Leedsichthys: The 'vacuum cleaner' of the Jurassic Sea was once misunderstood as a dinosaur

Leedsichthys (Leeds) is a giant fish first discovered in England in the 19th century by an aristocrat named Alfred Nicholson Leeds. An amateur scientific researcher who owns a lot of land in his hand, Alfred Nicholson Leeds leases people land and doesn't need to directly cultivate it, so he can spend a lot of time on his personal hobby - collecting Animal fossils.

In a loam pit (a soil pit composed mainly of sand, mud and a small amount of clay) near Peterborough, Leeds found gigantic fossils. In May 1886, John Whitaker Hulk, after seeing fossils found by Leeds, thought it belonged to a dinosaur in the Stegosaurus family.

And also because Halk said it was such a dinosaur, Leeds did not pay much attention to those fossils. On August 22, 1888, Marsh, a famous American paleontologist, who had a "fossil war" with Ted Koppel, visited England and was invited to Leeds' home. When he passed the fossils, Marsh confirmed that this was a giant prehistoric fish rather than a dinosaur, but at that time, because of the time that was not allowed, he could only say so and No further research on these fossils is possible.

Shortly after that brief visit, news of the discovery of Leeds' prehistoric fish was quickly spread throughout the United Kingdom and two months later, biologist Arthur Smith Woodward knocked on the door. of Leeds.

An expert in ichthyology, Woodward named the ancient giant fish, Leedsichthys problematicus, the next year, after studying the fossils that Leeds found. The name of the genus was taken from the name of the person who first discovered the fossil record of this species.

After the Leeds fish was named, a group of scholars said that "this name is too obscure and it must be changed!". So Woodward changed the name to Leeds fish to "Leedsia", but this new name has not been used to this day, and scientists still use the original "Leedsichthys" name, which is a name. or the naming convention in paleontologists.

Leeds, with the honor of being given the name of its own fossil, has gained even more motivation in finding the fossil of this giant fish. In addition to finding and purchasing fossils, he also sold them. On March 17, 1889, he sold a Leeds fishtail fossil to the British Museum of Natural History for £ 25.

During this period, Leeds also had a rival. A collector named Henry Keeping also raised the idea of ​​an ancient fish fossil of the land of fog. He purchased a fossilized Leeds dorsal fin in Wales at a low price through an amateur fossil miner and sold them to Cambridge University. In 1901, the famous German paleontologist Friedrich von Huene saw this fossil when he visited Cambridge University. He also mistakenly thought it belonged to a species of dragon sword.

In 2001, a fossil of Leeds fish was found at a fossil site called a "Starhole". Fossils of Leeds fish are often found here, so people think of the "on and on and on" slogan of the Ariston water heater brand and this newly discovered fossil is named "Ariston".

From 2002 to 2004, Jeff Liston, a paleontologist at the University of Earth Sciences at Bristol University, led the "Ariston" excavation. People moved tens of thousands of tons of rock and soil and were finally able to successfully excavate and clean up the fossil record. During the excavation, Radio Four UK recorded and produced The Big Monster Dig on TV. At that time, the BBC's "Sea Monster" was famous all over the world (with the arrival of Leeds), and Leeds became a "new phenomenon".

In the BBC's "Walking with Sea Monsters", the body length of the Leeds was set at 28 meters, the size of a blue whale.

In fact, the size of the Leeds fish has always been controversial. Woodward estimated that its length was 9 meters; by the 1980s, some people had used formulas to calculate and they assumed that the fish's body length was 27.6 meters, and even is 35 meters.

Upon discovering "Ariston" - a more complete fossil, Reston pointed out that Woodward's claim was reasonable, then he analyzed a large number of fossils, and eventually issued a comparison. Age and size comparison: Leeds fish when 20 years old have a body length of 10 meters, 31 years old from 11.4 to 14.9 meters, and when 45 years old 16.5 meters long. In fact, this does not mean the maximum size of a Leeds fish is 16.5 meters, but the oldest individual they find reaches this length. And if a Leeds individual reaches the age of 50, then it is certain that they will have a larger size.

Leeds fish are a filter feeder and they live like whales and bream sharks today, swimming around the sea with their mouths open all day. Seawater enters the oral cavity with plankton, algae, jellyfish, small fish, shrimp, etc., and then the seawater is filtered through their gills. Leeds fish have a special gill structure that acts as a filter to hold food. To be able to eat more, Leeds fish also dive to the ocean floor to stir sediment in search of food.

Through fossil analysis, paleontologists learned that the Leeds fish lived 160 million years ago, their fossils were found not only in England, but also in France, Germany, even in Chile.

Leeds fish lived during the Earth's era with many famous ancient creatures, including the Rock Chrysanthemum Stratum, Metriorhynchus, Ophthalmosaurus, Liopleurodon, Plesiosaurus .

In the eyes of many animals, the Leeds fish possesses a large but not aggressive body like when the food is stored mobile. Fossils of this fish often include the bites of the sea lizards Metriorhynchus and Liopleurodon, so it is not easy for a Leeds fish to grow from eggs until reaching the size of 16 meters. and the success rate seems to be very low because they have not grown up, it has become a good bait for other species.