Ancestor of T rex found in China
Tyrannosaurus rex may have had much smaller ancestors
Fossils found in China may give clues to the evolution of Tyrannosaurus rex.
Uncovered near the city of Jiayuguan, the fossil finds come from a novel tyrannosaur dubbed Xiongguanlong baimoensis.
The fossils date from the middle of the Cretaceous period, and may be a “missing link”, tying the familiar big T rex to its much smaller ancestors.
The fossils show early signs of the features that became pronounced with later tyrannosaurs.
Paleontological knowledge about the family of dinosaurs known as tyrannosaurs is based around two distinct groups of fossils from different parts of the Cretaceous period, which ran from approximately 145 to 65 million years ago.
One group dates from an early part of the period, the Barremian, and the other is from tens of millions of years later.
Before now it has been hard for palaeontologists to trace the lineage from one group to the other.
“We’ve got a 40-50 million year gap in which we have very little fossil record,” said Peter Makovicky, associate curator at the Field Museum in Chicago, who helped to lead the US/Chinese team that uncovered the fossil.
Hadrosaurs – duck-billed dinosaurs – spread rapidly in the late Cretaceous
But, he said, X baimoensis was a “nice link” between those two groups.
“We’re filling in that part of the fossil record,” he said.
Writing in the Royal Society’s journal Proceedings B, Dr Makovicky and colleagues suggest that X baimoensis is a “phylogenetic, morphological, and temporal link” between the two distinct groups of tyrannosaurs.
The fossil has some hallmarks of large tyrannosaurs such as a boxy skull, reinforced temple bones to support large jaw muscles, modified front nipping teeth and a stronger spine to support a large head.
But it also shows features absent from older tyrannosaurs, such as a long thin snout.
An adult would have stood about 1.5m tall at the hip and weighed about 270kg. By contrast, an adult T rex was about 4m tall at the hip and weighed more than 5 tonnes.
The same edition of Proceedings B features papers about two other sets of dinosaur fossils.
One discovery was made in China by many of the palaeontologists who found the tyrannosaur. The samples found in the Yujingzi Basin came from a dinosaur that resembled the modern ostrich.
While many of these ornithomimosaurs have been found before, analysis of the bones of the new species, dubbed Beishanlong grandis, suggest it was one of the biggest.
The specimen found by the palaeontologists was thought to be 6m tall and weigh about 626kg.
Alongside in Proceedings B was work on the remains of a duck-billed dinosaur found in Uzbekistan called Levnesovia transoxiana.
Analysis of the fossils, by Hans-Dieter Sues of the Smithsonian in Washington and Alexander Averianov of the Russian Academy of Sciences, may shed light on the waves of expansion hadrosaurs undertook during the late Cretaceous.
FOXNews - 22-apr-2009
A Tyrannosaurus rex ancestor and an ostrich-mimic have emerged as two new dinosaur species found among a treasure trove of skeletons in China’s Gobi Desert. …
«Jurassic Park» nell’isola di Wight
Scoperte le tracce fossili di un Velociraptor e di altri dinosauri dove suonò Bob Dylan nel 1969
DAL NOSTRO CORRISPONDENTE – LONDRA – I più giovani, forse, ne hanno sentito parlare di quell’ultimo giorno di agosto del 1969, ben 40 anni fa, quando su un prato dell’Isola di Wight migliaia e migliaia di ragazzi della beat-generation si ritrovarono ballare e cantare con Bob Dylan, vestito di bianco, e la sua «Band». Un concerto-festival entrato nella storia della musica e del costume. Bob Dylan non piacque a molti, ci fu chi scrisse su una pietra: qui giace il grande Bob. Fra la folla c’erano un certo John Lennon e un certo Paul Harrison.
