One thing that will have thrown the author off the trail is that he is holding a fossil of the organic parts of the snail and that is essentially a cast of the animal, not the shell. They are known as Steinkerns (stonecore).
The insides get replaced by minerals, which harden, the shell dissolves, then the only fossil remaining is a mould of the inside of what used to be the shell.
So on a fundamental level, the headline is wrong. He did not find any sort of shell...
True, but I actually had no idea that it was the soft parts rather than the hard parts that had been fossilized. (I haven’t verified it yet.) Either way, it didn’t read like a bad faith interpretation/comment.
It wasn't written to be one. If the author went to the trouble of making a 3D space filled with many shells, knowing the actual shell was most likely a different shape would be something they would probably want to know, so the position of their fossil could be placed more accurately in the graphed space.
I've been told by a friend -- a wierd thing -- in many places you can dig a hole and it will fill with water. And at some point in the future fish will be swimming in it.
with a "pond sized" hole, I have read that fish eggs arrive on the feet of ducks and other waterfowl attracted to the new pond. (I have never looked up whether this is a myth)
There's a lot more to morphology than just the shape of the shell, and indeed the shape can sometimes be misleading, in that very different species can have somewhat similar shells, and different individuals of the same species can have quite different shell shapes. You've got a gasteropod, so it would be good to pay special attention to the peristome and siphonal canal (based on the bio classes I took in the area, I'm no expert) but of course there's lots of features that could be helpful in an identification.
https://en.wikipedia.org/wiki/Gastropod_shell#Parts_of_the_s... is a good list, and maybe you've already done this but you would want to find a dichotomous key of gasteropod families native to the area to narrow it down. Good luck in figuring out your shell!
I'm a little confused about how significant of information can be derived from a 2d projection of the shell. This sort of mathematical modeling looks like phrenology.
Using PCA on 3d shapes is a proven method for identification. It's nothing like phrenology aside from both involving morphology. Former actually works, latter does not.
(I upvoted, seems a little weird that you were downvoted) So, I spent a little time looking up "Principal Component Analysis" and yeah, this method works well with these forms, and my comment comparing it to phrenology was definitely more out of ignorance!
I was most surprised that you could flatten a 3d structure down to 2d and not lose so much information that it would cause a very high rate of error. Someone else was skeptical enough to do a study as a critique on it, only to have it retracted. (funny in light of this post)
PCA (using eigenvectors for dimensionsional reduction) is kinda like moving the axis from an x/y/z grid and onto the shape itself. So it's not 2d in the sense of a simple projection where the loss of information is greater. It has a lot of useful applications, 3d shape recognition is just one.
"He swam at my feet,
Powerful arms in broad strokes
Sweeping the sand.
So I asked this man,
What seas do you swim?
And to this he answered,
'I have seen shells and the like
On this desert floor,
So I swim this land's memory
Thus honouring its past,'
Is the journey far, queried I.
'I cannot say,' he replied,
'For I shall drown long before
I am done.'"
I have quite an early memory of being on the somewhat remote property in Australia that my mother grew up on (Central NSW, near Condobolin).
My Uncle, who then ran the property, walked over to a rock, whacks it with a hammer or similar, shows me a bit of a trilobite (which are totally different to our sort of bytes). He did this a bunch of times. I still have the rocks. No amazing full horizontal cross-sections, but it certainly got my very young mind excited.
There were fossils RIGHT THERE from before there were dinosaurs!
Oh, and that central Australia used to be an Ocean!
These clear demos to young kids, or adults, are great, and the many other examples here in the comments are a testament to that (Vienna? wtf!).
St. Stephens cathedral in Vienna was built with sandstone that contains seashells. It's hundreds of kilometers away from the shore, but ~15 million years ago the area where it stands now was a seabed.
The stones are not from the exact location where it was built, but from close by. The quarry where the stones came from hundreds of years ago is still active, and you can find tons of fossils there. It's practically impossible to get a piece of rock from there without visible seashells.
If all the ice melted it would raise the oceans by something like 230 feet, so modern Vienna would still be above water at 495 – 1778 ft elevation.
Although some estimates suggest Earth loses 20 - 30 cubic kilometres of water to space annually. Plus whatever water is bound up in mineralisation annually.
450 million cubic kilometres of water lost over a 15 million year period would lower ocean by something like … a bit?
The total volume of water on Earth is presently estimated to be around the 1.386 billion cubic kilometre mark.
The volume of a sphere increases to the cube of its radius … carry the 1 … nup, that’s to hard for me.
