Stories tagged dinosaurs

Trampled tracksite surface: Geologist Winston Seiler with some of the many dinosaur tracks found along the Arizona-Utah border.
Courtesy Nicole MillerA dinosaur tracksite discovered recently in the southwestern United States contains so many footprints it’s being heralded as a “dinosaur dance floor”.

Winston Seiler, a geologist at the University of Utah published a paper in the October 2008 issue of the journal Palaios that details the new site. Professor Marjorie Chan, the chair of the university’s geology and geophysics department co-wrote the paper.

Along the dinosaur trail: Geologist Winston Seiler walks where dinosaurs once trampled the ground. The site is in the Paria Canyon-Vermilion Cliffs Wilderness along the Arizona-Utah border.
Courtesy Roger SeilerDuring the early Jurassic period - 190 million years ago - the region was a desert larger than today’s Sahara desert, and it’s thought the tracksite was located at an oasis where a variety of dinosaurs gathered for water. Today the ancient desert is a layer of sandstone located in the Coyote Buttes North area of the Paria Canyon-Vermilion Cliffs Wilderness along the Arizona and Utah border. Thousands of footprints litter the three-quarter-acre area – in some cases dozens of tracks per square yard. Walking across the tracksite reminded Seiler and Chan of a popular arcade game.

“Get out there and try stepping in their footsteps, and you feel like you are playing the game ‘Dance Dance Revolution’ that teenagers dance on,” said Chan. “This kind of reminded me of that – a dinosaur dance floor – because there are so many tracks and a variety of different tracks.”

Four separate types of tracks have been identified at the trample site along with some very rare dinosaur tail-drag marks. The study of trace fossils such as these is called ichnolology. The science has earned a growing respect in recent years after being long regarded as a secondary field of study. Major strides have been made in dinosaur behavior from studying the footprints they left behind. Since it’s difficult to ascertain the exact identity of the track maker (unless you find its skeleton at the end of its footsteps), dinosaur footprints are given their own classification such as Grallator, Eubrontes, and Sauropodomorph. You can read more about dinosaur track names here.

For a long time the footprints at Coyote Buttes North were thought to be nothing more than naturally occurring potholes eroded by water out of the Navajo Sandstone Formation. That opinion is still held in some circles but Seiler and Chan are convinced they were made by dinosaurs and display many footprint traits.

Map showing location of the tracksite
Courtesy Winston SeilerIf you’re interested in viewing the trackway yourself - get in line. Access to the area requires a permit (and a $7 fee) and advanced permit sales are already backlogged four months out. Call 435) 688-3246 or go online at http://www.blm.gov/az/st/en/arolrsmain.html (and click Coyote Buttes) for information. You can also take a chance to acquire one of the 10 additional daily permits issued a day prior to your visit to the site at the Paria Contact Station between March 15 and November 14 or at the Bureau of Land Management (BLM) Field Office in Kanab, Utah between November 15 – March 14.

University of Utah story
Discovery News blog story
Glen Kuban's great dinosaur tracks website
Myles J. McLeod's dinosaur track info site
More on Navajo Sandstone dinosaur ichnofossils

Tags : paleontology, track site, ichnology, fossil footprints, dinosaurs, dinosaur trackway

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Check out my horns: This is a slightly different sub-species of pachyrhinosaurus than the type that's been discovered in Alberta, Canada. Click on the link in the story to see the wild horn arrangement of this latest model.
Courtesy ArthurWeasleyThe wild array of spikes on a triceratops-like dinosaur may look menacing and good for fighting, but researchers think their main purpose may have been to attract mates.

Here’s the full report on the new findings about pachyrhinosaur lakustai, including a pretty wild photo. All totaled, the dinosaur had six spikes arranged around its head. And they weren’t there to pick a fight but rather to attract the other sex of the species.

Paleontologists have hit a gold mine of information on pachyrhinosaurs in a bone bed found in Alberta, Canada. So far they’ve found 15 complete skulls and pieces of 27 different specimens while having only dug in about five percent of the bone bed area.