SCAVATE TRE TONNELLATE DI TERRA - Oggi l’isola di Wight, al largo di Southampton nella Manica, fa parlare ancora di sé. Ma per ben altre ragioni. Steve Sweetman, dell’università di Portsmouth, ha ritrovato in quattro anni di ricerca le tracce fossili di un velociraptor, il Predatore Veloce del Cretaceo, di un pterosaurus, di tre sauropodi e di almeno quattro dinosauri erbivori, oltre a tre coccodrilli giganti e 48 specie sconosciute di animali. Il paleontologo ha dragato tre tonnellate mezzo di terra partendo da un minuscolo indizio: la mandibola di una salamandra. Che l’Isola di Wight avesse ospitato cento milioni di anni fa una piccola colonia di dinosauri gli scienziati lo avevano già accertato. Ma la scoperta, annunciata ieri, è sorprendente. Se non altro per la quantità del «tesoro» venuto alla luce. Jurassik Park è davvero esistito.
Dinosaur hunter unearths nearly 50 new species in Britain’s own Jurassic Park
Some 48 new prehistoric species have been unearthed by a British expert from Britain’s own Jurassic Park, including dinosaurs similar to the deadly velociraptor and giant flying pterosaurs.
Dal Cretaceo di Liaoning (Cina) l’ennesimo ritrovamento spettacolare: un piccolo pterosauro caratterizzato da un’ampiezza alare di soli 25 centimetri circa e da un becco appuntito e privo di denti.
Pterosaur Fossil With 10 Inch Wingspan Discovered
With a wingspan of only 10 inches, this weird fossil is one of the world’s smallest species of flying Pterosaurs.
It was recently discovered in the western part of China’s Liaoning Province, which is believed to have been a forested area during the early Cretaceous Period some 120 million years ago.
This pterosaur was equivalent to the size of a modern blackbird.
“The fossil is very well preserved and it has long sharp bill. It was toothless and its skull was just over 4cm (more than 1-inch) long.” said Wang Xiaolin of the Chinese Academy of Sciences.
Despite its small stature and wingspan, this small toothless reptile may well be the ancestor of gigantic Pterodactyls whose wing tips stretched 20-feet from wingtip to wingtip. This new species has been christened Nemicolopterus crypticus, meaning “hidden flying forest dweller”.
The slight shiver that might be crawling up your back is a reminder that in its own way that this fossil is a connection to all living things, humans included.
Un ritrovamento di una ricca fauna a dinosauri nel cretaceo terminale della Russia (Area sub-artica) sembra sconfessare il modello di estinzione lenta dei dinosauri.
——————————————————————————————————————————————-Published online 19 January 2009 | Nature | doi:10.1038/news.2009.40
Dinosaur fossils suggest speedy extinction
Arctic find challenges the idea that the massive reptiles declined slowly.
Fossils uncovered recently in the Arctic support the idea that dinosaurs died off rapidly — perhaps as the result of a massive meteor hitting Earth. The finding contravenes the idea that dinosaurs were already declining by this time.
Geological evidence indicates that an impact occurred near the Yucatán Peninsula at the end of the Cretaceous 66 million years ago. But whether the event created an all-out apocalypse that wiped out the dinosaurs is still a matter of debate. Despite many species dying out, many others survived, including mammals and the small feathered dinosaurs that were the ancestors of today’s birds.
Some palaeontologists suggest that non-avian dinosaurs were in decline before the impact — perhaps as a result of major volcanic events or global cooling.
Now, reporting in Naturwissenschaften1, Pascal Godefroit at the Royal Belgian Institute of Natural Sciences and his colleagues describe fossils found in northeastern Russia that suggest dinosaurs were not in decline at all. Although dinosaur fossils have already been found in the Arctic, the new find is unique because of its age: Godefroit and his team have dated the beds at between 68 million and 65 million years old — just before the time of the extinction.
“We found that there is no indication that the biodiversity of dinosaurs decreased just before the [extinction] event,” says Godefroit. The team found that herbivorous, duck-billed hadrosaurs and velociraptor-like bipedal theropods seem to be as common as they were in other parts of the planet at the time. Along with this discovery is the presence of the first dinosaur eggshells found in polar regions, hinting that the dinosaurs were residents rather than migrants.
Bang or whimper?
That such healthy polar populations existed just before the extinction would seem to strike a blow against the theory that the animals were already declining. But palaeontologists are cautious.
“The presence of these dinosaurs is certainly concordant with the idea of a sudden extinction, but not incontrovertible evidence for it,” says Tom Rich of Museum Victoria in Melbourne, Australia.
