The dinosaur with 500 teeth is Nigersaurus, a long-necked plant-eater that lived about 110 million years ago in what is now Niger. Its wide, straight-edged mouth held more than 500 teeth, most of them spares waiting in stacks. It held its head low and grazed on ferns and horsetails, replacing worn teeth as often as every 14 days.
Nigersaurus quick facts
- Nigersaurus had more than 500 teeth, most of them spares waiting in columns.
- It lived about 110 million years ago in what is now Niger’s Sahara Desert.
- It was about 30 feet (9 m) long, small for a long-necked sauropod.
- A 2013 study estimated it replaced each tooth as often as every 14 days, the fastest rate known for any dinosaur.
- Its skull was one of the first dinosaur skulls rebuilt from CT scans.
The dinosaur with 500 teeth
The animal that has 500 teeth is a dinosaur called Nigersaurus taqueti. It was a long-necked, plant-eating dinosaur that lived about 110 million years ago, in what is now the Sahara Desert in Niger, in West Africa.
Its skull held more than 500 teeth. Not all of them were in use at once. Many were spare teeth, lined up and waiting to replace the ones that wore out.
Its name means “Niger lizard”, after the country where it was found. You say it “nee-ZHAIR-uh-SORE-us”. The second part of its name, taqueti, honours the French palaeontologist Philippe Taquet.
| Nigersaurus at a glance | |
|---|---|
| Full name | Nigersaurus taqueti |
| Name means | Niger lizard |
| Lived | about 110 million years ago, Early Cretaceous |
| Found | Elrhaz Formation, Niger (Sahara Desert) |
| Length | about 30 feet (9 m) |
| Teeth | more than 500, in over 50 columns |
| New tooth | as often as every 14 days |
| Food | low plants such as ferns and horsetails |
Where and when it lived
Nigersaurus lived in the Early Cretaceous period, around 110 million years ago. That was long before Tyrannosaurus rex, which lived near the very end of the age of dinosaurs.
Its fossils come from a layer of rock in Niger called the Elrhaz Formation. Today the area is part of the Sahara, one of the driest places on Earth. Niger is a large country, and most of it lies inside this desert, where wind keeps uncovering old rocks and the fossils inside them.
Nigersaurus was about 30 feet (9 m) long, roughly the length of two family cars parked end to end. Its thigh bone alone was about 1 metre long. For a long-necked sauropod, that was quite small. It belonged to a group called the diplodocoids, which also includes the famous Diplodocus.
Nigersaurus in Time
- In which period of the age of dinosaurs did Nigersaurus live?
- What is the layer of rock in Niger where its fossils come from called?
- Why does the Sahara help people find old fossils there?
- Nigersaurus belonged to which group of long-necked dinosaurs?
How it was found
The first bones of Nigersaurus were picked up in the 1950s by French palaeontologists. But they were only scraps, and nobody knew what the whole animal looked like.
In 1997, a team led by the American palaeontologist Paul Sereno, of the University of Chicago, went looking in the Sahara. One of the team spotted skull bones of Nigersaurus.
On that expedition and the next, the teams collected about 80% of the skeleton. That is a lot for a dinosaur. Most are known from far fewer bones.
In 2007, Sereno and his colleagues described the whole animal in the science journal PLOS One. That is when Nigersaurus became famous for its teeth.
Finding Nigersaurus
- First scraps French palaeontologists pick up the first Nigersaurus bones, but nobody knows what the whole animal looked like.
- Sereno's expedition Paul Sereno's team searches the Sahara, and one member spots Nigersaurus skull bones.
- Most of a skeleton Over two expeditions, the teams collect about 80 percent of the skeleton.
- The full description Sereno and his colleagues describe the whole animal in the journal PLOS One.
- Counting tooth days Michael D'Emic's team estimates Nigersaurus replaced each tooth as often as every 14 days.
A mouth like a pair of scissors
Nigersaurus had a very unusual mouth. The front of its jaws was wide and squared off, with a straight edge, rather than rounded or pointed.
