Monday, August 24, 2015

A tale of two skulls

In early December 1695, a group of workmen were excavating some fine white sand from a quarry between the villages of Burgtonna and Gräfentonna, in Thuringia. The sand was valuable in a number of crafts, including filling hourglasses, so the workers were careful in their excavations. You probably know what happened next. They uncovered “some awful big bones” and sent word to the castle to find out what to do with them. Luckily for us, the lord of the land, Duke Fredrick II of Saxe-Gotha-Altenburg, was an enlightened despot who was both a patron of the arts and sciences and an avid collector. More than simply ordering the workmen to save the bones for his collections, he had them leave the bones in place and slowly uncover them. This modern style excavation would be an under-appreciated milestone in the development of paleontology.

What the diggers discovered that day were a pair of feet and lower legs pointing northward. The feet had five toes and short ankle bones. The spectators thought they looked more like human feet than any animal they knew. At that point, the weather turned nasty and the excavation was halted until after the new year. In January, the work resumed. Over a period of about two weeks, they uncovered the upper legs, pelvis, a complete vertebral column with ribs, the upper limbs with five digit hands or feet, and... a “hideous head” unlike anything anyone had ever seen. To one side of the top of the skull were two enormous, curved pieces of what appeared to be ivory. With the entire skeleton nicely uncovered, the Duke made a special trip from Gotha on January 23 to view it, bringing along a large retinue that included a number of doctors from the university and his personal librarian.

The doctors, led by Johann Christoph Schnetter, and the librarian, Wilhelm Ernst Tentzel, all had a good laugh over the silly peasants who had thought the bones were those of a giant. Although that would have been preferred explanation of many educated men earlier in the century, very few still believed that there had ever been giants other than the few individuals named in the Bible. While the doctors and Tentzel agreed on what the bones were not, they passionately disagreed about what they were. Schnetter and the doctors believed they were the natural formations that merely looked like bones while Tentzel believed that they were the remains of a real elephant. Duke Fredrick chose not to take sides. He ordered the doctors and Tentzel to each submit a brief summarizing their arguments.

Today, most people would look at the bones and say "any idiot can see that those are fossils of some kind of elephant." Most would probably pick a mammoth for that type of elephant. But, in the Seventeenth Century, idiots and educated alike had only the vaguest idea what an elephant looked like and even less idea what its skeleton looked like. The educated were aware that the lack of data for comparative anatomy was a problem, but there was nothing they could do about it. There weren't enough elephants to go around.

Between the end of the Roman Empire and the beginning of the Renaissance, we have records of exactly two elephants appearing in European Christendom. One belonged to Charlemagne and the other to Henry III of England. This began to change during the Sixteenth Century. After the Portuguese reached India by going around Africa, they began bringing back elephants that various Indian kings sent as gifts to their king. Manuel I sent one of those elephants named Hanno to Pope Leo X. The elephant died soon after. When Leo died he was buried with his elephant. The Portuguese kings sent least four others to their fellow monarchs during that century. In the Seventeenth Century, elephants were still rare, but the owners began sending them on tours, both to show off their wealth and to educate the population. Two elephants in particular influenced the debate between the doctors and Tentzel.

The first was named Hansken. After the Dutch East India Company beat the Portuguese out of the India trade, one of their agents acquired a young female elephant in Ceylon in 1637. Once in Europe, her owners taught her some tricks and and sent her on a tour of the continent where she performed before audiences in an approximation of modern circus acts. After eighteen years on the road, she injured her foot in Italy, developed an infection, and died in Florence on November 9, 1655. A special mass was written for her. Grand Duke Ferdinando II was obsessed with the new sciences and had most of the good parts of Hansken removed before burying her. He had the skeleton mounted as accurately as possible and had her skin stuffed with straw for his collection.

Hansken, by Rembrandt. The British Museum.

There is no name recorded for the second elephant. In June of 1681, a showman named Wilkins brought an elephant to Dublin, Ireland and set up a booth near the Custom House to show it. Early on the morning of Friday the seventeenth, the booth caught fire and the poor creature was killed before Wilkins could bring it to safety. Wilkins realized there was still money to be made from his elephant if he could salvage the skeleton and continue his tour displaying it. He arranged for a troop of musketeers to be sent over to guard the corpse from souvenir seekers while he set out to hire as many butchers as he could to clean the bones before the smell became a public nuisance.

Late in the day, a doctor named Alan Mullen heard about the elephant and rushed over to negotiate with Wilkins. Mullen wanted to have an orderly dissection with artists ready to make renderings of each part. Wilkins was willing to let Mullen direct the work of the butchers, but insisted they finish it in one day and dispose of the smelly parts before Sunday when they would not be allowed to work. Mullen ordered the butchers to start working immediately. They worked through the night and through Saturday, completing the work before the Sunday deadline.

