Fossil hyena feces, found in a cave in North Yorkshire, England, preserved in the Oxford University Museum.
(a) William Buckland; (b) his paintings of 1835, which show spiral-shaped fossils of feces; (c) fossils of feces he collected.
The spiral petal morphology of different fish is either dense or sparse.
A reconstructed drawing of an ichthyosaur eating squid, based on the stomach contents of an ichthyosaur from 199 million years ago. Image credit: Julian Kiely
The top is Ichthyosaurus, the upper right corner is Plesiosaur, the blue arrow indicates the predator-prey relationship studied in 2020, and the red arrow and black arrow are from the 2018 study.
The three bones inside the shark feces fossil are fish skulls in blue and green and yellow for the tail vertebrae of ocean crawling.
Workers in the mid-19th century were mining fossilized manure. Image credit: Buckinghamshire County Museum
Suspected fossils of Tyrannosaurus rex feces, found in South Dakota, USA. Image source: wikipedia
(Mysterious Earth uux.cn report) According to Popular Science China: Speaking of fossils, many people will think of dinosaur skeleton fossils for the first time, because they are shocking enough. And "heavy taste", I decided to talk to you about the excrement of ancient creatures - fecal fossils, and how to make my own fecal fossils.
Who encountered the first fossil of feces?
If you're a dinosaur fan, you won't be unfamiliar with William Buckland, who described and named the first dinosaur and was one of the first scientists to study dinosaurs. However, you may not know another important identity of Buckland, the "original fecal fossil hunter".
In 1821, when Buckland was investigating a prehistoric hyena cave in North Yorkshire, England, he found that there were some white balls scattered between the bones and teeth of the hyenas, suspected to be the feces fossils of the hyenas.
To confirm this conjecture, Buckland ran to the zoo to observe the droppings of African spotted hyenas. Because modern hyenas are very fond of eating the bones of other animals, they consume too much calcium and phosphorus, resulting in white stool, and it just so happens that the main chemical component of the white pellets in the cave is also calcium phosphate. So Buckland published a paper and received the Copley Medal of the Royal Society, and scientifically encountered the first pile of fecal fossils.
After emerging from the prehistoric hyena hole, Buckland set his sights on the seaside town of Lyme Regis.
The coastline is home to a large number of fossils of marine life from the Jurassic period, where the famous fossil collector Mary Anning discovered the first complete fossils of ichthyosaurs and plesiosaurs, and noticed that their abdominal cavities preserved many small dark gray stones, occasionally interspersed with bones and fish scales.
Although small stones were known locally as "cattle yellowstone" and were widely used as an antidote in the 16th century, based on the research of Mary Anning, Buckland believed that the small stones in the abdomen of the ichthyosaur were actually feces, and soon after he created a word "coprolite" (fecal fossil) to include all ancient feces.
Since then, the door to the research field of fecal fossils has officially opened.
The shape of the fossil feces is very strange, because no one in this world can pull out two identical pieces of feces. Moreover, normal feces are relatively soft and fragile, and will be deformed again during the burial process, and even damaged by fecal animals and baptized by wind and rain, resulting in spherical, ovate, cone, cigar-shaped, irregular shape and so on. Among them, there is nothing most fascinating to Buckland is the spiral fossil of feces.
Regarding the origin of spiral fecal fossils, Buckland believes that food residues will pass through a spiral-shaped intestine, gradually forming spiral-shaped feces, and excreting them in this form, and eventually burying them to form fossils.
This view is not whimsical, because the intestines of living sharks, lungfish, silverfish, and sturgeon have such a structure: the mucosal layers in the ileum are arranged in spiral lobes, like a spiral staircase. When the food rushes to the spiral flap, the circle after circle of structure can not only slow down the movement of food, but also increase the digestive area in the intestine, allowing the fish to absorb nutrients more fully.
The hands-on Buckland was able to spare these living examples, and he injected a cement that could quickly solidify directly into the intestines of the shark, and finally succeeded in replicating the cement version of the spiral feces. While tinkering with the study of fecal fossils, Buckland also customized a "dung fossil table" for himself, which was embedded with polished and polished fish dung fossils, which was used to entertain the dinner party.
What is the use of fossil feces?
A fossilized animal skeleton can make us truly feel the inconceivable nature of ancient life, which is incomparable to a pile of fecal fossils, so why is Buckland addicted to it?
Because fecal fossils can provide "alternative" paleontological information.
