Tyrannosaurus bataar

(Image credit: Wynne Parry)This nearly complete Tyrannosaurus bataar is set to go on auction. It is one of many rare natural history specimens Heritage Auctions plans to sell on May 20. An Asian relative of the North American Tyrannosaurus rex, this specimen's estimated value is between $1.4 and $1.8 million.

Preparing for the Auction

(Image credit: Wynne Parry)Four days before the auction, workers put the specimens to be auctioned off on display. The showroom is open to the public in the days before the auction.

Rare Minerals

(Image credit: Wynne Parry)The auction plans to sell not only dinosaur fossils, but also meteorites, tufts of mammoth hair and minerals, including those shown above. Only the taxidermy is not on display.

Gold in Quartz

(Image credit: Heritage Auctions)The tyrannosaur of the minerals, this gold nugget in quartz weighs more than 70 ounces (2 kilograms).

From the Water

(Image credit: Wynne Parry)From left to right, a sea lily or crinoid, a pregnant female ichthyosaur and a xiphactinus "bulldog" fish.

Centipede in Amber

(Image credit: Heritage Auctions)A centipede preserved 50 million years ago in stick tree resin, which became amber.

Meteor from Mars

(Image credit: Heritage Auctions)A meteor made of igneous rock from the planet Mars.

Ankylosaurid Skull

(Image credit: Heritage Auctions)An Ankylosaurid from Central Asia.

A Dodo

(Image credit: Heritage Auctions)A cast of one of the few existing skeletons of this now-extinct bird.