
Abundant fossil evidence first appeared in the geologic record during the Cambrian Period, around 541 million years ago. This period is known as the "Cambrian Explosion" because it marked a rapid diversification of marine life and the emergence of many major animal groups.
What is bigger than a century?
- millnniam 100 years 2. age 1000 millnniams 3. epoch 10 ages 4. period 10 epoch 5. era 10 periods 6. eon 5 eras
What are the four step scientists use to study fossils?
Scientists use the following four steps to study fossils: 1. Excavation - careful digging to uncover fossils, 2. Preparation - cleaning and preserving fossils, 3. Description - documenting physical characteristics of fossils, and 4. Analysis - using various methods to interpret the fossils' age, environment, and relationships to other organisms.
Did cavemen wash or have a bath?
It's believed that ancient humans, including cavemen, practiced some form of personal hygiene, although the methods would have been simple compared to modern bathing practices. They likely used water from natural sources like rivers or lakes to clean themselves.
