In 2014, Professor Adrian Lister began research for his book on the fossils collected by Charles Darwin on the Voyage of the Beagle. As part of his research, Professor Lister began to document the complex histories of these specimens from their point of collection to the present day. It soon became clear that the mammalian specimens had not been adequately documented or revised in the 185 years since their initial publication. This has meant that they have not been included in most modern scientific studies. This is despite the fact that the majority of the specimens in this collection are ‘type’ specimens (the reference specimens for that species), essential for scientific study of these species.
In 1831, Charles Darwin boarded the HMS Beagle, under the command of Captain Robert FitzRoy for a five year round-the-world voyage. Employed as the ship’s naturalist, Darwin kept detailed notebooks of his scientific observations and collected thousands of plants, animals, rocks and fossils during the journey, including the fossil mammals we hold in the collection.
Having survived a World War II bomb in 1941, the remaining fossil mammals collected by Darwin between 1832 and 1834 now include approximately 100 bones and fragments (from around 20 individuals). All of these specimens were collected from South America and are between 10,000 and 500,000 years old. Seven different species are represented in the collection, including four different species of ground sloth, two species of hoofed mammal and the remains of an extinct type of horse. These specimens were extremely influential on Charles Darwin’s developing theories (including that of Natural Selection).
The Toxodon, perhaps one of the strangest animals ever discovered…
Whilst staying with an Englishman named George Keen in Uruguay, Darwin heard about a peculiar skull which had been found washed out of a nearby riverbank and had been used by local children at a neighbouring farm as a game. They had propped the skull up against a post and had been using stones to knock the teeth out!
On the 26th November 1833, Darwin visited the farmhouse to see this skull. Although partially weathered and lacking almost all of its teeth, he recognised it as something immediately interesting. Having paid 18 pence for the specimen, he had it shipped onto England. The skull became the type of not only a new genus and species but was another indicator of the amazing array of prehistoric beasts to be found in South America. Toxodon platensis is now known to be a member of an extremely diverse group of extinct South American animals called notoungulates. The bizarre combination of features shown by Toxodon platensis puzzled both Richard Owen and Charles Darwin, who noted resemblances to a wide range of living animals.
The Toxodon, perhaps one of the strangest animals, ever discovered: in size it equalled an elephant or megatherium [an extinct giant ground sloth], but the structure of its teeth, as Mr. Owen states, proves indisputably that it was intimately related to the Gnawers [rodents], the order which, at the present day, includes most of the smallest quadrupeds: in many details it is allied to the Pachydermata [an obsolete term referring to animals with thick skins such as elephants, rhinoceroses, and hippopotamuses]: judging from the position of its eyes, ears and nostrils, it was probably aquatic, like the Dugong and Manatee, to which it is also allied. How wonderfully are the different Orders, at the present time so well separated, blended together in different points of the structure of the Toxodon!
The Museum has received funding from the Hartnett Conversation Trust and the Leche Trust to start a pilot project to fully document and 3D surface scan all of the existing Toxodon specimens collected by Charles Darwin (including the type skull). This project seeks to further the reach of these scientific and historically important objects while reducing risk to the specimens themselves.
To achieve this we will produce digital surrogates of these specimens for scientific research, education and public engagement purposes and use the scans to inform conservation of the specimens. We are also using this pilot to understand the challenges and opportunities that 3D surface scanning can bring to collections like these. This will enable us to apply and adapt the technique to the rest of the specimens within the Darwin Fossil Mammal collection, and to the Museum’s collections more widely. This technology will allow us to digitally reconstruct specimens that have been broken or damaged so that new generations of scientists can continue to learn from the specimens that inspired Charles Darwin.
These specimens are extremely delicate and in some cases they are broken into several pieces. These unique and valuable specimens need to be supervised both by Fossil Mammal expert Dr Pip Brewer and by our 3D scanning expert Kate Burton during all scans.
To image these specimens we use mobile handheld laser scanners to capture the profile of the surface, including any cracks, peaks, troughs and texture. 3D laser scanning lends itself well to large, static structures like fossils. Using the 3D models we are producing an entirely new resource for researchers and Darwin enthusiasts.
We will be releasing this data freely and openly to researchers around the world via the Museum Data Portal. Museum visitors, schools and our wider digital audience are able to interact directly with the 3D models that we publish on sketchfab.com.
For the next phase of the project we are hoping to raise money to scan and document the remaining fossil mammal specimens collected by Darwin on the Voyage of the Beagle. In the meantime, Professor Lister and Dr Pip Brewer are working to unravel the complexities of the specimen histories to be presented as a scientific paper.
We would love to hear about any ideas you have about what you would like to see. Get in touch with @NHM_Digitise on twitter to tell us how you would like to experience this collection. We hope that the 3D models will allow more access, provide new learning opportunities and bring these specimens into the 21st century, whilst helping us care for the collection and safeguard its future.