Dinosaur eggs and nesting behaviors: A paleobiological investigation. 2006. Gerald Grellet-Tinner et al. Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 232: 294-321.
Abstract: Although dinosaur eggs were first discovered and identified in the late 1800s, limited attention was given to the scientific value of oological fossils in contrast to observations based on skeletal features. Here, we offer a review of Mesozoic saurischian egg materials, in comparison with extant crocodilians and avians, and their paleobiological interpretation based either on the presence of embryos in ovo or brooding adults on egg clutches.
Our study focuses on the eggs of the oviraptorid Citipati osmolka (Mongolia), the troodontid Troodon formosus (North America), the theropod oospecies Macroelongatoolithus xixiaensis (China), the ornithothoracine bird (Argentina), an indeterminate theropod (Thailand), and titanosaurs (Argentina). Results show that (1) many oological characters and reproductive behaviors associated with modern birds are rooted among non-avian theropods, (2) there is a reproductive evolutionary cline from crocodilians to modern birds with (3) a noticeable pattern of coeval development between the accretion of eggshell layers, origination and size increased of larger air cells (inferred from egg polar asymmetry), and brooding/incubating behaviors.
Most of these pre-adaptations are grouped in two main clades of the saurischian cladogram: one at the level of Oviraptorosauridae and the other at Troodontidae. Although undeniably these two theropod taxa seem to represent two important phases for the evolution of avian reproduction, the phylogenetic distance between these clades and Titanosauria cannot be ignored. As such, the reproductive features that appeared in concert in oviraptorids might have gradually evolved across more basal theropod clades. Although Troodon formosus by its egg shape and nesting behavior seems to be in this study the precursors of modern avian reproduction, the importance of small-bodied theropods such as those who laid the Phu Phok eggs cannot be dismissed and the eggs of such dinosaurs could suggest a closer phylogenetic ties to Aves than troodontids.
At a higher level of inferences, there is a strong possibility that the evolution of these reproductive features is concurrent with profound physiological and metabolic changes that occurred in saurischian dinosaurs throughout their evolution.
Eggs from HERE.
Friday, March 31, 2006
The Emergence of Early Tetrapods
The emergence of early tetrapods. 2006. Jennifer A. Clack. Palaeogeography, Palaeoclimatology, Palaeoecology Vol. 232: 167-189.
Abstract: Study of Devonian tetrapods and their relatives spanning the so-called ‘fish–tetrapod’ transition has expanded almost exponentially in the last 15 years or so. This evolutionary event is now represented by at least nine named genera of Devonian tetrapod, several new ‘near-tetrapods’ and a number of new tetrapods from the Early Carboniferous.
The anatomy of Acanthostega has radically changed ideas about how this transition took place, and more recently the anatomy of Ichthyostega is being reassessed with some startling conclusions such as the unique construction of its ear region. The current state of research on this range of animals is summarized, followed by a consideration of the acquisition of limbs and digits among tetrapods including their possible forerunners, the development of digits and their original function, and the onset of pentadactyly.
The faunal relations and palaeoecological contexts of the Devonian tetrapods are brought together in an initial though necessarily brief survey, followed by an assessment of Devonian tetrapod diversity, which is seen to be much greater than previously realised. Finally, some hopes and ambitions for the future are set out.
Acanthostega from HERE.
Abstract: Study of Devonian tetrapods and their relatives spanning the so-called ‘fish–tetrapod’ transition has expanded almost exponentially in the last 15 years or so. This evolutionary event is now represented by at least nine named genera of Devonian tetrapod, several new ‘near-tetrapods’ and a number of new tetrapods from the Early Carboniferous.
The anatomy of Acanthostega has radically changed ideas about how this transition took place, and more recently the anatomy of Ichthyostega is being reassessed with some startling conclusions such as the unique construction of its ear region. The current state of research on this range of animals is summarized, followed by a consideration of the acquisition of limbs and digits among tetrapods including their possible forerunners, the development of digits and their original function, and the onset of pentadactyly.
The faunal relations and palaeoecological contexts of the Devonian tetrapods are brought together in an initial though necessarily brief survey, followed by an assessment of Devonian tetrapod diversity, which is seen to be much greater than previously realised. Finally, some hopes and ambitions for the future are set out.
Acanthostega from HERE.
Dinosaurs From The Chatham Islands
An Australian-based researcher said that he had found the first proof that land-dwelling dinosaurs lived on remote islands in the south Pacific.From Yahoo.News:
Jeffrey Stilwell, a fellow in palaeontology at Melbourne's Monash University, said he discovered the fossilized foot, finger and spinal bones of carnivorous dinosaurs on the Chatham Islands, about 850 kilometers east of New Zealand. The discovery confirmed that the Chathams were once connected to New Zealand by a finger-like extension, Stilwell told AFP.
"Prior to our discoveries, only a few isolated examples of dinosaur fossils had been found in the northern part of New Zealand," he said.
"Now we've found dinosaur remains almost 1,000 kilometers east out in the middle of the South Pacific," he said, adding that his team had already uncovered more dinosaur fossils in the Chathams than had been unearthed in New Zealand over the past 25 years.
While some dinosaur remains had been found along the Antarctic peninsula and in South America, this was the first such discovery in the southwest Pacific and is possibly unique in the southern hemisphere, he said. "They were on their own evolutionary path for probably 15 million years since the separation of the Chathams-New Zealand region some 85-80 million years ago," he said.
Stilwell found the first fossils by accident when he visited the Chatham Islands in 2003 in connection to other studies. But he said a subsequent trip to the islands in February yielded a "huge collection" of new fossils, which were still being analyzed.
Map from HERE.
Thursday, March 30, 2006
Today In History: Classification of Geological Eras
From Today In Science History:
In 1759, Italian geologist Giovanni Arduino (1714-1795) dated a letter to Professor A.Vallisneri the younger, in which Arduino proposed a classification of Earth's surface rocks according to four brackets of successively younger orders: Primary, Secondary, Tertiary and Quaternary. These are the four geological eras used today.
The volcanic rocks without fossils which he saw in the Atesine Alps that formed the cores of large mountains he called Primary. Overlying them, the fossil rich rocks of limestone and clay that were found on the prealpine flanks of the mountains he called Secondary. The less consolidated fossil-bearing rocks of the subalpine foothills, he named Tertiary, and the alluvial rock deposits in the plains were the Quaternary.
Image from HERE.
In 1759, Italian geologist Giovanni Arduino (1714-1795) dated a letter to Professor A.Vallisneri the younger, in which Arduino proposed a classification of Earth's surface rocks according to four brackets of successively younger orders: Primary, Secondary, Tertiary and Quaternary. These are the four geological eras used today.
The volcanic rocks without fossils which he saw in the Atesine Alps that formed the cores of large mountains he called Primary. Overlying them, the fossil rich rocks of limestone and clay that were found on the prealpine flanks of the mountains he called Secondary. The less consolidated fossil-bearing rocks of the subalpine foothills, he named Tertiary, and the alluvial rock deposits in the plains were the Quaternary.
Image from HERE.
More Evidence Chicxulub Was Too Early
A new study of melted rock ejected far from the Yucatan's Chicxulub impact crater bolsters the idea that the famed impact was too early to have caused the mass extinction that killed the dinosaurs 65 million years ago.From the GSA press release:
A careful geochemical fingerprinting of glass spherules found in multiple layers of sediments from northeast Mexico, Texas, Guatemala, Belize and Haiti all point back to Chicxulub as their source. But the analysis places the impact at about 300,000 years before the infamous extinctions that mark the boundary between the Cretaceous and Tertiary periods, a.k.a. the K-T boundary.
Using an array of electron microscopy techniques, Markus Harting of the University of Utrecht in the Netherlands has found that chemical compositions of the spherules all match what would be expected of rocks melted at the Chicxulub impact. The spherules are now found in several layers because after they originally hit the ground, they were "reworked" by erosion to create later layers of sediments, he said.
Above these, and younger still, Harting has also identified the famous layer of extraterrestrial iridium in sediments worldwide which was originally touted as the smoking gun for an impact somewhere on Earth at the K-T boundary.