Younger members of the species have few if any horns on their frills and face while older, larger specimens have much more facial spiking. That’s the clue that leads researchers to think that the spikes were as much a part of mate attraction as defense.

Interested in seeing some other freaky looking dinosaurs? Here’s another link that National Geographic has on some wild-looking specimens.

Tags : triceritops, paleontology, pachyrhinosaur, dinosaurs

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Name that dinosaur: Classic confrontation between Triceratops horridus and Tyrannosuaurs rex
Courtesy Mark RyanNowadays, when a new dinosaur is discovered (something that happens about every two weeks) it goes through a careful process of study and description before given an official name. Professor Michael Benton from Bristol University, UK, has made a study of how accurate dinosaur naming is, and if new discoveries are actually that or just duplicates of a previously named creature. His conclusion is that - lately anyway - paleontologists have been doing a pretty good job sorting the new from the old.

"My research suggests we're getting better at naming things; we're being more critical; we're using better material," said professor Benton. But that hasn’t always been the case.

Marsh and Cope: Othniel Charles Marsh (left) and Edward Drinker Cope (right). The pioneer paleontologists were once friends who became bitter rivals. During the famous 19th century Bone Wars they competed to collect and name as many dinosaurs as they could.
Courtesy WikipediaBack in the 1870’s when two titans of early American paleontology were battling each other for supremacy in their field, new dinosaurs were being described and named on the skimpiest of fossil evidence. During those contentious times, former friends Othniel Charles Marsh and Edward Drinker Cope named and described hundreds of dinosaurs, each trying to outdo the other in their quest to be paleontology's Top Dog. Great and wonderful discoveries arose from their fierce competition, but in the frenzy many mistakes were made that would require sorting out. Sometimes newly bestowed names were already in use for a completely different animal not necessarily even a dinosaur (preoccupied name), but usually one would name a dinosaur the other or someone else (including themselves) had already named previously (junior synonym) with similar but less complete remains. Once a name enters the scientific literature it becomes somewhat difficult to remove it.

Brontosaurus excelsus: Original illustration accompanying O.C. Marsh's monograph published in the American Journal of Science in 1883. The dinosaur became known scientifically as Apatosaurus after further study revealed the specimens the two names were based on were of the same species.
Courtesy Mark RyanThe most famous case of name confusion involved the Brontosaurus. Bones of the lumbering sauropod were discovered in Wyoming in 1879, and Marsh christened it Brontosaurus excelsus. But in 1903, four years after Marsh’s death, paleontologist Elmer Riggs determined that an earlier discovered sauropod called Apatosaurus ajax was a juvenile version of the same creature, Marsh had named that one, too, just two years before from very partial remains found in Colorado. Since the rules of scientific naming established by the ICZN give priority to the first published name, a compromise was made (Apatosaurus excelsus) and the name Brontosaurus was abandoned from official use, although it has remained in the vernacular.

"Big Al" the Allosaurus in Wyoming: Paleontologist O.C. Marsh named the carnivorous dinosaur Allosaurus fragillis in 1877 from fossil bones discovered in Colorado. The name refers to the strange lightness of the creature's vertebrae (Allosaurus = different lizard; fragillis = fragile).
Courtesy Mark RyanAnother well-known dinosaur, Allosaurus, had originally been named Antrodemus, based on a single partial tail vertebra given to Ferdinand Hayden when he was surveying the western United States. Hayden passed the fossil onto paleontologist Joseph Leidy who named it Antrodemus valens. Even though the name preceded Allosaurus by about seven years, the original fossil was determined just too fragmentary, and its source rock formation uncertain, so the name Allosaurus prevailed sending Antrodemus toward nomen obitum (forgotten name) classification. (Of course new evidence could reverse this). But that wasn’t the end of it. After the genus had been sorted out, many of the separate allosaur species named by Marsh and others were later deemed as either synonymous or having doubtful and invalid names.

