The severed head of the world’s first full-sized Pleistocene wolf was discovered on shore of the Tirekhtyakh Riverun, in the north of Yakutia, in Siberia.

The wolf, whose rich mammoth-like fur and impressive fangs are still intact, was fully grown and aged from two to four years old when it died.

The head, preserved since prehistoric times in permafrost, with its brain intact, was dated older than 40,000 years by Japanese scientists.

The Pleistocene wolf’s head is 40cm long, so half of the whole body length of a modern wolf which varies from 66 to 86cm.

‘This is a unique discovery of the first ever remains of a fully grown Pleistocene wolf with its tissue preserved. We will be comparing it to modern-day wolves to understand how the species has evolved and to reconstruct its appearance,’ said an excited Albert Protopopov, from the Republic of Sakha Academy of Sciences.

The astonishing discovery was announced in Tokyo, Japan, during the opening of a grandiose Woolly Mammoth exhibition organised by Yakutian and Japanese scientists.

Alongside the wolf the scientists presented an immaculately-well preserved cave lion cub. Scientists believe the cub died shortly after birth.

‘Their muscles, organs and brains are in good condition,’ said Naoki Suzuki, a professor of palaeontology and medicine with the Jikei University School of Medicine in Tokyo, who studied the remains with a CT scanner.

The cave lion cub named Spartak - previously announced - is about 40cm long and weighed about 800 grams.

The recent discovery follows that of the remains of three cave lions in 2015 and 2017 by the same team.

‘We want to assess their physical capabilities and ecology by comparing them with the lions and wolves of today.’