Questions tagged [paleontology]

Paleontology (also Palaeontology) is the scientific study of past life. Questions about the biological aspect of paleontology (such as taxonomy and anatomy) are off-topic here and should be asked on biology.stackexchange.com

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25
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1answer
683 views

How much have global GPP and biomass changed over Earth's history?

I'm curious about how much is known about this topic: how much has the total amount of life on Earth changed over the 4 billion years or so that it has existed on this planet? Are there estimates of ...
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6answers
8k views

Paleontology science fair ideas?

My daughter, age 8, wants to do her science fair project in paleontology. For the fair, we need to come up with a question that can lead to a hypothesis, then apply the scientific method to test this ...
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2answers
370 views

Did the impact event that caused the Chicxulub-Crater definitively and single-handedly cause the Cretaceous-Paleogene extinction?

Opinions abound on the web. What is the state of the current science regarding this theory and what is the best evidence? Is the theory gaining or losing traction? If it's losing what's the best of ...
14
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1answer
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Is there a geological explanation for the recent Mammoth tusk discovery 185 miles off the California coast?

A recently publicized discovery of a Columbian Mammoth tusk located well of the coast of California in quite deep water made me wonder if geological conditions 100,000 years ago can explain how it got ...
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4answers
10k views

Why are many fossils found in deserts?

Why are deserts famous for fossils? Is it a coincidence? Some examples: Giant Catfish Fossil Found in Egyptian Desert Chile's stunning fossil whale graveyard explained Giant Dinosaur Fossil Found ...
12
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2answers
1k views

How do we know graptolites were pelagic?

How do we know that graptolites were pelagic, and not benthic, creatures? I understand it has something to do with their being found in black shale, but I'm not sure why that is particularly relevant.
12
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3answers
374 views

What is the age of the earliest traces of life on Earth?

In the article Oldest rocks, earliest life, heaviest impacts, and the Hadean–Archaean transition (Moorbath, 2005), the author states (based on previous referenced research) that the $\ce{^13C}$ ...
12
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1answer
381 views

What kind of rock is this being eaten by a rock-eating worm?

The New York Times article This Creature Eats Stone. Sand Comes Out the Other End. describes the shipworm Lithoredo abatanica, an organism that appears to "eat solid rock". It links to the item in ...
12
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1answer
143 views

Barite and Acantharians

Acantharians are planktonic protists (abundant in today oceans), sister-group to polycystine Radiolarians, that have the particularity of biomineralizing complex skeletons in strontium sulfate SrSO4 (...
11
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1answer
519 views

What periods of the fossil record are most lacking in specimens?

What parts of the fossil record are most lacking in specimens? That is, if you were to trace the evolution of a modern mammal (humans, for example) from abiogenesis to now, which periods are the most ...
11
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1answer
838 views

How are organic walled microfossils preserved in the fossil record?

Organic walled microfossils have no hard mineralised parts, how are they preserved in the fossil record?
11
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2answers
29k views

How can I learn to spot fossils and fossil-bearing rocks on the Jurassic coast?

Due to a pleasant change in my circumstances, I have been to Lyme Regis several times recently, and it seems as though I'm going to be a regular visitor over the next few years. As a former biologist ...
10
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1answer
504 views

Is the Younger Dryas associated with an extinction event?

It's often said that, while warming and cooling have happened before, what is unusual about the current anthropogenic warming is that it's happening so fast, relative to previous warming phases$^1$. ...
10
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1answer
391 views

What evidence is there that plant evolutionary history "dances to a different beat" than that of animals?

Floral transformations have been due to gradual replacement and piecemeal, not mass extinction. Plant “geoevents”; have not been synchronous with epochal animal originations/ extinctions and hence ...
10
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1answer
190 views

How would a Mars rover identify a microbialite fossil?

I recently read of a company in Canada using robotic technology to study freshwater microbialites. Their claim is that greater understanding of terrestrial microbialites could help in the search for ...
10
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1answer
108 views

Biogenic origin of authigenic zeolites

Bohrmann et al. 1989 advanced the idea that the silicate phase from some clinoptilolites come from the diagenetic degradation of biogenic opal (from radiolarians in that case but presumably also other ...
9
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1answer
319 views

Why is the concept of "mass extinction" a relatively recent development in geology?

