The skeleton of a duck billed dinosaur known as Edmontosaurus annectens is to cross the block at Christie's.

It's expected to make around £200,000-300,000 ($257,589-386,383) in an October 19 Natural History auction in London

Edmontosaurus annectens was a herbivore preyed upon by T Rex and other theropods

The skeleton is well over eight metres long and was recovered from a site in the Hell Creek Formation in South Dakota, a hotspot for dinosaur hunters.

It would have lived around 66m years ago, making it one of the last dinosaurs to appear on the fossil record before the great extinction event at the end of the Cretaceous period.

A fossilised Rhamphorhyncus muensteri pterosaur is likely to prove another highlight, with a valuation of £90,000-120,000 ($115,954-154,606).

It dates to the Jurassic period, around 150m years ago, and was recovered from Sonholfen in Germany.

This region features soft limestone and many of the best preserved pterosaurs have been discovered here.

If dinosaurs aren't your thing, there's a wealth of other pieces offered - ranging from mineral samples to Enigma encoding machines.

A rare K model Enigma machine carries an estimate of £60,000-90,000 ($77,303-115,954).

It was built in 1936 and would likely have been used for civilian rather than military purposes.

The record for an Enigma machine at auction is $269,000, set for a 1944 model at Christie's last year.

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