Courtesy Radiological Society of North AmericaUsing state-of-the-art medical scanning and printing technology, German paleontologists have been able to scan and reconstruct a dinosaur vertebrae that survived a World War II bombing raid that left hundreds of fossils unidentified. Dug out of a clay pit south of Halberstadt, Germany in the early 20th century, the fossil was jacketed in plaster (for protection during transportation from the field) and stored in the basement of the Museum für Naturkunde in Berlin along with numerous other fossils from Halberstadt in southern Germany and another dig site in Tanzania. When the Allies made a bombing raid over Berlin during WWII, a portion of the museum was hit and collapsed, leaving the poorly labeled fossils in one big messy pile of plaster jackets and rubble. Museum workers sorted the jacketed fossils from the rubble but which fossil came from which dig? The labeled plaster jackets gave no clue.
Courtesy Mark RyanModern technology came to the rescue from technicians from the Department of Radiology at Charité Campus Mitte in Berlin. One of the jacketed fossils was first scanned with a CT (computed tomography) scanner - similar to those used to scan and diagnose medical patients. Because the radiation absorption (attenuation) of the fossil differs from that of the surrounding matrix - the rocky material in which the fossil is encased - making it easy to outline and create a digital copy of the fossil. The resulting image was compared to field drawings from the two expeditions and identified as a vertebrae of a Triassic Period prosauropod known as a Plateosaurus. The dataset was entered into a computer, cleaned up a bit, and then fed into a 3D printer where - layer by plastic layer - an exact replica of the hidden and unprepared fossil was "printed" in 3-dimensions.
CT scanning and 3D printing of fossils has been in use for a while now but this is a first time paleontologists have been able to identify and copy a dinosaur bone still encased in a matrix wrapped in a plaster field jacket.
In the past, this couldn't have been done without first cutting open the field jacket and spending long hours of detailed lab preparation - i.e. removing all the matrix from around the fossil. Making copies of fossils usually entails creating molds using rubber or something similar, then filling the void with plaster or other casting materials. Now with 3D printing technology, exact (or scaled) duplicates of important fossils can be created and shared with scientists or schools for study and comparison. The dataset of the scan can serve the same purpose.
Both the cost and size of the technology have been reduced in recent years, making it both affordable and portable for many museums. The following videos show the processes in action. Desktop scanning of dinosaur bones and the printing a dinosaur skull with a simple desktop 3D printer.
Courtesy Public domain via WikipediaI didn't enter anything this year but despite the 16 day government shutdown the 4th annual National Fossil Day Art & Photography Contest had plenty of submissions from other folks around the country. This year's theme was "Your nomination for a National Fossil". I'm not sure everyone's artwork expressed that but there are many fine pieces.
Courtesy Mark RyanIt's Earth Science Week and this year's celebration centers around maps and mapping and their importance in geology and other earth sciences. Then on Saturday, October 19th from 1-4pm, the Science Museum of Minnesota is celebrating National Fossil Day with some special fossil-related exhibits throughout the museum. This year's theme is Paleozoic life, which is exactly the types of fossils commonly found in the southern half of Minnesota. Unfortunately, the official National Fossil Day website is closed due to the US government shutdown that continues, but that shouldn't stop anyone from celebrating fossils. Join us Saturday for some fossil fun.
Courtesy Mark RyanA new study appearing in Biology Letters shows that trilobites - everyone's favorite prehistoric water bug - developed an effective survival strategy much earlier than previously thought.
Trilobite fossils from Early Cambrian rock formations in the Canadian Rockies and elsewhere lend evidence that some of the earliest trilobites used enrollment (i.e rolling themselves up into a ball like an armadillo) to protect themselves from predators or the environment. Trilobite fossils found here in Minnesota are several million years younger dating back to the Late Cambrian through Late Ordovician Periods (500 - 430 mya) and are often found enrolled. It was an effective survival strategy.
