Courtesy M. R. Smith / Smithsonian InstituteOne of the strangest and more mysterious critters that scurried across the Middle Cambrian seafloor has baffled paleontologist since it was first identified in the 1970s. Was it a worm? Which side was up? Did it have legs or spikes or both? Was its head actually its tail? Did it have any extant descendents or was it an evolutionary dead-end? The worm-like creature was so baffling and so bizarre, it was given the very apropos name of Hallucigenia.
The tubular, spiked-worm possessed seven or eight pairs of legs and ranged in length from 2/5th of an inch to one and 1/4 inches and looks like something out of a bad dream. Early interpretations of their fossils were all over the map. The stiff spikes on it back were first thought to be its legs, and its legs misidentified as tentacles. What was thought to be its tail ended up being its head.
Using modern imaging technology, researchers from the University of Cambridge have been closely studying fossils from the famous Burgess Shale quarry located high in the Canadian Rockies, and are uncovering Hallucigenia's secrets. By studying the claws at the end of its legs they have been able to link it to modern velvet worms (onychophorans). Scientists have long suspected the two were somehow related but until now have failed to find anything significant to prove it. By studying Hallucigenia's claws they've determined that they're constructed of nested cuticle layers, very similar to how the jaws of velvet worms are organized. The similarity is no surprise since jaws are known to have evolved from a modified set of front legs.
But besides giving Hallucigenia a place in the lineage of life on Earth, the Cambridge team during the course of their study also discovered something else: that arthropods - which include crustaceans, spiders, insects and trilobites - aren't in fact as closely related to velvet worms as previously thought.
“Most gene-based studies suggest that arthropods and velvet worms are closely related to each other," said co-author Dr Javier Ortega-Hernandez. "However, our results indicate that arthropods are actually closer to water bears, or tardigrades, a group of hardy microscopic animals best known for being able to survive the vacuum of space and sub-zero temperatures – leaving velvet worms as distant cousins.”
SOURCE and LINKS
Courtesy Paul J. MorrisNOVA's excellent 4-part documentary series "Australia: First 4 Billion Years" is scheduled to re-broadcast on July 16th, 23rd, 30th and August 6th. Check your local PBS schedule for times. But if the dates don't work for you, the entire series is (or at least was when I watched it) on YouTube. Here are the links:
The series is beautifully put together with gorgeous high definition video shot in locations all over Australia. The host, biologist Richard Smith, explains the science in a thoughtful and comprehensible manner while introducing viewers to many of the continent's stunning topographical features, and the strange and wonderful lifeforms - both past and present - found there. It's well worth your time.
Courtesy Mark RyanBritish paleontologist Phil Manning from Manchester University has been using 21st century technology to study prehistoric injuries on dinosaur bones.
Courtesy Mark RyanManning and his team of researchers employed a particle accelerator called a synchrotron rapid scanning X-ray fluorescence (SRS-XRF) to analyze and compare the chemical compositions of both healed and healthy bone of a 150 million-year-old Allosaurus fragilis, and those of a modern turkey vulture (Cathartes aura). Both animals are members of a group known as archosaurs that includes pterosaurs, and alligators and other crocodilians. The SRS-XRF directed intense beams of light ten billion times brighter than our sun onto areas of fossilized dinosaur bone that showed signs of injuries (pathologies) and healing that had occurred while the creature was alive. The same instrument was used previously to analyze the remains of both Archaeopteryx and Green River Formation fossils, revealing organic traces not detectible in visible light.
In the current study. thin sections made from the toe bones of Allosaurus fragilis unearthed from the Cleveland-Lloyd quarry in Utah were prepared at a Temple University facility in Pennsylvania, and then sent to the Stanford Synchrotron Radiation Lightsource in California for scanning. The Allosaurus sample was also analyzed at the Diamond Light Source (DLS) in Oxford, England.
During the analysis, a suite of trace-metal enzymes - copper, zinc, and strontium- all integral to the process of healing bone were detected. Copper plays a role in the strengthening the structure of collagen, zinc aids in ossification (the creation of new bone material), while strontium inhibits the break-down of bone cells. Enzymes composed from the same three elements are used for growth and repair in our own bones.
Normally when a bone suffers some kind of trauma, such as a fracture, the body repairs it by rebuilding new bone in much the same way it did when the skeleton first formed. Manning's fossil bone sections exhibited chemical ghosts of these essential elements in elevated amounts in the injured bone section than seen in the healthy bone surrounding it.
Courtesy Mark Ryan “It seems dinosaurs evolved a splendid suite of defense mechanisms to help regulate the healing and repair of injuries," Manning said. "It is quite possible you've got a reptilian-style repair mechanism combined with elevated metabolism, like that you'd find in alligators and birds respectively. So you've got a double whammy in a good way. If you suffer massive trauma, you've got the perfect set-up to survive it."