Along that straight edge were more than 50 columns of teeth, side by side. Together they worked like a pair of scissors about a foot (30 cm) long, snipping plants off close to the ground.
Its mouth was extremely wide for the size of its head, and its muzzle faced straight down at the ground. That tells scientists a lot about how it ate. An animal that feeds from trees needs to reach up and forwards. Nigersaurus was built to sweep along the ground.
A Mouth Like Scissors
- What shape was the front of Nigersaurus's jaws?
- About how long was the scissor-like row of teeth along the front of its mouth?
- Which way did its muzzle face?
How 500 teeth worked
Each column of teeth was a stack. At the front was the tooth being used. Behind it, more teeth were growing, ready to move up and take its place.
Scientists sometimes call a set of teeth like this a tooth battery. It works a bit like a pencil case full of new pencils. When one wears down, the next one is ready.
The 2007 study found that Nigersaurus could replace a tooth about once a month. A later study, published in 2013 by Michael D’Emic and his colleagues, looked more closely. It estimated that Nigersaurus replaced each tooth as often as once every 14 days. That is twice as fast as the earlier estimate, and by far the fastest rate known for any dinosaur.
Other long-necked dinosaurs were much slower. The same study found that Diplodocus replaced a tooth about every 35 days, and Camarasaurus about every 62 days.
How can anyone count days in a fossil? As a tooth grows, it adds a thin layer every day, leaving a faint line, a bit like the rings in a tree trunk. These daily lines are called von Ebner lines. By counting them, scientists can work out how many days a tooth took to grow.
Why so fast? Plants that grow close to the ground pick up grit, such as soil and sand. Nigersaurus was the sauropod most specialised for feeding low down, so it swallowed a lot of that grit. Chewing it wore teeth down quickly, so Nigersaurus needed a steady supply of new ones.
Plenty of animals today replace their teeth, too. Sharks, for example, keep growing new teeth all their lives. But few animals, living or extinct, have ever gone through teeth as quickly as Nigersaurus.
Tooth Battery Match
- Nigersaurus — A new tooth about every 14 days
- Diplodocus — A new tooth about every 35 days
- Camarasaurus — A new tooth about every 62 days
- Von Ebner lines — Daily growth lines inside a tooth
- Tooth battery — A stack of teeth waiting to move up
- Grit on low plants — Wore the teeth down quickly
Head down, like a cow
Many long-necked dinosaurs are pictured stretching up to eat leaves from tall trees, like a giraffe. Nigersaurus was different.
Its head was usually held with its muzzle pointing straight down. It ate plants close to the ground, mostly ferns and horsetails.
The scientists who studied it said it worked “more like a Mesozoic cow than a reptilian giraffe”, mowing down mouthfuls of greenery. The Mesozoic is the name for the whole age of dinosaurs.
Today, big plant-eaters feed in many different ways. Cows graze on grass, giraffes browse on trees, and elephants do a bit of both. Nigersaurus seems to have been a grazer.
Bones full of air
For such a big animal, Nigersaurus was built very lightly.
Its skull was extremely delicate. Some of its backbones were hollow, with more air space inside than bone. The walls of some of its neck bones were as thin as paper.
Scientists think these air spaces were linked to air sacs, like the ones birds have today. Light bones meant less weight to carry around, especially in that long neck.
Those delicate bones also help explain why good Nigersaurus fossils are rare. Thin, fragile bones break easily before they can become fossils.
Bones Full of Air: Fact or Myth?
- Some of Nigersaurus's backbones held more air space than bone.
- The walls of some Nigersaurus neck bones were as thick as a brick.
- Scientists think its air spaces were linked to air sacs like those of birds.
- Fragile bones make good fossils, so Nigersaurus fossils are very common.
- Light bones meant Nigersaurus had less weight to carry, especially in its long neck.
A skull rebuilt by computer
The fossil skull of Nigersaurus was too fragile to handle much. So scientists scanned it instead, using a CT scanner, the same kind of machine that hospitals use to look inside the human body.
