Showing posts with label paleontology. Show all posts
Showing posts with label paleontology. Show all posts

Wednesday, March 19, 2014

The Vilui rhinoceros

Peter Simon Pallas arrived in Irkutsk an hour before midnight on March 14, 1772. He was accompanied by a painter and three naturalists. The horses, he writes, we tired. It was a week before the equinox but the rivers were still frozen and there was plenty of snow on the ground in that part of the world. This was a feature, not a bug, as far as travel in Siberia was concerned. When the temperatures rose, the whole country would become one endless, roadless, mosquito-filled bog. Since the beginning of the Russian state, the fastest way to travel its vast expanses had been by sleigh in the winter. He could have used those frozen rivers and snowy ground to continue deeper into Siberia but Irkutsk was his goal. He wrote that he knew the city held curiosities he had to see and stories he had to hear about the unknown land across Lake Baikal. Irkutsk did not disappoint. The governor had a rhinoceros to show him.

Pallas had arrived in Russian four years earlier at the invitation of Catherine the Great. He had been offered a teaching position at the Academy University, but that title was more a description of his pay grade and social status than a job description. He immediately set to work preparing for a five year expedition into the eastern provinces of Catherine's empire. Before leaving, he took time to look through the Academy's collections where he discovered a rhino skull that had been discovered near the Amur River on the Chinese-Siberian border. Numerous bones of rhinos along with hippos, elephants, and other tropical animals had been found in his native Germany and other parts of Europe. He wrote a paper describing this skull, tying it to the problem of the Siberian mammoth. Like most thinkers of his time, he was inclined to explain their presence in the north as a result of the Biblical flood washing the bones of tropical animals north. Pallas did not follow the usual method of scientific explorers, which was to collect samples and take notes and then analyze and write about them on their return. He sent several scientific papers back to the Academy and two volumes of a travel narrative while still on the road.

When Governor de Brill told him that he had preserved parts of an unknown large animal, Pallas' first thought was probably of a mammoth. Westerners knew of tales of bloody preserved mammoth carcasses as long as they had known about the mammoth. Earlier in the century there had even been a report by a reputable European. In addition, Pallas had seen dozens, possibly hundreds, of mammoth bones since leaving St. Petersburg. In his Travels, he wrote that there was hardly a river east of the Don that did not produce a few. He must have been both surprised and delighted when de Brill produced the head and feet of a rhino. During his four years on the road, Pallas had begun to doubt the wisdom of his having come to Russia. Captain Cook was the superstar of exploratory science. It seemed to Pallas that the South Seas was the real frontier. In Siberia, he lamented, one could go a hundred miles without discovering anything. A preserved rhino was something to get excited about.

Pallas was exceptionally lucky that almost everyone involved in bringing the mammoth to his attention had understood its importance. The rhino had been discovered by a group of Yakut (Sakha) hunters in December on the banks of the Vilui River, a tributary that fell into the Lena well above the Arctic Circle. The rhino was nearly complete when they found it, but enough of it was in a bad state of decay that decided to cut the feet and head from the carcass and leave the rest behind. In any case, even if they had wanted bring the whole body, breaking it loose from the frozen ground would have been almost impossible during the winter. The hunters took these parts to Ivan Argunov, the district magistrate who took a notarized statement detailing the location and position of the carcass and sent the parts and statement to the regional capital on Yakutsk in January. The authorities there kept one foot and sent the rest on to Irkutsk, where it arrived in late February, just three weeks before Pallas' arrival.

The head and feet were in excellent condition. Almost all of the skin was present and covered with hair. The delicate structure of the eyelids remained. Muscles and fat were preserved under the skin. Though the horns were missing, from the spots where they had been attached, he could tell it had been a two horned rhino. Of immediate concern was making sure it remained preserved in the best condition possible. It had already begun to give off a stench that he compared to "an ancient latrine." He chose to dry it in an oven. The melting fat falling in the fire caused the oven to get much hotter than he wanted and one of the feet was burned beyond any hope of saving. Naturally, the loss was blamed on an inattentive servant although I feel confident in say that no one in Irkutsk had any experience in drying rhinoceros parts so we should cut him some slack. Pallas took careful measurements of the head and feet and wrote a detailed article (in Latin) for the Academy. He would have liked to have spent more time studying it, but the Siberian Spring was coming and he wanted to get across Lake Baikal before the ice broke. 

The Vilui rhinoceros as it appeared with Pallas' description (source)

Pallas' paper was published in the Academy yearbook for 1772 and eagerly read by scholars all over Europe. When he returned in 1774 he was covered in honors and eagerly sought out by other scientists. Moving to Russia turned not to have been a bad choice after all. he stayed in Russia for the rest of his working life. His rhino did not disappear into the Academy collections never to be seen again. During the Nineteenth Century, other scientists continued to study it. Its blood was examined, the remains of its last meal were picked out of its teeth, and, in 1849, Johann Friedrich von Brandt, the head of the zoology division at the Academy wrote a book length anatomical study of the remains. As an introduction to his study, Brandt went over the documents relating to the discovery.

In his rush to leave Irkutsk, Pallas regretted not having had time to make drawings of the remains. The Academy made up for this lack by having an artist prepare a detailed set of drawings of the head in profile and the remaining foot from the front and side. When Brandt made his study, he had an artist make new drawings, though not as detailed, of the head from all angles. By Brandt's time, enough other remains, especially horns had been made that they were beginning to be able reconstruct the Siberian rhino and see how different it was from living rhinos. One detail that particularly stood out was how unusual the horns were. Instead of being essentially conical, like those of living rhinos, The horns they were finding in Siberia were flat as a knife blade and ridiculously long, sometimes three or even four feet. Brandt had his artist match the skull up with one of the horns in their collection to give readers an idea of the horn's magnitude.

The Vilui rhinoceros as it appeared with Brandt's description. Because color printing was still rare, the illustration was most likely had colored. In either case, the use of color demonstrates the importance the Academy placed on the study. (source)

Like many extinct animals, the name of Siberian rhino has gone through many permutations over the years, from Rhinocerotis antiquitatis to Gryphus antiquitatus to Rhinocerotis tichorhini to its current name Coelodonta antiquitatis. It's commonly called the woolly rhino and is one of the best known ice age animals after the mammoth and sabre toothed tiger. Pallas never did have his name attached to it. It's curious that he didn't give it a name. At the time, he was working on his own naming system to fix the weaknesses that he saw in the Linnaean system. As it was, the naming credit has gone to Johann Friedrich Blumenbach who, coincidentally, also named the mammoth. Pallas needn't feel slighted; he named and has had named after him a number of other species.

Thursday, March 13, 2014

Monsieur Paquet's giant bone

Business must have been going well in 1779 for Monsieur Paquet, a Paris wine merchant. At least, that's what we can infer from his decision to expand his cellars that year. After removing part of the wall, He began digging into the yellow soil of mixed sand and clay. Two feet in, he discovered something very large and hard that was not a rock. At first, he thought he had run into a tree trunk, but, after clearing away more soil, he discovered that it was the biggest bone he, or anyone he knew, had ever seen. Paquet vanished from history soon after that, but the created a mini controversy and the last hurrah of the idea that mammoths were not elephantine in nature.

Paquet knew he had something valuable. He spent eight days trying to excavate it, but, with the soft walls collapsing, he finally had to give up. Using a sledge hammer and iron wedges, he broke off what he could see of the bone and built a wall over the rest. Even without the part still buried and other pieces chipped off, the bone weighted over 200 pounds. Several doctors came to view his bone and all agreed that it was one half of a giant pelvis. However, one learned visitor disagreed.

The exception was Robert de Paul de Lamanon, a promising new light on the French intellectual scene. As young men, Robert and his older brother, Pierre-Auguste, developed a habit of walking, rather than riding, wherever they went. This gave them the opportunity to examine all aspects of the countryside from agriculture to the living conditions of the peasantry to the geological structure of the land. After his father died, Robert dropped out of the seminary—as a student of Locke, Hobbs, and Rousseau he had no interest in religion—and set out with his brother to study the mountains of Switzerland. He estimated that they walked 1800 miles through the Alps that year. Based on his close-up observations of mountain valleys and the gravel deposits below the mountains, he developed a theory that the primary force shaping the earth was water—not the waters of the Biblical deluge, but rivers and periodic eruptions from enormous primal lakes in the mountains. This was the Lamanon who arrived in Paris and heard about Paquet's giant bone.