Harting is scheduled to present his latest findings on Monday, 3 April Backbone of the Americas-Patagonia to Alaska. The meeting is co-convened by the Geological Society of America and the Asociación Geológica Argentina, with collaboration of the Sociedad Geológica de Chile. The meeting takes place 3-7 April in Mendoza, Argentina.
The sediments from the region are also providing clues to what transpired during those 300,000 years between the impact and the K-T boundary die-offs. "Nothing happened between them," said Harting. "The K-T iridium layer is a totally different event."
Disconnecting the Chicxulub impact from the K-T boundary also helps make sense of some other oddities in the iridium layer. In the Gulf of Mexico, close to the impact site, iridium is found at a weak concentration, just one part per billion, says Harting. Yet farther away in Denmark, higher concentrations of iridium are found. "This doesn’t really make sense," he said, unless, of course, the impact and iridium layer are not related.
All this begs the question: What, then, created the worldwide iridium layer, if not a humongous impact? One possibility is that Earth and perhaps the entire solar system was passing through a thick cloud of cosmic dust 65 million years ago.
"You probably have a time when lots of meteorites are coming down and never touching the ground," said Harting. Instead they burned up as "shooting stars," depositing their iridium in the atmosphere. There it was quickly rained out, washed into lakes and oceans and buried in contemporary sediments.
Crater from HERE.
Wednesday, March 29, 2006
Fossilized Embryos
Much of what scientists learn about the evolution of Earth's first animals will have to be gleaned from spherical embryos fossilized under very specific conditions, according to a new study.From EurekAlerts.com:
Purported animal embryo fossils have been reported continuously over the last 12 years, mainly by paleontologists working in China. Scientists disagree about whether the fossils are actually animal embryos or even if they are animals.
"The fossils look great. The problem is, if you know anything about embryos, their fossilization just doesn't seem likely," said IU Bloomington Professor of Biology Rudolf Raff, one of the report's authors. "It's like trying to fossilize soap bubbles. Some investigators showed that these fossils are being preserved with calcium phosphate, but they haven't explained how embryos could survive long enough for that to happen. We do that."
The dead spherical embryos do not last long under normal seawater conditions. If the cell's own degradation processes don't destroy it, nearby bacteria will. The embryos must die in the presence of a so-called "reducing" substance, such as hydrogen sulfide. Such reducing substances slow or stop the internal degradation processes that occur very soon after cells die and also inhibit voracious bacteria.
Hydrogen sulfide is known to have been present in the environment half a billion years ago, at the time of the animal kingdom's origin, and when the embryos died, because sulfur-containing pyrite ("fool's gold") is found in the fossils. Today, hydrogen sulfide exists in significant concentrations at the bottom of the ocean, especially in the vicinity of deep sea vents. Because hydrogen sulfide is extremely toxic (and flammable), the scientists used beta-mercaptoethanol, which exerts similar effects.
The scientists also found that embryo size does not influence the fossilization process. Sea urchin species whose animal embryos are small (a tenth of a millimeter) were just as likely to be fossilized as those of larger cousins (about half a millimeter).
Much mystery surrounds the sudden appearance of animals in the fossil record, between 500 and 600 million years ago. Within a few million years, the fossil record goes from zero evidence of animals to great diversity in animal forms, including anomalocarids and trilobites. Harvard University biologist and historian Stephen Jay Gould brought this "Cambrian explosion" to the popular consciousness in 1990 with his book Wonderful Life.
Images from HERE.
Hooke Manuscript To Stay In Britian
Britain's Royal Society has won a last-ditch battle to regain possession of one of its most valuable treasures, a seventeenth-century manuscript handwritten by the physicist Robert Hooke, which the society claims was taken from its archives some 300 years ago.From News@Nature.com:
The document, which contains Hooke's minutes of Royal Society meetings from 1661 to 1682, was discovered in a private house last year and was due to be sold at Bonhams auction house in London today. It was expected to fetch as much as £1.5 million (US$2.6 million).
With minutes to go before the lot was called, however, Bonhams chairman Robert Brooks announced that the Royal Society had closed a behind-the-scenes deal.
The Society paid about £1 million for the manuscript, it said in a press statement. It is unclear how it raised the funds; when the documents were discovered last year, Royal Society president Martin Rees said that the society could not meet the asking price.
Rees says they intend to provide digitized versions of the manuscript on their website as soon as possible, and will put the originals on display during their summer science exhibition between 3 and 6 July. Among its 520 pages are notes concerning Hooke's confirmation of the first sightings of microbes by Antoni van Leewenhoek, discussions with Isaac Newton about gravity, and smatterings of personal comments.
"Robert Hooke was a colossal figure in the founding of modern science, and these documents represent an irreplaceable record of his contribution. They provide an insight into one of the great minds of early modern science," says Rees.
Tuesday, March 28, 2006
The Cult of Ray
A recent fax from Ray Harryhausen reminds me to remind you all that the appropriately titled “The Art of Ray Harryhausen” is now available from better bookstores.
If you order a copy from www.budplant.com you may still be able to snag one of 300 signed copies that they are selling.
The above is one of Ray’s rare colour paintings, done circa 1938/9.
Tim "The Professional" Flannery
Today’s Globe and Mail as a long piece on Australian palaeontologist Tim Flannery who is touring Canada promoting his new book, “The Weather Makers”. Here's a bit of the story:
The Weather Makers is 35 brief chapters written for the layman without stinting on the science, outlining the history and likely future of man-made changes to the Earth's climate. Flannery's particular focus is the effects of carbon-dioxide emissions on the atmosphere, "the great aerial ocean."
If the force of his argument, based on the most recent available science, leaves us depressed at our likely fate, he is by nature an optimist, so the book is leavened throughout with notions of what we might do to help avert disaster and has an action checklist at the end.
Still, he allows that the subject can be depressing. Trained as a paleontologist, Flannery is an evolutionary biologist by profession, so he'd never before done a comprehensive study of climate science. "I went through a period of unnatural pessimism for me. It was difficult to get out of bed in the morning, for about 12 months, as I was researching the book."
Still, Flannery, 50, has rings under his eyes and a little extra flesh on his frame and a some-time hangdog expression that make him look like the lonely hit man played by Jean Reno in The Professional [above], the one who takes a waifish Natalie Portman under his wing until he dies in a hail of police bullets [That's straight from the article folks! We don't make that kind of thing up here at the palaeoblog.]
The Weather Makers is 35 brief chapters written for the layman without stinting on the science, outlining the history and likely future of man-made changes to the Earth's climate. Flannery's particular focus is the effects of carbon-dioxide emissions on the atmosphere, "the great aerial ocean."
If the force of his argument, based on the most recent available science, leaves us depressed at our likely fate, he is by nature an optimist, so the book is leavened throughout with notions of what we might do to help avert disaster and has an action checklist at the end.
Still, he allows that the subject can be depressing. Trained as a paleontologist, Flannery is an evolutionary biologist by profession, so he'd never before done a comprehensive study of climate science. "I went through a period of unnatural pessimism for me. It was difficult to get out of bed in the morning, for about 12 months, as I was researching the book."
Still, Flannery, 50, has rings under his eyes and a little extra flesh on his frame and a some-time hangdog expression that make him look like the lonely hit man played by Jean Reno in The Professional [above], the one who takes a waifish Natalie Portman under his wing until he dies in a hail of police bullets [That's straight from the article folks! We don't make that kind of thing up here at the palaeoblog.]
Sunday, March 26, 2006
New Hominid Skull Found
Scientists in northeastern Ethiopia said Saturday that they have discovered the skull of a small human ancestor that could be a missing link between the extinct Homo erectus and modern man.From LiveScience:
The hominid cranium found in two pieces and believed to be between 500,000 and 250,000 years old “comes from a very significant period and is very close to the appearance of the anatomically modern human," said Sileshi Semaw, director of the Gona Paleoanthropological Research Project in Ethiopia.
Archaeologists found the early human cranium five weeks ago at Gawis in Ethiopia's northeastern Afar region, said Sileshi.
“The Gawis cranium provides us with the opportunity to look at the face of one of our ancestors," the archaeology project said in a statement. “Additionally, this fossil links us with the past by showing a face that is recognizably different and more primitive than ours."