The concept of "mass extinctions", with its catastrophic connotations, is a relatively recent development in the geological sciences. It evolved in the early 1980s, driven by two landmark publications ...
9
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1answer
457 views

What geological processes can cause local biases in the fossil record?

What are the main geological processes that can cause local biases in the fossil record, e.g. when comparing species diversity or species occurances in different areas from the same time period? I ...
8
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3answers
454 views

How do archaeologists address time dilation when analyzing carbon dating results?

It is a proven fact that the gravitational force exerted upon an object directly affects that objects experience of time; the greater the gravity, the slower time passes, and visa versa. While the ...
8
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1answer
679 views

Is the Principle of Fossil Succession accurate?

After wondering on the validity of the principle of Original Horizontality, I'm now focusing on the principle of fossil succession. This principle states that : Fossils of species that did not ...
7
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2answers
1k views

Life on Earth previous to us

I've seen in several places that there seems to be an extinction cycle on Earth of approximately 27 million years. I've read this here: http://www.dailymail.co.uk/sciencetech/article-1294372/Life-...
7
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1answer
646 views

What is the oldest fossil on Earth?

What is the oldest fossil ever found on Earth? Where and when was it found? What was the oldest fossil with a brain with 2 hemispheres ever found?
7
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1answer
147 views

Signatures of acid rain at KT boundary

I read in Walter Alvarez' book T. Rex and the Crater of Doom that the Earth's collision with the large meteor leading to the K-T extinction catalyzed the reaction of atmospheric oxygen and nitrogen ...
6
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4answers
176 views

Has there ever been a case where we have found what appears to be a prehistoric fossil but have no way of dating it?

I find that when ever I learn of a new fossil, the age of said fossil is always mentioned. This perplexes me given how intuitively rare it seems to have radioactive material to date a formation. I ...
6
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1answer
1k views

How do scientists measure the age of old animal remains?

The remains of a mammoth were recently unearthed in a Michigan farmer’s field [1]. This find could provide new information on the activity of early humans in the area, experts at the University of ...
6
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2answers
380 views

Are Pompeii and Herculaneum unique?

Has anyone ever found or gone looking for similar locations, i.e. volcanic eruption sites in which unfortunate victims – human and non-human – have been entombed in the volcanic ash, with the ...
6
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1answer
1k views

How long does earth take to recover from mass extinctions? What is "normal"?

Wikipedia states the following about the P-Tr extinction event: "Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after any other extinction event,[5]...
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1answer
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How to identify a predator's coprolite from an herbivore's?

I have a coprolite that is 8" by 5" and weighs 8 lbs. The shape is similar to a lumpy brain, the colors below outer crust are deep red and the crust is pastel green and grey. It has a strong density ...
5
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2answers
817 views

What is Oligo-Miocene radiation?

Some studies about Earth's fosilized plants/animals mention a "Oligo-Miocene radiation". Examples: Our study therefore strengthens previous suggestions that the absence of very large penguins ...
5
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1answer
519 views

Were dinosaurs with feathers common?

More and more evidence of fossilized dinosaurs with feathers are appearing. Did many dinosaurs have feathers and did this change during the Mesozoic?
5
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1answer
103 views

Book on the history of Earth and life on Earth

I am interested in getting a better overview of the full history of the Earth and the evolution of life. Therefore I am looking for a book that goes through the different geological time scales of the ...
5
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2answers
386 views

ID on a potential flint fossil

I was out in Swinley Forest in Bracknell(United Kingdom) last weekend. The area is a large pine forest but the ground is full of flint and is very sandy. I stumbled across a piece of flint and ...
5
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1answer
731 views

Circular patterns at bottom of rock, is it a fossil?

The image below was taken on a hike. Circular patterns at bottom (it is flatter on this face and round otherwise) appear either man-made or possibly it is a fossil. Any idea what this could be?
5
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1answer
103 views

How were smaller reptiles/mammals more successful at surviving the KT event than larger dinosaurs?

