Natural History Museum’s skulls and skeletons help researchers and customs officers

The old bones and hides illustrate the ancient territories and genetics of different species. This year many of the Museum’s skulls have been given a new shine – and some of them have been re-identified as different species.

Biologist Henry Pihlström and Senior Museum Technician Janne Granroth are standing on the ground floor of the Museum of Natural History next to a crocodile skeleton and whale vertebrae when their colleague apologises for interrupting our bone tour.

 “Do we have a porosus?”

What they want to know is whether the collections feature a saltwater crocodile, Crocodylus porosus, which they don’t. This despite the fact that the pest-proof, temperature- and humidity-controlled collection facilities have thousands upon thousands of specimens in addition to the objects on view in the exhibitions.

The beast looming in the nearby case is a marsh crocodile, Crocodylus palustris, and thus not what is needed.

The Museum can offer help to officials – perhaps most typically to customs, which monitors the international trade in animals both living and dead.

However, most of the people interested in the Museum’s bone and skin collection are researchers. Old specimens are the best – and sometimes the only – pathway to the past for researchers studying changes in the geographical distribution or genetics of animals.

These treasures from the vaults were restored in a major effort last summer, and information on the restauration has spread quickly. Inquiries have started pouring in. The specimens were also reclassified using contemporary criteria. This is of vital importance for research.

 “This work will never end,” says Granroth, meaning both the vast volume of specimens in the collection facilities and the constant specification of the taxonomy of animal species.


As new information about the genetic connections between species is unearthed, groups of animals formerly thought of as a single species are often reassigned into several different species. There are also many misunderstandings relating to the development of the species.

 “We started work with the oldest exotic specimens, which were most likely to be in need of updated identification,” says Pihlström, and reaches into a storage shelf, picking up a yellowed skull in a plastic bag tied with string.

 “The curling tusks of the babirusa can grow so long that they might even puncture the head of the animal itself!”

The label has writing in faded ink on it, written in outdated cursive.

 “This is typical, the label just says it’s from the island of Sulawesi, but no specifics. We now know that north and south Sulawesi have different varieties, and being aware of this distinction, we found out that our collections featured specimens from at least two different species. These little grooves in the skull are one of the identifying factors.”

Similarly, our understanding of the golden jackal has changed, and the Museum has reidentified some of its jackal specimens. It was previously thought that Africa and Eurasia had a single species of golden jackal, Canis aureus. But recently, the African variety was found to be a wolf, and a new canine species was discovered, a new wolf, for the first time in 150 years.

The Museum’s Finnish wolf specimens have also been in high demand as research questions about hunting and protecting this endangered species have turned into political issues.


Pihlström and Granroth used classic tools to go through the collection, with a measuring tape as their primary instrument. They took only a handful of DNA samples. A trained eye, combined with a library of literature about species identification accumulated by the scientific community over centuries, has taken them far.

The most important step of bone restoration is degreasing. Grease makes the specimen yellow and can erode it. Without it, the specimens are more durable. However, research specimens are not completely degreased to be as white as bones in the exhibition, as the natural yellowish tint helps researchers see the contours of the bone.

All it takes is a measuring tape and a trained pair of eyes.

Just in case, a small piece is retained of the skulls and bones before they undergo the degreasing operation. That piece is not processed, Granroth explains.

 “If we need to do DNA research in the future, we may be able to extract a better sample from an untreated bone.”

Let the beetles eat cartilage

The bones of a Namibian pangolin – an ant-eating, long-tongued creature, covered in scales – is slated for dermestid beetle treatment. The specimen was originally inexpertly cleaned, and there is dried cartilage or other tissue stuck to the side of the bone. While the beetles do not love this ancient food, they will gnaw the bones clean when no fresher nourishment is available. 

According to Granroth, the beetles in the Museum are of a very specific American variety, and they will treat the brittle bone gently.

 “A whale or bison specimen would be too much for them, however, so we do have enzyme cleaning equipment as well. The modern enzyme cleaning process is like something from a horror movie: a carcass is lowered into the machine, and a clean skeleton is pulled out.”

The strange fates of the aquatic mammals

 “The whales were a major endeavour,” says Senior Museum Technician Janne Granroth of the effort to inventory and restore the bone collections of the Museum of Natural History: the whale samples had never been systematically catalogued until last summer.

But the surprises they found in the sea mammal section were delightful enough to compensate for the hard work. Granroth picks up the skull of a beluga whale from Arkhangelsk, complete with a yellowed label. There is little information in the few lines of text on the small piece of paper, but even these words manage to raise several questions. And not just about animals, ecology or biology in general.