The SRS-XRF provides scientists with a superior method in analyzing and comparing the chemical processes involved with bone-building and healing that weren't discernible in the older histological examination methods used in studying thin sections, and could lead to further knowledge of how not only dinosaur bones - but our own - grow and repair themselves.
“The chemistry of life leaves clues throughout our bodies in the course of our lives that can help us diagnose, treat and heal a multitude of modern-day ailments. It’s remarkable that the very same chemistry that initiates the healing of bone in humans also seems to have followed a similar pathway in dinosaurs,” Manning said.
Courtesy Mark RyanOver in China, out of one of the richest hunting grounds for new and unusual dinosaur-era fossils, the earliest known member in the family of flying reptiles known as pterosaurs has been described in a paper published in Current Biology.
The flying reptile's name essentially means "first-born hidden serpent", the genus name Kryptodrakon referring to the popular martial arts film, "Crouching Tiger, Hidden Dragon" which was filmed near the location where the fossil was discovered in the Chinese autonomous region known as Xinjiang.
Sporting a wingspan of some 4.5 feet, Kryptodrakon lived in a floodplain environment during the Middle-Upper Jurassic period, about 163 million years ago. Descendents of the newly-discovered pterodactyloid would evolve into much larger flying reptiles such as the giant, Cessna-sized Quetzacoatlus found in Late Cretaceous sediments in Texas. Pterosaurs were not dinosaurs but share a common ancestor with them.
The research increases our knowledge of pterosaur development and was led by Brian Andres from the University of South Florida (USF), James Clark of George Washington Columbia College of Arts and Sciences, and Xu Xing of the Chinese Academy of Sciences.
This BBC documentary produced a few years back provides some valuable insight and information involving some of the dinosaurs included in the Science Museum of Minnesota's new upcoming exhibit Ultimate Dinosaurs which opens March 1.
Courtesy Mark RyanMy plan following my inevitable demise has long been to be cremated and have my ashes dumped into Amity Creek from the seventh stone bridge along Seven Bridges Road in Duluth, Minnesota so they eventually end up in Lake Superior some two miles downstream. But now, after watching this nifty and informative video detailing how to become a fossil, I may reconsider and just have my intact carcass dumped into the creek so it ends up at the bottom of the Great Lake and gets covered by sediment that eventually turns my bones to stone. Who knows? - some future reader of this post may be able to view my fossilized remains at some museum exhibit.
Courtesy FunkMonk via Wikimedia CommonsThe partial remains of a somewhat rare sauropod dinosaur have been discovered in Old Snowmass, near Aspen, Colorado. Paleontologist John Foster of the Museum of Western Colorado in Grand Junction said that fossils of a Haplocanthosaurus were found by college student Mike Gordon in 2005 on land owned by his mom and stepfather. If you remember, Snowmass was the site near Aspen where a large collection of mammoths, mastodons, and other Ice Age mammals were uncovered back in 2010. This latest discovery is about six miles from the other site but in a much, much older rock layer. Foster said the Lower Morrison Formation, from where Haplocanthosaurus remains were collected dates back to the Late Jurassic, about 155-152 million years ago.
It's a very exciting find because few specimens of Haplocanthosaurus exist. The first were also found in Colorado, in Garden Park near Canon City, by Carnegie Museum of Natural History paleontologists William H. Utterback and John Bell Hatcher in 1901. The type specimens (H. priscus and H. utterbacki) were described by Hatcher in 1903. The fossils were prepared under the direction of chief preparator, Arthur S. Coggeshall.
Courtesy ScottRobertAnselmo via Wikimedia CommonsCompared to its larger and heavier long-necked, small-headed cousins such as Apatosaurus and Diplodocus, the Haplocanthosaurus was a relatively small-sized sauropod dinosaur with a length of 35 to 40 feet and weighing maybe 14 tons. While most sauropods have hollow spaces in their backbones, a distinguishing characteristic of Haplocanthosaurus is the solidness of its vertebrae which Foster confirmed by doing a scan of the fossil bones at a local hospital in Grand Junction.
Courtesy Mark RyanThe only mounted specimen of Haplocanthosaurus is the referred species (H. delphsi) on exhibit at the Cleveland Museum of Natural History in Ohio. No skull of the sauropod has ever been found so the head is just a fabricated guess. Other post-cranial remains exist, including some here at the Science Museum of Minnesota that were collected in Wyoming, but in general fossils of the dinosaur are rare. Material from only 10 individuals are known.
So far the Old Snowmass site has provided some vertebrae, ribs and a pelvis. but the landowners have been very accommodating in allowing the museum access to the dig site, and Foster hopes to find more Haplocanthosaurus bones - maybe even some skull material - in the coming summer season.
SOURCES and LINKS
Aspen Times story
More Haplocanthosaurus info
Osteology of Haplocanthosaurus by John Bell Hatcher
Jurrassic West: The Dinosaurs of the Morrison Formation and Their World by John Foster
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.