Robert Spicer of the Open University’s Earth sciences department in Milton Keynes, UK, suggests that when the dinosaurs died out, the site may have lain along the edge of the Arctic Circle rather than deep within it.
“The weak link here is the palaeoposition of the site,” he says. “With that said, such diversity even at this latitude suggests that dinosaurs were far more robust than we give them credit for. It makes me ask very serious questions about what could make animals that were resilient enough to live under these conditions suddenly go extinct.”
Attributing the extinction to any one cause is risky, adds Bill Clemens of the University of California, Berkeley. Work by David Wake, also at the University of California, Berkeley, and Vance Vredenburg of San Francisco State University2, suggests that the decline of modern amphibians involved a variety of factors ranging from the introduction of predators to disease and habitat loss, Clemens says.
“Ask what is endangering modern amphibians, the answer varies according to species,” he adds. “I think the same was probably true with the dinosaurs.”
- Naturwissenschaften advance online publication doi:10.1007/s00114-008-0499-0 (2009).
- Proc. Natl. Acad. Sci. USA 105, 11466-11473 (2008).
Well-Preserved Dinosaur Guts Give Insight Into Prehistoric Diet
Thursday, September 25, 2008
An analysis of the gut contents from an exceptionally well-preserved juvenile dinosaur fossil suggests that the hadrosaur’s last meal included plenty of well-chewed leaves digested into tiny bits.
The fossil, Brachylophosaurus canadensis aka “Leonardo,” is the second well-substantiated case in which the gut contents of a plant-eating dinosaur have been revealed, said Justin S. Tweet, who was a graduate student at the University of Colorado at Boulder when he studied the fossil with colleagues there including paleontologist Karen Chin.
The dino, found in what geologists call the Judith River Formation, in Montana, will go on display to the public Friday at the Houston Museum of Natural Science’s “Dinosaur Mummy CSA: Cretaceous Science Investigation” exhibition.
“Our interpretation suggests that the subadult Judith River Formation brachylophosaur had a leaf-dominated diet shortly before its death,” the authors write in the September issue of PALAIOS, the journal of the Society for Sedimentary Geology.
Skin and scales
Leonardo is a 77-million-year-old duckbilled dinosaur whose remains are covered with patterned fossilized skin. The specimen has given scientists a rare peek inside a dinosaur. Digital technology and X-ray scans, some of which were conducted at NASA Johnson Space Center’s Ellington Field facility in Texas, has helped paleontologists reconstruct what Leonardo looked like in life, what it ate, its muscle mass and its limb movements.
An analysis of pollen found in the specimen’s gut region revealed a variety of plants, including ferns, conifers and flowering plants. Although the pollen could have been ingested when the dinosaur drank water, the tiny leaf bits, under 5 millimeters (a quarter-inch) in length, indicate that Leonardo was a big browser of plants, Chin said.
Hadrosaurs were certainly capable of processing food into tiny bits in part with their continually replacing teeth and grinding jaws.
The tricky part with the analysis was building a case that the plant matter found inside the gut came from the dinosaur’s last meal, not from material that penetrated the body or flowed into the area after death. The case was helped by the fact that Leonardo was buried quickly and undisturbed by scavengers, and its body cavity appears to be undisturbed. At least 12 percent of the gut contents in the carcass included organic matter, such as leaves. The rest was clay and grit. Some of the inorganic stuff probably flowed into the body after death, Tweet said.
Overall, the most exciting part of the research was working with material that could actually be gut contents, Tweet said.
“This is very rare for dinosaurs, where we usually have to settle for generalizations of feeding behavior based on skull anatomy,” he told LiveScience.
The research was funded by grants through the University of Colorado and its Museum of Natural History and a Geological Society of American Graduate Student Grant.
Houston Museum of Natural Science Curator of Paleontology Robert T. Bakker, one of the first scientists to work on the fossil, said that duckbill dinosaurs like Leonardo had large bills and jaws full of tiny teeth, about 800 of them, that ground and chopped tough plants and plant parts, including conifer needles, bark and twigs, like a “cranial Cuisinart.”