It was one of the first dinosaur skulls to be rebuilt digitally from CT scans, a kind of X-ray that takes pictures of an object in thin slices. A computer then put the slices together to make a 3D model.
The model let scientists study the skull from every angle, and work out how the head was usually held.
Sereno’s team also found the bones of a baby Nigersaurus. It was a hatchling, probably less than a year old when it died.
Nigersaurus and its world
Nigersaurus was a plant-eater, so it was what scientists call a primary consumer, an animal that feeds directly on plants. You can learn more about how living things depend on each other in our guide to ecosystems.
It is not the only prehistoric animal famous for its teeth. Millions of years later, a very different animal hunted with two huge fangs. Find out about it in our saber-tooth tiger facts for kids.
Three things people get wrong
Nigersaurus did not use all 500 teeth at once. Most were spare teeth, stacked up behind the working teeth and ready to replace them.
Nigersaurus was not a giant sauropod. At about 30 feet long, it was quite small for a long-necked dinosaur.
Nigersaurus did not reach up into trees. It held its head low and grazed on ferns and horsetails near the ground.
Did you know? Scientists described Nigersaurus as working “more like a Mesozoic cow than a reptilian giraffe”, because it grazed on low plants with its head held down.
Try it
Line up ten pencils in a row, with more pencils stacked behind each one. Take one from the front and slide the next one forward. That is roughly how a Nigersaurus tooth battery replaced worn teeth.
Knowledge check
Why did Nigersaurus need so many teeth?
Show answer
Because the gritty, low plants it ate wore its teeth down quickly, so new teeth kept moving up to replace them.
How did Nigersaurus usually hold its head?
Show answer
Low, with its muzzle pointing straight down at the ground.
Frequently asked questions
What dinosaur has 500 teeth?
Nigersaurus taqueti is the dinosaur known for having more than 500 teeth. It was a long-necked plant-eater that lived about 110 million years ago in what is now Niger.
Why did Nigersaurus have so many teeth?
Nigersaurus ate gritty plants near the ground that wore its teeth down fast. It kept stacks of spare teeth that moved up to replace worn ones, as often as every 14 days.
How big was Nigersaurus?
Nigersaurus was about 30 feet (9 metres) long, with a thigh bone about 1 metre long. That was fairly small for a long-necked sauropod dinosaur.
What did Nigersaurus eat?
Nigersaurus ate low-growing plants, mostly ferns and horsetails. It held its head low and snipped plants off near the ground with its wide, straight-edged mouth.
Where was Nigersaurus found?
Nigersaurus fossils come from the Elrhaz Formation in Niger, in the Sahara Desert. The first bones were found in the 1950s, and Paul Sereno’s team collected most of the skeleton from 1997.
What does the name Nigersaurus mean?
Nigersaurus means Niger lizard, after the country where it was found. Its full name, Nigersaurus taqueti, honours the French palaeontologist Philippe Taquet.
Sources
- PLOS One (Sereno and others, 2007): structural extremes in a Cretaceous dinosaur — teeth, jaw shape, head posture, age, size and hollow bones
- ScienceDaily: dinosaur from Sahara ate like a Mesozoic cow — the discovery, the name, the tooth columns, diet and paper-thin bones
- Paul Sereno, University of Chicago: Nigersaurus — the expeditions, the CT-scanned skull and the hatchling
- PLOS One (2013): tooth replacement rates in sauropod dinosaurs — how often Nigersaurus replaced its teeth and why
Nigersaurus Final Quiz
- Which scientist led the 1997 expedition that found Nigersaurus skull bones?
- Nigersaurus was about as long as what?
- How many times faster was the 2013 tooth-replacement estimate than the 2007 one?
- Scientists compared Nigersaurus to which animal because of how it fed?
- What does the word Mesozoic name?
- Which of these animals is described as mostly a browser that eats from trees?
- Why did scientists scan the Nigersaurus skull instead of handling it?
- How does a CT scanner take its pictures?
- Besides adults, what young Nigersaurus did Sereno's team find?
- What kind of consumer was Nigersaurus?