The text states that the skull was discovered at the beginning of the previous century, buried 50 meters underground.

 “Why was it there?” Granroth muses.

 “Who was digging around there? Soldiers maybe, or was somebody planning to start a mine?”

Nevertheless, this skull has been moved from one collection facility to the next between 1916 and 2016, ending up in Arkadiankatu, in its own slot in one of dozens of movable shelving units. But we will soon find out more about its history.

 “A research group of the university is working on radio carbon dating the skull to confirm the age of the specimen,” Granroth says and promises to let us know once the results are public.

However, the bowhead whale vertebrae, brought back from the Svalbard mountains by pilot Pauli Saarenpää, have not languished in a basement, as they have been on full display in the Museum’s bone exhibition. Before finding their way to the Museum, the vertebrae had been in a private home, used as stools in a sitting room, topped with cosy crochet cushions, says Granroth.

The first guess was that the vertebrae belonged to a whale killed in the 1700th century, when whaling was at its most intense. e.

 “Cooperation with the Chronology Laboratory and lichen researchers revealed that the specimens are significantly older. Our colleagues from the Botany Unit told us that even though the lichen growing on the bones looked very small, they had to be extremely old based on their size.”

The lichen-based estimate was later confirmed through radio carbon dating, when it was revealed that the older whale lived and died in the 14th century, and the younger one in the 15th.

 “This means that they are both from the time before humans arrived at the Svalbard mountains.”


Gallen-Kallela’s squirrels and rhinos

Some of the bones, skeletons and skins in the Museum are irreplaceable, says Henry Pihlström, as they are from species that cannot currently be ethically acquired. For example, there are only a few dozen Javan rhinoceroses alive in the world today.

 “Hunting safaris for specimens have been out of the question for aeons. However, in past centuries it was completely possible for a gentleman to hunt for game such as the rhinoceros. That’s why we have several specimens of the endangered black rhinoceros.”

Pihlström points to a skull that looks nothing like a rhinoceros to the casual observer.

 “That’s because the horn is not actually bone.”

The animal was shot by Akseli Gallen-Kallela in Africa, as was the plains zebra whose hide is peeking from the shelf of the skin collection. Gallen-Kallela, Finland’s national painter, is one of the big game hunters to have donated the most specimens to the Museum. However, he was also unusually interested in smaller, less magnificent species.

 “We also have squirrels shot by Gallen-Kallela’s expedition in the collections. He was just interested in science.”


The taxidermied animals donated by Gallen-Kallela are of the highest technical quality among the historical specimens, believes Granroth.

 “He must have given meticulous instructions to the taxidermist, and sketched the animal in natural poses for reference.”

Some of Gallen-Kallela’s donations were taxidermied by artist and museum conservator Jussi Mäntynen.

 “Mäntynen also had a fantastic touch in taxidermy. His works are comparable with our finest contemporary specimens.”

Big game hunters were valuable donors for the Museum, in the sense that they would carefully document their hunting experiences.

 “In some cases, it’s possible to reconstruct each day of a hunting expedition that took place centuries ago.”

Sometimes the hunters were even a little too precise with their documentation.

 “When a text from a hundred years ago cites the name of a gorge in Kazakhstan, and the spelling may be a little creative, we have to spend quite some time flipping through atlases to find out the original location. And that may be what the identification of the species depends upon.”

At the moment, most of the Museum’s new exotic specimens come from Helsinki zoo, or from private individuals who want to get rid of the decorative antelope antlers or exotic pelts passed down through their family.



Video: Perttu Saksa

Manuscript: Virve Pohjanpalo

Reader: Arja Tuusvuori

This article was published in Finnish in the Y/5/17 issue of Yliopisto magazine.

Evert Bonsdorff’s legacy

Last summer, a six-person workgroup restored the Natural History Museum’s vertebrate collection named after its founder, Evert Julius Bonsdorff, a professor of anatomy who completed a doctorate in medicine in 1840. The professor did not go on safaris or travel the world for specimens, but accrued his collection by buying, trading and otherwise acquiring bones while in Helsinki. The quality and quantity of the specimens – approximately 2,000 in total – mean that the collection also had international significance.

The full collections of the University’s Natural History Museum feature vastly more zoological specimens. The insect specimens in particular bring the total number of items to around ten million.

When the bone collection was being restored, new labels were printed with the names of the researchers who conducted the repairs and identifications to certify that the information is correct and to make it easier to verify. The finest samples from the Bonsdorff collection are featured in the Story of Bones exhibition on the Museum’s ground floor.