The cranium dates to a time about which little is known -- the transition from African Homo erectus to modern humans. The fossil record from Africa for this period is sparse and most of the specimens poorly dated, project archaeologists said.
That's a picture of 'Lucy' from HERE.
More On Chinese Fossil Eggs
From the Sydney Morning Herald:
Illegal trade in prehistoric fossils is rife, says an Australian mineral dealer prosecuted in the US for importing protected Chinese dinosaur eggs. Mr Kapitany, 45, will spend a year on criminal probation and was fined $27,175 in a plea bargain made in the US to avoid trial.
Dinosaur eggs are freely on sale in China and Chinese officials often take suitcases of fossils to sell when they go overseas, says Tamas "Thomas" Kapitany. But the Melbourne dealer, who imported several Chinese eggs into California, says he has been unfairly singled out.
"Because I'm the biggest dealer in Australia, they wanted to make an example of somebody and I was an easy target," said Mr Kapitany, who spoke about the incident for the first time today after flying home from Los Angeles this morning.
A dinosaur egg can be bought in Hong Kong for $60 and sold for $5000 after about 40 hours' cleaning and preparation, Mr Kapitany said. "You can go to Hollywood Road in Hong Kong and freely buy dinosaur eggs in a dozen stores there," he said.
"If you're really nice and look like you've got some money to spend they'll take you to the basement where they've got crates of fossils and antiquities.
US prosecutors accused Mr Kapitany of mis-labelling the Chinese dinosaur eggs as Australian minerals. But the cleaning process added more than 50 per cent of the eggs' original value and qualified them as Australian products, Mr Kapitany said.
Illegal trade in prehistoric fossils is rife, says an Australian mineral dealer prosecuted in the US for importing protected Chinese dinosaur eggs. Mr Kapitany, 45, will spend a year on criminal probation and was fined $27,175 in a plea bargain made in the US to avoid trial.
Dinosaur eggs are freely on sale in China and Chinese officials often take suitcases of fossils to sell when they go overseas, says Tamas "Thomas" Kapitany. But the Melbourne dealer, who imported several Chinese eggs into California, says he has been unfairly singled out.
"Because I'm the biggest dealer in Australia, they wanted to make an example of somebody and I was an easy target," said Mr Kapitany, who spoke about the incident for the first time today after flying home from Los Angeles this morning.
A dinosaur egg can be bought in Hong Kong for $60 and sold for $5000 after about 40 hours' cleaning and preparation, Mr Kapitany said. "You can go to Hollywood Road in Hong Kong and freely buy dinosaur eggs in a dozen stores there," he said.
"If you're really nice and look like you've got some money to spend they'll take you to the basement where they've got crates of fossils and antiquities.
US prosecutors accused Mr Kapitany of mis-labelling the Chinese dinosaur eggs as Australian minerals. But the cleaning process added more than 50 per cent of the eggs' original value and qualified them as Australian products, Mr Kapitany said.
RTMP Ceratopsids
Darren Tanke hard at work prepping a ceratopsid I started collecting with Don Brinkman a few years back as part of my Ph.D. work. As it turns out most of the skeleton and skull was collected but we're missing the parietal (frill), so we'll be back to Iddesliegh, Alberta, this summer to find it.
Darren holds the nasal horncore of a Styracosaurus in place on a specimen currently under prep. Note that's its length is pretty modest.
Thursday, March 23, 2006
New Sauropod From Mongolia
Illustration by Jason Brougham
From National Geographic News:
Scientists say they have found the fossil of a new species of sauropod that had special air sacs in some of its bones to help support its massively long neck.Living more than 100 million years ago in what is now Mongolia, the dinosaur had a 7.5-meter-long neck. The newly described species is named Erketu ellisoni. Erketu, the god of might, was one of 99 deities from pre-Buddhist Mongolian tradition.
Paleontologists Daniel T. Ksepka and Mark A. Norell of the American Museum of Natural History in New York discovered the fossil in Mongolia's Gobi desert in 2002. The partial fossil skeleton includes a single neck vertebra that measures nearly 0.6 meters in length.
This is bigger than the same vertebra found in fossils of Diplodocus —another, much larger four-legged sauropod that measured up to 27 meters in length.
Their analysis of the find is detailed in last week's issue of the museum's journal, Novitates.
Postings will continue sporatically over the next few days, depending on my access to the internet, and my recovery from emergency root canal surgery.
Tuesday, March 21, 2006
More Dinos From China
From the People’s Daily Online:
A large fossilized dinosaur has recently been discovered in Central China's Henan Province during an exploration by Chinese geologists and paleontologists. This is the first time a large dinosaur fossil has been found in Central China, Dong Zhiming, a dinosaur expert, told Xinhua on Monday.
Dong, a researcher with the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, said that the fossilized dinosaur was a vegetarian and could be dated back to the early and middle Cretaceous period, or about 100 million years ago.
"A rib of the dinosaur we found is about 2 meters long so we can estimate that the dinosaur was more than 20 meters long," said Dong. The species of the dinosaur is yet to be determined, Dong added.
The fossilized dinosaur was found in Shaping Village, Liudian Township, Ruyang County of Henan Province. A large number of fossilized dinosaur eggs were found in Xixia County, about 100 kilometers away from the Ruyang County, more than 10 years ago.
The number of the dinosaur eggs in Xixia County accounts for half of the total in China and one third of the total around the world. However, no complete dinosaur fossil had been found in the region previously.
He Mingbo, a leader of the Liudian Township, said for many years local residents believed a kind of "dragon bone stone" could be used to treat wounds. "Many people have found such kind of 'dragon bone stones' in fields or on hills," He said.
An 85-year-old villager, surnamed Cao, said "I have broken several thousand kilograms of 'dragon bone stones' to sell as traditional medicine over the past decades. I didn't know they were such a precious thing. I'm sorry about that."
Experts said more dinosaur fossils might be found in the region. Local government has posted notices in the village explaining fossils to villagers and forbidding the stealing and selling of fossils.
A large fossilized dinosaur has recently been discovered in Central China's Henan Province during an exploration by Chinese geologists and paleontologists. This is the first time a large dinosaur fossil has been found in Central China, Dong Zhiming, a dinosaur expert, told Xinhua on Monday.
Dong, a researcher with the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, said that the fossilized dinosaur was a vegetarian and could be dated back to the early and middle Cretaceous period, or about 100 million years ago.
"A rib of the dinosaur we found is about 2 meters long so we can estimate that the dinosaur was more than 20 meters long," said Dong. The species of the dinosaur is yet to be determined, Dong added.
The fossilized dinosaur was found in Shaping Village, Liudian Township, Ruyang County of Henan Province. A large number of fossilized dinosaur eggs were found in Xixia County, about 100 kilometers away from the Ruyang County, more than 10 years ago.
The number of the dinosaur eggs in Xixia County accounts for half of the total in China and one third of the total around the world. However, no complete dinosaur fossil had been found in the region previously.
He Mingbo, a leader of the Liudian Township, said for many years local residents believed a kind of "dragon bone stone" could be used to treat wounds. "Many people have found such kind of 'dragon bone stones' in fields or on hills," He said.
An 85-year-old villager, surnamed Cao, said "I have broken several thousand kilograms of 'dragon bone stones' to sell as traditional medicine over the past decades. I didn't know they were such a precious thing. I'm sorry about that."
Experts said more dinosaur fossils might be found in the region. Local government has posted notices in the village explaining fossils to villagers and forbidding the stealing and selling of fossils.
Monday, March 20, 2006
3D Chasmosaurus
Completely under the radar, the Canadian Museum of Nature has posted a wonderful and highly informative series of animations of one of the dinsoaurs I co-described, Chasmosaurus irvinensis, HERE.
"Here at Nature we have a special camera that can scan objects and make three-dimensional images of them. The images can then be used in such a variety of ways that the possibilities seem almost limitless. We've begun by exploring scientific hypotheses while having some fun!
Our main subject has been Chasmosaurus irvinensis, a dinosaur that lived 65 million years ago in what is now Alberta. Researchers at the CMN identified the species in 2001. This specimen is the holotype, which is the specimen upon which all future identification of other specimens is based, and it is held in our collections. You'll also see life-sized, fleshed out models of this dinosaur at our museum. These models were based on the holotype."
