The La Plata Museum is one of the most important museums in Latin America hosting innumerable specimens of both extant and fossil organisms. Within it, scientific activities are developed both for research and for the preparation of materials (taxidermy, assembly, tracing, preparation and cleaning of fossils, maintenance of collections, just to mention a few). The museum is located in La Plata city, capital city of Buenos Aires province. The building is surrounded by Ginkgo biloba, eucalyptus, and araucaria trees, and located in front of the zoo and the observatory of the Faculty of Astronomy.
Within the museum, the different scientific activities are distributed into divisions according to their study object and the collections preserved. They range over a wide thematic scope, including several anthropological and natural science disciplines, such as archaeology, geology, zoology, etc. One of the divisions is the Division of Vertebrate Paleontology, which is a legacy of the dedication and work of Rosendo Pascual. This division consists of more than forty people working in all the vertebrate taxonomic groups, including researchers, PhD students, technicians, and enthusiastic collaborators. The diverse staff, along with a wide collection of fossil vertebrates that include more than 5000 specimens and historical holotypes, make this division one of the largest paleontology workgroups in the world. Recently, a project directed by the chief of the division, Eduardo P. Tonni, has allowed us to build a 3D scanning and printing laboratory for the division with the aim of progressively digitizing the collection.
The laboratory was created for the 3D digitization of fossil specimens from the collection, as well as the printing of high-quality 3D replicas. It operates under the project “Three-dimensional studies in fossil vertebrates“, financed by the PICT-E 2014, and with the collaboration of the National University of La Plata and the Faculty of Natural Sciences and Museum of La Plata.
For the digitization of materials, the laboratory has two NextEngine HD scanners that use laser triangulation with an accuracy of 100 microns in Macro mode and 300 microns in Wide mode. These scanners have several interesting features, such as being portable, not having a maximum scan size (large scans can be done in parts and then joined), and offering very complete and user-friendly assembly and post-processing of the scans.
Also for the digitization of the pieces, we use a Roland LPX-600 scanner. It is a three-dimensional scanner that uses a laser method to explore solid objects; it has a resolution of 0.2 to 254mm (width) and 0.2 to 406mm (height) and an approximate precision of 0.05 mm. One of the most interesting details presented by the Roland is a robotic arm, fully programmable, with a “Pre-scan” function that allows you to significantly optimize the scan time.
Among the most important objectives of the fossil digitization project is to create a virtual repository of the collection and thus safeguard the most fragile objects.
The digitization of fossil materials allows for the processing of morphometric data used in different lines of research, including systematic-evolutionary, paleobiological, and anatomical studies, among others.
So far, the lab has recorded 3D images of bone elements of Serïot (Capello) and three Selk’nam individuals who were then repatriated to the original “Rafaela Ishton” community of Tierra del Fuego (4/19/2016), as well as other individuals repatriated to the Cacique Pincén Mapuche Tehuelche Indigenous Community of Trenque Lauquen (8/10/2016).
Another of the activities carried out in the 3D laboratory is what is called “retro-deformation,” which is achieved once the scanning of a piece is complete. Retro-deformation is essentially deforming a piece to resemble its original, pre-depositional state. This process allows researchers to have a more precise idea of the material being studied.
In cases where we do not have all or a portion of the specimen available, our lab is able to recreate it through digital sculpture using anatomical descriptions and photographs from scientific papers or direct observation of analogous specimens.
The second step is the digital modeling, which is done with software that allows you to sculpt organically and easily. The program allows us to place the images that were collected in the previous step in the background. So far, numerous sculpted models have been made, many of which are on display in some of the rooms of the Museum of La Plata. Paleo-sculpts have also been made available in a didactic application, which allows students to have access to materials that are very complicated to display, either because of the maintenance they require (preservation in formalin, for example) or because they are difficult to access. An example is the following patterned crocodile brain model, which is currently used to teach classes in the cathedra of Comparative Anatomy.
On Sketchfab you can find us and see the large number of scans and models that we have created!!
The laboratory has a Stratasys objet30 Pro printer, which features POLYJET technology. This is the ideal complement to the digitization that is carried out in the laboratory, and allows us to materialize all our work. Polyjet technology works basically like a home ink printer, except that instead of expelling ink, a plastic polymer is ejected. At the same time, the printer has two print heads that allow the printing of different materials at the same time—typically the support material is in one head and the material itself is in the other. This system of heads, combined with the thin layer of plastic ejected per layer (one hundred layers in a millimeter), generates highly precise pieces with a ceramic finish.
Numerous prints have been made of unique items in the collection; these replicas have been shown to researchers who have noticed an absence of significant morphological differences between the original and the replica.
The contribution that this type of technology makes to the scientific field is interesting. For example, through the 3D digitization-printing system, a scientist may be examining an object somewhere in the world while another scientist may be looking at a printed replica of exactly the same specimen in another part of the world. It is for this reason that more and more researchers are adding links in their publications where models can be viewed and downloaded.
The laboratory works jointly with an extension group called “Caminando con Glyptodontes y tigres dientes de sable”(Walking with glyptodonts and saber-toothed tigers) that conducts numerous workshops, talking about paleontology to students and professors who would not normally have access to the field, and recreating models of the fossil megafauna, as well as models specially designed for people with reduced visual abilities. In this way, the students have direct contact with the statuettes.
Finally, it is worth noting the important role that Sketchfab plays for both the laboratory and the museum. It is a simple, direct, and serious way in which scanned and modeled objects can be published. It also allows us to exchange information with other world-class institutions. One of the goals of the laboratory is for Sketchfab to serve as the digital platform where the work carried out within the Division of Vertebrate Paleontology and the museum can be displayed and shared. In this way, people anywhere in the world can see what is being accomplished in the division.