The contents of the gastrointestinal tract then were processed by digestive juices and gut microbes.
Leonardo has a pebbly skin texture, like the lower leg of an ostrich or another big bird, Bakker said, but on the front of Leonardo’s ankle and shin, the skin becomes very thick like armor which helped it move through the underbrush.
The fossil was discovered in the summer of 2000 during an expedition to a cattle ranch about 15 miles north of Malta, Mont. Leonardo was named after graffiti found on a nearby rock that read: “Leonard Webb loves Geneva Jordan 1916.”
The Houston exhibition will also feature an icthyosaur “mummy,” which has contents of her intestines and four babies preserved inside her body, and the only mummified Triceratops skin ever found. The exhibition’s opening was delayed a week as a result of conditions and power losses in the Houston area after Hurricane Ike, including five days without primary power at the museum. Leonardo and other exhibition specimens were unharmed, a museum spokeswoman said.
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Probable Gut Contents Within A Specimen Of Brachylophosaurus Canadensis (Dinosauria: Hadrosauridae) From the Upper Cretaceous Judith River Formation Of Montana
Justin S. Tweet, Karen Chin, Dennis R. Braman, and Nate L. Murphy
PALAIOS 2008 23: 624-635. [Abstract] [Full Text] [Figures Only] [PDF]
Abstract – An exceptionally preserved subadult specimen (JRF 115H) of a hadrosaurid, Brachylophosaurus canadensis, from the Judith River Formation near Malta, Montana, contains abundant plant fragments concentrated within the body cavity. We examined the taphonomy of the carcass and analyzed the gut-region material to test whether the organic remains represent fossilized gut contents. The dinosaur was buried in a fluvial channel setting, and the excellent articulation, integument impressions, and lack of scavenging indicate rapid burial. The organic material occupies a volume of at least 5750 cm3, and comparable material is not found outside the carcass. The carcass contents include about 63% clay, about 16% undetermined matrix, about 12% organic matter, and about 9% larger inorganic clasts—mostly 50–100 µm quartz grains. Most of the organics appear to be mm-scale leaf fragments. The most parsimonious explanation for the presence and composition of the gut-region material is that much of the plant fossils represent reworked brachylophosaur ingesta influenced by flowing water that entered through openings in the carcass and introduced clay. The evidence strongly suggests that the hadrosaurid ate significant quantities of leaves and processed them into small pieces. This study provides baseline information for analyzing other cases of putative gut contents in herbivorous dinosaurs.
a) google scholar
Oldest Gecko Fossil Ever Found, Entombed In Amber
ScienceDaily (Sep. 3, 2008) — Scientists from Oregon State University and the Natural History Museum in London have announced the discovery of the oldest known fossil of a gecko, with body parts that are forever preserved in life-like form after 100 million years of being entombed in amber.
Due to the remarkable preservative power of being embalmed in amber, the tiny foot of this ancient lizard still shows the tiny “lamellae,” or sticky toe hairs, that to this day give modern geckos their unusual ability to cling to surfaces or run across a ceiling. Research programs around the world have tried to mimic this bizarre adhesive capability, with limited success.
This gecko’s running days are over, however, as only the foot, toes and part of a tail are left in the stone. The rest might have become lunch for a small dinosaur or other predator during an ancient fight in the tropical forests of Myanmar during the Lower Cretaceous Period, from 97 million to 110 million years ago.
The find is at least 40 million years older than the oldest known gecko fossil, shedding additional light on the evolution and history of these ancient lizards that scampered among the feet of giant dinosaurs then and still are common in tropical or sub-tropical regions all over the world.
The findings were just published in Zootaxa, a professional journal.
“It’s the unusual toe pads and clinging ability of some geckos that make them such a fascinating group of animals, so we were very fortunate to find such a well-preserved foot in this fossil specimen,” said George Poinar, Jr., a courtesy professor at OSU and one of the world’s leading experts on insects, plants and other life forms trapped in amber, a semi-precious stone that begins as tree sap.