You can watch a series of animations of this dino walking around based upon laser scans of the individual bones of the skeleton which were then reassembled and fleshed out digitally.
You can also manipulate a 3D model of the foot based on scans of the original bones.
"Here at Nature we have a special camera that can scan objects and make three-dimensional images of them. The images can then be used in such a variety of ways that the possibilities seem almost limitless. We've begun by exploring scientific hypotheses while having some fun!
Our main subject has been Chasmosaurus irvinensis, a dinosaur that lived 65 million years ago in what is now Alberta. Researchers at the CMN identified the species in 2001. This specimen is the holotype, which is the specimen upon which all future identification of other specimens is based, and it is held in our collections. You'll also see life-sized, fleshed out models of this dinosaur at our museum. These models were based on the holotype."
You can watch a series of animations of this dino walking around based upon laser scans of the individual bones of the skeleton which were then reassembled and fleshed out digitally.
You can also manipulate a 3D model of the foot based on scans of the original bones.
Sunday, March 19, 2006
Corythosaurus Pull
I’m in Edmonton at the moment helping friends dig out from the near-record snow fall. Tomorrow I head over to the University of Alberta to photograph some fossil material that Philip Currie and I are working on. Then it’s down to Drumheller to continue research at the Royal Tyrrell Museum of Palaeontology.
While I spend the evening shoveling snow enjoy these images from last summer.
In the summer of 2005 a Corythosaurus (duck-billed dinosaur) skull was collected from quarry 246, Dinosaur Provincial Park. To get the blocks out to a place where they could be picked up by a vehicle, Dr. Don Brinkman decided to use a modification of a "palaeo-cart" first developed by then RTMP technician Kevin Kruger.
Martin Kundrat and Nick Longrich assemble the cart. It's a series of light weight, pre-assembled aluminum scaffolding bolted together, with an axle with two wheelbarrow wheels.
The first block is flipped onto the scaffolding and lashed down with mountaineering rope. That’s Nick in the middle holding the rope and Don on the right. In the back Dr. Julia Sankey (blue shirt) and Dr. Brad Belluk (in red) supervise.
After rope loops are tied for handles the 1.5 km walk out is begun.
The only major obstacle to overcome is the 30m cliff to get down. Our final destination is the just beyond the low badlands in the middle distance.
A combination of lowering and dragging the cart down the coulee wall was successful. Time to travel from quarry to truck was under 45 minutes.
Stay tuned for more updates.
All photos © Michael Ryan
While I spend the evening shoveling snow enjoy these images from last summer.
In the summer of 2005 a Corythosaurus (duck-billed dinosaur) skull was collected from quarry 246, Dinosaur Provincial Park. To get the blocks out to a place where they could be picked up by a vehicle, Dr. Don Brinkman decided to use a modification of a "palaeo-cart" first developed by then RTMP technician Kevin Kruger.
Martin Kundrat and Nick Longrich assemble the cart. It's a series of light weight, pre-assembled aluminum scaffolding bolted together, with an axle with two wheelbarrow wheels.
The first block is flipped onto the scaffolding and lashed down with mountaineering rope. That’s Nick in the middle holding the rope and Don on the right. In the back Dr. Julia Sankey (blue shirt) and Dr. Brad Belluk (in red) supervise.
After rope loops are tied for handles the 1.5 km walk out is begun.
The only major obstacle to overcome is the 30m cliff to get down. Our final destination is the just beyond the low badlands in the middle distance.
A combination of lowering and dragging the cart down the coulee wall was successful. Time to travel from quarry to truck was under 45 minutes.
Stay tuned for more updates.
All photos © Michael Ryan
Thursday, March 16, 2006
Court Dismisses Lawsuit Against Berkeley Evolution Website
From the UC Berkeley press release:
Without ruling on the merits of the suit, Judge Phyllis J. Hamilton of the U.S. District Court for the Northern District of California granted the University of California's motion to dismiss the case on the grounds that the plaintiffs lacked standing – that is, they did not have a sufficiently strong personal interest in the outcome of the case.
"We are very pleased with the judge’s decision and are hopeful that the defendants can now concentrate on helping to educate students about science," said Christopher M. Patti, university counsel with the UC Office of the President.
The lawsuit named not only two UC Berkeley professors, but also an administrator at the National Science Foundation (NSF), which partly funded the website. Judge Hamilton has yet to rule on NSF's motion to dismiss.
"The lawsuit cost us a lot of time, in terms of preparation and reviewing and Xeroxing a lot of paper, plus the legal fees," said Roy Caldwell, one of the UC Berkeley professors named in the suit. "I'm glad the court saw that the case should be dismissed."
Visit the excellent “Understanding Evolution” website.
A lawsuit by a Roseville couple who claimed that a University of California, Berkeley, website used evolution to promote religion was dismissed Monday, March 13, in San Francisco federal court.
Without ruling on the merits of the suit, Judge Phyllis J. Hamilton of the U.S. District Court for the Northern District of California granted the University of California's motion to dismiss the case on the grounds that the plaintiffs lacked standing – that is, they did not have a sufficiently strong personal interest in the outcome of the case.
"We are very pleased with the judge’s decision and are hopeful that the defendants can now concentrate on helping to educate students about science," said Christopher M. Patti, university counsel with the UC Office of the President.
The lawsuit named not only two UC Berkeley professors, but also an administrator at the National Science Foundation (NSF), which partly funded the website. Judge Hamilton has yet to rule on NSF's motion to dismiss.
"The lawsuit cost us a lot of time, in terms of preparation and reviewing and Xeroxing a lot of paper, plus the legal fees," said Roy Caldwell, one of the UC Berkeley professors named in the suit. "I'm glad the court saw that the case should be dismissed."
Visit the excellent “Understanding Evolution” website.
Dinosaur Locomotion:Beyond The Bones
Figure 1. Basics of limb anatomy and redundant degrees of freedom in a dinosaur limb.
Scientific theory combines with Hollywood wizardry to bring dinosaurs to life in a News and Views feature in this week's Nature (but go HERE instead to John's own webpage). In films, dinosaur locomotion is a result of clever software and the artistic interpretation of special effects departments. Now scientists are using improved software tools that have a firm grounding in physical principles, rather than artistic intuition, to test their own hypotheses on how dinosaurs walked the Earth.
John Hutchinson and Stephen Gatesy present a Tyrannosaurus rex case study of how to use modern computer tools to reconstruct dinosaur movement. They focus on the problems of determining the position of the limbs - its pose - at specific instants during a stride. By using combinations of motion-based and force-based criteria, the authors are able to filter out unlikely or impossible poses and establish a motion 'starting point'. The authors demonstrate the powers of computer simulation when combined with sound scientific theory and propose its application to factors, such as feeding, in other extinct animals. They highlight the need of palaeontologists to become better functional biologists to ensure that questions on popular science don't overtake basic evidence.
From John’s web page:
Figure 2.The stance and swing phases of a stride., and possible limb motions during stance.
What the paper DOES say:
1. Bottom Line: We critically review the many techniques used to reconstruct how dinosaurs moved. Then we take a cold hard look at increasingly popular animation and simulation methods, arguing that the best approach is not to reconstruct exactly how dinosaurs moved, but instead to use a range of criteria to exclude motions that they did NOT use.
2. Summary: We can do better than just animating dinosaur locomotion using only artistic or scientific intuition. Methods using living analogs of dinosaurs, how bone shape changes with dinosaur size (scaling), fossil footprints, functional anatomy, evolutionary analysis, and biomechanics all offer useful insights but all have their inherent limitations. A common limitation is the redundancy of the limb joints-- many poses are possible for any instant in time. Computer animation/simulation tools now can tackle any question we can think of, but they too are very limited, and sometimes these limits are overlooked. If there are thousands or millions of possible ways that any one dinosaur moved, some researchers might just choose some arbitrarily and assume these are the correct poses. We favor an approach where impossible/implausible poses are explicitly winnowed out using motion and force-based criteria. We show how this approach can be used to reveal how dinosaurs did not move, moving us progressively closer to reconstructing what kinds of motions they may have used. This approach requires extensive validation from living animals to establish constraints, and cautious sensitivity analysis of unknown parameter values.