Almost any surface on earth was once under the water. You can find sea shells and various sea deposits high on some 8000m peaks or 1000kms inland.
Everybody who cares at least slightly knows this, and I am pretty sure author knows this too, he could have spared us the initial hyperbole. Analysis itself is good but not everything needs to read like dramatic novel.
Herodotus wouldn’t have written it quite the same — no Jupyter notebook for example,
Jupiter being a Roman term; the nearest equivalent for the Ancient Greeks was Zeus.
yea, finding shells all over was one of those things I was taught in elementry school. We even had a field trip to some place to find them along with geography lessons on the various layers of the area
Gemini says "As the crow flies (Straight-line distance): Approximately 900 to 920 kilometers (roughly 560 to 570 miles) directly north of the coast at Karachi"
Maybe some geology buffs can correct me, but as I understand it there has been three periods with ocean on top of the crust we call Pakistan today. The Proto-Tethys, Paleo-Tethys, and Tethys Ocean. Many hundreds of millions of years of being ocean.
Maybe a nitpick but Latamber is not directly north of Karachi and it's about 1000 kilometers away (the closest coast is 950 km but not in Karachi). It's easy to see and to measure on a map.
I've got some 'shells' from the deserts near Siwa Oasis. Quite a cool feeling walking on top of what used to be the floor of the Tethys Ocean, especially when everything around you is just rock and sand without a drop of water in sight.
He is losing a lot of information in that normalization pipeline (whole shell reduced/feature engineered into nothing but an outline). A CNN or something similar would be better and he can maybe get a better depth map of the mouth shape.
The analysis is nice, flashy, and wrong. Several weak assumptions here leading to hallucinate an obviously wrong result.
Taxonomy IS a science. Just use the wide corpse of knowledge that has been built for the last 229 years, where the class Gastropoda was created.
First wrong assumption. This is a seashell.
This probably is a seashell, yes.
But fresh water snails have also shells; and savannas can have a lot of lagoons before eventually turning into deserts. If you train your model only using zebras, your model will happily conclude than an hippo is a sort of non stripped obese zebra.
1) The model use incomplete data. The data used to train the model is based in 7800 species alive. After wikipedia, Gastropoda have more than 75000 species alive, plus 15000 fossil species known. (We can assume safely that this is a snail, but remember that some cephalopods also have coiled shells).
2) The model use spurious data. All clams and Tusk shells must be removed (because we want to classify a snail). This means that the number of snails available to train the model is much lower than 7800. Including non-snails just gives us a false confidence in the strength of our model.
3) The model covers only one couple traits in this species, but this particular traits can vary within members of the same species. Taxonomy uses thousands of traits to classify a mollusc and some are particularly fastididious. Dozens of items only to describe the shell. Often the soft parts are needed (Is the penis shaped like a club? this genus, shaped like a whip? this other one; the penis in your sample is contracted because you didn't put to sleep the animal first with mint crystals, though luck, we'll never know).
4) The model is based in extant alive species, but we want to identify a fossil. Alive species have non-distorted shells. Fossils often lose their shape by the weight of sediments and compression. Only the thickest shells would keep its real height/wide proportions.
5) The model ignores important details. The species found in the desert has a very evident shell groove at the top of the spire, that the targeted species does not have. This alone, tells a newbie taxonomist that the result is wrong.
Why would you write a lot of software to find the closest match (which doesn't even seem that good) if you could also ask a subject expert? I guess you could even just post a photo to some subreddit with people who could tell you what it is...
Also: "it shouldn't be here; the nearest coastline is Dammam's, 500 km away." - are people really that ignorant about plate tectonics and sea fossils in mountains?
I found a seashell in the middle of the forest in (well inland) Mississippi. That was an interesting find, and lead me to learn that much of the continental US used to be covered in a sea, I believe https://en.wikipedia.org/wiki/Western_Interior_Seaway
This means the shell was dozens of millions of years old, and may be the oldest thing I’ve ever held, except maybe some rocks.
It's interesting that saying the Earth is more than 10,000 years old is not haram in Saudi Arabia. I thought it would be, since they are so religious, but it turns out the Koran doesn't make any claims about the age of the Earth, so you are free to say that the Earth is billions of years old and not be accused of blasphemy.
I mean, even in countries with extremely high levels of Christianity, such as Romania, you won't be accused of blasphemy for just... agreeing with science. Both Christianity and Islam are pretty similar after all, so hopefully that is not too surprising.
I can't think of a country where you even might be accused of blasphemy, though I'll admit I am not very familiar with the topic.