Mullen wrote up descriptions and measurements of the elephant’s parts and sent an account to Will Petty of the Royal Philosophical Society in London. His examination was far superior to anything that been published in Europe (in India, veterinary treatises on elephants had been available for centuries). Petty had Mullen’s letter published as a pamphlet. In the forty-two pages Mullen describes all of the major organs and some of the muscle groups, but gives surprising little space to the bones. This lack is made for by a trifold diagram of the reconstructed skeleton, which Wilkins had managed to assemble and take back on the road, and a separate drawing of the skull.

Mr. Wilkins' elephant. Falvey Memorial Library.

The Gotha doctors' belief that the bones were natural mineral occurrences and not organic remains was a peculiarly European idea. In most of the rest of the world, people had very little problem believing that unfamiliar old bones, even petrified and damaged ones, were organic remains. Renaissance Europeans had a tradition, derived from Neoplatonic philosophy, of a certain "power" in nature that allowed spontaneous generation. Things might grow based on no visible cause. Flies grow from poop, small pebbles appear in peoples' kidneys, Scottish geese grow out of driftwood, and, as even we moderns know, a crop of rocks grows in our gardens every winter. Another tradition, derived from a number of philosophic sources, held that certain other "powers" could give shape to growing things. This is why a piece of agate might have a landscape in it, another might have an image of the Virgin Mother in it, and other stones might be shaped like bones.

The doctors organized their arguments, Schnetter wrote them up, and they had them published and distributed to great thinkers around Europe by St. Valentine's day. The entire pamphlet is seven pages long and a sizable chunk of it is dedicated to describing the discovery. They spend very little space laying out the argument itself. They assume that most of their audience is already familiar with the basic elements of it. The largest part of the pamphlet is dedicated to citing contemporary thinkers who might agree with them. Between these two parts, they make a preemptive strike against Tentzel by explaining why the supposed bones could not be an elephant. One point is that, while the bones are not scattered, they are somewhat disarticulated. Each bone is separated from the next by at least the thickness of a hand. A second point is that the tusks appear to be hollow, not solid ivory. What appears to be the most damning point is that the skull looks nothing like an elephant. Why are the tusks up by the eyes and not by the mouth where everyone knows they should be?

Tentzel wrote a short response, which he submitted directly to the Duke (it still exists in the Gotha archives, but I haven't seen it). He took more time writing a full statement of his case and, by taking more time, was able to prepare a full rebuttal to the doctor's argument. He had a special advantage in preparing his case. As curator of the Duke' collections, he had access to fossils and other curiosities that he could compare with the bones. He had the bones themselves; the Duke had had him collect as many of the remains as he could. By taking more time he was able to interview the diggers and other witnesses to excavation. And he had Mullen's pamphlet with its detailed drawings of the skeleton and skull.

Tentzel's public presentation appeared in the April issue of a journal that he wrote every month called Monatliche Unterredungen einiger guten Freunde von Allerhand Büchern (Monthly Conversations between Good Friends about All Kinds of Books). It runs 108 pages with an illustration of the skull. After a detailed description of the discovery, the fictional friends of the title take sides. Caecilius and Passagirer take Tentzel's position and Aurelius and Didius defend the doctors”. Naturally, most of the space is given to the former.

Mullen's pamphlet is liberally quoted to show that the Tonna bones have the same proportions as the Dublin ones. Tentzel admits that there is a problem here; his elephant is twice as big as the Dublin one. He has an answer to that problem. Among the observers he interviewed was a Dutch sailor who had spent many years in India. The sailor informed him that elephants keep growing. By the size of the tusks, he estimated that the Tonna elephant must have been at least 200 years old. Caecilius and Passagirer describe many other recent discoveries of large bones and ivory described by reputable witnesses. When Aurelius and Didius get their turn, to Tentzel's credit, they give an accurate summary of the doctor's position rather than a parody of it. They still lose the debate.

Along with his summary of Mullen's pamphlet, Tentzel mentions Hansken and says he is writing to some illustrious colleagues in Italy to get accurate measurements of it. In July, he published a long letter in Latin to Antonio Magliabechi, the personal librarian to Cardinal Leopoldo de Medici, the brother of Grand Duke Ferdinando. Magliabechi was one of the major figures of the Republic of Letters during that generation and widely renowned for his disgusting personal hygiene. In his letter, Tentzel repeated most what he had written in Monatliche Unterredungen, leaving out the literary floutishes and defense of the doctors' position. Magliabechi and his Italian peers enthusiastically endorsed Tentzel's conclusions and sent the detailed information he requested. Italian scholars, as opposed to those north of the Alps, had no trouble accepting the presence of elephants on their lands. First, there were the war elephants of Pyrrus and Hannibal. Later, there were the many elephants brought by the Romans to be slaughtered in the circuses for entertainment. Magliabechi and several others wrote their own pamphlets and letters to journals.