What the paper DOES NOT say:
1. It does not give specific results on how Tyrannosaurus or other dinosaurs moved. It is more about the methods and approaches that one might use to get such results.
2. It does not say that reconstructing dinosaur locomotion is impossible, or that any one method is completely flawed. It explains that all methods have their limitations and one must be very wary of these. Animation and simulation are powerful tools, but just because something is animated, it doesn't make it physically possible or biologically plausible.
3. It does not argue that computer animation/simulation is the only method that is useful for reconstructing dinosaur locomotion. It may be the most promising method, but this promise can hide many problems. The complexity and visually seductive nature of computer graphics makes it easy to mislead viewers that there is rigorous science underlying it all. There can be, but that is far from simple to do.
Watch the videos of T. rex animations HERE.
Wednesday, March 15, 2006
Juravenator Ruffles Feathers
A new carnivorous dinosaur from the Late Jurassic Solnhofen archipelago. 2006. Ursula B. Göhlich and Luis M. Chiappe. Nature 440, 329-332.
Abstract: Small Late Jurassic theropod dinosaurs are rare worldwide. In Europe these carnivorous dinosaurs are represented primarily by only two skeletons of Compsognathus, neither of which is well preserved. Here we describe a small new theropod dinosaur from the Late Jurassic period of Schamhaupten in southern Germany. Being exquisitely preserved and complete from the snout to the distal third of the tail, the new fossil is the best-preserved predatory, non-avian dinosaur in Europe. It possesses a suite of characters that support its identification as a basal coelurosaur. A cladistic analysis indicates that the new taxon is closer to maniraptorans than to tyrannosauroids, grouping it with taxa often considered to be compsognathids. Large portions of integument are preserved along its tail. The absence of feathers or feather-like structures in a fossil phylogenetically nested within feathered theropods indicates that the evolution of these integumentary structures might be more complex than previously thought.
The fossil is a juvenile carnivorous dinosaur about 2 1/2 feet long that paleontologists have named Juravenator for the Jura mountains in southern Germany where it was found.
The fossil's exceptionally well-preserved bone structure clearly puts it among feathered kin on the dinosaur family tree. Because all of its close relatives are feathered, paleontologists would expect Juravenator to follow suit.
But a small patch of skin on Juravenator's tail shows no sign of feathers. And the skin also doesn't have the follicles that are typical of feathered dinosaurs, said Luis Chiappe, director of the Dinosaur Institute at the Natural History Museum of Los Angeles County. He and Ursula B. Gohlich of the University of Munich describe the fossil in Thursday's issue of the journal Nature.
"It has a typical scaly dinosaurian skin," Chiappe said.
The paleontologists believe Juravenator's closest known relative may have been a fully feathered dinosaur from China, Sinosauropterix.
Read the rest HERE.
Abstract: Small Late Jurassic theropod dinosaurs are rare worldwide. In Europe these carnivorous dinosaurs are represented primarily by only two skeletons of Compsognathus, neither of which is well preserved. Here we describe a small new theropod dinosaur from the Late Jurassic period of Schamhaupten in southern Germany. Being exquisitely preserved and complete from the snout to the distal third of the tail, the new fossil is the best-preserved predatory, non-avian dinosaur in Europe. It possesses a suite of characters that support its identification as a basal coelurosaur. A cladistic analysis indicates that the new taxon is closer to maniraptorans than to tyrannosauroids, grouping it with taxa often considered to be compsognathids. Large portions of integument are preserved along its tail. The absence of feathers or feather-like structures in a fossil phylogenetically nested within feathered theropods indicates that the evolution of these integumentary structures might be more complex than previously thought.
A 150 million-year-old fossil from southern Germany has paleontologists ruffled over how feathers arose in the line of dinosaurs that eventually produced birds.From the Houston Chronicle comes this article:
The fossil is a juvenile carnivorous dinosaur about 2 1/2 feet long that paleontologists have named Juravenator for the Jura mountains in southern Germany where it was found.
The fossil's exceptionally well-preserved bone structure clearly puts it among feathered kin on the dinosaur family tree. Because all of its close relatives are feathered, paleontologists would expect Juravenator to follow suit.
But a small patch of skin on Juravenator's tail shows no sign of feathers. And the skin also doesn't have the follicles that are typical of feathered dinosaurs, said Luis Chiappe, director of the Dinosaur Institute at the Natural History Museum of Los Angeles County. He and Ursula B. Gohlich of the University of Munich describe the fossil in Thursday's issue of the journal Nature.
"It has a typical scaly dinosaurian skin," Chiappe said.
The paleontologists believe Juravenator's closest known relative may have been a fully feathered dinosaur from China, Sinosauropterix.
Read the rest HERE.
Tuesday, March 14, 2006
T. rex Talk At CMNH
Wednesday, March 15 at 7 pm, as part of the Curator’s Forum at the Cleveland Museum of Natural History, Dr. Michael Ryan, Curator of Vertebrate Paleontology, presents a talk entitled:
“101 Years of Tyrannosaurus rex: The Evolution of an Icon”
Image © Mike Skrepnick
Tyrannosaurus rex is arguably the most famous dinosaur ever discovered. First described by Henry Fairfield Osborn in 1905, it quickly caught the public's attention. More recently, the discovery and controversy surrounding the spectacular specimen "Sue" gave T. rex "dino diva" status. Dr. Michael Ryan traces T. rex's fascinating story, from its initial discovery to its present top spot in the popular imagination, by examining its evolution in the realms of science and pop-culture. Learn why T. rex is the "Tyrant King" of all dinosaurs!
Like the above image? It's the cover from "T. Rex: Hunter or Scavenger?" illustrated by Mike Skrepnick.
“101 Years of Tyrannosaurus rex: The Evolution of an Icon”
Image © Mike Skrepnick
Tyrannosaurus rex is arguably the most famous dinosaur ever discovered. First described by Henry Fairfield Osborn in 1905, it quickly caught the public's attention. More recently, the discovery and controversy surrounding the spectacular specimen "Sue" gave T. rex "dino diva" status. Dr. Michael Ryan traces T. rex's fascinating story, from its initial discovery to its present top spot in the popular imagination, by examining its evolution in the realms of science and pop-culture. Learn why T. rex is the "Tyrant King" of all dinosaurs!
Like the above image? It's the cover from "T. Rex: Hunter or Scavenger?" illustrated by Mike Skrepnick.
New Fossil Spider From Alberta
FOSSIL OONOPID SPIDERS IN CRETACEOUS AMBERS FROM CANADA AND MYANMAR. 2006. D. Penney. Palaeontology Volume 49: 229.
Spider from HERE(not the new species).
From Today’s Edmonton Journal:
A 75-million-year-old spider found in amber near Lethbridge has been named after Alberta. The spider, measuring only about one millimetre long, was found in the 1970s preserved in a piece of amber.
It was stored in a collection of fossils at the Royal Tyrrell Museum in Drumheller and examined in 2003 by visiting scientist David Penny of the University of Manchester, England.
The scientist determined it was a unique specimen and named in Orchestina albertensis, after the province. It is the first fossilized spider species to be identified based on a specimen from Alberta.
The new fossil species belongs to the family Oonopidae, which contains about 450 living species of small-bodied, fast-moving and nocturnal hunters. This is the first record of the family Oonopidae in Canada. Fossils of this family have also been found in New York, the Dominican Republic, Africa, Asia and Europe. No living species of this family are found in Canada, with the closest occurrences in the southern and eastern USA.
The Order Araneae, or spiders, contains approximately 40,000 living species. Spiders have a lengthy fossil record dating back 390 million years to the Middle Devonian, before the appearance of the first amphibians.
Thanks to the Digital Dream Machine Blog for this news!
Spider from HERE(not the new species).
From Today’s Edmonton Journal:
A 75-million-year-old spider found in amber near Lethbridge has been named after Alberta. The spider, measuring only about one millimetre long, was found in the 1970s preserved in a piece of amber.
