Real-life KRAKEN: Giant octopuses roamed oceans 72 million years ago

The ancient oceans were once ruled by giant 'kraken-like' octopuses that measured up to 62 feet (19m) long, new research reveals.

Scientists have discovered evidence of a colossal beast that hunted the Late Cretaceous seas between 72 and 100 million years ago.

They competed with - and perhaps even preyed upon - large ocean apex dinosaurs such as the ferocious mosasaur.

This is unusual, the experts said, because they evolved to have soft bodies instead of protective shells.

However, this may have given them unprecedented mobility, vision and intelligence.

The discovery was made after a team re-examined 15 large fossil jaws from ancient octopus relatives and found two new species - one of which grew to remarkable lengths.

This species, called Nanaimoteuthis haggarti, featured extensive wear in their jaws, indicating they were active carnivores that routinely crushed hard shells and bones with powerful bites.

It's also believed they used their long, flexible arms to seize large prey while dismantling it with their strong beaks - a behaviour that has been linked to advanced intelligence.

Scientists have discovered evidence of a colossal beast that hunted the Late Cretaceous seas between 72 and 100 million years ago

They competed with - and perhaps even preyed upon - large ocean apex dinosaurs such as the ferocious mosasaur

'This extensive wear suggests dynamic crushing of hard skeletons,' the team, from Hokkaido University, wrote in the journal Science.

'With a calculated total length of (up to) 62 feet (19m) these octopuses may represent the largest invertebrates thus described, rivalling contemporaneous giant marine reptiles.'

For comparison, humans measure, on average, 5ft6 (1.7m) tall while elephants reach a height of around 10 feet (3m).

This ancient octopus would also have eclipsed a London bus, which comes in at around 36 feet (11m) long.

While it was comparable to the length of a sperm whale, at 66ft (20m) long, it wouldn't have quite measured up to a blue whale, which can grow up to 90 feet (27m) long.

The other newly-discovered species, called Nanaimoteuthis jeletzkyi, was also a predator but was on the smaller size, growing up to 26 feet (8m) in length.

The researchers said the findings indicate these two species were not merely prey.

Instead, they were highly active participants in shaping marine ecosystems while occupying roles previously attributed only to large vertebrates such as sharks.

The team said the wear and tear found on fossilised jaws indicated they were active carnivores that routinely crushed hard shells and bone

How it measures up

Human - 5ft6 (1.7m) tall

Elephant - 10ft (3m) tall

London bus - 36 feet (11m) long

Giant octopus - 62ft (19m) long

Sperm whale - 66ft (20m) long

Blue whale - 90ft (27m) long

'In the largest individuals, the jaws showed extensive wear with once-sharp features in small juveniles becoming blunted and rounded over time,' the scientists said.

'The long scratches distributed on wide areas of their jaw reflect the dynamic use of the entire jaw for dismantling prey.'

They said that the loss of jaw edges isn't even on each side, indicating the octopuses had a 'preferred' side to chew on.

This has been linked to a highly-developed brain and cognition, indicating 'that the earliest octopuses already possessed advanced intelligence'.

'Long after the rise of vertebrate top predators, octopuses evolved body plans capable of rivalling them, as demonstrated here,' the team concluded.

Researchers previously said the skin patterns that octopuses create while they are snoozing may indicate they are capable of something similar to dreaming.

Like people, octopuses transition between two sleep stages - a quiet stage and an active stage that resembles rapid eye movement (REM) sleep in mammals.

While awake, octopuses create a number of different skin patterns which they use to camouflage themselves in different environments, and in social or threat displays, such as warning off predators and communicating with each other.

The size of N. haggarti compared to other marine predators of the time. A human is also depicted - showing the sheer size of the ancient colossal beast

The animals cycled through these same skin patterns during active sleep, the study found.

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Other ancient octopus-like predators include the oldest known ancestor of the vampire squid, that had extra-long suckers and hair-like strands on its arms that it used to trap prey.

This differs from the modern-day vampire squid, which feeds only on organic drifting matter and is not built for active hunting, with less robust suckers.

A research team from Sorbonne University in France used a three-dimensional imaging technique on a 164 million-year-old fossilised specimen of this cephalopod.

They found evidence of muscular suckers on the tips of two specialised, long dorsal arms, suggesting it was an active predatory hunter.

OCTOPUS DEFENCE MECHANISMS

One of the most effective ways octopuses avoid predation is by camouflaging with their environment.

They have special pigment cells allow them to control the colour of their skin, much like chameleons.

As well as colour change they can manipulate the texture of their skin in order to blend in with the terrain.

As well as camouflage they can escape predators by using a 'jet propulsion' method of escape, where they rapidly shoot out water to propel them through the water rapidly.

The jet of water from the siphon is often accompanied by a release of ink to confuse and evade potential enemies.

The suckers on the tentacles of the eight-legged beasts are extremely powerful and are used to drag prey towards a sharp beak.

As well as protection from other animals, it has been recently found that octopuses can detect the ultrasonic waves that preempt a volcanic eruption or earthquake, giving them enough time to escape.