As Northwestern Europeans began to accept the presence of elephants on their lands, the discoveries of Italian scholars were frequently cited to make the idea easier to accept. However, in the long run this delayed the acceptance of the idea of other, extinct, elephant-like species. Tentzel had his own cautious approach to the responses of his Italian correspondents. He was glad to have their endorsement for his conclusion that the remains were elephantine in nature. However, he distanced himself from the idea that the remains came from historical times. In his Monatliche Unterredungen, piece, he had Caecilius and Passagirer carefully go over various historical arguments and reject them. This could not be Charlemagne's elephant because it died in Northern Germany. This could not have been an elephant of Attila's because he moved to fast to have used elephants. It could not have belonged to some unknown merchant or returning crusader because no one would have abandoned something as valuable as the tusks. The very location of the tusks argued against human agency. Tentzel pointed out that the clear layering of strata above the remains showed that the ground had never been disrupted by human action.

Tentzel's arguments appear quite modern up to this point. His conclusion will appear less so to most contemporary readers. Tentzel was quite firm in arguing that the position of the remains was proof of the Noachian Deluge. This was a special interest of his ans a topic he regularly returned to in Monatliche Unterredungen. It's possible that his main interest in the boned was that he saw them as proof of the Deluge. To him, the northward orientation of the skeleton showed that it had drifted up from the south. The neat layering of the strata above it was the sort of deposition he expected from the receding flood waters.

Tentzel's argument that the bones were the actual organic remains of an elephant had an additional strength. As scientific communication moved from letters, however widely distributed, to printed journals, with much wider distribution, illustrations became much more important and accurate. Perhaps the most important parts of Mullen's pamphlet were the illustrations. Only a small number of living scholars had seen a live elephant and only a very tiny number had seen a skeleton. Tentzel took very conscious advantage of the importance of Mullen's skull illustration.

The skull of Mr. Wilkins' elephant. Falvey Memorial Library.

It took me a few looks to understand this illustration. Why do the tusks look so short compared to the profile? What's with that little hook at the end? I went back to my sources on elephant dentition (it's a surprisingly complex topic. Some day I'll write about it. I'm not sure how much the book needs). My first thought was that it was the tusk core, but that's soft tissue, not bone and, in any case, it doesn't have that hook at the end. Then it occurred to me, we're looking at the tusks from the tips. Most illustrations would tilt the skull to emphasize their length. Mullen already showed their length in the full skeleton profile. The tusks curve forward from the skull. A front-on view of the skull dramatically reduces the apparent length of the tusks.

Tentzel's illustration shows the same apparent shortness. By his own measurements, the tusks should be longer that the skull. To emphasize the similarity with Mullen's illustration, he portrayed his skull with the same orientation. It lacked the drama that tipping the skull forward and showing of the tusks would have had, but it strengthened his larger argument that the Tonna remains were those of an elephant.

The majority of scholars agreed with Tentzel about the remains being elephants though a significant minority sided with a doctors. A small minority still held out for giants. The great majority also agreed about the Deluge being the cause of their deposition, though a small number had begun to doubt the historical reality of a global flood. It would be another century before they became a narrow majority.

The Tonna elephant would be cited by proto-paleontologists for decades but their significance would evolve over time. At first they were nothing more than an argument for the organic nature of fossils. Later, as the debate over mammoths developed, they would become an argument for the idea that elephants had once lived far north of the tropics. Next, they would be cited as a mammoth, rather than an elephant.

The remains are probably gone now. If any parts are still in the Gotha collections, they are no longer identified as such. That doesn't mean we can't identify the species. In recent years, paleontologists have returned to the Tonna quarries and worked the layer of white sand. They have dated it to the late Eemian, the warmest period before the last ice age. The most common proboscidean in that strata is the straight-tusked elephant (Palaeoloxodon antiquus). This species was first identified in 1847. It had a fairly wide range across Europe. Some of them wandered into Sicily when the seas were low during the glacial maxima. There, constrained by the limited resources of an island, they underwent a process of dwarfing, eventually becoming Elephas mnaidriensis, the cyclops skeletons I wrote about a few weeks ago.

Tentzel only published Monatliche Unterredungen for one more year after his treatment of the Tonna remains. The following January, he wrote a shorter piece quoting the responses he had received from Italy. At the turn of the century, he moved on to a new job with King of Saxony and briefly published a new journal. During that time a second skeleton was found at Tonna and he and Schnetter went at it one more time, but neither added anything new to their arguments. The job with the King of Saxony didn't work out and Tentzel died in poverty. Despite his relevance during the next century, he has largely been relegated to footnote status since. This appears to changing. He's had some attention lately for his role as a science communicator. I'm doing my best to see that he gets some attention for his science as well.


Gav said...

"a crop of rocks grows in our gardens every winter"

See for example Kimigayo " ... until the pebbles grow into boulders ... "

"elephant dentition ... I'm not sure how much the book needs"

Probably less than you might think.

John McKay said...

There was a long going debate over how many teeth an elephant has that continued into the 19th century, but there's no way to make that very interesting. Maybe a footnote.