It was stored in a collection of fossils at the Royal Tyrrell Museum in Drumheller and examined in 2003 by visiting scientist David Penny of the University of Manchester, England.
The scientist determined it was a unique specimen and named in Orchestina albertensis, after the province. It is the first fossilized spider species to be identified based on a specimen from Alberta.
The new fossil species belongs to the family Oonopidae, which contains about 450 living species of small-bodied, fast-moving and nocturnal hunters. This is the first record of the family Oonopidae in Canada. Fossils of this family have also been found in New York, the Dominican Republic, Africa, Asia and Europe. No living species of this family are found in Canada, with the closest occurrences in the southern and eastern USA.
The Order Araneae, or spiders, contains approximately 40,000 living species. Spiders have a lengthy fossil record dating back 390 million years to the Middle Devonian, before the appearance of the first amphibians.
Thanks to the Digital Dream Machine Blog for this news!
Happy Birthday: Steve Bissette
S. R. Bissette’s Tyrant is © & ® S. R. Bissette.
Steve has an always interesting blog, MyRant, that is worth a read. He features big news for Godzilla fans HERE.
Image from HERE. Visit the Wall of Fame at TEGNESERIEMUSEET I DANMARK (The Denmark Comics Museum).
Monday, March 13, 2006
Cleveland Rocks ... err, make that NYC
Released this day in 1973: Pink Floyd's "Dark Side of the Moon"
If The Rock and Roll Hall of Fame is in Cleveland why are the induction ceremonies in New York City? The Sex Pistols get the nod this year but they (ie. Mr. Lydon) are none to happy about it.
And to all my friends still asking me how I like living in Cincinatti, the last time I walked to work (today) the Cleveland Museum of Natural History is still in Cleveland.
Congratulations to Dr. Pat Druckenmiller
Happy Birthday: Philip Currie
Photo of PJC in the Gobi © M. Ryan
FYI, Dr. Currie will be speaking in Calgary this Saturday at the Alberta Palaeontological Society's Annual Symposium.
Sunday, March 12, 2006
Born This Day: William Buckland
March 12, 1784 – August 15, 1856
From The Victorian Web: Buckland was the first man to identify and name a dinosaur (Megalosaurus), although the name dinosaur had not yet been coined by Richard Owen. Partly in response to the controversial works of Cuvier, Buckland wrote Reliquiae Diluvianae (1823) in which he argued that the evidence of geology alone demonstrated that a great flood had covered the entire globe. This move helped to make geology look more respectable in a religiously conservative England and perhaps to advance Buckland's own career at Oxford by making geology appear to be a respectable companion to the classics.
Buckland was a bit of an eccentric, given to outlandish dress and behavior. Although Buckland was immensely influential as a scientist, his rakish reputation gave many of his staid early Victorian contemporaries considerable difficulty in accepting his work.
More info from HERE. Image from HERE
From The Victorian Web: Buckland was the first man to identify and name a dinosaur (Megalosaurus), although the name dinosaur had not yet been coined by Richard Owen. Partly in response to the controversial works of Cuvier, Buckland wrote Reliquiae Diluvianae (1823) in which he argued that the evidence of geology alone demonstrated that a great flood had covered the entire globe. This move helped to make geology look more respectable in a religiously conservative England and perhaps to advance Buckland's own career at Oxford by making geology appear to be a respectable companion to the classics.
Buckland was a bit of an eccentric, given to outlandish dress and behavior. Although Buckland was immensely influential as a scientist, his rakish reputation gave many of his staid early Victorian contemporaries considerable difficulty in accepting his work.
More info from HERE. Image from HERE
Saturday, March 11, 2006
The Australian Museum's Support For Fossil Fish Flounders
From The Australian comes this report:
When contacted by The Weekend Australian last month, AM assistant director and head of research and collections Les Christidis denied claims the museum was reducing support for the Age of Fishes Museum in Canowindra, near Orange in central NSW.
Although the AM provides no funding to the smaller institution, AM paleontologists such as Alex Ritchie - whose 1993 excavation at a nearby fossil site provided the inspiration for The Age of Fishes Museum - voluntarily offer scientific expertise, and AM collections manager Robert Jones advises on housing the fossils.
Dr Christidis acknowledged that monthly visits by Mr Jones would cease at the end of this year, but said the AM was providing "heaps of material and heaps of advice". He added: "There never has been an official affiliation between the two institutions."
But documents obtained by The Weekend Australian show otherwise, supporting the Age of Fishes Museum's claims that the AM is cutting back on its support.
Age of Fishes Museum manager Fiona Ferguson said she was "bitterly disappointed" by the AM's response.
The Australian Museum (AM) is withdrawing support for a popular small regional museum despite public assurances to the contrary, local officials claim.The Australian revealed last month that scientists and supporters of the, feared it could struggle without continued ties and scientific support from the Australian Museum in Sydney. The latest claim comes as the AM, Australia's oldest museum, considers a shift in its research priorities away from traditional fields such as paleontology and mineralogy to more "contemporary" areas.
When contacted by The Weekend Australian last month, AM assistant director and head of research and collections Les Christidis denied claims the museum was reducing support for the Age of Fishes Museum in Canowindra, near Orange in central NSW.
Although the AM provides no funding to the smaller institution, AM paleontologists such as Alex Ritchie - whose 1993 excavation at a nearby fossil site provided the inspiration for The Age of Fishes Museum - voluntarily offer scientific expertise, and AM collections manager Robert Jones advises on housing the fossils.
Dr Christidis acknowledged that monthly visits by Mr Jones would cease at the end of this year, but said the AM was providing "heaps of material and heaps of advice". He added: "There never has been an official affiliation between the two institutions."
But documents obtained by The Weekend Australian show otherwise, supporting the Age of Fishes Museum's claims that the AM is cutting back on its support.
Age of Fishes Museum manager Fiona Ferguson said she was "bitterly disappointed" by the AM's response.
Go Read A Book
The 13-strong longlist of popular science books vying for the prestigious 2006 Aventis Prize has been announced.The award, which celebrates the very best in popular science writing, is now in its 18th year. A cash prize of £10,000 and a certain sales boost await the winner, to be announced on 16 May at a ceremony at the Royal Society in London.
Fiammetta Rocco, on announcing the longlist, said, "This year's submissions were of remarkably high quality, which made the job of picking out just a dozen books especially difficult. In fact, the longlist has 13 books because we didn't want to lose a single one.
The Aventis prize is managed by the Royal Society, the UK's academy of science, and supported by the Aventis Foundation.
The full longlist for the 2006 Aventis General Prize:
Electric Universe - How Electricity Switched on the Modern World, by David Bodanis (Little Brown)
Collapse - How Societies Choose to Fail or Survive, by Jared Diamond (Penguin Allen Lane)
The Elements of Murder - A History of Poison, John Emsley (Oxford University Press)
The Gecko's Foot - Bio-inspiration - Engineering New Materials from Nature, by Peter Forbes (Fourth Estate)
The Silicon Eye - How a Silicon Valley Company Aims to Make All Current Computers, Cameras, and Cell Phones Obsolete, by George Gilder (WW Norton)
Note: And he’s up for a Science award? Gilder helped found the Discovery Institute, originally a moderate group which aimed to privatize and modernize Seattle's transit systems but it later became the leading think tank of the intelligent design movement, with Gilder penning many articles in favor of ID and opposing evolution. (info from HERE; thanks to Sukie for pointing this out!)