Last night, I was watching this programme on TV The Real T Rex where the presenter pointed out that smaller reptiles (crocodilians and mammals) "somehow managed" to survive the KT extinction event ...
5
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1answer
189 views

Geological feature - what is it?

Hello, We were walking in Bundoran in Donegal County, Ireland today and we encountered the geological feature shown in the picture (from above from cliffs and from very close up at beach level). We ...
4
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1answer
590 views

Why were the early lifeforms of Proterozoic formation of India devoid of hard parts?

According to Ravindra Kumar's Historical Geology and Stratigraphy, early lifeforms of Proterozoic time could not be preserved as fossils, since they were devoid of hard parts. In addition to that, it ...
4
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1answer
116 views

What is this fossil? What is this crystal?

My daughter found this fossil while walking through the Swabian Jura, in Southern Germany. She asked me about it, but I have absolutely 0 clue about geology. The crystal part is 3cm in diameter, but ...
4
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2answers
634 views

Aligator or Dinosaur Fossil skin type rock

The more I looked at this stone and touched it, the more this thing looked like it was wrapped in some kind of reptile skin. It may just be a random rock. More photos if needed. Does this look like ...
4
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1answer
217 views

Do you have any informations about fossil-rich cherts from Scandinavia?

Me and some of my friends have found many rocks similar to these in central Europe - we believe that it is fossil-rich chert that originally comes from Scandinavia. There are many interesting fossils ...
4
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1answer
407 views

I have found this fossil tooth, could it be pliosaur ? Or maybe theropod?

Lenght: 10 mm, striated, circular cross-section Site: Brno-Hády (limestone quarry), Moravia, Czech republic, central Europa Age: Jurassic, oxford The site is a good source of fossil shark teeth, ...
4
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1answer
2k views

What are 'articulate shells'?

I can not really find a definition, not even in a geologic dictionnary: What are articulate (resp. inarticulate) shells? To be more specific, the term is related to tsunami deposits (tsunamite).
4
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1answer
109 views

Did geologists determine the age of rocks and fossils before the advent of modern scientific dating methods?

Did geologists determine the age of rocks and fossils before the advent of modern scientific dating methods such as radiometric, electron spin resonance and thermoluminescence? If they did, does ...
4
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1answer
115 views

Fossil ID: possible fauna fossil, from Perlis, Malaysia

I found this fossil while doing my fieldwork in limestone area. Description below may help to identify it. Location: NW Perlis, Malaysia (Setul Formation). Hilly Area. My Observation: Have a curly ...
3
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2answers
151 views

What is this fossil found in flint in Kent?

My 7 year old son found this fossil whilst cracking open flint in Deal, Kent. The fossil (assuming it is) looks like scales/cells/shell and is chalky. The oblong lines are raised and well defined and ...
3
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2answers
89 views

How far into the past would you have to go before you couldn't breathe the atmosphere?

Not counting temporary events, like mass extinctions.
3
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2answers
393 views

Was the last glacier too hard for the Neanderthal?

I know several theories are proposed to explain Neanderthal extinction: Consanguinity. Homo Sapiens competence. Climate change. But Finlayson et al (2008) quote the last ones lived south of the ...
3
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2answers
69 views

How older is this snail shell possible could be?

Last weekend I was in Xınalıq(the village in Azerbaijan) and found this snail shell. I am wondering how old is this?
3
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1answer
285 views

Fossil from North Norfolk coast, UK

This palm-sized rock is from the beach at Eccles-on-Sea (North Sea coastline). I can see four types of material: A brown, slightly translucent, 6cm tubular fossil(?) that I can mark with a steel ...
3
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1answer
160 views

What type of mammal does this fossil tooth belong to?

The fossil tooth was found western South Dakota in the early 1980s. I can't be sure on the location. It might have been collected from Belle Reservoir, near Belle Fourche, Butte County, South Dakota, ...
3
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2answers
487 views

What makes pollen varieties useful index fossils?

What makes pollen varieties useful index fossils? Should pollen not be a poor index fossil?