Taking spiral fecal fossils as an example, it can directly reflect the internal structure of the digestive tract of excretors, indicating that the intestines of ancient fish also have spiral valves, which are conducive to absorbing nutrients; they can also be used as the basis for fish classification, because the spiral patterns on the surface of fecal fossils are related to the number and density of spiral valves in the intestine, such as the spiral valves of modern shark intestines are very dense, followed by lungfish, and cartilaginous hard scale fish are very sparse; it can also reflect the upper limit of the excretor's body size, such as the number of spiral fossils < 5 circles, and the upper limit of excretors' body length is 1~ 2 meters.
Just as you eat Enoki mushrooms, fossil feces contain undigested food scraps such as bones, teeth, scales, plants, and microbes, which reflect the physiology of paleontologists' prey selection behavior, food preferences, and digestion patterns. Simply put, it is a recipe for reconstructing paleontology.
Buckland's collection of fossils of ichthyosaur dung off the coast of Lyme Regis contains not only fish scales, fish bones, and small ichthyosaur skeletons, but also some blackened dung fossils. Later, after analysis, the black pigment in the fecal fossils had the same chemical composition as the ink of mollusks such as squid, so that it was known that there were also squid in the recipes of the ichthyosaur. Does this remind you of the "torture" of red heart dragon fruit?
When there are enough fossil feces, it is also possible to reconstruct the food web of the ancient ecosystem.
This 1830 watercolor painting, showing the Jurassic-era Lyme Regis Coast, is based primarily on William Buckland's scientific research and the fossils collected by Mary Anning, and is the first attempt to reconstruct an ancient ecosystem. Believe it or not, while the plesiosaur and the ichthyosaur were fighting each other, they were still quietly pulling - the oval object under the belly of the plesiosaur was feces.
Due to the limitations of the times, the first reconstruction of the food web was not perfect.
Today, we can adopt new science and technology to peek into the world in the feces. In October 2020, scientists at the University of Bristol in the United Kingdom performed CT scans of hundreds of fossils of feces, identified various bones, scales and teeth, and reconstructed a shallow sea food web in the Bristol region more than 200 million years ago: marine reptiles and sharks ate small fish, smaller fish ate smaller fish and lobsters, and ichthyosaurs may even nibble on oysters.
Ct scans also showed that the bones and scales inside the various fecal fossils were barely damaged, meaning that prehistoric marine animals had poor digestion and could not dissolve their bones like most modern carnivores, and had to struggle to pull the bones out of their bodies with their scalps. Most interestingly, the one-centimeter-long fossil shark dung was mixed with three bones, one from a fish skull and two from the tail vertebrae of a small marine reptile.
As for the shark being scavenged and leaking carcasses? Or did he nibble on the head of a fish alive and then nibble at the end of the tail of a marine reptile? We don't know.
When fossil feces accumulate into layers, they also form phosphate rocks with economic value.
In the mid-19th century, the British realized that phosphate could increase crop yields, so fossil manure with high phosphate content began to be mined for fertilizer. Over the decades, fossil mining areas have sprung up, forming large-scale industries, and adjacent catering facilities, homes and churches have also developed.
Although the industry has long since declined and pits have been backfilled, important fossils that have been destroyed, used as fertilizer, and sold have long since disappeared.
Whose, yours?
Seeing this, you may wonder, why scientists can find the owner of the fecal fossil?
In fact, in the world of paleontology, it is very difficult to know who is pulling the. Accurate judgments can only be made when fecal fossils are preserved in the abdominal cavity of an animal. Most of the time, it is necessary to obtain information about the fecal fossil itself, but also to analyze it in combination with the background of the times, the geographical environment, and the animal fossils of the same strata, so that it is possible to know who pulled the.
For example, this lump is 44 cm long, 13 cm high, and 16 cm wide, containing a very high proportion (30-50%) of skeletal fragments, far larger than common carnivorous feces, and located in North America in the late Cretaceous Period, so it is speculated to be the feces of some kind of tyrannosaur.
Because the general law shows that the volume of the fecal fossil is proportional to the size of the excretor (although there is no quantitative relationship), it is clear that the tyrannosaur class is more worthy of this dung fossil than other animals in the area, after all, the small man can pull out 63.5 cm of feces.
Among the many owners of fecal fossils, the number of carnivores is much higher than that of plant-eating animals, because the main component of fecal fossils is calcium phosphate, and bones and meat can provide more minerals and promote fecal mineralization.
Finally, if you want to have your own fossil feces, first eat meat, eggs and milk, and consume calcium and phosphorus; second, choose a good natural toilet, such as a sedimentary environment such as lakes or deep seas; then ensure that the feces land safely and enter the burial stage; and finally leave it to luck. Hopefully, after millions of years of geological changes, your dung will be exposed to the surface as a fossil and will be picked up by "posterity"...