The restored skeleton of an ancient sea predator is expected to fetch up to £120,000 at auction.

The skeleton of a Tylosaur marine reptile – known to be the biggest of the prehistoric mosasaurs from the late Cretaceous period – is set to go under the hammer later this month with a starting price of £60,000.

Mosasaurs, which are most closely related to snakes and lizards, and dinosaurs became extinct about the same time.

The remains of the Tylosaur were discovered in Kansas, which was once covered by sea.

Rupert van der Werff, expert at Summers Place Auctions in West Sussex, said the Tylosaur was the “star of the show” at the upcoming sale.

Its powerful jaws and teeth allowed it to easily rip up its prey, and paddle-like limbs enabled it to swim quickly.

The auction house says in its item description: “It was a huge and ferocious creature and is scientifically named a Tylosaur.

“It was immortalized in paint by the celebrated Czech artist Zdenek Burian in one of the masterpieces he created depicting prehistoric life.

“This particular example is one of only very few specimens that have ever left the USA.”

Fossils of mosasaurs have been found all around the world.

Also expected to receive high bids – of between £30,000 and £50,000 – is the skull of a Eurhinosaurus, a type of Ichthyosaur. Dating from the Lower Jurassic period, Eurhinosaurs had a very long and slender upper jaw similar to today’s swordfish.

Mr van der Werff added: “The second most valuable lot in the sale would actually fit in the palm of your hand.

“It’s a piece of Burmese amber that’s got a tetrapod preserved in it – a complete creature from 100 million years ago – which is phenomenal, the flesh, everything is there.”

The auction also features a rare Blue Bird of Paradise from the late 19th century, displayed under a glass dome. The bird is known for its upside-down dance, in which it displays its blue plumes, as seen in one of Sir David Attenborough’s nature documentaries.

It is expected to fetch between £12,000 and £18,000, while a huge polar bear could sell for up to £50,000.

The sale is to take place on 23 November at the auction house and online.

Additional reporting by PA