Builders dug up giant bones in 1998. Twenty-seven years later, scientists gave them a name: Tongnanlong, a long-necked dragon as long as two school buses and then some.
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Quick Answer
The 90-foot dinosaur is Tongnanlong zhimingi, a giant long-necked plant-eater that lived about 147 million years ago. Its bones were dug up at a building site in Tongnan, Chongqing, in 1998, and scientists named it on July 10, 2025. It was about 25 to 28 meters (82 to 92 feet) long, making it one of the biggest dinosaurs ever found in Asia.
Tongnanlong Fact File
Name
Tongnanlong zhimingi
Say it
tong-NAN-long jee-MING-ee
Length
about 25 to 28 m (82 to 92 ft)
Lived
about 147 million years ago (Late Jurassic)
Found
1998, at a building site in Tongnan, Chongqing, China
Named
July 10, 2025
Diet
Plants 🌿
Family
Mamenchisaurids, the extra-long-neck dinosaurs
How Big Was the 90-Foot Dinosaur?
Tongnanlong next to a grown-up, drawn to scale. Illustration by Puffsaurus.
Scientists' best guess is that Tongnanlong was about 25 to 26 meters (82 to 85 feet) long, and it may have reached 28 meters (92 feet). That's where the “90-foot dinosaur” headlines come from. Lay it down on a road and it would stretch past two school buses parked end to end, with room to spare!
Most of that length was neck and tail. Its body was only a small part in the middle. Like other long-necks, its bones were full of air pockets, a bit like a bird's, which made such a huge animal lighter than it looks.
How long is 90 feet? Tongnanlong was more than twice as long as a T. rex and almost as long as a blue whale.
How the 90-Foot Dinosaur Was Found
Nobody went looking for this dinosaur. It turned up by surprise, then waited a very long time for its name.
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About 147 million years ago
A giant lives by a river
In the Late Jurassic, a huge long-necked plant-eater walked along rivers and lakes in what is now the Sichuan Basin in southwest China. When it died, mud covered its bones and slowly turned them to stone.
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1998
Builders hit something big
Workers were digging at a building site in Tongnan District, part of the city of Chongqing. Their digging uncovered enormous fossil bones in the purple-red rock. The bones were carefully excavated.
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The next 27 years
Waiting in a museum
The bones were kept at the Tongnan Museum. Studying a giant dinosaur takes a lot of time, money and experts, so for many years nobody knew exactly which dinosaur they belonged to.
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Recent years
Measuring every bone
A team led by Dr. Xuefang Wei of the Chengdu Center of the China Geological Survey measured the bones and compared them, feature by feature, with other long-necked dinosaurs.
🎉
July 10, 2025
A brand-new dinosaur!
The team announced in the science journal Scientific Reports that the bones belong to a dinosaur nobody had seen before. They named it Tongnanlong zhimingi.
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2026
The world hears about it
News sites around the world shared the story with headlines like “92-foot dinosaur found by accident at a construction site in China.” That's how many people first heard of the 90-foot dinosaur.
🤯 Fun fact: the bones waited 27 years to be named. That's longer than most of the kids reading this have been alive!
What Bones Did They Find?
The orange bones were found. Everything else was worked out by comparing with relatives. Illustration by Puffsaurus.
Scientists didn't find a whole skeleton. That's normal for giant dinosaurs! For Tongnanlong, they have:
🦴3 back bones · vertebrae from the middle of the back
🦴6 tail bones · vertebrae from the tail
🛡️Shoulder blade · 1.82 m (6 ft) long!
🔩Coracoid · a bone that joins the shoulder to the chest
🦵Back leg bones · including a fibula from the lower leg
The shoulder blade was the biggest clue. It is about 1.82 meters (6 feet) long, taller than most grown-ups. A shoulder blade that big had to belong to a truly enormous animal.
Just one of Tongnanlong's bones is taller than a grown-up. Illustration by Puffsaurus.
What Does Tongnanlong Mean?
Lots of dinosaurs from China end in “long,” the Chinese word for dragon. Here's how this one got its name.