Parallel Worlds - The Science of Alternative Universes and our Future in the Cosmos, by Michio Kaku (Penguin)
Power, Sex, Suicide - Mitochondria and the Meaning of Life, by Nick Lane (Oxford University Press)
Venomous Earth - How Arsenic Caused the World's Worst Mass Poisoning, by Andrew Meharg (Macmillan)
Empire of the Stars - Friendship, Obsession and Betrayal in the Quest for Black Holes, by Arthur I. Miller (Little Brown)
Seven Deadly Colours-The Genius of Nature's Palette and how it Eluded Darwin, by Andrew Parker (Simon & Schuster)
The Truth About Hormones - What's Going on when we're Tetchy, Spotty, Fearful, Tearful or Just Plain Awful, by Vivienne Parry (Atlantic Books)
Stalking the Riemann Hypothesis - The Quest to Find the Hidden Law of Prime Numbers, by Dan Rockmore (Jonathan Cape)
The Fruits of War - How War and Conflict have Driven Science, by Michael White (Simon & Schuster)
Friday, March 10, 2006
Thomas Jefferson on Megalonyx
From Today In Science History:
On this day in 1797, Thomas Jefferson (1743-1826) presented a paper on Megalonyx to the American Philosophical Society. It was published as "A Memoir on the Discovery of Certain Bones of a Quadruped of the Clawed Kind in the Western Parts of Virginia," Transactions of American Philosophical Society 4:255-256, along with an account by Caspar Wistar (1761-1818). In 1822, this huge extinct sloth was named Megalonyx jeffersoni by a French naturalist.
The species name Megalonyx is derived from the Greek language and refers to the large claw on the third digit of each of the sloths hind feet. It was a bear-sized ground sloth, over 2 meters tall, widespread in North America during the last Ice Age. Image from HERE
On this day in 1797, Thomas Jefferson (1743-1826) presented a paper on Megalonyx to the American Philosophical Society. It was published as "A Memoir on the Discovery of Certain Bones of a Quadruped of the Clawed Kind in the Western Parts of Virginia," Transactions of American Philosophical Society 4:255-256, along with an account by Caspar Wistar (1761-1818). In 1822, this huge extinct sloth was named Megalonyx jeffersoni by a French naturalist.
The species name Megalonyx is derived from the Greek language and refers to the large claw on the third digit of each of the sloths hind feet. It was a bear-sized ground sloth, over 2 meters tall, widespread in North America during the last Ice Age. Image from HERE
Laonastes & The Lazarus Effect
Laonastes and the "Lazarus Effect" in Recent Mammals. 2006. Mary Dawson et al. Science 311: 1456 – 1458.
Abstract: The living Laotian rodent Laonastes aenigmamus, first described in early 2005, has been interpreted as the sole member of the new family Laonastidae on the basis of its distinctive morphology and apparent phylogenetic isolation from other living rodents. Here we show that Laonastes is actually a surviving member of the otherwise extinct rodent family Diatomyidae, known from early Oligocene to late Miocene sites in Pakistan, India, Thailand, China, and Japan. Laonastesis a particularly striking example of the "Lazarus effect" in Recent mammals, whereby a taxon that was formerly thought to be extinct is rediscovered in the extant biota, in this case after a temporal gap of roughly 11 million years.
From the article at LiveScience.com byBjorn Carey:
"It is an amazing discovery and it's the coelacanth of rodents," said Dr. Mary Dawson. "It's the first time in the study of mammals that scientists have found a living fossil of a group that's thought to be extinct for roughly 11 million years. That's quite a gap. Previous mammals had a gap of only a few thousand to just over a million years." Laonastes is currently in the process of being officially reclassified in the Diatomyidae family.
Diatomyidae were squirrel-sized rodents that lived during the middle Tertiary period 34 million to 11 million years ago in southern Asia, central China, and Japan. They also had highly characteristic molar teeth and jaw structure, which is how the researchers reclassified Laonastes.
A recently discovered fossil of Laonastes matched the "living" specimen in skull shape and overall size. The only difference is that the "living" specimen's teeth are slightly more pointed.
Image of Laonastes from HERE.
"It looks like possibly one of the things that's been changing in family is improved cutting of vegetation," Dawson told LiveScience. "But over 11 million years you'd expect some differences in the structures."
Western scientists still haven't seen a living Laonastes specimen, which will be critical in conserving what may be a threatened species. "Biologists need to get out there and find some living ones," Dawson said. Finding living specimens and understanding how they live could be key to determining why the rodents moved from central Asia into the Indian subcontinent.
Abstract: The living Laotian rodent Laonastes aenigmamus, first described in early 2005, has been interpreted as the sole member of the new family Laonastidae on the basis of its distinctive morphology and apparent phylogenetic isolation from other living rodents. Here we show that Laonastes is actually a surviving member of the otherwise extinct rodent family Diatomyidae, known from early Oligocene to late Miocene sites in Pakistan, India, Thailand, China, and Japan. Laonastesis a particularly striking example of the "Lazarus effect" in Recent mammals, whereby a taxon that was formerly thought to be extinct is rediscovered in the extant biota, in this case after a temporal gap of roughly 11 million years.
From the article at LiveScience.com byBjorn Carey:
"It is an amazing discovery and it's the coelacanth of rodents," said Dr. Mary Dawson. "It's the first time in the study of mammals that scientists have found a living fossil of a group that's thought to be extinct for roughly 11 million years. That's quite a gap. Previous mammals had a gap of only a few thousand to just over a million years." Laonastes is currently in the process of being officially reclassified in the Diatomyidae family.
Diatomyidae were squirrel-sized rodents that lived during the middle Tertiary period 34 million to 11 million years ago in southern Asia, central China, and Japan. They also had highly characteristic molar teeth and jaw structure, which is how the researchers reclassified Laonastes.
A recently discovered fossil of Laonastes matched the "living" specimen in skull shape and overall size. The only difference is that the "living" specimen's teeth are slightly more pointed.
Image of Laonastes from HERE.
"It looks like possibly one of the things that's been changing in family is improved cutting of vegetation," Dawson told LiveScience. "But over 11 million years you'd expect some differences in the structures."
Western scientists still haven't seen a living Laonastes specimen, which will be critical in conserving what may be a threatened species. "Biologists need to get out there and find some living ones," Dawson said. Finding living specimens and understanding how they live could be key to determining why the rodents moved from central Asia into the Indian subcontinent.
Thursday, March 09, 2006
Siberian Trap=Mass Dino Extinction?
University of Leicester geologists, Professor Andy Saunders and Dr Marc Reichow, are taking a fresh look at what may actually have wiped out the dinosaurs 65 million years ago and caused other similarly cataclysmic events.The idea that meteorite impacts caused mass extinctions has been in vogue over the last 25 years, since Louis Alverez’s research team in Berkeley, California published their work about an extraterrestrial iridium anomaly found in 65-million-year-old layers at the Cretaceous-Tertiary boundary. This anomaly only could be explained by an extraterrestrial source, a large meteorite, hitting the Earth and ultimately wiping the dinosaurs – and many other organisms - off the Earth’s surface.
Current research suggests that the causes of the extinctions may come from within our own planet – the eruption of vast amounts of lava that brings a cocktail of gases from deep inside the Earth and vents them into the atmosphere.
Flood basalt eruptions are an alternative kill mechanism. These do correspond with all main mass extinctions, within error of the techniques used to determine the age of the volcanism. Furthermore, they may have released enough greenhouse gases (SO2 and CO2) to dramatically change the climate. The largest flood basalts on Earth (Siberian Traps and Deccan Traps)coincide with the largest extinctions (end-Permian, and end-Cretaceous). The gases released by volcanic activity lead to a prolonged volcanic winter induced by sulphur-rich aerosols, followed by a period of CO2-induced warming.
The 250 million year old Siberian Traps are the largest known continental flood basalt province. Using radiometric dating techniques, they hope to constrain the age and, combined with geochemical analysis, the extent, of the Siberian Traps. Using these data they hope to be able to assess the amount of SO2 and CO2 released into the atmosphere 250 million years ago, and whether or not this caused climatic havoc, wiping out nearly all life on earth.
More information is available HERE.
Volcano from HERE.
NB: This is an interesting example of a press release for work that has not yet been done – it’s an announcement for a grant that has been received to start the research. The suggestion that the Siberian and/or Deccan Traps are the real cause of Earth’s major extinction events has been around for some time now. We’ll see what they come with in a year or two.
Wednesday, March 08, 2006
Early Land Animals Could Walk & Run Like Mammals
Tuataras and salamanders show that walking and running mechanics are ancient features of tetrapod locomotion. 2006. S. M. Reilly et al. Proceedings: Biological Sciences. Early on-line publication.
Tuatara from HERE.
“Tuataras (above) are the oldest living models of early tetrapods (four-legged animals) still alive today; that’s what makes them so interesting,” Reilly said.