Antrodemus then became what is known as a senior synonym, a name preceding the more established Allosaurus but, in this rare case, no longer in use. (Other questionable genera such as Creosaurus, Epanterias, and Labrosaurus are considered by many paleontologists as junior synonyms for Allosaurus or even numen dubium because they haven’t been studied enough to establish distinct genera). All had been collected and named during the Marsh and Cope Bone Wars. Of course Marsh and Cope weren't alone in all this. Many other duplicate and unsubstantiated type specimens have been established by other paleontologists through the years.

Professor Benton’s study, which has been published in the journal Biology Letters, delved into the background of the more than 1000 dinosaur ever named, and re-examined the material used to establish the type specimens. These are the fossils upon which the original research, descriptions and figures (illustrations) were based that led to the naming of the dinosaur. In some cases better and more complete remains were used, and professor Benton he was able to whittle the list down to about 500 distinct species of dinosaurs,

"There's no point somebody such as myself doing big statistical analyses of numbers of dinosaur species through time - or indeed any other fossil group - if you can't be confident that they really are genuinely different," Benton said.

LINKS

University of Bristol press release
Bristol Dinosaur Project (for kids)
Scientific Frontline story
List of dinosaur names

Tags : species, speciation, scientific nomenclature, paleontology, nomenclature, dinosaurs

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A crurotarsan: Pretty cool, but don't put any bets on it.
Courtesy ArthurWeasleyJust as those of us who have hands know the backs of them well, just as all of us know that the Hulk is stronger than the Thing, just as we know that it’s a good idea to keep our lips off that thing… We all know that dinosaurs are pretty awesome. They are, perhaps, the most awesome.

Dinosaurs did, after all, strut their fine stuff across the surface of the planet for more than 150 million years. How else would one explain that, if not for the fact that dinosaurs were clearly more awesome than any and all of the competition? It can’t be done.

Except…

Scientists at the American Museum of Natural History are now saying that at the outset of their reign, the during Triassic, dinosaurs succeeded where other groups did not simply because they were lucky. Dinosaurs didn’t make it because they were stronger or able to adapt more quickly, but because they did well at the craps table. As it were.

See, the reptiles that survived the Permian extinction would eventually give rise to dinosaurs and a group called “crurotarsans.” The only living descendants of the crurotarsans are crocodiles and their ilk, but during the Triassic the group included a wide range of large predators, armored herbivores, and agile little crocodilians. At the end of the Triassic, however, the crurotarsans became almost entirely extinct, while the dinosaurs flourished.

When one group dies out and another succeeds under the same conditions, scientists usually expect to find that the “winning” group has a greater range of physical traits, or appears to be able to adapt much faster. The study done by the AMNH indicates the opposite in this case: as a group, the crurotarsans had twice the range of body plans as the dinosaurs, and seemed to be adapting just as fast. Subjected to the changing environmental conditions at the end of the Triassic, the greater variety of body designs should have given the crurotarsans a leg up in surviving to the Jurassic.

Not only should they not have died out, but the scientists behind the study say that if they could have bet—during the Triassic—who would dominate the planet for the next 130 million years, they would have picked the crurotarsans, not dinos. It just so happened that the crurotarsans were hit particularly hard at the end of the Triassic. Of all the extinction-inducing changes that could have occurred, the planet went through one that the crurotarsans couldn’t deal with: global warming. Dumb luck.

It seems like the study was missing something, however. What was it about global warming (or about the crurotarsans) that made them die out, even with their great diversity? Even if luck was the reason, what was the mechanism?

I’m inclined to think that the dinosaurs’ coolness had something to do with it. Sort of an opposite James Dean effect.

How about that, though? But for the roll of the biological dice, children across the world could have lunch boxes and notebooks covered in crurotarsans.

Tags : evolution, dinosaurs, Triassic, Crurotarsi, paleontology

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Tarbosaurus
Courtesy BogdanovJapanese and Mongolian scientists have successfully recovered the complete skeleton of a Tarbosaurus (related to the giant carnivorous Tyrannosaurus) from a chunk of sandstone they dug up in the Gobi Desert in Mongolia.
The dinosaur came from a geological layer created about 70 million years ago in the late Cretaceous period.

