Description of the Rochester Shale Locality
It is a barren ten-acre tract of land in Lockport, New York (a stone's throw from Buffalo), a quarry that possesses all the inherent charm of a near-lifeless landscape on some distant, alien moon. The color scheme of this Rochester Shale outcrop is grey, upon grey, upon grey, with only a hearty pale green weed occasionally poking up through the solid rock to break the monochrome monotony. Water has gathered in spots where the hard, Silurian age strata has been worn - or torn - away, and during the short Lockport summer (in these climes there are rumored to be two seasons, July 4th and winter) tadpoles scurry about in small algae covered pools in an attempt to grab one of the countless insects that have chosen to make this unforgiving plot of land their home.
Despite the initially forsaken appearance this piece of property presents, the quarry at Lockport is “sacred ground”. Wherever one walks on the hard mudstone deposits, they unknowingly tread on ghosts from Earth's long-forgotten past. Beneath some twenty feet of stratified overburden - rock that has accumulated since this part of the world was part of a shallow ocean system some 425 million years ago - the quarry is home to some of the most beautiful Silurian-age fossils in the world. Silurian deposits are relatively rare in North America, with the short (in paleontological terms) 27 million year period, which stretched from 443 to 416 million years ago, ranking well behind deposits from much longer and more renowned periods - the Cambrian, the Ordovician and the Devonian - in terms of both their scientific élan and their availability to collectors. Yet, in Lockport, and in immediately surrounding regions, the Silurian rules! From the legendary eurypterid quarry one hundred miles to the east, to the famous shale deposits along the near-by Erie Canal, where ever a sharp-eyed paleontologist looks, the Silurian period, a time of giant invertebrate marine predators and tiny, bizarre sea organisms, lives again.
At the present time the Lockport quarry is the center of attention for a team of fossil collectors, who busy themselves for up to ten hours a day, seven days a week during the region's short digging season (apparently there is no rest for either the weary or the paleontologist) in their attempts to pry their prizes from their ancient homes. Contained within the various layers of sedimentary rock that comprise the 15-foot-thick Silurian foundation (of what has become known as Caleb’s Quarry) are some of the most coveted Rochester Shale fossils in the word. There are perfectly preserved brachiopods, magnificent crinoids and some of the best fossil starfish to be found in North America, all waiting to be freed from the rock that has encased them for eons.
But those fossils are only appetizers for what these diggers are really looking for. Their sweat and toil is inspired by a singular dream; the chance to recover some of the most famous and beautiful trilobites ever unearthed. Just mentioning names such as Arctinurus boltoni, Trimerus delphinocephalus, Bumastus ioxus and Dalmanites limulurus is exciting enough for most fossil enthusiasts. For this Rochester Shale quarry's heavily calloused collectors, however, mere names mean little - nothing short of the "real thing" will do. They'll spend weeks on end performing their laborious, back-breaking, rock-splitting task over and over again, merely for the thrill of being the first human eyes ever to glimpse a particular fossil specimen. Forget for a second that Arctinurus specimens remain among the most coveted trilobites on earth, or that the rich Lockport soils are yielding once-rare Dalmanites specimens by the dozens. These diggers perform their work for one primary reason - a pure love for what they do.
"This is the greatest job in the world," said Ray Meyer, who owns a lengthy lease on the Lockport quarry. "Each day I jump out of bed ready to go, never knowing exactly what I might find. The thrill of the unknown is just part of the excitement of working the Rochester Shale. It's a labor of love, and the rewards can be incredible."
People have been working the rocks in and around Lockport for the better part of 200 years. It was back in the early 1800s that work was begun on the Erie Canal, the waterway that stretches from Albany to Buffalo and connects the Hudson River with Lake Erie. Almost immediately, diggers near Buffalo began discovering strange "shapes" in the Silurian age rocks they were extracting. There were objects they could recognize - sea shells and corals -and things they couldn't… most notably trilobites. Some intrepid canal workers decided to hold on to the various strange rocks they encountered until they had a chance to show them to their superiors. Unfortunately, many of those early specimens were quickly discarded by Erie Canal officials. Still, somehow, a number of important finds were made during the Erie Canal dig, and many specimens from that landmark project still reside in the Buffalo Museum of Science.
Then in the 1830s, one of America's most noted paleontologists, James Hall (later the director of the Museum of Natural History of Albany) began the first extensive excavation of the fossil rich outcrops of western New York State. Effectively utilizing the rock exposures left from the canal dig - which was completed in 1825 - Hall collected an amazing array of invertebrate fossil finds. In fact, his discovery of an early specimen of Arctinurus in 1834, created quite a ruckus at the time, causing many groups (including leading religious factions) to question exactly what this strange, ancient creature might actually be. So much pressure was placed upon Hall and his benefactors by those who looked askance at his findings, that his funds were frequently cut off by the State of New York, and it wasn't until he published his landmark three-volume treatise, The Invertebrate Fossils of New York, in 1847, that many of his historic discoveries came to light.