Trilobites were arthropods, which meant they possessed exoskeletons, segmented bodies and jointed appendages. Their closest extant relative is the horseshoe crab. Trilobite bodies - for the most part - were comprised of a head (cephalon) positioned on a body (thorax) that was divided into three lobes: essentially an axial dividing a left and right pleura, and a tail (pygidium). The mouth (hypostome) was located on the underside. It's thought that most early trilobites were predators and/or scavengers who spent their lives roaming the sea floors looking carcasses, detritus or living prey to feed upon. Most trilobites possessed complex eyes (although some were eyeless). Like other arthropods (e.g. today's lobsters), trilobites would outgrow their exoskeletons, discarding them (molting) as they grew in size or changed shape. Their newly exposed soft skin soon hardened into a new, tough, outer casing. Once hardened, their segmented exoskeletons (composed of calcium carbonate) were ventrally flexible, giving them the ability to roll up into a ball should they need sudden protection from whatever threatened them.
Some early trilobite forms from Middle Cambrian-aged fossils had been viewed as incapable of enrolling but the new research based on much older fossils found in mudstones in the Canadian Rockies in Jasper Park pushes back the origins of the strategy to some of the earliest trilobites to appear in the fossil record (Suborder Olenellus). These appeared 10-20 million years earlier at the very beginnings of the Cambrian Period and show evidence of having already developed the ability to enroll.
Trilobites in some form or another existed across a span of more than 270 million years, a very successful run by any measure. The enrollment strategy certainly contributed to their longevity. Although trilobites were already in decline, the last of their kind were wiped out in the great extinction event that marked the end of the Permian Period and the start of the Triassic. They weren't the only casualty of the extinction: nearly 90 percent of Earth's species were terminated along with them.
Even though trilobites are extinct (they died out in the Permian Mass Extinction along with around 90 percent of Earth's species) they were an extremely successful and adaptable life form. No wonder they remain today a favorite among fossil collectors.
Courtesy ap2il via FlickrOne of the strangest creatures to emerge from the famed Burgess Shale in the mountains of British Columbia, is the rightly named Hallucigenia, a strange spiky, wormlike creature that once scuttled across the Cambrian sea bottom more than 500 million years ago. Originally considered a totally unique (and baffling) creature, Hallucigenia has now been linked to other similar-aged wormlike creatures found around the world.
Hallucigenia first came to light in 1909 after Charles Doolitle Walcott, an expert in trilobites and secretary of the Smithsonian Institute, discovered a Lagerstätte in the mountains of British Columbia that was unlike any other found before.
Courtesy Mark RyanLocated in Yoho National Park on a steep slope between Mount Field and Wapta peak above the railroad town of Field, B.C., Walcott's quarry produced some of the strangest creatures - many of them soft-bodied and rarely found in the fossil record. The rock section, previously known as the Stephens Formation became known as the Burgess Shale, after nearby Burgess Pass. In the years following the discovery, Walcott and other scientists studied the strange fossils in an effort to decipher them and the environment in which they had lived and died.
Because of the high degree of preservation, the creatures that made the fossils were most likely buried suddenly in some sort of giant underwater mudslide that quickly entombed an entire marine community in an anoxic environment where decomposition was stifled. A perfect environment for preserving the soft-bodied tissue.
Courtesy Mark RyanSome of the Burgess Shale denizens appeared to be of completely new and unknown phyla with bizarre and unfamiliar body plans and no known descendents in the modern age. Hallucigenia certainly led the pack in this department. The tiny strangely constructed worm was only about an inch in length and confounded Walcott and other scientists for more than a century. They couldn''t even say for sure which side was up or down. Early Hallucigenia fossils showed a row of seven tentacles along one side. The opposite side contained seven sets of stiff spikes that were interpreted to be legs. A truly bizarre, aptly named freak-show creature that would be right at home in your average nightmare.
New evidence can often turn an old idea on its ear - or in this case, on its back. Recent scrutiny of newer, better-defined Hallucigenia fossils has revealed another set of "tentacles", leading scientist to realize they had Hallucigenia all flipped around. What they once thought was its top side was actually its bottom. Its dorsal "tentacles" were actually its legs. And its spiky "legs" belonged on its back, probably to serve as protection against predators.