Even with AI, to try to replicate this on my own would take me a really long time, maybe impossible. Despite the use of AI,it would be a huge undertaking , such as having to come up with the blueprint and procedure for classifying the shells, setting up all of the environments, setting up repository, understanding the math, writing it up, coding the tool, etc.
This should allay fears that AI will render people jobless or automate everything.
One thing that will have thrown the author off the trail is that he is holding a fossil of the organic parts of the snail and that is essentially a cast of the animal, not the shell. They are known as Steinkerns (stonecore).
The insides get replaced by minerals, which harden, the shell dissolves, then the only fossil remaining is a mould of the inside of what used to be the shell.
So on a fundamental level, the headline is wrong. He did not find any sort of shell...
Splitting hairs in bad faith is not constructive to the points being made here.
True, but I actually had no idea that it was the soft parts rather than the hard parts that had been fossilized. (I haven’t verified it yet.) Either way, it didn’t read like a bad faith interpretation/comment.
It wasn't written to be one. If the author went to the trouble of making a 3D space filled with many shells, knowing the actual shell was most likely a different shape would be something they would probably want to know, so the position of their fossil could be placed more accurately in the graphed space.
Reads to me like a fascinating and relevant distinction.
No, a layperson doing a bunch of math but barking up the wrong tree theory-wise is actually super instructive for this forum of autodidacts.
And I say that as one of the autodidacts.
how is that splitting hairs? it’s an actual interesting point
I've been told by a friend -- a wierd thing -- in many places you can dig a hole and it will fill with water. And at some point in the future fish will be swimming in it.
Or trilobites?
with a "pond sized" hole, I have read that fish eggs arrive on the feet of ducks and other waterfowl attracted to the new pond. (I have never looked up whether this is a myth)
There are also fish that can walk overland to find new ponds. Weird, but real, with obvious implications for the origin of land tetrapods.
The iterative narrowing approach works well for broad research queries.
Cool find and a very interesting analysis!
There's a lot more to morphology than just the shape of the shell, and indeed the shape can sometimes be misleading, in that very different species can have somewhat similar shells, and different individuals of the same species can have quite different shell shapes. You've got a gasteropod, so it would be good to pay special attention to the peristome and siphonal canal (based on the bio classes I took in the area, I'm no expert) but of course there's lots of features that could be helpful in an identification.
https://en.wikipedia.org/wiki/Gastropod_shell#Parts_of_the_s... is a good list, and maybe you've already done this but you would want to find a dichotomous key of gasteropod families native to the area to narrow it down. Good luck in figuring out your shell!
I'm a little confused about how significant of information can be derived from a 2d projection of the shell. This sort of mathematical modeling looks like phrenology.
Using PCA on 3d shapes is a proven method for identification. It's nothing like phrenology aside from both involving morphology. Former actually works, latter does not.
(I upvoted, seems a little weird that you were downvoted) So, I spent a little time looking up "Principal Component Analysis" and yeah, this method works well with these forms, and my comment comparing it to phrenology was definitely more out of ignorance!
I was most surprised that you could flatten a 3d structure down to 2d and not lose so much information that it would cause a very high rate of error. Someone else was skeptical enough to do a study as a critique on it, only to have it retracted. (funny in light of this post)
https://elifesciences.org/reviewed-preprints/94685v1/pdf
PCA (using eigenvectors for dimensionsional reduction) is kinda like moving the axis from an x/y/z grid and onto the shape itself. So it's not 2d in the sense of a simple projection where the loss of information is greater. It has a lot of useful applications, 3d shape recognition is just one.
"He swam at my feet, Powerful arms in broad strokes Sweeping the sand. So I asked this man, What seas do you swim? And to this he answered, 'I have seen shells and the like On this desert floor, So I swim this land's memory Thus honouring its past,' Is the journey far, queried I. 'I cannot say,' he replied, 'For I shall drown long before I am done.'"
― Steven Erikson, Deadhouse Gates
I have quite an early memory of being on the somewhat remote property in Australia that my mother grew up on (Central NSW, near Condobolin).
My Uncle, who then ran the property, walked over to a rock, whacks it with a hammer or similar, shows me a bit of a trilobite (which are totally different to our sort of bytes). He did this a bunch of times. I still have the rocks. No amazing full horizontal cross-sections, but it certainly got my very young mind excited.
There were fossils RIGHT THERE from before there were dinosaurs!
Oh, and that central Australia used to be an Ocean!
These clear demos to young kids, or adults, are great, and the many other examples here in the comments are a testament to that (Vienna? wtf!).
