Pleistocene wolf

The Pleistocene wolf lived during a time long ago called the Pleistocene. These wolves were found all over the Northern Hemisphere. Some of these ancient wolves, like the Beringian wolves and those from Japan, were much bigger than the wolves we see today, such as the modern gray wolf.

Lithograph of Pleistocene wolf remains from Britain

Scientists have studied the remains of these old wolves and found that they shared many genes with each other, even though they lived far apart. This means that the wolves could travel and mix their genes, keeping their populations similar. Today’s wolves mostly come from some groups of these ancient Siberian wolves. After a very cold time called the Last Glacial Maximum, these Siberian wolves became the main ancestors of the wolves we know now.

Taxonomy

Pleistocene wolves were a special type of wolf called an ecomorph of Canis lupus. In Europe, some ancient wolf fossils were named Canis lupus spelaeus by scientists, often called the cave wolf.

Biogeography

Ukok Plateau, one of the last remnants of the mammoth steppe

The Late Pleistocene era was a time of big changes in Earth's climate and landscape. During this time, a huge grassy area called the mammoth steppe stretched from Spain all the way across Eurasia, over Beringia into Alaska and the Yukon. The climate swung very quickly and sharply, which affected many large animals.

Wolves lived all over this vast area. Because the places they lived were so different, the wolves changed to fit their surroundings. This means that wolves in different areas started to look and act a little differently from each other. The wolves we see today are related to these ancient wolves, but their numbers dropped when many other big animals disappeared at the end of the Pleistocene era.

Genetics

A haplotype is a group of genes inherited together from one parent, and a haplogroup is a group of similar haplotypes sharing a common ancestor. Scientists study these to learn about ancient animals.

mDNA phylogenetic tree for wolves. Clades are denoted I–XIX. Key regions/haplotypes are indicated and new haplotypes are displayed in bold. Late Pleistocene samples are represented by the numbers 1–10. Beringian wolf (Alaska 28,000 YBP) haplotype found in the modern clade XVI from China.

In 2010, researchers compared DNA from 24 ancient wolves from western Europe with modern wolves. They found 75 different groups of DNA, called haplotypes, in modern grey wolves. These haplotypes fell into two main groups, or haplogroups. Most ancient European wolves belonged to haplogroup 2, but over time, haplogroup 1 became more common in Europe. In North America, only haplogroup 1 is found today.

Studies also show that ancient wolves from places like Beringia and Belgium likely ate large animals that disappeared about 12,000 years ago. These ancient wolves shared similar DNA with each other, suggesting they were part of a large, connected population across northern Eurasia and North America. Modern wolf populations likely come from wolves that lived in southern areas during cold periods.

Description

Diagram of a wolf skull with key features labelled

During the time of the Late Pleistocene, we know from fossils that wolves changed in size and shape. These changes might have happened because the wolves hunted bigger animals, which could make them grow larger too. Many of these old wolves had stronger jaws and teeth than wolves today. They also often had shorter faces and bigger muscles, which helped them bite harder and chew bones. These features suggest they were very good at hunting large animals and eating their remains.

Scientists have found that these old wolves often had broken teeth, especially on the front and sides of their mouths. This is similar to what we see in animals today that regularly eat bones, like hyenas. It shows that these wolves probably ate a lot of bones from big animals. Some studies also show that the size of their teeth changed with the types of large animals they hunted, not just because of the climate. Overall, these wolves were very strong and adapted to eating big, tough prey.

Diet

Location of a dog's carnassials; the inside of the 4th upper premolar aligns with the outside of the 1st lower molar, working like scissor blades

Pleistocene wolves ate large animals like horses, bison, woodland muskox, and mammoth. This shows they could hunt and eat very big animals. They were better at eating meat than modern wolves, with teeth and jaws built for catching and eating large herbivores. When these big animals disappeared, many Pleistocene wolves did too, leading to less variety in their types and genes.

Habitat

Wolves lived across the northern parts of the world during the time called the Late Pleistocene. During this time, which included parts of what we call the Ice Age, the land looked very different than today. There was a big, open grassland called the mammoth steppe that stretched from Europe all the way to Alaska.

Paleoecology

The last glacial period, or Ice Age, lasted from about 125,000 to 14,500 years ago. During its peak, huge sheets of ice covered many lands. As the ice melted, sea levels rose and changed the shape of the land. Many large animals that lived during this time are called Pleistocene megafauna. These included huge creatures that are now gone.

Shrinking of the Bering land bridge

Beringia

Beringia was a region around the Bering Strait that included parts of Russia and Alaska. During times when ice locked up much of the world’s water, sea levels dropped and a land bridge connected Asia and North America. This land bridge allowed animals, including wolves, to move between the two continents.

East Beringia

In Alaska, scientists studied wolf bones from between about 45,500 and 12,500 years ago. These wolves had special skull shapes that helped them hunt big animals that lived at the time. Their DNA shows they were different from modern wolves and had more genetic diversity.

West Beringia

Near Lake Taimyr in Siberia, scientists found a wolf skull that was about 16,220 years old. This wolf was small, and some think it might have lived close to humans or been partly tamed. Its skull showed it ate a lot of tough food like bones.

In 2019, a fully grown Pleistocene wolf with amazing fur and teeth was found preserved in Yakutia, Russia. Scientists are excited to study this wolf to learn how it looked and how it compares to today’s wolves.

Arctic Siberia

The Greenland dog carries 3.5% shared genetic material (and perhaps up to 27%) with the extinct 35,000 YBP Taimyr wolf

Taimyr wolf

In 2015, a piece of wolf bone was found near the Taimyr Peninsula in Arctic Siberia. It was about 34,900 years old and gave scientists a lot of information about ancient wolves. This wolf’s DNA showed it was a separate group from modern wolves and dogs, and it lived before a big cold period called the Last Glacial Maximum.