This information along with a new study published in Proceedings of the Royal Society B now places Hallucigenia within a group of other worm-like creatures whose fossils are found around the world, including China, Canada, Great Britain, and Australia. It also links it to a living group - Onychophora - the velvet worms that mostly inhabit the tropical forests of the Southern Hemisphere.
"They may not be exactly the same species, but they are all probably related to the same group of worm-like creature that we call lobopods," said Dr. Jean-Bernard Caron, curator of invertebrate paleontology at the Royal Ontario Museum and the study's lead researcher. Caron is an expert in Burgess Shale fossils and his study of Hallucigenia and other fossils from the formation continues to glean new knowledge about the strange creatures that existed in the so-called Cambrian Explosion. Check out Caron's Burgess Shale website. It's full of great information about the quarry and the incredible fossils found there.
Courtesy Mark RyanWalcott's Burgess Shale quarry has been designated a World Heritage site. The only way to visit it (or the fossil fields on nearby Mt. Stephen) is through guided hikes led by either Parks Canada or The Burgess Shale Geoscience Foundation. The 10 hour round-trip hike (rated moderate to difficult) takes participants up 2500 feet in elevation to Mt. Fields and requires reservations and a deposit. Fossil collecting is prohibited but the views are said to be spectacular.
SOURCE and LINKS
The Province story
The Burgess Shale at Smithsonian website
Dr. Caron's Burgess Shale website
Parks Canada Burgess Shale info
Courtesy Mark RyanI've had the great fortune of being able to volunteer in the paleontology lab at the Science Museum of Minnesota. I'm in my fourth month there and it's been a real blast. My first project was preparing (cleaning) the skull of a small oreodont collected from the White River Formation in Wyoming. This is the same formation exposed in the fossil-rich South Dakota Badlands. By cleaning, I mean removing all the rock (matrix) in which the skull is encased. I've also helped patch up the casts of a couple of lambeosaurus skulls, and spent a few days puzzling over a crocodile skull reduced to about 1000 pieces.
Courtesy Mark RyanAt the moment, preparators been working on the remains of a 52 million year-old gar collected from the Green River Formation in southwestern Wyoming. Most of the work is being done by the more experienced volunteers in the lab but I've been able to help a little, taking my turn with the air scribe to reveal some caudal scales in their rocky grave. This particular specimen, an ancient member of Lepisosteus, was collected in Lincoln County, Wyoming. It's fascinating work uncovering something that last saw sunlight more than 50 million years ago. Now, at least, its remains can bask in the glare of the paleo lab's artificial lights.
Courtesy Mark RyanFifty some million years ago, the gar lived in a large body of water known as Fossil Lake, one of three intermountain lakes that existed at different times in a sub-tropical environment in that part of Wyoming. The intermountain basin in and around the lake teemed with both floral and faunal life that over about 4000 years lived and died and were fossilized forming one of the great Lagerstätten in the world. The surrounding mountains were composed mainly of limestone, and the rivers and streams eroding those mountains carried high levels of calcite (CaC3) into the lake, resulting in a high sedimentation rate that added to the ideal fossilization environment.
Most of the fossils coming out of the Fossil Lake strata have been fossilized by a process called permineralization, where mineral-rich water permeates all the spaces and pores in the skeleton and the minerals (in this case calcite) crystallize out of the water replacing bone material down to the cellular level. Some carbonization is also involved. This process depletes the remains of volatiles and is caused by the heat and pressure of sediment compression, which also crushes and flattens the fossils, and tends to color them either brown or black.
Courtesy Mark RyanThat's very apparent with our gar. Although only portions of the fish's remains have been exhumed (its head and tail) the fossil is already providing some information about what followed the gar's death (taphonomy). Lepisosteus favored the shallow, swampy edges of Fossil Lake and when it died it probably floated on the surface for a while giving bacteria time to enter its mouth and gills and begin their decomposition work before the corpse was buried beneath sediments.