St. Stephens cathedral in Vienna was built with sandstone that contains seashells. It's hundreds of kilometers away from the shore, but ~15 million years ago the area where it stands now was a seabed.
The stones are not from the exact location where it was built, but from close by. The quarry where the stones came from hundreds of years ago is still active, and you can find tons of fossils there. It's practically impossible to get a piece of rock from there without visible seashells.
Was the land lower, the seas higher, or some combination, way back when?
I'm not sure, I would guess both.
I would wager that the land was lower than the sea back then.
Ha! Indeed.
If all the ice melted it would raise the oceans by something like 230 feet, so modern Vienna would still be above water at 495 – 1778 ft elevation.
Although some estimates suggest Earth loses 20 - 30 cubic kilometres of water to space annually. Plus whatever water is bound up in mineralisation annually.
450 million cubic kilometres of water lost over a 15 million year period would lower ocean by something like … a bit?
The total volume of water on Earth is presently estimated to be around the 1.386 billion cubic kilometre mark.
The volume of a sphere increases to the cube of its radius … carry the 1 … nup, that’s to hard for me.
Beach front property in Vienna, at a guess?
https://www.usgs.gov/faqs/how-would-sea-level-change-if-all-...
https://www.ewash.org/how-much-water-disappears-from-earth-e...
https://science.nasa.gov/earth/earth-observatory/the-water-c...
Land lower - Alps and Carpathians hadn't formed yet: https://en.wikipedia.org/wiki/Paratethys and its predecessor https://en.wikipedia.org/wiki/Tethys_Ocean
Not Vienna or Europe, but N. America: https://en.wikipedia.org/wiki/Western_Interior_Seaway
It’s a very common occurrence. It’s fascination to find maritime fossils far away from the shore, but also very common.
Almost any surface on earth was once under the water. You can find sea shells and various sea deposits high on some 8000m peaks or 1000kms inland.
Everybody who cares at least slightly knows this, and I am pretty sure author knows this too, he could have spared us the initial hyperbole. Analysis itself is good but not everything needs to read like dramatic novel.
Thank you for a great write up. Concise, to the point and really interesting.
It would be nice if your local detractors noticed your steely insistence on remarking where you are coming from.
I think it would be superb if some ... experts ... in most spaces learned about the beauty of brevity.
Herodotus did it first, and even speculated that that region must have been covered by water at some point.
Herodotus wouldn’t have written it quite the same — no Jupyter notebook for example, Jupiter being a Roman term; the nearest equivalent for the Ancient Greeks was Zeus.
Safe to assume Herodotus would have used a Zeus notebook.
"If by some fiat I had to restrict all this writing to one sentence, this is the one I would choose: The summit of Mt. Everest is marine limestone."
John McPhee from the wonderful Annals of the former world
I also recommend a quick search for "whale skeleton mountaintop". The mythology of dragons probably came from a find like that.
I really love that book and also couldn’t help but think about it while reading this.
Cool write up, a little weird that you were surprised to find it in the first place though.
yea, finding shells all over was one of those things I was taught in elementry school. We even had a field trip to some place to find them along with geography lessons on the various layers of the area
I found a sea shell in a visit to Latamber in Pakistan (NWFP): https://www.flickr.com/photos/hendry/73369720/
Gemini says "As the crow flies (Straight-line distance): Approximately 900 to 920 kilometers (roughly 560 to 570 miles) directly north of the coast at Karachi"
Maybe some geology buffs can correct me, but as I understand it there has been three periods with ocean on top of the crust we call Pakistan today. The Proto-Tethys, Paleo-Tethys, and Tethys Ocean. Many hundreds of millions of years of being ocean.
Because of the Indian subcontinent colliding with the Eurasian plate there's a wide variety of origins for the surface geology in that region.
An incredibly detailed and descriptive map:
https://upload.wikimedia.org/wikipedia/commons/5/52/1964_Pak...
Maybe a nitpick but Latamber is not directly north of Karachi and it's about 1000 kilometers away (the closest coast is 950 km but not in Karachi). It's easy to see and to measure on a map.
Are you sure that's a fossil and not just a rook that happens to look kinda like a snail's shell?
Finding a chess piece out there would be very interesting
I found an article about finding a seashell in the middle of the desert on GitHub...
More seriously, I wonder if there's anything inside. Somewhat reminds me of the https://en.wikipedia.org/wiki/Coso_artifact
I've got some 'shells' from the deserts near Siwa Oasis. Quite a cool feeling walking on top of what used to be the floor of the Tethys Ocean, especially when everything around you is just rock and sand without a drop of water in sight.
She sells seashells in the Sahara was my first association, but then the article clearly states that we're talking about a different desert.
