Were all mammoths woolly?

“About two million years ago we find a species called Mammuthus meridionalis,” says Adrian. “It survived for about a million years and there are very abundant fossils all the way from Britain to China.”

Mammuthus meridionalis is also known as the southern or ancestral mammoth. As the climate in Asia became more seasonal and grasslands known as steppes started spreading, a group of southern mammoths eventually broke off in the east. These evolved into the steppe mammoth, Mammuthus trogontherii.

This change in species and habitat preference can be seen in their teeth. Micro-wear patterns on their teeth show that southern mammoths were mostly browsers, eating from shrubs and trees. Steppe mammoths’ teeth, on the other hand, indicate they were mostly grazing on grass. 

Oceans now entirely separate Eurasia and North America, but in the time of mammoths, there was a strip of land that connected the eastern tip of Russia to western Alaska. This is known as the Bering land bridge and it allowed plants and animals, including people, to pass from one continent to the other. Steppe mammoths crossed this into North America about 1.5 million years ago.

Woolly mammoths, Mammuthus primigenius, evolved about 800,000–600,000 years ago in northeast Siberia. Scientists think a population of steppe mammoths that were well-adapted to the incredibly harsh conditions evolved into the hairy icons we know and love. These then spread west across Eurasia and east into North America.

Artwork of woolly mammoths sometimes places them against stark, snowy backdrops. But while they were adapted to cold conditions, they were living in richly vegetated landscapes, mostly away from deep snow cover. Otherwise, as Adrian notes, what would they have had to eat!

Columbian mammoths, Mammuthus columbi, lived in North America, from southern Canada down to Costa Rica. But plotting exactly when they arose on a timeline is tricky. The shape of their teeth indicates they’re descendants of steppe mammoths. However, DNA tells a slightly different story, with a study of 13,000-year-old fossils showing that Columbian mammoths were actually a hybrid species. They had half steppe mammoth DNA and half early woolly mammoth DNA, stemming from a hybridisation event 400,000 years ago.

The trouble is the earliest fossil evidence we have of woolly mammoths in North America is only 200,000 years old. Another curiosity is that Columbian mammoths’ teeth look the same before and after this particular hybridisation event. This is a big puzzle that scientists like Adrian are trying to unpick.

In total, there were around 10 species of mammoth that roamed the planet long before the iconic, ice age species we know as the woolly mammoth.

We know woolly mammoths were covered in hair, but the question is were its mammoth relatives dressed for winter weather too?

Were all mammoths hairy?

About 2.5 million years ago, at the beginning of the Pleistocene Epoch, the planet’s climate began to cool, causing forests to retreat and open habitats to spread. It was the start of the ice age and animals, including mammoths, had to adapt to survive. But answering definitively whether mammoths were always hairy or if it was an ice age adaptation isn’t easy because our evidence is limited.

“The only ones where we’ve got preserved woolly mammoth soft tissue are from Siberia and Alaska. There’s also a small amount of soft tissue from a Columbian mammoth – it has a somewhat hairy coat, but we can’t really say how much,” Adrian explains. 

As for their ancestor, the steppe mammoth, while we don’t have physical evidence of hair, we do have their DNA.

In 2021, Adrian collaborated with a team of researchers who extracted and sequenced DNA from a 700,000-year-old woolly mammoth tooth and a 1.2 million-year-old steppe mammoth tooth. They could then look at the differences and similarities.

They found that genes that could help an animal survive in the Arctic Circle – such as those coded for long hair, fatty deposits and a tolerance to cold – were present in the older steppe mammoth DNA.

“The first species where we find fossils in the Arctic Circle is the steppe mammoth,” Adrian explains. “By then, the climate had deteriorated significantly and there was extensive tundra.”

“With the DNA we can see that steppe mammoths were already quite cold adapted in their physiology. Then woolly mammoths pushed it to an extreme in terms of adaptation to that environment.”

“But as for earlier mammoths, we really don’t know. The early part of the Pleistocene wasn’t so cold – there were still lots of warm, forested areas, and we know that mammoths lived in those regions.”

From Adrian’s perspective, in terms of adaptations, the biggest step was probably from the southern mammoth and earlier species to the steppe mammoth. By comparison, the step from steppe mammoths to woolly mammoths was a relatively small one.

But we can’t claim that older mammoth species that lived in warmer environments were totally bald. If you look at modern Asian elephants that live in the tropics, you’ll see they’re sparsely covered in hair. It’s possible that early mammoths in Africa were too. 

Were there mammoths in Britain?