We can deduce this scenario by the manner the remains are preserved. The bones of the gar's skull and jaws are scattered and jumbled in a mish-mash of bones and scales. The head appears to have been blown apart, and that's probably what happened. As the microbes feasted on the fish's head, they released gases inside the corpse which built up, and bloated the gar to a point where it burst from the internal pressure. The mandibles, the cranium, and other bones broke apart before settling to the bottom and are disarticulated. The very end of the tail, however, shows no such disruption. The rays of the caudal fins looking almost as fresh as they did when the gar died half a million centuries ago.
Courtesy Mark RyanThe scales of its mid-section are beginning to come to light. These diamond-shaped structures were covered with ganoin, an enamel-like tissue containing less than five percent organic material. The mineralized tissue gave Lepisosteus a very tough, predator-resistant exterior when it was alive but not so resistant to the bacteria that attacked the gar from the inside after it died. Preliminary work of the mid-section is showing signs of decomposition there but further work required.
One of the major experts on the fossils found in the Green River Formation is Lance Grande, a graduate of the University of Minnesota (and elsewhere) who has been working at Chicago's Field Museum for the past few decades. In the early '80s, Dr. Grande wrote a hefty bulletin titled Paleontology of the Green River Formation for the Wyoming Geological Survey, and has now come out with a new book titled The Lost World of Fossil Lake: Snapshots from Deep Time. In a recent television interview, Dr. Grande talked about his book and about the fossils found in the Green River Formation.
Hundreds of thousands of finely preserved fossils from Fossil Lake deposits can be found in museum displays and on rock shop shelves world-wide. The best fossils were buried quickly and preserved in near pristine condition. Many of these come from what used to be the deep center of the lake where conditions were probably anoxic and burial fairly swift. At times during Fossil Lake's history events like seasonal algal blooms or rapid turnovers of the water column occurred and caused massive die-offs of fishes. Other fish, like our gar, probably just died a regular death.
Courtesy Mark RyanEvery fossil tells a story, and our gar is no exception. Back in the Eocene epoch it lived for a short time in the then subtropic environment of southwest Wyoming, doing what gars do before it finally died along the shores of Fossil Lake. After it was buried, it was fossilized, dug up, and transferred to the collections vault of the Science Museum of Minnesota. A few months ago, it was retrieved from the vault and brought into the paleo lab where it's been worked on each week by several people. Whatever the gar was thinking when it was alive back in the late Eocene, you can be sure it was unaware that its post-mortem life would provide hours of detailed work, study and fascination for another curious life-form 52 million years later.
SOURCES AND LINKS
Courtesy Mark RyanIn response to last week's tragedy at the fossil quarries in Lilydale Regional Park, science writer Anne Brataas has written about the importance of continuing the practice of taking field trips outside the classroom, despite the inherent dangers real life can present.
Brataas is the CEO and founder of The Story Laboratory, LLC, as well as an instructional designer and science historian.
Courtesy Mark RyanA rescue effort is underway right now in St. Paul where three children are reported to have gotten stranded in Lilydale Regional Park. A helicopter and several rescue units are on site. Two children has already been recovered and taken to hospital but one child is still missing. The children were part of a group of 4th-graders on a field trip from St. Louis Park.
Lilydale is a popular fossil collecting site for school field trips and others but the Decorah shale in the quarries where most of the fossils are found can become very treacherous in wet weather. The crumbly shale reconstitutes into a very thick, slippery muck when it rains making the steep quarry walls very unstable. Three inches of rain have fallen in the Metro area over the past few days.
A firefighter reportedly sustained injuries to his head from a falling rock during one of the rescues. Let's hope everything else turns out okay.
Courtesy Mark RyanDo you like fossils? Do you like to draw or take photographs? Then you should know that the 4th annual National Fossil Day Art and Photography Contest is now accepting submissions. The contest runs until next autumn (submissions must be postmarked by October 4th) when judges will select the winning entries. It's all part of the many celebrations of fossils that take place across the country on and around the official National Fossil Day on October 16, 2013. The celebration is a combined effort by the National Park Service along with several federal and state agencies, and earth science related organizations.