He is losing a lot of information in that normalization pipeline (whole shell reduced/feature engineered into nothing but an outline). A CNN or something similar would be better and he can maybe get a better depth map of the mouth shape.
Looks like ampullospira, documented in Saudi Arabia. Age (middle-upper Jurassic) and actual location also match.
Good candidate
Awesome, someone finally found one of the seashells I drop for entertainment when I go for a ride across the desert
This loading screen looks great!
I found may under 12feet in desert of Thar, India.
It was River or flood deposited according to my research.
The analysis is nice, flashy, and wrong. Several weak assumptions here leading to hallucinate an obviously wrong result.
Taxonomy IS a science. Just use the wide corpse of knowledge that has been built for the last 229 years, where the class Gastropoda was created.
First wrong assumption. This is a seashell.
This probably is a seashell, yes.
But fresh water snails have also shells; and savannas can have a lot of lagoons before eventually turning into deserts. If you train your model only using zebras, your model will happily conclude than an hippo is a sort of non stripped obese zebra.
More points for though
1) The model use incomplete data. The data used to train the model is based in 7800 species alive. After wikipedia, Gastropoda have more than 75000 species alive, plus 15000 fossil species known. (We can assume safely that this is a snail, but remember that some cephalopods also have coiled shells).
2) The model use spurious data. All clams and Tusk shells must be removed (because we want to classify a snail). This means that the number of snails available to train the model is much lower than 7800. Including non-snails just gives us a false confidence in the strength of our model.
3) The model covers only one couple traits in this species, but this particular traits can vary within members of the same species. Taxonomy uses thousands of traits to classify a mollusc and some are particularly fastididious. Dozens of items only to describe the shell. Often the soft parts are needed (Is the penis shaped like a club? this genus, shaped like a whip? this other one; the penis in your sample is contracted because you didn't put to sleep the animal first with mint crystals, though luck, we'll never know).
4) The model is based in extant alive species, but we want to identify a fossil. Alive species have non-distorted shells. Fossils often lose their shape by the weight of sediments and compression. Only the thickest shells would keep its real height/wide proportions.
5) The model ignores important details. The species found in the desert has a very evident shell groove at the top of the spire, that the targeted species does not have. This alone, tells a newbie taxonomist that the result is wrong.
And to end this, 6) the model ignores all knowledge about the species and its habitat
Sphincterochila candidissima is a western Mediterranean species. It lives from Spain to Libia. The fossil is from Saudi Arabia.
Very interesting story and also hands-on walkthrough of PCA.
Why would you write a lot of software to find the closest match (which doesn't even seem that good) if you could also ask a subject expert? I guess you could even just post a photo to some subreddit with people who could tell you what it is...
Also: "it shouldn't be here; the nearest coastline is Dammam's, 500 km away." - are people really that ignorant about plate tectonics and sea fossils in mountains?
I think that sentence was more to show why it had to be a fossil in the first place and not just an ordinary seashell you'd pick up on the beach.
I found a seashell in the middle of the forest in (well inland) Mississippi. That was an interesting find, and lead me to learn that much of the continental US used to be covered in a sea, I believe https://en.wikipedia.org/wiki/Western_Interior_Seaway
This means the shell was dozens of millions of years old, and may be the oldest thing I’ve ever held, except maybe some rocks.
It's interesting that saying the Earth is more than 10,000 years old is not haram in Saudi Arabia. I thought it would be, since they are so religious, but it turns out the Koran doesn't make any claims about the age of the Earth, so you are free to say that the Earth is billions of years old and not be accused of blasphemy.
I mean, even in countries with extremely high levels of Christianity, such as Romania, you won't be accused of blasphemy for just... agreeing with science. Both Christianity and Islam are pretty similar after all, so hopefully that is not too surprising.
I can't think of a country where you even might be accused of blasphemy, though I'll admit I am not very familiar with the topic.
Even with AI, to try to replicate this on my own would take me a really long time, maybe impossible. Despite the use of AI,it would be a huge undertaking , such as having to come up with the blueprint and procedure for classifying the shells, setting up all of the environments, setting up repository, understanding the math, writing it up, coding the tool, etc.
This should allay fears that AI will render people jobless or automate everything.
land snails ?
In the middle of a desert?
Where does the water come from?
[;)]
At this time of the year?
... At this time of the day?
... In this part of the country?
... Localized entirely within your kitchen?
Snails have shells too. Just saying
freshwater lakes have shellfish too, so it doesn't automatically mean that place was a sea.
couldn't it be a snail?