After studying the creatures at the Toledo Zoo, Stephen Reilly and Eric McElroy determined that they use both forms of locomotion, which are energy-saving mechanisms generally believed to be important only in fast-running animals such as mammals and birds.
Force data used to study the movement of these creatures’ center of mass showed the telltale vault and dip of center of mass movements in different strides – confirmation that the creatures mechanically walk and run. Because they are the oldest living examples of four-legged animals, the new findings suggest that both energy saving mechanisms appeared when the first vertebrates moved onto land, Reilly explained. In comparison to previous research on other vertebrates, this also suggests that all terrestrial vertebrates – except for turtles, which are limited by their shell – can walk and run.
The researchers also showed, however, that walking and running in tuataras occur at the same speed and use about the same amounts of energy. Reilly believes that this could be a pre-adaptation in these primitive animals that have not evolved the need for speed, unlike other animals.
The research also shows for the first time a clear difference in locomotor mechanics between “lumbering” animals with clumsy, ungraceful gaits and “cursorial” animals that move fast and smoothly. In lumbering animals, up and down movements dominate the mechanical energy of locomotion. These movements are smoothed out in cursorial animals such as in dogs and horses, where more energy is shifted to forward movement, and the center of mass oscillates relatively less with each step.
Tuatara from HERE.
Salamanders and the tuatara, a lizard-like animal that has lived on Earth for 225 million years, were the first vertebrates to walk and run on land.From Ohio University Research News:
“Tuataras (above) are the oldest living models of early tetrapods (four-legged animals) still alive today; that’s what makes them so interesting,” Reilly said.
After studying the creatures at the Toledo Zoo, Stephen Reilly and Eric McElroy determined that they use both forms of locomotion, which are energy-saving mechanisms generally believed to be important only in fast-running animals such as mammals and birds.
Force data used to study the movement of these creatures’ center of mass showed the telltale vault and dip of center of mass movements in different strides – confirmation that the creatures mechanically walk and run. Because they are the oldest living examples of four-legged animals, the new findings suggest that both energy saving mechanisms appeared when the first vertebrates moved onto land, Reilly explained. In comparison to previous research on other vertebrates, this also suggests that all terrestrial vertebrates – except for turtles, which are limited by their shell – can walk and run.
The researchers also showed, however, that walking and running in tuataras occur at the same speed and use about the same amounts of energy. Reilly believes that this could be a pre-adaptation in these primitive animals that have not evolved the need for speed, unlike other animals.
The research also shows for the first time a clear difference in locomotor mechanics between “lumbering” animals with clumsy, ungraceful gaits and “cursorial” animals that move fast and smoothly. In lumbering animals, up and down movements dominate the mechanical energy of locomotion. These movements are smoothed out in cursorial animals such as in dogs and horses, where more energy is shifted to forward movement, and the center of mass oscillates relatively less with each step.
Lake Champlain's Monster Sighted Again
"Champ" from www.uhaul.com.
From an article by Joe Nickell in the Skeptical Inquirer as reported by LiveScience.com:
Dubbed “North America’s Loch Ness Monster,” the purported leviathan of Lake Champlain, “Champ,” has just resurfaced. On Feb. 22, 2006, Good Morning America aired exclusive video footage of “something” just below the surface of the water, possibly the lake’s fabled creature.The incident added to a long list of Champ sightings, which have described a chameleonesque creature that is black, gray, brown, moss green, reddish bronze or other colors, and is between 10 and 187 feet long, with multiple humps or coils as well as horns or a mane or glowing eyes or “jaws like an alligator”—or none of those features.
Such sightings may be due to large fish like sturgeon, schools of fish, and other marine creatures. For example, otters, swimming in a line, can mimic a single long, serpentine creature moving in an undulating fashion. Other Champ suspects include wind slicks, boat wakes, driftwood, long-necked birds, and many other possibilities.
The newspaper noted that the Champ legend dated from 1609 when French explorer Samuel de Champlain described a creature the Native Americans called Chaousarou. In his journal, Champlain wrote that the species was reputed to range up to 10 feet long and that he had personally seen some half that length and “as big as my thigh”—words subsequently echoed by eyewitness Bodette. Champlain noted that Chaousarou resembled a pike with an exceedingly long snout and “dangerous teeth”—certainly alligator-like features. In short, Champlain’s description seemingly tallies with the creature the Vermont fishermen encountered.
The apparent match is instructive: the explorer was almost certainly describing a longnose gar, one of the Ganoidei subclass, which includes sturgeons and other varieties.
Although the video is insufficient for a positive identification, the men’s description does permit this tentative solution to the mystery. For four centuries gar have been astonishing people on Lake Champlain. During one of my investigative trips to the lake I interviewed a fisherman who had just witnessed a friend hook a longnose gar that—he insisted—was “monster” sized, measuring about 6 feet 4 inches long. He called this “the real Champ,” and dubbed it, appropriately, “Gar-gantua.”
Read the rest of the article HERE.
Tuesday, March 07, 2006
Bakker On Dinos
The traveling AMNH exhibit “Dinosaurs: Ancient Fossils, New Discoveries” opens Friday at Houston Museum of Natural History. Read an article featuring Dr. Bob Bakker, curator of paleontology for the HMNS.
"You can proclaim, you can shout down the hall, that dinosaurs are not extinct, because birds are dinosaurs," Bakker said. "They're not cousins, they're not nieces and nephews, they're not relations that crossed the bayou. They are dinosaurs. If you want to understand the essence of Tyrannosaurus rex, you must think big bird, really big bird."
Born This Day (1930): Stanley Lloyd Miller
Miller is an American chemist who made a series of famous experiments beginning in 1953, to determine the possible origin of life from inorganic chemicals on the primeval earth.
Read about it HERE.
Read about it HERE.
Monday, March 06, 2006
Smallest Triceratops Skull Described
Photo by Mark Goodwin, UC Berkeley Museum of Paleontology
A cast of the foot-long skull from the youngest Triceratops fossil ever found is on display in the Library of University of California, Berkeley's Valley Life Sciences Building. The actual skull is described by Mark Goodwin in the March issue of the Journal of Vertebrate Paleontology"The baby Triceratops confirmed our argument that the horns and frill of the skull likely had another function other than sexual display or competition with rivals, which people have often argued, and allows us to propose that they were just as important for species recognition and visual communication in these animals," Goodwin said.
The baby's skull, along with a few vertebrae, teeth and bony tendons, were discovered by amateur fossil hunter Harley Garbani in 1997 in Montana's Hell Creek Formation, the source of many Triceratops and T. rex fossils
Although Goodwin's conclusions about the lifelong growth of Triceratops will be published later this year, the baby skull offers its own insights. For one, the surface of the skull shows grooves were blood vessels used to be, evidently to nourish a fingernail-hard covering of keratin that was similar to the thicker layer that covered the adult skull. Such horny coverings are often brightly colored in the living descendents of dinosaurs - the birds - suggesting that adult Triceratops and their young may have been colorful, too.
In addition, the scalloped edges of the baby's frill became mere wavy edges in the adults, although the scallops foreshadowed the development of triangular scales along the edge of the adult frill, probably an attribute of sexual maturity, Goodwin said. The two brow horns started out straight and short in the baby - they're about an inch long - but ended up long and curved forward in the adult, while the nose horn became larger, like that of a rhinoceros, although it was made of bone in Triceratops.
The brain case of the baby also changed significantly, he said. Hidden beneath the boney frills of the skull, the hazelnut-sized brain of the baby fit snuggly within protective bones not yet fused, so as to allow further brain growth. In the adult, the brain, about the shape and size of a small sweet potato, was completely encased in fused bones. The relative position of the bones of the braincase as the animal matured recapitulates the cranial evolution of Triceratops from a more basal ancestor, such as Protoceratops.
Mark’s coauthors on the new paper are William A. Clemens, a UC Berkeley professor of integrative biology and Museum of Paleontology emeritus curator who opened up the Montana area for fossil exploration more than 30 years ago; field colleague Jack Horner of the Museum of the Rockies at Montana State University in Bozeman; and Kevin Padian, UC Berkeley professor of integrative biology and Museum of Paleontology curator.