Today, Britain’s largest land animal is the red deer, which is about 1.2 metres tall at the shoulder. But back in the Pleistocene, our ecosystem sustained animals much larger than that.

Fossils of southern mammoths, steppe mammoths and woolly mammoths have all been found in Britain. Some of these are part of the collection we care for, which, according to Adrian, “represents one of the best, most complete collections, showing the evolutionary change through time”.

Scientists from around the world use these specimens to get a clearer picture of mammoths, from genetics to tracking their diets over time.

If you want to see a mammoth up close for yourself, we have one of Britain’s best specimens on display in our Mammals Gallery. The Ilford mammoth skull, which belongs to a steppe mammoth, is the largest and most complete of its kind ever found in Britain. It was discovered by workers in Ilford in East London in 1864 who were digging for clay to make bricks.

“We have hundreds of teeth from that same Ilford site,” Adrian explains. “It’s kind of an intermediate stage between the steppe mammoth and the woolly mammoth – about 200,000 years old. It’s a very important sample.”

Another significant British discovery is a complete steppe mammoth skeleton that Adrian helped to excavate in Norfolk in the 1990s. It’s cared for by Norfolk Museums Service, and in 2024, served as inspiration for a limited-edition coin produced by The Royal Mint. Adrian worked with palaeoartist Robert Nicholls to ensure the commemorative coin and its educational packaging are accurate.

Why did woolly mammoths go extinct?

Today, even in the planet’s iciest regions, mammoths are missing. Elephants are just about hanging on in Asia and Africa, but what happened to their cousins?

Scientists have been debating the mysterious case of mammoth extinction for a while, finding themselves with two main suspects.

“There’s an ongoing argument among researchers as to what is the relative contribution of climate change and vegetation change on one hand, and human hunting on the other hand,” Adrian explains.

The climate started shifting again towards the end of the Pleistocene as Earth crept out of the last ice age. For mammoths, this meant that their open habitat started shrinking and being replaced by forest and tundra. In line with that change, the fossil record shows mammoth populations shrinking and contracting around this time.

“But some people would argue that that happened cyclically because we had many ice age climate cycles,” Adrian notes.

Woolly mammoths were adapted to life in cold conditions, so during warm periods – known as interglacials – they would have been squeezed into smaller areas where conditions were still favourable, known as refugia. As the climate cooled again in the glacial periods, their range would have expanded.

“Their populations were probably repeatedly squeezed into refugia, but then they survived and bounced back. So why did they only go extinct the last time around?”

But this extinction also lines up with growing numbers of humans with sophisticated – albeit stone-age – hunting technology. Mammoths were important to our ancestors for food, as well as for their bones, ivory and skins. They were significant enough to feature in cave art, such as the 158 mammoths depicted on the walls of Rouffignac Cave in south-west France, by people 13,000 years ago.

“We have evidence they were occasionally hunted – there’s a few mammoth fossils with broken ends of spear points in them,” Adrian says. “But that doesn’t mean they were hunted to extinction.”

“I think it may be a combination of the two. I think the data better fits the climate model as the main driver, but we can’t rule out that humans contributed.”

We last see Columbian mammoths in the fossil record about 12,000 years ago, indicating they may have gone extinct alongside lots of other large Pleistocene mammals. 

Woolly mammoths died out on the mainland a little later, around 10,500 years ago. But populations survived on the islands left behind after the Bering land bridge was swallowed by the sea. On Alaska’s St Paul Island, they lasted until 5,600 years ago and, further north, on Wrangel Island until 4,000 years ago.

“Humans didn’t get there until very late. We’re almost 100% certain that there were no people on St Paul until the eighteenth century or so,” Adrian explains. “Five and half thousand years ago, there were drought conditions and limited freshwater and that’s probably what drove them extinct.”

On Wrangel, it’s a bit more complex. We get the first signs of humans on the island only a few hundred years after the last mammoth fossils. With how close together those pieces of evidence are, there’s a question of whether the mammoth population was hunted to extinction or was already gone by the time people got there.

“We have evidence of people hunting marine mammals like seals, but no evidence they were hunting mammoths,” says Adrian. “But we also haven’t identified any significant environmental change on Wrangel about 4,000 years ago. There’s nothing obvious in climate or vegetation.”

The end of this iconic species might sound like yet another mammoth mystery, though recent evidence provides some clues. It’s possible that genetic mutations in this small and isolated population may have led to poor health and ultimately extinction.  

The story of mammoths may be longer and more complex than you expected. But with woolly mammoths lasting a few thousand years longer than other species, it means that for a while all mammoths were, in fact, woolly.