After rather roughly wresting it from the ground, Paquet kept the bone in the hopes of selling it for the sizable amount of 800 livres (at the time, Lamanon was living on a budget of 600 livres per year from his father's estate). Despite his high hopes for selling the bone, Paquet was willing to let Lamanon spend several days examining it. Lamanon hired an artist named Martin to help him and the two used their time to take measurements, make drawings, and even construct clay models of the bone. Based on his examination, Lamanon argued that it couldn't possibly be a pelvis. He pointed out that several structures were missing, most importantly, the acetabulum, the socket that meets the ball at the top of the femur to form the hip joint. To his eye, it looked like the lower part of a skull. Building on that observation, he stated that the bone bore no resemblance to the skull of an elephant or hippo or any other known terrestrial animal, which was true enough. Therefore, he concluded, it must have belonged to a whale. He admitted that the only whale skull he had seen was the damaged skull of a young whale left behind by a showman as he skipped town ahead of his creditors.

Monsieur Martin's drawing of the bone (source)

It was no coincidence that Lamanon specifically called out elephants and hippos for comparison. Besides being the largest of terrestrial animals, they had both been suggested as identities for other giant bones found around the Northern Hemisphere. In Asia and Europe, the bones were called mammoth and assigned to elephants. In the Ohio country of North America, mastodon bones, then as yet unnamed, showed features common to both elephants and hippos. Lamanon used his analysis of Paquet's bone to question those identifications. The mere resemblance of certain bones, he wrote, specifically referring to tusks and teeth, does not necessarily mean they come from the same animal. The teeth of a horse resemble those of donkey and the teeth of a cat those of a dog. Mammoth teeth resemble those of an elephant, but those of the mastodon do not. Couldn't this mean that mammoth, mastodon, and elephant are three completely different animals, or that mammoth and mastodon finds were not the remains of single animals but the co-mingled bones of several different animals, some elephant-like and some not? This was the position of the great Louis Jean-Marie Daubenton regarding the unknown animal of the Ohio. As for the Siberian mammoth, he pointed out that, even though the offer of a substantial reward for a complete skeleton had been in effect since the time of Peter the Great, no one had yet been able to produce one.

That Paquet's bone might have come from a whale was the starting point in the argument Lamanon wanted to make. His next point was the idea that other large bones were not necessarily those of known terrestrial animals. Having set his argument up, Lamanon moved on to his objective: using Paquet's bone to support his geological theories. The primal lakes that Lamanon envisioned shaping the geology of the north were really inland seas and their draining was a series of explosive, catastrophic events. He argued that whale bones in places like the Paris basin didn't come up from the ocean; they came down from the mountains. Mixed bones, such as those that Daubenton believed the Ohio animal to be made of, Lamanon saw as evidence of the violence of the lakes' draining. Even if the bones included those of elephants or hippos, these were animals living downstream, swept up, and deposited far north of their native habitats.

Most naturalists believed that the mammoth was an elephant and the mastodon was something similar, but there was still enough room for doubt that Lamanon's argument that they were not wasn't scandalous. What did scandalize some was the fact that he directly challenged Georges-Louis Leclerc, the Comte du Buffon and intendant of the royal museum (Jardin du Roi). Buffon was without question the most influential man in French science. Buffon's theory of the earth was that it had started out as a molten sphere and cooled first at the poles and that the habitable part of the world had expanded from there. He further claimed that only hot climates were hospitable for large animals. By this, he explained giant bones, such as the mammoth's, were relics of a time when the climate of the North was tropical. His theory of the relationship between temperature and size so annoyed Thomas Jefferson that he dedicated a large part of a chapter of his Notes on the State of Virginia to refuting it. Lamanon refuted Buffon by pointing out that there were plenty of large animals in the North such as moose, but especially fish and whales.

A childhood friend of his later wrote that "a thousand voices were against him, he was assailed on all sides, the newspapers rang with accusations of arrogance, audacity, boldness, ignorance itself.” One such outrages person was one Baudon, who published a nitpicking response to Lamanon five months after his paper came out. Boudon upbraided Lamanon for having the temerity to contradict his betters. He followed this by assuring his readers that his only motive was his love of truth and not currying favor for his forthcoming book. August was embarrassed enough by his brother that he wrote a letter of apology to Buffon on his behalf.

Neither Buffon himself nor his protege Daubenton seemed particularly offended. Buffon was happy to take advantage of Lamanon's geological observations in his later works. Daubenton's curiosity was sufficiently aroused to make a trip to Paquet's wine cellar to examine the bone and convince the merchant to dig out the rest of the bone. Daubenton was the perfect man to settle what kind of bone it was. Forty years earlier, he had been chosen by Buffon to catalog the zoological collections at the Jardin du Roi. In that capacity, he had handled and measured the bones of hundreds of animals, both living and fossil. Later he had helped Buffon write his encyclopedic Histoire naturelle, générale et particulière by contributing anatomical essays on 182 species of quadrupeds. He was easily the most knowledgeable comparative anatomist in Europe. Daubenton took one of Lamanon's clay models and compared it to the bones in the royal collection. The closest match he found confirmed what Lamanon's observations. In a short paper read before the Academy, he set out his reasons for believing the bone was part of the sphenoid process, a lower part of the skull, of an especially large whale.

Daubenton was accompanied on his visit to Paquet's by the chemist Berniard. Lamanon asked Berniard if it was possible to determine, by chemical analysis, whether a bone came from a land animal or from a sea animal. Berniard admitted he didn't know. Since none of the three of them had heard of such an experiment. They secured a piece of Paquet's bone and Daubenton brought from the royal collections pieces of whale, elk, porpoise, and human bones; a walrus tusk; an elephant's molar; and one of the teeth of the unknown animal of the Ohio. As to the primary question, Berniard determined that there was no significant difference between the bones of land and sea mammals. For his readers he also pointed out that there was not enough difference between the human bones and the other animals to claim a special place for humans in creation. At least, not based on biology.

This was the final scientific word on Paquet's bone, but it was not the final word on Lamanon's paper. A year after the first appearance of his paper, Journal de physique, de chimie, d'histoire naturelle et des arts published a short paper by P. de la Coudreniere that challenged both Buffon's and Lamanon's theories of the earth and used mammoths as his main evidence. Coudreniere made a reasonable argument against each theory. Of Buffon's cooling theory he points out that because the earth is a flattened sphere, the poles are closer to the internal fires within than are the tropics and, by his calculation, should be the last to cool, meaning something else must determine the temperature gradient. Of Lamanon's lakes theory, he points out that the largest salt lake on earth, the Caspian Sea, doesn't host anything larger than beluga sturgeon and small seals. It certainly doesn't contain whales. So far, so good. Then he goes off the rails.

Coudreniere next turns his attention to the mammoth and the animal of the Ohio, which he assumes to be local breeds of the same beast. What does the animal look like? What does it eat? Where is its food found? It can only be, he informs us, a bear, specifically the giant bear of Greenland. How that answers the latter two questions, he doesn't explain. There is no known animal more voracious than polar bears, he tells us, but there might be an even bigger bear never seen by Europeans, known only to the Eskimos. Quoting an anonymous history of Greenland, he describes a black bear, reputed to be thirty-six feet high, though, he admits, the size was probably exaggerated. The reason the mammoth/bear is rarely seen in Eurasia and North America is that Greenland is its primary range and it only migrates into the other continents during times of famine. That Greenland was attached to the other continents by an unmapped polar land was a fairly common belief at the time. That elephant sized bears roamed that land was a less common belief.

Lamanon wrote very little about Paquet's bone after his article was published. After Baudon's piece was published he sent a short letter to the editor saying he never had the pleasure of meeting Baudon, but wished to assure him that he had no animosity toward Buffon or any other great men. He worked behind the scenes with Daubenton and Berniard but soon moved on to other projects. He never responded to Coudrenier's giant bear thesis. In 1785 he sailed on the la Pérouse scientific expedition to the South Pacific—the French equivalent of Captain Cook. He was killed in Samoa in December 1787.