There are four age categories: ages 5-8, 9-13, 14-18, and for us old-timers, 19 and up. You can find all the information you need here on the official National Fossil Day contest site.
This year's contest theme is: "Your nomination for our National Fossil". Maybe you think it's should be a dinosaur, or a trilobite, or one of the famous fossil fish found in the Green River shales of the western USA? Whatever you think, get out your pencils, pens, paints, or cameras and make your case for our national fossil.
By the way, Minnesota is one of 10 states in the union lacking an official state fossil. That needs to be remedied. Do you have a favorite fossil found in Minnesota? Maybe you found one yourself at one of the fossil collecting sites around the Twin Cities. If so, let us know in the comments.
Courtesy Peabody Museum of Natural History, Yale UniversityOn this day in 1877, railroad worker William Harlow Reed came over a ridge-top with the remains of a freshly killed antelope slung over his shoulder, and spotted huge fossilized bones exposed on the side of the steep bluff located a half-mile south of Como Station, a desolate railroad stop on the High Plains of Wyoming. It was a discovery that would forever change his life.
Reed and station master, William Carlin, began collecting up as much as they could, dreaming of money and employment other than railroad work. They waited several months before announcing the discovery in a letter to Yale professor Othniel C. Marsh, at the time one of America's prominent paleontologists. When a crate of bones - along with the guarantee of many more - arrived at Yale, Marsh realized they were dinosaur remains and hired both men to excavate and send him as much as they could, and to keep out any interlopers to his claim. Marsh knew if he could keep it secret - at least for a short time - the fossils at Como Bluff could give him a huge advantage in his rivalry with Philadelphia paleontologist, Edward Drinker Cope, and their notorious Bone Wars.
Courtesy Mark RyanThe dinosaur-rich strata at Como Bluff (the Morrison Formation) are found in the exposed flanks of an anticline (an upward fold), the center of which has been carved out by erosion [see diagram]. All three periods of the Mesozoic Era (Triassic, Jurassic, Cretaceous) are represented in the rock layers found there. Besides dinosaurs, fossils of fish, crocodiles, flying and swimming reptiles have also been found there. A significant number of important Late Jurassic mammalian fossils were discovered and collected by William Reed from Quarry 9 on the east end of Como. Reed also discovered and removed the great Brontosaurus excelsus skeleton that stands today in Yale's Peabody Museum.
Courtesy Peabody Museum of Natural History, Yale UniversityIn the years following its discovery hundreds of tons of dinosaur remains quarried at Como Bluff were shipped to Yale and other institutions pushing America into the forefront of vertebrate paleontology, and heavily influencing how museums would be constructed throughout the world.
Courtesy Mark RyanThe dinosaur halls at the American Museum of Natural History have several mounted specimens found at Como Bluff as does the Smithsonian in our nation's capitol. Well-known genera like Allosaurus, Diplodocus, Apatosaurus, Stegosaurus and Camptosaurus are just a few of the dinosaurs pulled from the mudstones and sandstones at Como Bluff. In the early 20th century it was thought that Como had exhausted its supply of dinosaur remains and exploration there for the most part tapered off for several decades. But in recent years, paleontologist Robert Bakker has been re-examining the quarries and uncovering additional secrets still buried in the Jurassic bluffs at Como.
Courtesy Mark RyanWilliam Reed worked for Marsh for several more years and the two men remained friends until the Yale professor's death in 1899. Reed continued in the field of paleontology, working independently, and for a time with the American Museum of Natural History in New York, and the Carnegie Museum in Pittsburgh. He finished out his career as a popular geology professor and museum curator at the University of Wyoming, just sixty miles from Como Bluff, the great dinosaur graveyard that changed not only the course his life but also that of American paleontology.
Como Bluff was added to the National Register of Historic Places in 1973. It's also been designated as one of Wyoming's National Natural Landmarks by the National Park Service.