Last year, St. Petersburg State University celebrated the 160th anniversary of its graduate, V.P. Amalitsky, a famous geologist and paleontologist. The scientist compared fossils from Russia, Africa, and India, and was the first to hypothesize that in the past, all the land on Earth was a single continent. Later this continent was named "Pangaea".

St. Petersburg State University has prepared an exhibition for the anniversary of the paleontologist. Among the exhibits, they decided to show plaster casts of the skulls of three lizards: scutosaurus, inostrancevii and dvinosaurus. These skulls were found by V.P. Amalitsky himself at the end of the 19th century, conducting excavations on the banks of the Malaya Severnaya Dvina River in the Arkhangelsk region.

Their replicas at the beginning of the 20th century were also performed by the professor himself. Therefore, now, after more than a hundred years, the copies are interesting not only from a scientific, but also from a historical point of view. But first the plaster skulls had to be restored. The scientists were faced with the task of carefully restoring the original appearance of the casts.

There was another problem. Massive casts look impressive, but it's inconvenient to work with them. We needed a way to digitize the artifacts — but without losing the slightest nuances of the shape and texture of the skulls. Therefore, the scientists chose a professional 3D scanner RangeVision Spectrum, accurate and convenient.

Restoration

Ekaterina Ageeva, a graduate of the Department of Restoration, was engaged in the restoration of plaster skulls. This project became her thesis. All three lizards in question lived in the Permian period, more than 250 million years ago.

Scutosaurs were slow-moving herbivores up to three meters long. Their skin was ossified in some places, hence the name (Latin scutum - "shield"). According to one version, they spent half their lives in the water — like hippos. They were the first of the fossil lizards to be found and exhibited in Russia in the form of an entire skeleton.

A cast of a scutosaurus skull after restoration. One of the zygomatic collars has been restored.

The alien was a large predator over three meters long. The huge canines of the aliens grew up to 30 cm in length and changed over the course of the animal's life. V.P. Amalitsky named the lizard Inostrancevia alexandri in honor of his scientific supervisor, geologist Alexander Inostrancev.

The foreigners were given back the broken bones of the nose. In order not to distort the shape, I had to request photographs of the original skull from the Orlov Paleontological Museum of the Russian Academy of Sciences in Moscow.

An impression of a foreigner's skull with reconstructed nasal bones. 

Dvinosaurus was also a predator, but much smaller. These amphibians, with a body length of up to one meter, spent their entire lives in the water. They breathed through external gills that stuck out to the sides. The spots with chipped paint on the dvinosaurus skull were tinted without disturbing the original texture.

A cast of a dvinosaurus skull. The chips on the surface are tinted without disturbing the texture.

3D scanning

After the restoration work, Dmitry Grigoriev, Associate professor of the Department of Vertebrate Zoology, removed exact three-dimensional copies from the exhibits using a RangeVision Spectrum 3D scanner. According to the scientist, virtual fossils make it possible to avoid using museum valuables in the educational process.

3D models are better suited for everyday research work, because they convey more information about an object. It is much easier to teach comparative animal anatomy using them, and especially valuable fossils and historically important casts lie quietly untouched in the museum's storage. 

Scientists and students of St. Petersburg State University will now be able to mark individual parts of the skeleton and examine them on any scale, as well as visually compare them or print them using a 3D printer. Working with a massive plaster figure on a metal frame is much harder in the full sense of the word.

This project shows how great the potential of 3D scanning is in the fields of science, education and museum business. A virtual copy of an object is much easier to study, it is clearer, more mobile and more accessible. At the same time, the originals do not suffer from wear and tear, but remain in complete safety for posterity.

The text is based on St. Petersburg State University publications.