Robert de Paul de Lamanon (source)

Paquet's bone did not achieve the fame of some other bones, but its impact on science was not totally insignificant. Berniard's comparative chemical analysis of bones would be cited several times over the following decades. The bone became an important piece of evidence for scientists deciphering the geology of the Paris basin. Freshwater shells and the strata of gypsum that underlie the city all point to an age when the basin was covered by water. Georges Cuvier, who occupied a position of authority in the first third of the Nineteenth Century equivalent to that of Buffon in the last half of the Eighteenth, frequently cited the works of Lamanon in establishing that fact. Cuvier also sought out the bone and was able to add to our knowledge of it. Lamanon and Daubenton were able to identify the bone as having come from a whale, but they could only speculate about the species. The collections at the Jardin du Roi were sadly deficient in whale bones. Daubenton used a small sperm whale, which is a toothed whale, for comparison and documented enough points of similarity to be confident that it was a whale, but could go no further than that. By the time that Cuvier approached the problem, that deficiency in the collection had been alleviated—partly through new donations and partly through directed looting by the revolutionary armies. Cuvier was able to narrow the species down further to a type of baleen whale. He thought that it most resembled a Greenland whale.

Though Lamanon's name was remembered and Paquet's bone was remembered, Paquet's name was not. He became merely "a wine merchant" in the literature. In 1785 he was finally able to sell the bone. In the six years since he had dug it out of his cellar wall, it had attracted attention, but no buyers. He was forced to lower his asking price. He was probably relieved when a Dutch collector offered him ten Louis d'or. Though less than a third of his original asking price, it was a sizable chunk of money and probably something of a record for a damaged partial bone. The buyer was Martinus van Marum, an agent for Teyler's Museum in Amsterdam. The museum was a rare public collection that was the brainchild of the late Pieter Teyler, a rich banker who left his entire fortune and personal collections to a foundation dedicated to bettering the arts and sciences. Marum, no doubt, grabbed the bone for the museum's grand opening that year.

Over the years, others have had a chance to examine the bone. It is indeed the sphenoid process of a Greenland whale or, as we would call it today, a North Atlantic right whale (Eubalaena glacialis). The taxonomy of the right whale went through several permutations in the Nineteenth Century being lumped together with other baleen whales at times and split into multiple species at others. For a time, Paquet's bone was seen as the type specimen of a species Balaena lamanoni. Paquet had been forgotten by then. By the beginning of the Twentieth Century, Lamanon would no longer have his own whale.

The bone today (source)

The final word on the bone is a bit anticlimactic. The website of Teyler's Museum, tells us that the bone was neither a fossil—which was known when it was found—nor even very old. Though the bone was an important piece of evidence in convincing scientists of Cuvier's generation that Paris had once been deep underwater, it might be that it wasn't there at the time. Researchers at Teyler's think that it might have been nothing more than a waste product of the women’s undergarment industry. Fragments of whales' ribs have been found in the same district that are known to have come from the manufacture of hoop skirts and corsets. This has not caused Teyler's to remove the bone from their collections. Whatever its age, it's a piece of history. It remains on public display in the same room as Homo diluvii testis, one of the most famous fossils in the history of paleontology and one of the Beringer lying stones and equally famous counterfeit. That's pretty good company.

If I ever get to Amsterdam, I'll definitely visit Paquet's bone.

NOTE: One of the annoyances of working with Seventeenth Century journals, especially French journals, is the convention of rarely using first names. Some modern countries, such as Russia, have a convention using initials rather than first names, but Seventeenth Century French journals rarely give even those. Everyone is "M" (Monsieur). This makes finding biographical details a bit of a challenge. Buffon and Daubenton are influential enough that I wouldn’'t have had to go further than Amazon to find out who they were if I didn't already know. Lamanon is the only person in this post whose full name was given on his paper, and he was important enough that I could have picked up the few details I needed from Wiki. I'm not surprised at the lack of information about Paquet. It wouldn't have been unusual for the time if Lamanon had referred to him as "a wine merchant" and left it at that. This leaves Baudon, Berniard, and Coudrenier. I can find nothing else by or about Baudon. It looks like he never found a publisher for his book. Berniard, as I mentioned, was quoted into the next century, not just on bones but on other studies as well. Yet, no one in that century seems to have known what is name was. I was tempted to identify him with Pierre Berniard, another chemist who, however, I found out was in Poland at the time. Finally, I found a library entry for one of his articles that gave him the first initial "L". Maybe they were related. That leaves P. de la Coudreniere. I have two candidates: Henri Peyroux de la Coudreniere and his brother Pierre. Henri was a land speculator who left a small mark in history by encouraging Acadian refugees to settle in Louisiana. Pierre stayed out of his brother's schemes and stayed home to take care of their elderly mother. Henri would be the more fun of the two to work into the story, but I have no good reason to believe it was either one. Although it's unlikely in that century, I can't exclude the possibility that one of Baudon, Berniard, or Coudrenier might have been a woman.

Saturday, February 08, 2014

Orcas in bottles

Most orca populations around the world have low genetic diversity, which can present a conservation problem for those populations. A new genetic study finds that one population is fairly diverse. These two facts might help us better understand the effects of climate on ocean systems.

First the Orcas. Researchers from Durham University in the UK conducted a genetic study of orca populations around the world. What they found was that most populations have very low genetic diversity. What does that mean? It means the members of each group are fairly closely related. This happens when a species goes through a genetic bottleneck. That is, most of the species died off and later generations are descended from the few survivors. Since we became fully human, our species has done this at least once. It might explain how we separated from our sibling species such as the Neandertals.

Over time, new mutations will appear in a population's genome creating new diversity. By assuming the existence of a genetic clock--that is, a steady rate of mutation--it's possible to estimate when a population passed through a bottleneck. Naturally, it's a lot more complicated than that, but that's the gist of it. The importance of the current study is that the genomes of various orca populations around the world show they all went through a genetic bottleneck about 40,000 years ago. All except one. The orca population off the coast of South Africa has a high level of genetic diversity, suggesting they maintained a large population through the event that cut back all of the other populations.

In naming that event, the Durham researchers point an accusing finger at the last ice age. That works pretty well. An ice age doesn't just mean a lot of ice up north and down south; it means the whole global climate changes. If you've learned anything about the current climate crisis, that should be it. Global warming doesn't mean it gets a little warmer every year; it means entire patterns of climate change. For the orcas, what we're concerned about is ocean currents. Increased cold in the far north and south doesn't sound like something that should hurt orcas. After all, most of us think of orcas as cold water animals. But it can hurt them a lot.

Just as with land climate, the ice ages didn't merely chill the water in the north and south; it changed circulation patterns all over the globe. To grossly simplify things, there are two patterns of ocean currents: one on the surface and one in the deeps. In a few places around the world the two connect. At one end, surface waters get cold and heavy and plunge into the deep. At the other end, the waters of the deep run into a continent and are pushed back to the surface. These upwellings bring nutrients to feed the small organisms that are the base of the entire ocean food chain. There are other sources, such as river mouths, but the upwellings create enormously fertile ecosystems.

The Durham researchers point out that most upwellings were disrupted or completely collapsed during the ice ages. The one that didn't was the Bengeula upwelling near South Africa. That fact pulls it all together. Less food at the bottom of the food chain means less food at the top of the food chain. As apex predators, orcas are very sensitive to disruptions at the bottom of the food chain. Only the South African orca population had sufficient food to make it through a bottleneck that affected orcas everywhere else. For future research, the Durham team suggest looking at other apex predators to see if they experienced a similar bottleneck.

I'd like to suggest another line of research. Climate and weather don't move in straight lines, they seesaw. The weather gets cool for a few years then it gets warm for a few years. This is not a smooth cycle. Lately, both the colds and warms have been getting warmer. The direction of these cycles has been getting warmer for the last 150 years and the speed upwards has been increasing. The seesaw is moving up, rapidly. In a scale of thousands of years, climate works in bigger seesaws. In the scale of your lifetime, the weather seesaws up and down. You might not even notice the pattern that is climate. On a scale of centuries, those seesaws form an even greater seesaw that helps historians understand the rise and fall of civilizations. One more step up and it gets interesting.

