Siberian Trilobites - The Roots of a Family Tree
Lena river cutting through Lenskie Stolbi National Park.
Siberia. The name alone generates a variety of powerful images within the mind's eye -- and few of them are particularly pleasant. Perpetually frozen landscapes… endless vistas of barren tundra… the outpost where “wayward” Soviet citizens were sent during the height of the Cold War, most never to be heard from again.
The fact is that Siberia is all that we imagine -- and more! Part of the Russian Empire since the 17th Century, this immense land mass covers over 7 million square miles (the US, by comparison, covers less than 4 million square miles… and that includes the enormity of Alaska) and stretches from the Ural mountains in the west, to the borders of Mongolia and China in the east. And while it accounts for nearly 80 percent of Russia's total land area, only 27 percent of the nation's population calls this often-inhospitable area home, with the net result being that Siberia ranks among the most sparsely populated places on the planet.
While Siberia might not boast the requisite credentials to rank high as a potential tourist destination (though, in all honesty, it does possess its share of breathtaking vistas, especially during summer), it does earn high marks within paleontological circles -- usually for its extensive Pleistocene fauna. Among the creatures that have been found fossilized within the 12,000 year old Siberian permafrost include mammoth, bison, cave bear, and a particular species of wooly rhinoceros that sported a nose horn that frequently reached three feet in length. In addition, a pair of perfectly preserved cave lion cubs -- with even their fur intact -- were recently found, igniting hope that science may someday soon be able to extract enough viable DNA from such creatures to facilitate attempts at regenerating a long-lost species.
Yet despite the notoriety generated by these Pleistocene discoveries, the rough and rugged Siberian landscape also houses a variety of other sedimentary strata… some of which may prove to be of equal or even greater scientific import. Indeed, in recent years these outcrops have begun to attract the attention of scientists and collectors around the globe. The reason for such interest is simple; among these layers are the Pestrotsvet and slightly younger Sinsk Formations, Lower Cambrian strata that has produced some of the world's earliest representatives of the trilobite line.
In all honesty, reaching these locations and their inherent fauna requires more than the mere desire to do so; it takes persistence, patience and an appetite for facing some of the most imposing obstacles that Mother Nature has at her disposal. Quite simply, perhaps the biggest problem facing those intent on finding trilobites in Siberia is that just getting to these various Cambrian sites can present enough logistical headaches to make any right-minded soul second guess their original intent. Outsiders often need requisite visas and credentials, and even Russian citizens can find organizing a proper expedition to be difficult, at best. In this corner of the world, roads are often little more than centuries-old animal trails. Even four-wheel drive vehicles frequently find themselves bogged down in the thick layer of muck that rises above the permafrost during the short summer months, when digging in Siberia is even possible.
While the legendary Trans-Siberian Railway passes through this immense land, it doesn't come close to reaching any of these fossiliferous locales. Just about the only means of reaching many of these distant sites is by helicopter. By its very definition the use of such a craft translates to both high expense and a severe limitation in terms of both expedition members and available equipment. But as is often the case with even the most remote trilobite locations, getting there can be half the “fun”. And once you've managed to reach one of these remote Paleozoic sites, the rewards may very well justify any expense or annoyance.
“An expedition to Siberia is limited right from the start,” said Arkadiy Evdokimov who runs the world's largest commercial outlet for Russian trilobites. “The sites are usually inaccessible and the rock tends to be hard to work with. We have done a great deal of research just to know where to go, because if you don't, you will just waste your time. It is expensive and difficult. Thus, every specimen you find is precious.”
The fact is that more than half a billion years ago, things were far different in Siberia than they are today. Back in the Lower Cambrian, what is now the snow-swept steppes of the central Siberian plateau was located near the equator, with what later became these fossil layers laying just offshore of a large island-continent in the southern quadrant of the Panthalassic Ocean. It was apparently a very rich environment, one in which scientists now believe some of the first trilobites may have emerged. Siberian species such as Profallotaspis and Bigotina appear to stand at the very base of the entire trilobite family tree, creatures that some 521 million years ago provided ample proof that complex, multi-cellular life could indeed survive on this “hostile” planet called earth.
While early members of the trilobite line were almost simultaneously emerging in other “hot spots” around the globe, as evidenced by outcrops recently found in Spain, Nevada and Morocco, none predate the material being found in these distant Siberian formations. Interestingly, not all of these early trilobite locales shared a similar climate; Siberia lay squarely within a tropical zone near the ancient equator, while the Moroccan and Spanish outcrops were then to be found in southern seas far more temperate in climate. Science has yet to present a comprehensive analysis of the role Cambrian water temperatures may have played in the development of the trilobite line. It seems virtually certain, however, that a hospitable climate -- as well as relative isolation, which allowed for the development of unique species -- played vital roles in the successful emergence of these ancient arthropods.
