This week looks like being the most spectacular of the scientific auction year with three landmark auctions of scientific documents and specimens crossing the block. The three important artifacts are a 13-m (43-ft) Diplodocus skeleton at Aguttes in Paris on June 13 (US$1.5 million to $1.8 million), one of three original copies of Luca Pacioli's Summa de Arithmetica at Christie's in New York on June 12 ($1.0 million to $1.5 million) and a presentation copy of the first edition of Charles Darwin's On the Origin of Species by Means of Natural Selection at Bonhams in New York on June 13 ($ 200,000 to $300,000).

Rare 13-meter Diplodocus Skeleton

Estimate: $1.5 million to $1.8 million

Little more than a century ago, a dinosaur skeleton was in the same auction price bracket as the work of a Grand Master. That was before we understood the age of our stratified natural history and advanced geological surveying enabled us to map the age of the Earth's surface.

Once we understood where the undisturbed land of the dinosaurs reached the planet's surface, dinosaur remains became a lot easier to find, and these days the skeletal remains of these real life mythical creatures are common enough to be within the reach of your average scientifically-besotted ultra-wealthy individual.

It's still not that often that a dinosaur skeleton comes to auction, and even rarer still is a Diplodocus skeleton. This particular skeleton comes from the Diplodocus family, but is described by Parisian auction house Aguttes as a "cousin of the Diplodocus" and likely belongs to a new genus of basal diplodocid.

Dubbed "skinny", this Diplodocus skeleton is one of just seven known that are largely complete and it is one of the most complete (even likely the most complete) sauropod skeletons ever discovered in the Morrison Formation.

The above image shows the original bones of the skeleton to go to auction marked in red. Unlike other most other dinosaur skeletons, skinny's restoration process has been fully documented, so that it is ready for scientific study.

Large patches of scaly skin are extensively preserved around different parts of skinny's skeleton; the first time that such an amount of skin impressions can be found directly associated with skeletal elements in a sauropod.

Only a few Diplodocus skeletons have ever reached auction, with the most recent being the above 12-m (39-ft) skeleton which fetched $1,733,384 (€ 1,180,000) at French auction house Binoche et Giquello in April, 2018. The previous Diplodocus skeleton to reach auction was 17 m (56 ft) long and sold for $650,735 (£400,000) by Summer Place Auctions in 2013.

UPDATE, June 14, 2019: Skinny the diplodocus attracted a bid of €1.15 million, but the reserve price of €1.2 million was not met, so the lot was was passed in.

Luca Pacioli's Summa de Arithmetica

Estimate: $1.5 million to $1.8 million

There are several books which can be reasonably argued as being one of the most influential books ever written, and Somma di arithmetica, geometria, proporzioni e proporzionalità is one of them.

It is essentially a 600-page mathematics encyclopedia written by Luca Bartolomeo de Pacioli (1447 – 1517), a University Mathematics professor, Franciscan friar and the man who taught mathematics to Leonardo da Vinci. The book provides a comprehensive summary of practical mathematics, arithmetic, basic algebra, geometry and most importantly, accounting.

As it was written in vernacular Italian (as opposed to Latin, and hence accessible to far more people), and was published in 1494 (Gutenberg's printing system was developed in 1439), the 1,000 copies printed in the first edition quickly spread across Europe, being translated into many languages, and catalyzing an understanding of mathematics in general and accounting in particular, that had previously been unavailable.

It is a small chapter in the book that unquestionably catalyzed an understanding of trade and commerce which had not been previously available to the merchants of Europe.

Volume 1 Chapter 9 of Somma di arithmetica, geometria, proporzioni e proporzionalità is the chapter which describes double entry book-keeping, a practice that had been pioneered by the Jewish community of the Middle East in the 11th century, and had been in use for at least 200 years by the merchants of Italy prior to Paciloli Venice codifying the system in this book. By writing it down, explaining it, promoting the Hindu-Arabic numeral system over the still-in-use Roman numerals, and giving a raft of practical examples, Pacioli earned a place in history as the father of accounting.

Auction House Christie's, which is auctioning this book, describes Summa de Arithmetica as "the birth of modern business."

With this fundamental enabling technology for commerce explained and printed in Venice, the knowledge propagated internationally. At that time, Venice was the most influential European trade hub, with established links to all the major European trade hubs and the merchants therein. For context, Jane Gleeson-White, the author of Double Entry: How the Merchants of Venice Created Modern Finance, describes Venice at that time as "a cross between New York and Silicon Valley."

The auction copy of Luca Pacioli's Summa de Arithmetica is the only known copy with its original binding, and one of only three complete copies recorded at auction in the last 50 years.

UPDATE, June 14, 2019: Luca Pacioli's "Somma di arithmetica" fetched US$1,215,000

Charles Darwin's On the Origin of Species

Estimate: $200,000 to $300,000

Charles Darwin's masterwork, On the Origin of Species by Means of Natural Selection, is unquestionably one of the most important books ever published. "The most important single work in science" (Dibner), and "a turning point, not only in the history of science, but in the history of ideas in general" (DSB) are just two examples of learned opinions of On the Origin of Species by Means of Natural Selection.

Just 1,200 copies were printed of the first edition of this book, and five of those first editions sold at auction in 2018, with the copy sold by Morton Subastas in Mexico City the most expensive at MXN5,551,200 (US$288,660). Other first editions sold in 2018 for $284,839 (£212,500 at Sotheby's on July 10), $162,500 (at Christie's New York on December 4), $125,869 (€109,946 at Artcurial Paris on November 19) and $138,698 (£105,000 at Bonhams London on June 20).

The reason for the particularly high price of the Morton Subastas copy is that it was one of 23 courtesy copies that were delivered by the publisher to scientists and renowned people of the time.

The copy going to auction this week is the first "first edition" to reach auction this year, and is an early presentation copy of the first edition. It is described by Bonhams as "one of the finest presentation copies extant" and is "uncut and partially unopened." It is inscribed by a publisher's clerk as: "Professor Caspary / Koenigsberg / from the author."

The highest price ever fetched by this book was a copy of the third edition, which had Darwin's hand-written revisions in the margins. As the 23 known presentation copies are all devoid of any inscriptions by Darwin's own hand, the third edition copy sold for $1,054,100 (£788,75) at a Christie's auction on December 13, 2017.

UPDATE, June 14, 2019: "On the Origin of Species by Means of Natural Selection" fetched a record US$500,075

View gallery - 8 images