There wasn't just one ice age. Ice ages come in sets. What caused the ice age is an incredibly complex question. Roughly put, first the earth has to be in a state where ice ages are possible--the continents must be in the right shape, the mountains must be the right height, and the air must have the right chemical composition. Even then, a series of astronomical cycles determine whether an actual ice age happens. In the current period, we have had around nineteen ice ages (called glacial maxima (maximums)). Finally, when all the conditions are just so, it usually requires a nudge to tip the first domino. We are in a period in which ice ages are possible, but the seesaws within seesaws in and out of glacial maxima do not form a regular curve up and down. From a warm period (called an interglacial), such as the one we are in, the climate seesaws down to the coldest period, then rather abruptly (in geological terms) jumps up into the interglacial climate. Right now we should be seesawing down into the next glacial maximum; instead, our climate is reaching temperatures not seen in millions of years.

And the orcas? What intrigues me about this study is that 40,000 years ago is not the coldest part of the last glacial period. It's the second coldest. There was one seesaw colder. The coldest time was 23-17,000 years ago. If the bottleneck for orca diversity happened when they say it did, there must be another factor involved that they haven't discovered. Finding that factor could be a major key to understanding how species deal with bottleneck situations. The Durham team might be onto something with major implications for managing our current climate crisis.

Friday, October 18, 2013

Mammoth or mastodon?

Let's suppose you've decided to make a name for yourself in cryptozoology. Everyone and their chupacabra is out looking for sasquatches and lake monsters. Your way to fame will be through finding your own monster and carving out your own turf. So you pack up your extra grainy, black and white camera (the preferred tool of cryptozooligists everywhere) and head off to a lost valley in Montana known only to you and the wizened shaman who told you about it. After a day of fruitless searching, you're heading back to camp. It's that hour between day and night when the light is at its most deceptive. Suddenly, you hearing a crashing the underbrush and there it is. It's the biggest animal you've ever seen! It's covered with long hair! It has a trunk and tusks! You've discovered the last mammoth! Or mastodon. Are they the same thing? If they're not, what is the difference?

First of all, they are not the same thing. They are not even that closely related. They are two different species, in two different genera, in two different families of the order Proboscidea. They are about as closely related as you and a ring-tailed lemur. Today, the order Proboscidea is represented by three species, in two genera of the same family, but, in its evolutionary history, the order has produced at least two suborders, eight families, thirty eight genera, and almost two hundred species. At the end of the last ice age, the number of poboscidean species wandering the earth was in the high teens. They inhabited every continent except Australia and Antarctica. They lived in forests, prairies, jungles, around the edges of deserts, and out on the tundra. They could be found on seacoasts, islands, and high in the mountains.

If mastodons are way over there, where is the mammoth? Mammoths, and there have been about eight species, have their own genus, Mammuthus. They split off from Asian elephants (genus Elphas) about six million years ago. This was after the latter split off from African elephants (genus Loxodonta). At the time, all three genera lived in Africa. As mammoths moved north from Africa into Europe and Asia, they gradually evolved from one species into another to adapt to new climates and in response to the world cooling into the ice ages.

Eventually, two species of mammoth made their way into North America. Yes, two. There is nothing simple about elephant evolution. The steppe mammoth (Mammuthus trogontheri) evolved in northeastern Asia somewhat less than two million years ago. This was early in the ice ages. This species was adapted to a cool dry climate. It spread to the north and west. The northern group crossed the Bering Straits during a period of low sea levels--that is, just before or just after a glacial period when lots of water is still locked up in ice caps, but the climate in Alaska is still somewhat temperate (my own opinion is that it was after a glacial maximum). This group moved into North America and adapted to grasslands and lightly forested areas. In time, it populated most of the contiguous US and Mexico down to the valley surrounding Mexico City. This population, adapted to a temperate and we call the resulting species the Columbian mammoth (Mammuthus columbi).

The steppe mammoths that stayed in Asia eventually spread back across the grasslands of central Eurasia (the steppes) all the way to Ireland and Spain. These mammoths adapted to the coldest climate. They became a keystone species involved in creating an Arctic grassland in areas that are now tundra. We call this lost ecological system, the mammoth steppe. As opposed to the current steppe which runs through central Eurasia south of the forest zone, the mammoth steppe existed in the dry, cold region north of the forests. These mammoths became shorter and stockier that other than the Columbian mammoth. Their hair became longer and the developed a layer of wool next to their skin. AS you may have guessed, this is the woolly mammoth (Mammuthus primigenius). During an interglacial period about 500,000 years ago, a population of these mammoths crossed into North America. During the last few glacial periods, they created mammoth steppes on both sides of the American ice sheets, in the northern US states and Canadian prairie provinces and in Alaska and the Yukon.

Okay. I understand the mammoths. What were the mastodons doing during all of this? Mastodons were going nuts, creating new species left and right. The ancestors of mammoths and mastodons split from each other early in the evolution of Proboscidea, possibly over forty million years ago. The majority of proboscid species are on the mastodon side of the order. The ancestors of mastodons entered the New World long before mammoths, possibly in more than one wave. There were three or four species living in South America when humans arrived and the best known species (Mammut americanum) living in North America. Mastodon remains have been found all over the forty eight contiguous states and as far south as Honduras.

We're finally there. We have mammoths and we have mastodons and we have them living side by side in North America. Doesn't that pose a problem? How can you have two large hungry animals filling the same ecological niche? The answer is: you almost never can. Mammoths and mastodons didn't fill the same niche. Forty million years of separate evolution produced two similar looking animals, but the two animals had different feeding habits. Mammoths were primarily grazers. The ate grasses and herbs. They can eat other plant matter, such as tree bark, but their teeth and digestive systems are best suited for ground plants. Mastodons were primarily browsers. They ate mostly leaves and small branches. Where we have found gut contents for mastodons, it has been mostly made up of conifers such as pine, spruce, and fir. Mammoths were found mostly on prairies and grasslands and mastodons in boggy forests. There would have been some overlap around the edges of their ranges, but no extensive contact.

Mammoth tooth discovered during the Thirty Years War. Source.

The first evidence of this difference was their teeth. Mammoths, like elephants, had big loaf shaped teeth made up of parallel plates that were used to grind their food. They had one in each jaw, for a total of just four. Grinding eventually destroys the teeth, so they grew a new pair every ten years or so. Mastodon teeth look more like a familiar molar. They were enamel covered and had high knobby cusps. They had two in each jaw, for a total of eight. This kind of tooth is good for tearing branched apart.

When large numbers of mastodon bones arrived in Europe in the Eighteenth Century, the teeth presented a problem. The ivory and other bones made it easy to recognize it as similar to elephants and mammoths. Were the remains found in some unique place where mammoths came to die, leaving all their bones, except the teeth, and where some other large animal came to die, leaving none of its bones, except the teeth? Putting the teeth and skeletons together as a single animal created a particularly horrifying image. Molars with pointed cusps, like the mastodon had, were thought to be a sign of meat eating. Some of the published descriptions of the animal imagined it pouncing on entire herds of buffalo and tearing them to shreds.

Mastodon tooth found near the Ohio River in 1739. Source.

By the end of that century, people like Ben Franklin on this side of the Atlantic and Baron Cuvier on the other, had managed to convince the scientific community that mastodons and mammoths were distinct species, separate from elephants, and, almost certainly, extinct. That last part was a disturbing idea that bordered on religious heresy. Extinction implied that God's creation came with extra, unnecessary parts. This flew in the face of how Europeans conceived of creation. The world, to them, was a perfect machine. Every part had its own mysterious purpose. Superfluous parts meant the world was not perfect and, possibly, that God was not perfect. Many flat out refused to believe that extinction was possible. These animals had to still exist in some unexplored corner of the world. When Thomas Jefferson sent Lewis and Clark to explore the headwaters of the Missouri river and continue on to the Pacific coast, his instructions explicitly included orders to look for mammoths and mastodons.