The almost complete young dinosaur find will be useful toward discovering more about the growth and development of dinosaurs.

Read more and view a photo at USA Today.

Tags : tarbosaurus, Takuji Yokoyama, Mongolian Academy of Sciences, Hayashibara Museum of National Sciences, dinosaurs

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Signs of color preserved in stone?: Fossil feather from Brazil (left) displays similarities with recent woodpecker feather (right)
Courtesy J.Vinther/YaleResearchers at Yale University are reporting the discovery of pigmentation within the fossilize feather from a bird or dinosaur. Using a powerful electron microscope, paleobiologist Jakob Vinther and his team claim that particles seen in the 100-million-year-old fossil appear to be similar to those seen in the feathers of living birds. This could mean that color - a characteristic long-thought lost in the fossil record - could someday be determined from the remains of pigment.

Vinther’s colleagues included Yale paleontologist Derek E. G. Briggs and Yale ornithologist Richard O. Prum. The results of their study will appear in an upcoming issue of Biology Letters. The research shows that dark stripes in the Cretaceous-aged feather display many similarities to the make-up of black melanin particles found in modern bird feathers. Melanin compounds determine color in plants and animals, a trait useful for such things as camouflage, species identification, and courtship display. In humans, melanin colors our skin and also protects us from overexposure to sunlight.

For a long time, the dark granules seen in fossilized feathers were thought to be the carbon remains of bacteria that had worked at decomposing the organism prior to fossilization. But advances in electron microscope technology have given scientists a closer - and clearer – picture of the feather’s structure, and instead show them to be fossilized melanosomes containing melanin pigment.

"Feather melanin is responsible for rusty-red to jet-black colors and a regular ordering of melanin even produces glossy iridescence,” Vinther said. “Understanding these organic remains in fossil feathers also demonstrates that melanin can resist decay for millions of years."

Under the scope, the lighter bands of the fossilized feather showed only the rock matrix, while the darker bands displayed traces of residue closely resembling the organic compounds found in the feathers of modern birds.

“You wouldn’t expect bacteria to be aligned according to the orientation of the feathers,” said Vinther.

Another bird fossil showed similar organic traces in the feathers surrounding its skull. The 55-million-year-old fossil from Denmark also preserved an organic imprint of the eye that showed structures similar to the melanosomes found in eyes of modern birds.

Nanostructure studies could one day provide paleontologists with evidence of colors other than just black and gray tones, and not just in fossil feathers. Vinther figures other organic remains such as fur from prehistoric mammals or fossil skin impressions from dinosaurs could prove to be the remains of the melanin.

LINKS
ScienceNews story
Yale website story
Cosmos magazine website story
Melansome info

Tags : paleontology, nanostructure, nano technology, fossils, dinosaurs, color, ancient birds

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Fossil Cabin Museum: Como Bluff is located just over the ridge seen in the background.
Courtesy Mark RyanOut on the High Plains of Wyoming about 50 miles northwest of Laramie sets one of the wackiest constructions in the world, a museum built entirely from fossilized dinosaur bones!

Known today as Fossil Cabin Museum, the structure sets smack dab on the border of Carbon and Albany counties near the nose-end of the Como Bluff anticline. It still operates as a museum, but access to it is spotty, depending on whether anyone’s around to let you in.

Fossil Cabin Museum wall: Fragments of 150 million year-old dinosaur bones make up the museum's exterior walls.
Courtesy Mark RyanThe oddity was built using 5,796 dinosaur bones fragments, more than 50 tons of them! At the time of construction traffic flowing past the site was heavy with motorists on their way east or west along Highway 30, the popular Lincoln Highway route.

