What is fossils: Definition and 24 Discussions

A fossil (from Classical Latin: fossilis, literally 'obtained by digging') is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood, oil, coal, and DNA remnants. The totality of fossils is known as the fossil record.
Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host.
There are many processes that lead to fossilization, including permineralization, casts and molds, authigenic mineralization, replacement and recrystallization, adpression, carbonization, and bioimmuration.
Fossils vary in size from one-micrometre (1 µm) bacteria to dinosaurs and trees, many meters long and weighing many tons. A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates. Fossils may also consist of the marks left behind by the organism while it was alive, such as animal tracks or feces (coprolites). These types of fossil are called trace fossils or ichnofossils, as opposed to body fossils. Some fossils are biochemical and are called chemofossils or biosignatures.

View More On Wikipedia.org
  1. BillTre

    Anomalocaris Video (Earth's First Predator)

    Here is a nice video (about 10 minutes) on Anomalocaris, a Cambrian animal known for its weird fossils. The video goes over how it was figured out from fossils (took a long time), how it worked as a predator (it could be two feet long and was the Cambrian's apex predator), how it...
  2. Al-Layth

    How do evolutionists construct descendency trees from fossils?

    Looking at the result of a great number of fossil expeditions, I understand how you can construct the full or partial skeletons of a number of different animals, you would be able to certainly identify certain bones as belonging to a distinct animal. That's great. you now know there were these...
  3. Isopod

    Dinosaur killed in asteroid strike found

    Scientists have presented a stunningly preserved leg of a dinosaur. The limb, complete with skin, is just one of a series of remarkable finds emerging from the Tanis fossil site in the US State of North Dakota. But it's not just their exquisite condition that's turning heads - it's what these...
  4. Isopod

    Which Dinosaur Was Discovered Almost Perfectly Preserved?

    ( https://www.nationalgeographic.com/magazine/article/dinosaur-nodosaur-fossil-discovery ) 1. Whats your favourite dinosaur? 2. Have you ever found a fossil (dinosaur or otherwise)? 3. Do you have any favourite non-dinosaur extinct creatures? 4. If you could travel back in time to see dinosaurs...
  5. 256bits

    What prehistoric treasures lie beneath Los Angeles?

    Ever wonder what is under the ground you are walking on? No, neither do I, usually. But, if anything, at least a record of the history of the Earth lies under your feet. https://phys.org/news/2017-12-subway-paleontology-la-unEarth's-fossil.html
  6. N

    What is the best guess for this image of a 720x466 dinosaur fossil?

    What could this be?
  7. Drakkith

    Fossils of Closely Related Species

    Hey all. I've got a question regarding fossils. Each individual person is unique, and the variation between any two people can be significant. How large are the differences between individual humans compared to the differences between closely related species in our fossil record? How do...
  8. Calpalned

    Neanderthal fossils never frozen?

    There have been incidences where woolly mammoths were frozen in ice and as a result very well preserved with the brain and hair intact http://www.dailymail.co.uk/news/article-2812854/World-s-best-preserved-woolly-mammoth-goes-display-Moscow-39-000-years-trapped-glacial-ice.html. Neanderthals...
  9. Goodies

    Fossils: 95% Plants, 1/4% Vertebrates - Fact or Fiction?

    Hello! I read this post on Facebook and I am curious as to its validity and accuracy: 95% of the fossil record is made of plants. Shellfish & coral make up most of the rest while vertebrates (fish, amphibians, reptiles, birds & mammals) make only 1/4 of 1% of the fossil record & only 1 of...
  10. Patzee

    How Often Are Insect Fossils Found in Amber?

    How common is it to find fossilized insects entombed in Amber? I ask because there is a jewelry vendor here in Maui who claims that her amber jewelry encapsulating a variety of insects were created naturally, mined in the Baltic area and are thousands of years old. She sure has a lot of these...
  11. Evo

    Plant or Animal? Mysterious Fossils Defy Classification

    Interesting finds. Continued... http://www.livescience.com/12883-plant-animal-mysterious-fossils-defy-classification.html
  12. H

    Using the decay rate of rubidium isotope to determine age of fossils

    Hello! i was just wondering if anyone could help me with this, The rubidium isotope 87-Rb is a beta emitter with a half life of 4.9 x 10^10 yr that decays into 87-Sr. It is used to determine the age of rocks and fossils. Certain rocks contain a ratio of 87-Sr to 87Rb of 0.0100. Assuming there...
  13. sophiecentaur

    How did Victorians estimate the ages of fossils?

    They didn't have Carbon 14 and I think fossil tree rings (dendochronology?) is a modern method so where did they get their millions of year from?
  14. Evo

    What Fossils Can You Find Outside?

    Here are a few of my fossil rocks I picked up outside, they are everywhere. I am going to post some large ones for detail, so sorry if you have to scroll. I was going to post this in Earth but images are disabled. Bear with me as I add pictures.
  15. Janus

    Dino-might exhibit of Chinese fossils at OMSI

    We went to see the exhibit of Chinese fossils at OMSI (Oregon Museum of Science and Industry) this last weekend, and I thought I'd share some photos. along with the fossils, they had some animatronic versions...
  16. N

    Fossils of a Pre-Historic One-Tonne Rodent Discovered

  17. Evo

    Scientist Fights Church Effort to Hide Museum's Pre-Human Fossils

    It's frightening to see that there are groups of people that want to hide reality from the populace. I hope the Museum has the guts to realize they have a responsibility to the public not to cave into fanatic groups. "Famed paleoanthropologist Richard Leakey is giving no quarter to...
  18. H

    Problems with understanding fossils dating

    We're using, Concepts in Modern Biology. On page 410, it says that layers of rock determine the age of a fossil, and few lines later that using a fossil we may determine the age of the layer. Does it work in this way that, they determine the age of the fossil using radioactive dating and then...
  19. H

    Carbon dating of fossils older than 10,000 years

    Hello, I'm just wondering, is it fine to predict the age of fossils older than 10,000 years with Carbon Datin? After all, I think nobody knows how much carbon-14 there was back then, and whether the animals consumed less or more carbon-14 than now. How exact are such long-term predictions?
  20. L

    Methods for finding the age of fossils at death

    I'm curious in the processes used to date the age of a human fossil, not in terms of how many thousands of years ago the human died, but the age of the human when they died. Are there any special processes that are used to determine this, or are humans mearly matched up in terms of degeneration...
  21. Loren Booda

    When will bones become fossils?

    Over how long is skeletal calcium essentially replaced by mineral depositation?
  22. A

    Are micro-organisms fossils on so-called Martian meteorite true?

    Are micro-organisms fossils on so-called Martian meteorite true? I think it is more likely contaminated by life on Earth...
  23. U

    Fossils on Mars: A Convincing Case

    This person has come up with a very good case for fossils on mars, well at least it's got me convinced. What do you think? http://home.cfl.rr.com/aichip/marsfoss.htm
  24. W

    Are fossils really nonrenewable?

    are fossils really nonrenewable?