From the above, you've probably guessed that the chief determiner of their uniqueness was the teeth. When Baron Cuvier presented the paper that was seen as the final word in the argument, he coined the name mastodonte. The etymology is from the Greek "masto" meaning breast or nipple and "dont" meaning tooth. Cuvier thought the cusps of the teeth look breast like. He probably needed to get out more often. Jefferson, with his American charm, called the mastodon "bubbie toothed." Cuvier was too late with his name. Just a few years earlier, his peer Joseph Blumenbach had taken the initiative in giving the two extinct animals Linean binomials. The mammoth, he thought, was too close to the Asian elephant to deserve separate genus. He named it Elphas primigenius, meaning the primeval, or first, elephant. This was factually wrong. Woolly mammoths evolved much later than Asian elephants. The mastodon, he confusingly named Mammut americanum, meaning American mammoth. When paleontologists eventually decided to put the woolly mammoth in its own genus, along with later discovered mammoths, they named it Mammuthus primigenius which is still wrong because it was the last mammoth.

Let's get back to your budding cryptozoology career. The beast in the brush did not stop long enough to give you a big toothy grin so you could figure out its dietary preferences. Don't worry, despite two centuries of bad illustrations making them look the same, there are significant enough differences in appearance to make an identification. Thanks to finding almost intact frozen mammoths, we know more about them than any other prehistoric, extinct animal. This includes details of their appearance. We know what their ears looked like and what the very tips of their trunks looked like. We don't know as much about fine details of mastodon appearance, but we know enough.

A very nice person made this and donated it to Wikipedia. Source.

Woolly mammoths have a distinct and well known profile. Their back slopes down from their shoulders to their hips. This is not formed by and great difference in the length of their legs. Instead, it is caused by long dorsal spines on their thoracic vertebrae. This humped area is used to store fat for the winter. The woolly has a high domed head tight against its shoulders and tusks that begin pointing almost straight down before making a tight corkscrew curl back up almost to eye level. Columbian mammoths differ from woollies by being taller. Their legs are longer and the hump is less pronounced. Their hair probably wasn't as dense as on the woolly.

Mastodons had shorter legs and longer bodies than either mammoth. The line of their back was fairly straight. Their heads projected further forward as did their tusks. The curve of the tusks was more like those of modern elephants. Baby mastodons had short tusks in their lower jaws, though they shed these when their adult teeth came in and reshaped their jaws. Mastodons probably had longer tails than woolly mammoths, though you would only notice that if you saw them together. Like the Columbian mammoth, mastodons didn't have fur as thick as the woolly's wool.

There you have it, the key to a good photographic identification of a mammoth or mastodon is to catch them in profile, maybe in the crest of a hill, silhouetted by the setting sun. Good luck with that.

Monday, August 05, 2013

The first paleontological dig in the Americas

The first known Europeans in the New World to see fossils of large land animals were Hernán Cortés and his lieutenants. In the fall of 1519 they began their march inland to the Aztec capital of Tenochtitlan. Their path over the Sierra Madre Mountains led through the territory of Tlaxcala. Tlaxcala was one of the last remaining Nahua states to remain free of Aztec rule and its leaders had no intention of letting anyone's army enter their territory. An army was sent to stop the invaders. Although the Tlaxcalans had an opportunity to destroy the Spanish force, internal politics of the state led them to accept an offer of peace from Cortés. While the Spanish rested in Tlaxcala, the leaders of the state made every effort to curry favor and impress the strangers. The Spanish were fed and entertained. The leading houses allowed their daughters to be baptized. They promised an army to aid Cortés in his assault on Tenochtitlan.

At some point during the three weeks the Spanish stayed in Tlaxcala, a group of Spaniards began to question their hosts about their history. Bernal Díaz del Castillo, who wrote a history of the campaign described their answer. 
They said that their ancestors had told them, that in times past there had lived among them men and women of giant size with huge bones, and because they were very bad people of evil manners that they had fought with them and killed them, and those of them who remained died off. So that we could see how huge and tall these people had been they brought us a leg bone of one of them which was very thick and the height of a man of ordinary stature, and that was the bone from the hip to the knee. I measured myself against it and it was as tall as I am although I am of fair size.
 The Spanish helped themselves to the bone and sent it to the king on the first treasure ship. The bones of both Columbian mammoths and American mastodons have been excavated in that part of Mexico, but a bone as long as the one Díaz described probably came from an earlier mastodon species such as Rynochotherium tlascalae. In researching her book Fossil Legends of the First Americans, Adrienne Mayor went searching for this femur. Although museum officials in Spain couldn't identify that specific bone, they didn't exactly rule out its being there. The records for those years are just too sparse to be sure. It very well might be sitting, unlabeled, in a warehouse somewhere in Madrid.

Díaz wasn't the only Spaniard to report on the presence of large bones and legends of ancient giants. Cortés himself had a collection of bones at his estate. Later travelers, José de Acosta and Antonio Hererra y Tordesillas, also recorded the Tlaxcala legend and were shown giant teeth and bones. However, the most interesting report didn't come from Mexico, it came from Ecuador.

The conquest of the Inca Empire was nowhere near as easy as that of the Aztecs. For almost forty years, the Viceroyalty of Peru was plagued by civil wars and uprisings—not to mention actual plagues—among both the indigenous populations and their Spanish conquerors. In the 1540s, two very different men were thrust into the chaos. One was a soldier, Pedro Cieza de Léon, and the other a clerk, Agustin de Zárate. What they had in common was a strong sense of curiosity for the natural world. Near Quito, they both recorded the same story told by the local population. Long ago, horrible, deformed giants arrived on the Santa Elena Peninsula from across the sea. They raped and murdered the coastal people and ate all the food in the area. The people were defeated in every attempt to fight the giants, until: 
All the natives declare (wrote Cieza) that God our Lord brought upon them a punishment in proportion to the enormity of their offence. While they were all together, engaged in their accursed [sodomy] a fearful and terrible fire came down from heaven with a great noise, out of the midst of which there issued a shining angel with a glittering sword, with which, at one blow, they were all killed, and the fire consumed them. There only remained a few bones and skulls, which God allowed to remain without being consumed by the fire, as a memorial of this punishment.

 An angel destroys the Santa Elena giants in the 1700, French edition of Zárate. Source.

 Neither Cieza nor Zárate was able to go to the peninsula to see the bones. Cieza heard from enough from Spaniards who had seen giants’ bones in other parts of the Americas to accept that the story must be true, though probably exaggerated. Zárate wrote that the story seemed too fantastic to believe until he heard of another Spaniard who had been to the peninsula. 
Withal, what the Indians told about these giants was not fully believed until, in the year 1543, when the captain Juan de Olmos, a native of Trujillo, was lieutenant governor at Puerto Viejo, he caused excavations to be made in the valley, having heard of these matters. They found ribs and bones so large that, if the heads had not appeared at the same time it would not have seemed credible [i.e., that the remains were] of human beings.
What Olmos did was quite advanced for his time. He could easily have ordered the natives to bring him a few bones. Instead, he went to the place where the bones had been reported and examined them in situ. He recovered the complete bones of an individual and tried to reconstruct what it might have been based on the knowledge and worldview that he had. Europeans at the time still firmly believed in giants. The first intellectual challenges to the belief in giant wouldn't happen until the next decade. The debate over the historical reality of giants would continue well into the Enlightenment two hundred years later. That the skeleton did not perfectly match the proportions of a human skeleton wasn't a problem. Giants, by definition, were monsters. That it looked heavy-limbed and twisted was to be expected.

Both the central highlands of Mexico and Ecuador have remained rich sites for proboscidean fossils. In 1802, Alexander von Humboldt collected giant bones in Ecuador and in Mexico which he identified as resembling the elephant of the Ohio country. He also mentioned that the local people called one of the locations the Field of Giants. Humboldt sent the bones to his colleague Georges Cuvier in Paris. In an 1806 paper, in which he coined the name Mastodonte for the genus that included the Ohio animal, Cuvier determined that Humboldt’s bones represented three separate mastodon species (one of which he named M. humboldtii) and a giant ground sloth. Since then, several other proboscideans have been identified in Central and South America (the exact number is in constant flux). Some look quite different from the familiar mammoth and mastodon from further north. Some had four tusks. Some had short, almost fang-like tusks. Most paleontologists who work in the area probably don't realize that Latin America paleontology long predates its Anglo American sibling. Most don't know that the field began with a few soldiers who took time off from their wars to look at the world around them and ask questions.