Thomas Boylan, the guy who put together this strange museum, came to Wyoming from California, and established a homestead on the site in 1902. Boylan’s land was within walking distance of Como Bluff, an historic dinosaur graveyard from which 30 years before many of the first Jurassic-aged dinosaurs were dug up and introduced to the world. Boylan spent a lot of time hunting for dinosaur fossils and after 15 years had amassed quite a collection bone fragments. His dream was to construct an entire skeleton out of them.

“At first I planned to get enough of them together to mount a complete dinosaur skeleton, however erecting such a skeleton is a long and costly task for an individual to undertake so I abandoned the idea and proceeded to use them the best I could,” Boylan said.

Fossil Cabin postcard c. 1936
Courtesy Mark Ryan collectionCost and time weren’t the only reasons Boylan abandoned his dream. After consulting with paleontologists at the University of Wyoming Geological Museum he also learned that although he certainly had a boatload of dinosaur bones, they were from a large variety of species and didn’t amount to an entire skeleton of any one creature. Whatever the case, he and his son Edward (who for a time would serve as the museum’s curator) spent late 1932 and early 1933 constructing the building out of his collection.

Fossil Cabin postcard c. 1936
Courtesy Mark Ryan collectionNearby, they also built a residential home that - while not constructed out of dinosaur bones - was intentionally built to approximate the length of a Diplodocus in order to give visitors an idea of the size of one of the larger creatures extracted from the nearby dinosaur pits. Boylan also operated a service station alongside the roadside attraction, filling visitors’ cars with gasoline, as his museum filled their heads with science.

In 1938, Robert Ripley of “Ripley’s Believe It or Not” fame mentioned the museum in his syndicated newspaper feature calling it "The Oldest Cabin in the World". But the museum has gone by several other names including Fossil Museum, Dinosaurium, Creation Museum, and Dinosaur House. Boylan often referred to it as “The Building That Used to Walk”.

Fossil Cabin Museum entry
Courtesy Mark RyanThe Boylans operated the roadside exhibit throughout the 30s and 40s, playing host to tourists and the occasional paleontologist revisiting the historic fossil fields. After Tom died in 1947, his wife Grayce continued the operation until the new interstate was built through Laramie in the late 1960s and tourist traffic past the museum all but disappeared. Nearby towns like Bosler, Rock River and Medicine Bow faded as well. In 1974, Mrs. Boylan sold all the property to Paul and Jodie Fultz, who tried to keep the attraction going, but the Fossil Cabin’s glory days had passed.

I’ve visited the area a few times and only once was anyone around to let me inside the museum. It looked closed, but I walked up to the nearby residence and knocked on a door framed by two large sauropod femurs. A young kid appeared, and was kind enough to allow me inside the museum for a $2 admission fee. As I “toured” the museum, he explained in a western drawl how he and his dad were living on the property, watching over it for the owner who had moved to Medicine Bow. They worked mainly as hunting guides for animals a little more current than what made up the museum’s exterior walls.
Fossil Cabin Museum information sign: Brontosaurus was first named for a specimen discovered at Como Bluff.
Courtesy Mark RyanThe displays inside had seen better days, and I regret not taking photographs. A couple dusty glass cases held some large dinosaur bones, minerals, and marine fossils found around Como. A few faded and out-of-date science posters hung in tatters on the otherwise bare walls. Generally, it was a shambles. Which is too bad, because it could be a very nice little museum, and probably was in its time.

If anyone’s interested, the property is currently for sale. I know if I won the lottery it’d be the first thing I’d buy. With a little paint and wallpaper, and a pullout bed or futon, it’d make a nifty summer cabin for visits to Wyoming. Or a pleasant addition to the Dinos and Fossil gallery here at the Science Museum of Minnesota.

I should mention that this building is not the first of its kind. Bone Cabin Quarry, a rich dinosaur fossil site located along the Little Medicine river about 10 miles north of Como Bluff, was named after a sheepherder’s cabin built in the late 1800s. The cabin’s foundation had been created from the abundant dinosaur bones found in the region.

Tags : prehistoric, paleontology, fossils, dinosaurs, como bluff, Americana

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