Courtesy Eduard Solà via WikipediaIf you missed last week's PBS broadcast of Your Inner Fish, the documentary based on paleontologist-anatomist Neil Shubin's book by the same name, you have another chance to catch up on the first of three segments on the web. It's an excellent opening segment of the 3-part series, but is only available (for free!) right here through April 23, 2014.
The series deals with Shubin's search for the connections we all have with our fishy and reptilian ancestors. His discovery of the remarkable transitional fossil named Tiktaalik roseae on Ellesmere Island in the Canadian Arctic has added great evidence of our ties with our distant piscean relatives. The flat-headed, 375 million year-old Tiktaalik possessed the exact features - such as both lungs and gills, a wrist and neck - that you'd hope to find in a transitional form between swimming fish and land-walking tetrapods.
The next episode, titled Your Inner Reptile airs Wednesday, April 16th on your local PBS station. It's on here in the Twin Cities at 9pm but check your local listing for times in your area.
Courtesy Mark RyanResearchers from the University of Miami Rosentiel School of Marine and Atmospheric Science have detected a new, massive magma chamber beneath Kilauea, the most active volcano in the world.
By analyzing seismic waves that traveled through the volcano, scientists from the school's geology and geophysics departments have been able to piece together a 3-dimensional velocity model of what's taking place deep below the volcano's caldera.
"It was known before that Kilauea had small, shallow magma chambers," said Guoqing Lin, lead author of the study. "This study is the first geophysical observation that large magma chambers exist in the deep oceanic crust below."
Located in oceanic crust between 5 and 6.8 miles beneath the volcano's East Rift Zone, the new chamber has been determined to be several kilometers in diameter. The seismic data also revealed that it's lava is composed of a slushy mixture of about 10 percent magma and 90 percent crystal.
According to co-author and professor of geology and geophysics, Falk Amelung, the information is useful in understanding magma bodies and a high priority for the researchers because of the possible hazards created by the volcano.
"Kilauea volcano produces many small earthquakes and paying particular attention to new seismic activity near this body will help us to better understand where future lava eruptions will come from," he said.
Kilauea has been active for more than 30 years and is located in Hawaii Volcanoes National Park on the Big Island of Hawaii.
The paper appeared in a recent edition of the journal Geology.
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 National Portrait GalleryLast month, on November 22nd, while many people in the country were observing the 50th anniversary of president John F. Kennedy's assassination by shots fired from the Texas School Book Depository, there was another significant event happening that day involving Texas schoolbooks. That same Friday, despite objections and obstructionist tactics by creationists, the Texas Board of Education approved several public school science textbooks that included full coverage of evolution and climate change. The vote came late in the day and although the creationist faction did manage to make the adoption of two biology books contingent on a committee ruling regarding some alleged "flaws" in the text, the Texas Freedom Network (TFN), a watchdog group instrumental in countering the irrational creationist attacks, expects the passage to stand.
“It’s hard to overstate the importance of today’s vote, which is a huge win for science education and public school students in Texas,” said Kathy Miller, TFN's president. “Four years ago this board passed controversial curriculum standards some members hoped would force textbooks to water down instruction on evolution and climate change. But that strategy has failed because publishers refused to lie to students and parents demanded that their children get a 21st-century education based on established, mainstream science.”
Courtesy Mark RyanA new and troubling paper from the Committee on Understanding and Monitoring Abrupt Climate Change and its Impacts predicts possible and somewhat grim outcomes for some of Earth's natural systems from climate change that could rival the extinction event of the non-avian dinosaurs at the end of the Cretaceous Period 65 million years ago.
The abrupt impact could be coming faster than previously expected and would negatively affect human and physical climate systems as well. The document warns that the abruptness of the changes could be unanticipated and could find us unprepared to deal with them
Records of past climate preserved in tree rings, ice cores, and ocean sediments show that the atmosphere contains higher levels of carbon dioxide than it has in a very long time. Carbon emissions from human activity continue to add to this rising concentration. Other activities including deforestation and resource extraction place additional environmental pressures on our climate and other natural systems.
At the end of the Cretaceous, all species of non-avian dinosaurs, along with the megafauna of flying and swimming reptiles were wiped off the face of the Earth. Many dinosaur species showed signs of decline even before the Chicxlub asteroid delivered the final kibosh on their existence.
Dr. James W.C. White, a professor of Geological Sciences and of Environmental Studies at the University of Colorado at Boulder chaired the committee which included more than a dozen earth scientists and ocean researchers from universities in both Canada and the United States, and from the National Academy of Science.
A prepublication copy of the entire 201-page paper is available to read without charge on the National Academies Press page. You can also download it for free although it was a little tricky getting it to my computer.
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.
With the announcement of the Ultimate Dinosaurs: Giants of Gondwana exhibit comming to the Science Museum of Minnesota, I was thinking back to all the questions I have had regarding dinosaurs.
Courtesy Mark Ryan
Questions like: "Who gets to name Dinosaurs?" "What is this dinosaur named after?" and "What does this name mean?". I thought that I'd take some time here to answer these questions.
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 WikipediaFilm goers will have the chance to travel through space this weekend with the blockbuster movie "Gravity" hitting the theaters. Its a ficticious story about two American astronauts dealing with disaster during a space shuttle mission.
I've come to expect Hollywood to place loose and easy with actual science when it comes to movies with scientific themes. And then today I stumbled upon this article in Time by Jeffrey Kluger, the co-author, with astronaut Jim Lovell, of Lost Moon: The Perilous Voyage of Apollo 13, which was the basis of the Apollo 13 movie released in 1995.
He applies his extensive space knowledge to fact check what's depicted in the new George Clooney/Sandra Bullock film. Here's his analytical summary: "So, that’s a lot that Gravity gets wrong. But you know what? So what? The shuttle, space station and spacesuits are painstakingly recreated; the physics of moving about in space—thrusts requiring counterthrusts, spins requiring counterspins, the hideous reality that if you do go spiraling off into the void your rotation never, never stops—are all simulated beautifully, scarily and accurately."
Click on the link above to get detailed analysis of what's scientifically right and wrong with Gravity.
Have you seen the film? What do you think about its accuracy in portraying the science of living and traveling in space?