Monday, June 03, 2013

Leibniz's unicorn

Otto von Geuricke was not a fool. During his lifetime he was a philosopher, diplomat, Mayor of Magdeburg for thirty-one years, and a respected scientist and inventor. It was for his work the last two capacities that he is probably best remembered. Geuricke invented the vacuum pump and performed public experiments with it that made him a welcome member of the European scientific elite. With that resume, it might surprise modern readers to find him calmly describing a unicorn in his main scientific work before moving on to more important topics.

His description is short. In its entirety, it reads:
It happened in the year 1663 in Quidlinberg, that on the Mountain the common people call Zeunickenberg, where lime is mined, inside the rock a unicorn skeleton was found. The rear portion of the body, as is common in a beast, lay back, head up, but, extending lengthwise from the brow was a horn, the thickness of a human leg, and so in proportion to the length of almost five cubits. Primarily through ignorance, the skeleton of the animal was broken and extracted in pieces. Together with the head with the horn and some ribs, spine, and bones, were given to the Reverend head abbess of the place.
The passage gives no indication whether Geuricke ever saw the bones himself, though he had plenty of opportunity to do so. Quedlinberg is less than thirty miles from Magdeburg and much of Guricke's technical innovation was aimed at making mining safer and more efficient, so he must have visited the mining regions. However, there is nothing in his writings to indicate that he ever looked further into the story. Guericke was an important enough scientist that his books were read and discussed by the scientific elite all over Europe. The Quedlinberg unicorn was mentioned a few times over the next few years and would have been forgotten except for the fact that the great Gottfried Wilhelm von Leibnitz repeated the story and produced a drawing of the skeleton.

In the years 1691-3, Leibniz was working on a geological history of that part of Germany as a Michener-style prologue to his history of the house of Brunswick and their lands. A large part of his work dealt with fossils. The presence of entire strata of salt water seashells on high ground disturbed and intrigued Seventeenth Century natural philosophers. Leibniz catalogued and analyzed the shells in his region. Following that, he looked at some of the other difficult organic remains buried in the mountains. Buried ivory was right at the top of the list.

Buried ivory had several names, one of the most common, at least to people who spoke Latin, was "unicornu fossili"--fossil unicorn. At that time, the word "fossil" was evolving from its original meaning of "something from the ground" into its modern meaning of "petrified organic matter." Another transformation happening at the time had to do with the word "unicorn." The belief in, and giving a damn about, the animal unicorn peaked during the Renaissance. Unicorn horn was a protection against poisons and a universal antidote should you be poisoned. No one was anyone unless someone wanted them dead. Unicorn horn’s medical powers were not limited to poison. It was also useful in treating “Scurvy, Old Ulcers, Dropsie, Running Gout, consumptions, Distillations, Coughs, Palpitation of the Heart, Fainting Fits, Convulsions, Kings Evil, Rickets in Children, Melancholly or Sadness, The Green Sickness, Obstructions, and all Distempers proceeding from a Cold Cause." Fragments of unicorn horn were worth more than their weight in gold. A complete horn was worth more than a medium sized town.

Its very success doomed the unicorn. Nothing about the unicorn could stand up to extended scrutiny. From one side, physicians questioned the idea of a universal antidote. Nature was composed of pairs of opposites, hot vs. cold, wet vs. dry. How could the same medicine counteract a wet poison and also a dry poison? Naturalists hunted the world for the unicorn animal and found hints and claims, but no actual unicorns. By the late Seventeenth Century, faith in the existence of an actual unicorn animal was fading fast. Several different writers demonstrated that the straight spiral horn, so beloved by medieval artists, actually came from a sea animal caught in the icy waters surrounding Greenland. Other pieces of unicorn horn were shown to be walrus tusks, elephant ivory, or cheaper substances such teeth and bones of farm animals. The last great hope for unicorn believers was fossil ivory. Finding ivory in the ground was pretty amazing. Guericke adhered to the belief that it actually grew there. Not that it was a plant, but that it was real ivory created by some generative power within the earth. If fossil ivory had such had such a wonderful origin, crediting it with diverse medical powers was no great stretch of the mind.

When Leibniz repeated Guericke’s story, he made it clear that, in his opinion, unicornu fossili was the remains of real animals. What’s more he was sure it was the remains of known animals. He allowed that in rare cases it might ivory of elephants washed into the North by the Biblical deluge, but he confident that in most cases it was the remains of walruses and narwhals that had lived there when the shoreline of the North Sea was far to the south of its present location. Still, Guericke was a man of impeccable reputation and the story was an interesting one. Following his recounting of the story as told by Guericke, Leibniz added: “The same has been reported to me. An illustration was added which it is not inappropriate to submit here.”

Leibniz’s unicorn. Source.

Leibniz never finished his history. In fact he never went any further than writing the geological preface. Both the text and the drawing sat in his papers until 1749, over thirty years after his death. In that year, Ludwig Scheidt, the librarian of the house of Brunswick, edited the treatise into chapters and had the drawings Leibniz had collected engraved onto printing plates. The result was published in Latin and German as Protogaea, or A Dissertation on the Original Aspect of the Earth and the Vestiges of Its Very Ancient History in the Monuments of Nature. The unicorn appeared on the same page as the tooth of a mammoth (referred to as that of a “marine animal”) and carried the caption “Image of a skeleton excavated near Quedlinberg.”

The image and description have gone on to become quite famous. While the bizarreness of the image has a lot to do with that fame, the image has a valid claim to being a significant milestone in paleontology. Science writers often call it the first paleontological reconstruction. To call it that, requires a few qualifiers. Every time a medieval parish priest laid out some large bones and imagined his village had discovered a giant, he was making a paleontological reconstruction of sorts. What made the Quedlinberg unicorn special was that published and directed at a scientifically literate audience.

But that’s not the whole story of the Quedlinberg unicorn. Over the years, both Guericke and Leibniz have been credited as the artists. Guericke is an unlikely source. His book was well illustrated and, if he found the story interesting enough to add to his book, it seems that he would have used the illustration if he had had it in his possession. Leibniz is definitely not the artist. He explicitly says he received the drawing from an unnamed person whose account backed up Guericke’s. As I mentioned above, Leibniz and Guericke was not the only writers to draw attention to the story. The most interesting publication happened in 1704, while Leibniz was still alive. In a catalog and commentary on the great collections of Europe, Michael Bernard Valentini published a version of the reconstruction. Valentini wrote that the illustration was based on a sketch by Johann Mäyern, a counselor at Quedlinberg. Valentini’s illustration is of much lower quality than Leibniz’s. Was Mäyern Leibniz’s other source or was there a third drawing that they both copied? Unless Mäyern’s original drawing shows up, we will probably never know.

Valentini’s unicorn. Source.

In the early Twentieth Century, the Austrian paleontologist Othenio Abel took an interest in the Quedlinberg unicorn. Abel had already casually mentioned the story in several of his books before he decided to get serious and try to figure out what the skeleton really was. They actual bones had long since disappeared and no other drawings or descriptions had ever been made of them. The best evidence he had to work with was Leibniz’s drawing. Abel immediately recognized that this not a single skeleton that had been reassembled in a whimsical manner. The bones came from at least two individuals and two different species. The skull is that of a woolly rhinoceros. The teeth, scapulae, and vertebrae are from a mammoth. Most of the spine has been reassembled backwards and upside down. What at first glance look like ribs are really dorsal spines that are part of the individual vertebrae. The loop at the bottom is the first cervical vertebra. And the horn; what is the horn? It’s too long to be a walrus tusk and too wide to be a narwhal tooth, Leibniz’s preferred explanation for fossil ivory. Rhinoceros horns are not made of bone or ivory. They’re made of keratin, the material as hair and finger nails. It’s unlikely that the learned burgers of Quedlinberg would have mistaken that for a unicorn horn. That leaves a mammoth tusk, which easily meets the length and width requirements. It takes a little more speculation to explain its being straight and not curved. There are two possibilities here. One is that the tusk was badly enough broken up that the people who reassembled it had the freedom to make it any shape they wanted. The other possibility is that it came from a different kind of extinct elephant, such as the palaeoloxodon, a species that went extinct about 15,000 years before the mammoth and that had much straighter tusks.