Tongnan 📍
The district of Chongqing where the bones were found at a building site.
long 🐉
Chinese for “dragon.” So Tongnanlong means “Tongnan dragon.”
zhimingi 👴
Honors Dong Zhiming, a world-famous Chinese dinosaur scientist who discovered and named many dinosaurs from the Sichuan Basin.
Say it like this: tong-NAN-long jee-MING-ee.
Tongnanlong's Long-Neck Family
Tongnanlong belongs to the mamenchisaurids, a family of Chinese sauropods famous for having super-long necks. Its closest relative is Mamenchisaurus, and one member of that group holds the record for the longest neck of any animal ever. Find out how long in Which Dinosaur Had the Longest Neck?
For a long time, scientists thought this family lived only in East Asia. But the team that named Tongnanlong compared it with a long-neck called Wamweracaudia from Tanzania, in Africa, and concluded that mamenchisaurids were spread all around the world by the end of the Jurassic.
What Was China Like When Tongnanlong Lived?
About 147 million years ago, the Sichuan Basin was a warm land of rivers and lakes. The mud from those rivers became the purple-red rock that scientists call the Suining Formation. Today that red rock is all over Chongqing, which is why builders there sometimes bump into fossils.
Tongnanlong had plenty of neighbors:
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Mamenchisaurus anyuensis
Another long-neck from the same rocks, and one of Tongnanlong's close cousins.
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Qijianglong
A long-necked dinosaur from the same rock layer, found near Chongqing. Its name means “Qijiang dragon.”
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Turtles
Plesiochelys turtles paddled in the rivers and lakes.
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Lungfish
Ceratodus, a fish that could gulp air, swam in the water.
Is It the Biggest Dinosaur Ever?
Not quite! Tongnanlong is one of the biggest dinosaurs ever found in Asia, but giants from South America like Argentinosaurus and Patagotitan were even longer and much heavier.
What makes Tongnanlong exciting is when it lived. It shows that long-necked dinosaurs were already becoming giants in the Jurassic, long before the record-breakers of the Cretaceous. Another long-neck, Nagatitan, made similar headlines in 2026. Read its story in New Dinosaur Found in Thailand.
Frequently Asked Questions
What is the 90-foot dinosaur found in China?+
It is Tongnanlong zhimingi, a giant long-necked, plant-eating dinosaur (a sauropod) that lived about 147 million years ago. Scientists think it was about 25 to 28 meters long, which is roughly 82 to 92 feet. It was named in July 2025.
Was it really found by accident at a construction site?+
Yes. The bones were dug up in 1998 at a building site in Tongnan District, Chongqing, in southwest China. They were kept at the Tongnan Museum and only studied and named many years later.
Why did it take so long to name the dinosaur?+
Giant fossils take a long time to clean, measure and compare with other dinosaurs, and there are only so many experts to do it. The bones waited in a museum from 1998 until a team led by Dr. Xuefang Wei finished the study, published on July 10, 2025.
What does the name Tongnanlong mean?+
“Tongnan” is the district in Chongqing where the bones were found, and “long” is the Chinese word for dragon, so it means “Tongnan dragon.” The second name, zhimingi, honors Dong Zhiming, a famous Chinese dinosaur scientist who studied many dinosaurs from the Sichuan Basin.
How do scientists know how long it was if they only found some bones?+
They compared the bones they had, especially the huge 1.82-meter shoulder blade and the leg bones, with the same bones in more complete relatives like Mamenchisaurus. Then they scaled the whole body up to match. That's why the length is a range (about 82 to 92 feet) instead of one exact number.
Is Tongnanlong the biggest dinosaur ever?+
No. It is one of the biggest dinosaurs found in Asia, but South American giants like Argentinosaurus and Patagotitan were longer and much heavier. Tongnanlong is special because it shows how big long-necked dinosaurs were already getting in the Jurassic.
Where can I see Tongnanlong?+
The real bones (specimen TNM 0254) belong to the Tongnan Museum in Chongqing, China.
Sources: Wei et al., “A new mamenchisaurid from the Upper Jurassic Suining Formation of the Sichuan Basin in China and its implication on sauropod gigantism,” Scientific Reports 15, 24808 (July 10, 2025).
All illustrations on this page are original artwork by Puffsaurus. Tongnanlong's outline is based on its close relative Mamenchisaurus, because most of its skeleton has not been found.
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