With the appearance of that work, however, the "legend" surrounding the Rochester Shale deposits of western New York began to take shape. For the next 140 years, diggers and collectors would wander up to the Erie Canal rock cuts, wait for a canal lock to drain to the proper low level, then attempt to extract a few fossil prizes from the hard, unforgiving rock exposures before it would begin to fill again. The work was, at best, an “iffy” proposition, and complete specimens were indeed rare prizes. In fact, it is estimated that no more than a dozen near-complete Arctinurus specimens from New York State existed prior to the opening of the Lockport quarry's full-time operation in 1991.
"There's a lot of history involved with the region and with these trilobites," Meyer stated. "When you dig in these deposits, you sometimes need to stop and think about the past. You sense that you're really fortunate to be dealing with something so significant. The rock around here is certainly hard, but that sense of history always makes digging interesting - if not always a pleasure."
Working the sedimentary layers at Lockport is unquestionably difficult. But freeing trilobites from their ancient rock casings is only the first step in a long process needed to properly prepare a fossil specimen for study or display. According to Meyer, he has occasionally gone for as long as a week, moving up to two tons of rock by glove-covered hand a day, without finding a single "keeper". Arctinurus heads and Trimerus tails are relatively common finds (these trilobites, like all others, molted their hard outer shells at regular intervals, leaving behind many tantalizingly fragmented fossilized remains), but good, complete specimens of the up to 19 cm Arctinurus, 24 cm Trimerus or 4 cm Bumastus are indeed rare. On one notable occasion, Meyer found three complete Arctinurus specimens in one day, and a recent visitor to the quarry landed two Trimerus in one thirty-minute stretch, but such moments are few and far between. It is the memories of such events, however, that inspire these intrepid collectors to venture out into the 90 degree July heat or the sub-freezing October cold (the quarry operates roughly from late April until early November) in search of their elusive Paleozoic prizes.
"Digging is something you either love or you hate," Meyer said. "There are some people who can't get enough of it, and there are others who just can't stand it. But if you love fossils, I think as soon as you find something, you'll be hooked. It's hard not to turn over a heavy rock, find an incredible trilobite, and not be enthused to keep on going. It really gets into your system."
Unfortunately, once discovered, the trilobites don't just pop out of the rock ready for display. On more than one occasion, extremely rare specimens (including a near-perfect Dicranopeltis nereus, a 5 centimeter lichid that is perhaps the quarry's most elusive trilobite) have been destroyed by a careless hammer blow or poor excavation technique. Electric saws and fancy European rock hammers are utilized to remove such specimens from the hard surrounding matrix, but even then, totally "clean" perfect examples are rare. Usually, a trilobite emerges in a number of pieces, perhaps with eyes or parts of the hard outer shell still encased in the "negative" side of the rock puzzle, desperately in need of a well trained "preparator" in order to regain much of its former glory. Prepping a bug from the Lockport quarry can often take from 10 to 20 hours of detailed work; removing clinging bits of matrix, realigning disarticulated segments and often painstakingly reattaching tiny fragments of shell. But the results are worth the effort.When completed, the specimens possess a beautiful black exoskeleton and retain much of their original 3-D appearance. By the way, it is surmised that most Silurian trilobite species were bottom dwellers, either using their intricate forms (Arctinurus, Dicranopeltis) to settle on the bottom like a modern-day flounder, or utilizing their smooth bodies (Bumastus, Trimerus) to burrow into the mud.
"I get as much pleasure out of preparing as I do digging," said Eugene Thomas, long the principle preparator for the Lockport quarry, and a renowned weekend digger. "Sometimes you really don't know what you have until you start putting it all together. Finding a good specimen is really exciting, but restoring it to top condition is a close second."
With the unprecedented quality and quantity of specimens being unearthed in the Rochester Shale quarry at Lockport, science is being provided with a unique glimpse of what life was like in those long-ago Silurian seas. Arctinurus trilobites exhibiting bite marks from some unknown predator (many wounds showing healed spines and appendages), Dalmanites possibly exhibiting sexual dimorphism and Trimerus growth series specimens ranging from less than an inch to over seven inches in length, have provided paleontologists with an unprecedented depth of information concerning ancient sea life.
Quite simply, the finds at the Lockport quarry are helping to bring "alive" creatures that have been dead for more than 400 million years! It is exciting, unpredictable and satisfying work, with the incredible specimens being uncovered more than compensating for the back breaking labor involved with each and every discovery. For those with a touch of imagination, the notion of unearthing these unique treasures of our planet's past holds a fascination few other earthly delights can match.
"I can't wait to see what we discover next," Meyer exclaimed. "I think we may have just touched upon what's within those rocks. Recently we came up with a previously undescribed Proetid trilobite - and that's just a start! There are millions of years of treasures out there just waiting for us to find them.”