There is a cave near Quedinberg called the Einhornhöhle or Unicorn Cave. Even before the gypsum miners on Zeunickenberg found their strange skeleton, the locals had been bringing bones out the local caves and selling them to apothecaries as “genuine” unicorn horn. This explains why the Quedlinberg burgers had unicorn on their minds as they tried to make sense out of a pile of broken bones. No doubt, someone had the idea of getting in on the unicorn trade. But the price of unicorn horn was crashing in the late Seventeenth Century and any plans they might have had never came to fruition. Leibniz visited the area in 1686 and crawled through several caves, but didn’t find any unicorns, which explains his noncommittal tone when he repeated Guericke’s story six years later.

That’s not the end of the story. In the Nineteenth Century, paleontologists explored the caves in the Harz Mountains and identified the bones of dozens of species of Pleistocene mammals. In the Twentieth century, the local governments realized the tourist potential of the caves and dug comfortable entrance tunnels into them. There are several small museums in the region proudly showing off the bones. There are several full sized models of the unicorn on display. One of them guards the entrance to the Einhornhöhle. Tourist shops sell paperweights and t-shirts adorned with Leibniz’s drawing. The Quedlinberg unicorn lives on.

Sunday, April 07, 2013

Shetland mammoths were bigger than shetland ponies

A few weeks ago, some surveyors in the Shetland Islands north of Scotland came across an interesting piece of bone. It was about a foot in length, thick, curved and broken at both ends. They thought it might be a piece of walrus tusk, but it was unusual enough that they took it to Val Turner, the island archaeologist. Turner is not a paleontologist, but she knew enough to realize this was not a walrus tusk. She bundled it up and sent it to the Paleontology Museum of Uppsala University in Sweden.

Based on the nature of this blog, I'm sure you can all guess what it is. If I was there I could have told them in less than a minute that it was a piece of tusk from a proboscid, and determined whether it was from a mammoth or a modern elephant (the trick is to look at something called Schreger lines). That is what Uppsala told Turner.

Why is this a big deal? Sections of mammoth ivory are found all over the North and this one is a pretty ratty looking piece. What makes this piece unique and explains Turner's inability to identify is that no evidence of mammoths has ever been seen on the Shetlands.

The islands were completely buried under the ice during the last glacial maximum. Because so much water was locked up in the ice caps the oceans were several hundred feet lower during the glacial maxima. Britain was attached to the mainland and most of the North Sea was dry (or ice covered land). Mammoth ivory is fairly common in England and Ireland and trawlers regularly bring up mammoth bones and ivory from the sea.

This brings up two possibilities to explain the ivory. First, is that a small population of mammoths established themselves on the islands after the ice melted, but before the ocean had risen to its current level. Second, is that this is a piece of ivory washed up from the North Sea during a storm. Hurricane force storms are not uncommon in those parts.

For now, the Shetland Amenity Trust has closed the area where the tusk was found. This week, experts from Uppsala arrived to hunt for other mammoth bones. I'll be watching for follow-up news.

Wednesday, February 06, 2013

Boltunov's drawing

In the winter of 1803-4, Roman Boltunov, a merchant from Yakutsk, worked his way down the Lena River selling and trading his goods. At that time of year, the main currency of the native Sakha and Evenki* would have been freshly trapped furs. In March, Boltunov reached Kumak Surka, the last village before the Lena Delta. There, the local headman, Ossip Shumachov, showed him two very nice mammoth tusks, which Boltunov promptly bought for fifty rubles in goods. Mammoth tusks weren't exactly rare on the coast east of the delta, and he was always happy to buy them if they were in good condition. What was special about this pair was where Shumachov said he found them: They had still been attached to a mammoth.

Anyone who spent any amount of time in Siberia knew about mammoths. Their horns or teeth or whatever they were sometimes found in the northern part of the country, usually in the coast or on the banks of rivers and they were valuable. Over the last forty or fifty years a whole profession of ivory hunting had grown up around them. The mammoth animal itself was a mystery. No one had ever seen a live one. On very rare occasions, dead ones were found on river banks, their flesh still bloody, as if they had died only days before. The Siberians, Russian and native, had many legends about them. One of the most common was that seeing a mammoth corpse was bad luck and that they should be avoided. On the other hand, educated Russians from the West and other Europeans were quite interested in mammoths and would even pay for information about them.

Since Shumachov didn't seem particularly afraid of the mammoth, Boltunov was able to convince him to take him to place where the rest of the carcass was. This involved more than a day trip. The mammoth remains were on the far side of the Bykovsky Peninsula facing the Arctic Ocean. The route led across the Lena and over a high range of hills, two days each direction. But Shumachov was proud of his find and maybe a few more goods were exchanged to encourage him.

It was snowing heavily when they got there. Scavengers had already gotten to this large block of free meat and eaten parts of it. Much of the face had been torn away. Still, the majority of it was still there and in one piece. Boltunov cleared away enough snow to get a good look at it and examined the head. What he saw was bigger than any animal he had ever seen or heard of. It was covered with long rust-colored hair. It had a fat body and thick legs. He made some measurements on the spot. Later on, he wrote down some of the details and, on the opposite side of the same sheet, made a drawing from memory. He was correct that the trip would be worthwhile; when he returned to Yakutsk the head of the merchant’s guild bough his notes and drawing. This is the first reconstruction that we have of a mammoth that is based on more than just bones.

Two years later, the drawing came to the attention of an Adjunct member of the Imperial Academy of Sciences, Mikhail Adams, a botanist who passed through Yakutsk on his way to collect specimens on the lower Lena. Though he was not impressed with the drawing—he described it as "very incorrect"—Adams dutifully forwarded it to the Academy with the notice that he was going directly to Kumak Surka to see if anything of the mammoth could be saved. The Academy was extremely excited by the discovery and published Boltunov's notes as a letter in their popular Russian language newspaper, Technological Journal.** Adams continued the coast and was able to recover most of the bones, three quarters of the skin, and a large sack of hair.

Sixty years later, Karl von Baer went looking for Boltunov's drawing. Baer is usually remembered as the father of embryology, but he also did geological research in the Russian Arctic and was interested in mammoths. Baer could not find the original in the Academy archives but he knew copies of it had been sent abroad. Wilhelm Keferstein at Göttingen University was able to find one among the papers of Johann Blumenbach. Baer suspected that it might even have been the original. It’s probably a copy. Wilhelm Tilesius, writing around 1810, said the original was still in the Academy archives. Keferstein sent Baer a sketch based on Blumenbach’s document and a transcription of the notes on the document. Baer was nice enough to write it up and publish it where I could find it. Copies of Keferstein's sketch were published in several journals at the time. The drawing along with the hair and skin samples are preserved in the Göttingen museum.

Roman Boltunov’s reconstruction of the dead mammoth on Bykovsky Peninsula, 1804. This is the first reconstruction of a mammoth based on more than bones. Source.

Adams wrote that the drawing was "very incorrect…something between a pig and an elephant." Tilesius called it "a poor drawing of a monstrous figure…a most inexperienced and unskilled work." At first glance it's hard to disagree with them. But, considering the information he had to work with, it’s not a bad reconstruction. It demonstrates an intelligent mind and an active curiosity attempting to extract the most information possible from a small amount of information. It is very possible, even likely, that Boltunov had never seen a picture of an elephant and had no reference point for elephantness. He would, however, have seen a boar. Most large mammals he would have been familiar with—dogs, cattle, horses, reindeer—had long relatively thin legs and heads that rose up from the body. Only bears and pigs had thick bodies, heavier legs, and heads that protruded forward from the body. Whether consciously or subconsciously, he used a boar as a model to fill the gaps in his knowledge.

The trunk was gone when he saw the carcass; the base of the trunk could very well have resembled a pig's snout. The tusks in his drawing look bizarre; one seems to be pointing up while the other points down. Baer believed that Boltunov was inexpertly trying to indicate that he believed the tusks should have pointed outward. Even in Baer's time, most scientists believed they pointed outward. The tusks are correctly placed in the upper jaw, not in the lower as they would have been in a boar. The way the tusks are pushed together in the snout is also correct. Mammoth’s tusks start much closer together than those of living elephants. At the top of the drawing is a separate drawing a mammoth’s tooth, which would have been very different from any mammal he was familiar with.