Europe

Canis lupus spelaeus

Illustration of a Pleistocene wolf cranium that was found in Kents Cavern, Torquay, England

In Europe, there was a special kind of wolf called the cave wolf. It was first found in a cave in Germany and was a bit larger than today’s European wolves. These wolves lived all over Europe until a colder time when they were replaced by smaller wolves.

East Asia

Japan (Canis lupus hodophilax)

Before the Ice Age’s coldest time, wolves from Siberia reached Japan through a land bridge from Korea to Honshu. These wolves spread across most of Japan but did not reach Hokkaido, which was later settled by modern gray wolves. Over time, the Japanese wolves became smaller because they lived on an island. Sadly, they disappeared by around 1905 after diseases and human actions reduced their numbers.

Main article: Japanese wolf

Comparison of *Canis lupus* variation in Britain from 243,000 YBP (MIS refers to Marine isotope stage)
Time YBP	Variables
243,000 MIS 7	Paleoenvironment was open grasslands with summer temperatures between 16 °C and 23 °C and winter temperatures between −7 °C and −6 °C dominated by steppe mammoth and horse. Competitors included the lion, brown bear, and rarely the spotted hyena. The wolves of MIS 7 were slightly smaller in body size than MIS 5 wolves and those found in Sweden today. These wolves were out-competed by the larger competitors, leading to a more omnivorous diet with increased crushing ability in an open environment that supported more types of prey and more non-meat foods than the MIS 5 period. They had shallower and narrower jaws than MIS 5 wolves and those found in Sweden today, which indicated that they could take only small to medium-sized prey. They exhibited a lower percentage of tooth breakage comparable with MIS-3 wolves. However, they had the highest percentage of moderately worn teeth.
82,000 MIS 5A	Paleoenvironment was cold, open tundra with summer temperatures between 7 °C and 11 °C and winter temperatures between −10 °C and −30 °C dominated by reindeer and bison. A large form of brown bear was top predator, with no hyena at this time. The wolves of MIS 5 were larger in body size than those found in Sweden today. These wolves suffered from a severe climate, low prey availability and dietary stress leading to a more carnivorous diet, with increased scavenging of frozen carcasses and bone consumption. They developed strong jaws and the highest flesh-slicing ability compared to the other wolves, with shallower jaws than the modern wolf but broader and deeper jaws than MIS 7 and MIS 5 wolves. They exhibited the longest and narrowest upper P4 that suggests improved slicing ability, and longest upper M1 and M2 but with reduced width and therefore reduced crushing ability, indicating a hypercarnivore. They exhibited a higher percentage of tooth breakage and severely worn teeth compared to the other wolves, and may have been using their upper P4 and lower m1 to crush bone rather than their molars, leading to a higher frequency of damage.
57,000 MIS 3	Paleoenvironment of open grasslands with summer temperature of around 12 °C and winter temperature around −20 °C dominated by woolly mammoth, woolly rhinoceros, horse, and giant deer. Competitors included the lion, brown bear, and the spotted hyena as the top carnivore. The wolves of MIS 3 were smaller in body size than MIS 5 wolves and those found in Sweden today. These wolves were out-competed by the lion and hyena, leading to a more omnivorous diet with increased crushing ability in an open environment that supported more types of prey and more non-meat foods than the MIS 5 period. They had shallower and narrower jaws than MIS 5 wolves and those found in Sweden today, which indicated that they could take only small to medium-sized prey. They exhibited a lower percentage of tooth breakage comparable with MIS-7 wolves with moderate tooth wear.
Today (Sweden)	Wolves have been extirpated in Britain but not in Sweden, where the temperatures are similar to those of Britain during the MIS 7 period. Environment of boreal forest with summer temperatures between 14 °C and 18 °C and winter temperatures between 1 °C and −10 °C. The prey species includes elk, reindeer, roe deer, boar, hares, rabbit, and beaver. Competitors include the brown bear and lynx but the wolf is top carnivore. The wolves found in Sweden today are smaller in body size than MIS 5 wolves but larger than those of MIS 7 and MIS 3. The upper M1 and M2 length is longer than for MIS 7 and MIS 3 wolves, and the jaws deeper and broader, which indicates the ability to hunt and subdue large prey. However, the large molars retained a crushing ability and to process non-meat foods. These wolves live in boreal forests where small to medium game is hard to detect and labour-intensive to subdue, leading to an adaption for hunting larger game with higher reward. They are hypercarnivores similar to MIS 5 wolves but not with the same slicing ability.

Relationship with the domestic dog

Further information: Origin of the domestic dog § Europe

Studies of DNA show that dogs came from a group of wolves that lived during the Pleistocene time, which was different from the wolves that live in Eurasia and North America today. Some research says that all living wolves are more related to each other than to dogs, but other research says dogs are more related to Eurasian wolves than to American ones. Most dogs are thought to be closely related to the remains of a wolf found in the Kessleroch cave near Thayngen in Schaffhausen, Switzerland, which lived about 14,500 years ago. Scientists believe the ancestor of both dogs and modern wolves lived about 32,100 years ago. This suggests that an ancient wolf from the Pleistocene might have been the first ancestor of dogs, with today’s wolves being the closest living relatives to dogs. A study from 2024 also found that the Japanese wolf was more closely related to dogs than to wolves from America or other parts of Eurasia, which supports the idea that dogs were first tamed in Eastern Asia.