More than three centuries ago, Dodo birds — a species endemic to the Mauritius Islands — were slowly being hunted down, eventually leading to their extinction.

Although this flightless animal no longer exists, we still know of them through historical accounts and the remains they left behind.

Now, a rare, composite skeleton of the Dodo bird will be sold at the Summers Place Auctions in West Sussex, England. The skeleton comes from a collector who compiled bones from auctions and private collections in the 1970s and 1980s.

According to The Independent, it was about a decade ago when the seller realized that there were nearly enough bones in his collection to complete the skeleton of the Dodo bird. The skeleton was missing one claw and a section of the skull. Both parts have been reconstructed for the auction.

Rupert van der Werff, Summers Place Auctions director, says individual bones of the Dodo bird come up for sale occasionally. However, this is the first time that an almost-complete skeleton is being sold since the early 20th century, he says.

“The rarity and completeness of this specimen cannot be over emphasized," says van der Werff.

The director believes that the skeleton offers individuals or an institution the unique opportunity to own a specimen of this extinct species.

No price guide has been disclosed for the Dodo bird's skeleton, but it is expected to go high.

Van der Werff says a huge part of auction estimates depend on precedent of similar objects being offered, which is quite impossible in this case. Given the skeleton's desirability and rarity, the auctions are anticipating a price in a high six-figure sum, he says.

In 1598, the Dutch East India company found the bird in Mauritius island, and hunted them for food. As more ships from Europe arrived, so did animals such as rats, cats, dogs and monkeys which fed on birds. Within a century after its discovery, the Dodo bird was wiped out.

And unfortunately, this has turned the Dodo bird into a symbol of how humans can negatively impact the natural world.

What's more, even after the animal was gone, its remains "were treated with little preservation," according to The Christian Science Monitor.

The Dodo bird is known for being "clumsy" or "stupid," but previous studies have shown that the animals were actually well-adapted to their life on the islands. The animals also might have been as intelligent as a common pigeon, as reported by Tech Times.