The drawing shows tiny ears on top of the mammoth’s head, which do not match Boltunov's written description. In the latter, he says the ears were six arshins (about eleven inches) long and on the “outside” of the head. I suspect this contradiction means he wrote his notes and made his drawing at two different times. The eyes are far too high on the head. This I think is a result of faulty memory. The skin around the eyes and top of the head was still there when Adams arrives two years later. The body is more elephant-like than boar-like, boxy with pillar legs and a short tail. The only boar-like details on the body are what appear to be fetlocks and thin hooves. Finally, Boltunov drew little lines around the mammoth that show the hair running the full length of its body.

Adams would have done well not to have dismissed Boltunov so quickly. Boltunov saw the mammoth a full two years before Adams when the carcass was in much better condition. By comparing Boltunov's observations with his own, Adams would have avoided some of the mistakes that he made. The mammoth still had its tail when Boltunov saw it. He not only drew the tail, he measured and took note of its length. The tail was gone when Adams arrived and he concluded that the mammoth never had had one. Most of the hair was still on the mammoth when Boltunov saw it and his drawing shows hair the same length over most of the body. Most of the hair had fallen off by the time Adams arrived and, based on where he found hair on the ground, he concluded that the mammoth had a great mane.

Adams was remarkably incurious about the mammoth. His memoir of the trip to recover it is more of a travelogue than a scientific paper. Other scientists complained about his lack of relevant details, but it never occurred to any of them to contact Boltunov (or Shumachov, for that matter) to collect information from a witness who was very curious. Except for Baer’s 1866 paper, I can find no reference to Boltunov that treats his drawing as anything other than an example of how wrong ignorant Siberians could be. Of course, cultural arrogance is hardly unique to that century. The scientists of the time could have gained useful information by mining Boltunov's notes and drawing for data. They could have gained much more if they had written to the governor and had someone interview him. Even though Boltunov has little to tell us today about mammoths, he has plenty to tell us about Boltunov and how people of his time, location, and class viewed their world. Maybe it’s time to take Boltunov's drawing a little more seriously.

* Sakha is the preferred name by those people who, until recently, were called Yakuts by outsiders. The Evenki are the largest of several peoples who are usually lumped together as Tungus.

** This is not the same as the official journal of the Academy, Mémoires de l'Académie Impériale des Sciences de St. Pétersbourg, which was in Latin. Later, they would make the very sensible decision to keep the French title and publish the articles in German.

Sunday, February 03, 2013

An early description of permafrost

At the beginning of the Nineteenth Century, permafrost was a very strange idea to European scientists. The word wouldn't be coined until 1943. The earliest descriptions from the century before were simply of frozen ground running deeper than it should. The idea was completely alien to anything they understood. If the ground was deeply frozen, how could trees grow? Any mining engineer could tell you that it gets hotter as you go down, not cooler. No, they determined, deeply frozen ground was just a myth of superstitious natives.

In 1806, while traveling on the Arctic coast near the Lena delta, Mikhail Adams made some passing references to permafrost that included, as far as I can tell, the first short descriptions of ice wedges and patterned ground. Adams came to the coast attempting to recover a frozen mammoth. Prior to his trip, fewer than a half-dozen mammoth carcasses had been described and one woolly rhinoceros had been recovered. None of these descriptions described them as being frozen, only buried. Adams, in describing his mammoth specifically went into the fact that it had first been sighted in frozen soil. While at the discovery site, he made some casual observations of the place where it was found that included more details than simply stating that the ground was frozen.

First, a few words about permafrost. Permafrost is much more that frozen mud with a foot or so of mushy mosquito maternity wards (tundra) on top, though that's what it mostly is. It's actually a very complex geological phenomenon that still isn't completely understood. Permafrost can contain walls of almost pure ice (ice wedges), mysterious round hills that look like burial mounds (pingos), thousands of small oval ponds that appear and disappear (thermokarst lakes), and rings on gravel beaches and mile after mile of honeycomb patterns on the ground (patterned ground).

Patterned ground is caused by ice wedges. Very simply put, cracks form in permafrost in polygonal patterns similar to cracks in dried up lakebeds during a drought  The case is different but the appearance is the same and the permafrost patterns are much larger. During the summer, melt water fills the cracks. The next winter, the ice expands, as ice will and that widens the crack. The next summer more water can get in, which widens the crack even more. Repeat for a few decades and the permafrost will be thoroughly broken up into a pattern. Because the ice wedge also expands upward, it will create the rice paddy pattern below (Fig. 1). Later in the summer, when the wedge has melted some, the pattern will be the exact opposite with the cracks being lower than the permafrost blocks.

 Fig. 1. Patterned ground. Source.

Back to Adams. The place where Adams recovered his mammoth was a bluff overlooking the sea. Rather than looking at the permafrost through a hole dug into it from above, he has able to see a huge slice of it. The bluff he looked at was well over a hundred feet tall and several miles long. The mammoth had eroded out of a relatively high point on the bluff and tumbled to the beach. While waiting the boat that would take him and his mammoth back to civilization, Adams climbed the bluff to a place near where the mammoth had first appeared. He described it thusly: 
Sa substance est une glace claire pure et d'un goût piquant, elle s'incline vers la mer, sa cime est couverte d'une couche de mousse et de terre friable d'une demie archine d'épaisseur. 
My translation of this is: 
Its substance is pure clear ice and has a pungent taste, it leans towards the sea, its top is covered with a layer of moss and soft earth half an archine thick [14 inches]. 
Two different English translations were published, essentially identical to mine. This passage caused some confusion for Nineteenth Century scientists. All other mammoth carcasses discovered in that century were found in frozen mud, not clear ice. Furthermore, the expeditions that visited the site found only mud. They chalked it up to the fact that Adams was a bit flaky and, outside his field, he was botanist, his work was rather sloppy. However, the existence of ice wedges might redeem Adams' reputation. At least, in this instance.

It just happens that Mamontovy Khayata, the place where the mammoth was found, has been the site of a joint German/Russian permafrost research project for the last twenty years. The picture below (Fig. 2.) is of the bluff in 2002. The light section of the bluff is a section of ice wedge. Beyond it is muddy permafrost and beyond that, the beginning of another ice wedge. It's most likely that Adams did, indeed, find clear ice that tasted terrible. 

Fig. 2. Mamontovy Khayata. Source.

On to the polygons. After examining the bluff, Adams walked inland to collect plant samples. He also poked at the tundra to see if the thickness changed. He saw a great amount of drift wood both on the shore and on the hills. The wood on the hills his Evenki hosts called Adam's wood. The wood on the beach, which came down the Lena every spring, they called Noah's wood. First Adams' comments on the Lena floods: 
J'ai vu dans les grandes fontes de glaces des grosses mottes de terre se détacher des collines, se mêler à l'eau et, former des torrens épais et argilleux qui roulent lentement vers la mer. 
All three English translations agree on the substance of this sentence. 
I have seen, in great thaws, large pieces of earth detach themselves from the hillocks, mix with the water, and form thick and muddy torrents, which roll slowly towards the sea. 
The next sentence is the one that I think describes patterned ground. 
Cette terre forme des figures de coins qui s'enfoncent entre les glaçons. 
The first published English translation (1807) reads: 
This earth forms in different places lumps, which sink in among the ice. 
The second English translation (1820) reads: 
This earth forms wedges which fill up the spaces between the blocks of ice. 
Finally, my crude translation: 
This earth forms figures, which settle among the ice. 
Mine, more or less, agrees with the first, but I've discovered errors in the first. The very reason I've made my own translation is to figure out which one is right when I discover variations. I've also retranslated two German translations because I'm that anal.

In context, the earth (terre) he mentions must be the same muddy earth that he saw during the spring thaw. That would be the same frozen mud that makes up the majority of permafrost. This ice (glaçons) should be the same as the ice (glace) he saw on the bluff face. Knowing what we know about permafrost, it makes much more sense for the earth to be surrounded by ice and not for the ice to be surrounded by earth. The Germans agree with me, though they also call the earth wedge-shaped (diese Erde bildet sodann keilförmige Figuren, welche sich zwischen den Eisschollen festsetzen). If anyone is fluent in French I'd like your opinion on this passage.

Ultimately, it's not important whether or not he got all of the details right. The important thing is that, at that early date, he mentioned the figures on the surface of the ground and correctly identified the underlying structure as being made up of separate parts of ice wedges and regular frozen mud permafrost. At a time when many scientists didn't even recognize the reality of permafrost, that was quite an accomplishment.