“It now appears that all early trilobite species initially arose in either equatorial or temperate regions of the planet,” said Bill Barker, an Arizona-based trilobite authority. “And the regions in which they emerged were quite diverse. In the early Cambrian, Gondwana, on which Spain and Morocco were located was in the Southern hemisphere while the Siberian island-continent was centrally located, very near the equator.”
While the Siberian search for The World's Oldest Trilobite has garnered a lion's share of attention in certain paleontological circles, we would be negligent if we failed to mention that the neighboring, slightly more recent, Sinsk Formation also contains a significant Lower Cambrian fauna. And while the Pestrotsvet Formation that produces Profallotaspis and its ilk has continually proven to be among the most “miserly” of trilobite layers -- having so-far produced only a few complete, articulated specimens -- the material in the Sinsk, while not what anyone would call bountiful, is clearly more abundantly distributed.
Many of the specimens in these layers have been discovered in outcrops that emerge along the closely aligned Anabar and Lena rivers. These “sister” waterways are located in Siberia's remote Sakha Republic, and cut through the central Siberian plateau for a length of nearly 600 miles. There, in a variety of spots, such species as Bergeroniellus asiaticus, Jacutus primigenius and Delgadella lenaica have been found in locations where the Sinsk Formation has been exposed by the strong river currents. A number of these exposures occur within the confines of the beautiful Lenskie Stolbi National Park, which has recently been nominated for designation as a UNESCO world heritage site.
Despite the allure of these particularly ancient species, we should not jump to the conclusion that only Lower Cambrian trilobites can be found within the sedimentary outcrops of Siberia. The fact is that Middle Cambrian species are also strongly represented within the area's layers. These trilobites can be found in an equally remote locale, the 510 million year-old Mayan Stage of the Anabar plateau. Indeed, while these trilobite sites are no easier to reach than those that hold their Lower Cambrian brethren, the Middle Cambrian material discovered-to-date has been significantly more prolific. There have, in fact, been enough examples found of such species as Hitangia scita, Michaspis librata andUrjungaspis picta (among approximately a dozen recognized trilo-types from this area) that they have become readily available on the open market.
“We have had a bit more luck finding the Middle Cambrian trilobites,” Evdokimov said. “But they are still very difficult to find. It is a remote setting, and the rock is very hard. There are also many more partial specimens found than complete ones. But you try not to get too discouraged; the national park is beautiful, one of the most impressive places in all of Siberia. It alone is worth a visit --whether you find trilobites, or not.”
Certainly, trilobites are not the only “treasure” to be found in this isolated area. The Anabar region has long been renowned for possessing the largest diamond-producing deposits in the world outside of Africa and Australia. These deposits -- highlighted by the legendary Mir mine, which produces over $600 million worth of precious stones annually -- have allowed Russia to rank among the major players in the world's diamond market for decades. These gems, along with the nation's immense oil reserves, have served as primary sources for much of the country's natural wealth and international power.
Siberian “wealth” goes even beyond diamond extravagance and half-billion year old trilobites. If one is searching for something particularly unusual in the area's Cambrian outcrops, within these same formations lurks a strange trilobite-like arthropod known as Phytophilaspis pergamena, which has come to be commonly referred to as a “bilobite”. While these large -- 10 to 15cm -- creatures bear a striking superficial resemblance to trilobites (and share such characteristics as prominent eyes, a large pygidium and even the outline of their hypostome) they are also quite different due to the shape of their facial sutures, the reduced size of their thorax and the fact that their limited number of thoracic pleura are fused to one another.
When all that we know is considered, however, perhaps it shouldn't be too surprising that large non-trilobite arthropods exist in these rocks… after all, similar, but decidedly different creatures appear in other Lower Cambrian outcrops, perhaps most notably those of Chengjiang, China. And with our knowledge of life's earliest steps growing exponentially on an annual basis, it has become abundantly clear that whether one considers the fossils found in the rocks of China, Australia, British Columbia or Siberia, the Cambrian seas were bursting with life, and never before or since have the forces of nature been more inventive or unpredictable.
“We are learning more about the Cambrian Explosion all the time,” said Barker. “As recently as 2015 a major, new Burgess Shale outcrop was discovered in Canada. On top of that, Chengjiang and Emu Bay in Australia are still offering up surprises in terms of their arthropod content. And Siberia remains something of an under-studied resource. Hopefully it will reveal more of its amazing secrets in the years ahead.”
So while for many of us Siberia may still hold a bleak image as one of our planet's true “off the grid” locations, the fact is that this is a land rich with both natural reserves and paleontological resources. And though it is highly unlikely that many who are reading this will one day find themselves ankle deep in tundra muck on their way to a dig in the Sinsk formation, life could present far worse options. Indeed, merely considering the chance to dig for perhaps the oldest trilobites on the face of Planet Earth should stir the fossil-loving souls within each of us.