Beasts from Earth’s past

These fossils were discovered and presented last year, but I only came across them now in a “best of” selection.

On land:

Fossil hunters working in an open-pit coal mine in Colombia have unearthed the remains of several giant prehistoric snakes, thought to be the largest ever to have slithered on earth.

The boa constrictor-like beasts, aptly named Titanoboas, weighed more than one and a quarter tonnes and measured at least 13m long from nose to tip. At their widest, the snakes would have come up to the waist of an adult human.

The partial skeletons of eight individuals were uncovered at the site, alongside the fossilised remains of what may have once have been the creatures' dinner: a 2m-long giant turtle and an ancient ancestor of the modern crocodile.

The fossils were encased in rock dating back 60m years, and so give scientists an unprecedented insight into the large animals that ruled the tropics after the sudden demise of the dinosaurs 65m years ago.

"Now we have a window into the time just after the dinosaurs went extinct and can actually see what the animals replacing them were like," said Jason Head, a paleontologist at the University of Toronto.

The region of Colombia where the snakes were found was very different 60m years ago. It would have been a thick rainforest cut through by a network of rivers, resembling the modern Amazon.

The discovery has lifted a veil on the climatic conditions at the time the beasts were alive, since cold-blooded animals grow much larger in warmer environments. The largest cold-blooded animals alive today live in the tropics where it is hottest, but farther away from the equator they get steadily smaller.

Based on the snakes' size, the researchers calculated that the tropics were on average 5C warmer than they are today. The study marks a first in using the size of animals from their fossilised remains to infer the climate of the world tens of millions of years ago.

And underwater:

The fossilised skull of a "sea monster", which may be the largest of its type ever found, has been unearthed on the Dorset coast.

The skull from the ferocious prehistoric predator the pliosaur is 2.4 metres long and could belong to a creature measuring up to 16 metres in length from tip to tail and weighing up to 12 tonnes.

Pliosaurs were a form of plesiosaur, a group of giant aquatic reptiles that terrorised the ocean 150m years ago, around the same time that dinosaurs roamed the Earth.

They had short necks and huge, crocodile-like heads that contained immensely powerful jaws and a set of huge, razor-sharp teeth.

"It could have taken a human in one gulp; in fact, something like a T-Rex would have been breakfast for a beast like this."

"They had massive muscles on their necks, and you would have imagined that they would bite into the animal and get a good grip, and then with these massive neck muscles they probably would have thrashed the animals around and torn chunks off.

"It would have been a bit of a blood bath."

Scary creatures for sure.