“There’s a gecko society, gecko clubs, just a lot of interest in these animals because of their unusual characteristics,” Poinar said. “So there are a lot of people pretty excited about this.”
Based on the number of lamellae found on its toe pads, this gecko was probably a very small juvenile of what would have become a comparatively large adult, possibly up to a foot long, the researchers say. Modern geckos get no more than about 16 inches long, although it’s possible there were larger species millions of years ago. The juvenile gecko found in the fossiljuvenile gecko found in the fossil was less than an inch in length when it died – possibly by being eaten or attacked, since only partial remains were found.
The discovery has been announced as a new genus and species of gecko, now extinct, and has been named Cretaceogekko. It had a striped pattern that probably served as camouflage.
There are more than 1,200 species of geckos in the world today , common in warm or tropical regions, including parts of the southern United States. They are frequently kept as pets, and often are welcome in the homes of some tropical residents because they help control insects. Some are very colorful. They use long tongues to lick, clean and moisturize their eyes.
“Geckos are territorial, and when I lived in Africa in the early 1980s we used to have them in our house,” Poinar said. “They are pretty friendly and don’t bother humans. Certain individuals would move into the house, we’d give them names, and they would run around the house, catch mosquitoes, help control bugs. They would crawl across the ceiling and look down at you.”
The new study provides evidence that geckos were definitely in Asia by 100 million years ago, and had already evolved their bizarre foot structure at that time. The amber fossil was mined in the Hukawng Valley in Myanmar, and during its life the gecko probably lived in a moist, tropical forest with ample opportunities for climbing.
The ability of geckos to walk on vertical walls or even upside down is due to the presence of thousands of “setae” on their toes, very tiny, hairlike structures that have tips which attach to surfaces by van der Walls forces. It’s a type of incredibly strong, dry adhesion shared by virtually no other group of animals.
It’s not known exactly how old this group of animals is, and when they evolved their adhesive toe pads. However, the new study makes it clear that this ability was in place at least 100 million years ago, in nature. Modern research programs still have not been able to completely duplicate it.
Scientists at the University of California at Berkeley reported earlier this year that they have developed a new “anti-sliding” adhesive that they said was the closest man-made material yet to mimic the ability of geckos – they think it might help a robot climb up the side of walls. A research team at the Massachusetts Institute of Technology this year created a waterproof adhesive bandage inspired by geckos, that may some day be used in surgery. And of course, geckos have become an advertising icon for the insurance company Geico.
This study is just one of many in which Poinar and colleagues have used the unusual characteristics of amber to study ancient life forms and develop information on the ecology of ancient ecosystems.
As a stone that first begins to form as sap oozing from a tree, amber can trap small insects or other life forms and preserve them in near-perfect detail for observation millions of years later.
Is the 87-million-year-old praying mantis recently found encased in amber in Japan a “missing link” between mantises from the Cretaceous period and modern-day insects?
It is a rare find indeed and its true significance is still to be deciphered.
Discovered in January of this year by Kazuhisa Sasaki, director of the Kuji Amber Museum, the fossil mantis measures 0.5 inch (1.4 centimeters) from its antennae to the tip of its abdomen.
It was found buried more than six feet below the surface of an amber mine in a part of Japan that is famous for producing large amounts of amber, the northeastern Iwate Prefecture.
“I found it in a deposit that had lots of other insects—ancient flies, bees, and cockroaches—but this was the only praying mantis” said Sasaki.
The fossil mantis is partially well preserved, although its wings and abdomen are badly crushed.
According to Kyoichiro Ueda, executive curator of the Kitakyushu Museum of Natural History, it is the oldest mantis fossil ever found in Japan and only one of seven in the entire world from the Cretaceous Period.
Even more unique is the fact that this mantis is different from the other six, in that it has two spines protruding from its femur and it has mysterious, tiny hairs on its forelegs.
No mantis from this particular time period has ever been found with spines, although modern mantises have five or six on their forelegs, which help them catch prey.
“The years of the late Cretaceous period were a kind of transition phase between the ancient and modern worlds, and this fossil displays many intermediate elements between the two eras” said Ueda.
Time alone will reveal the significance of this important find.
Fossilized Pregnant Turtle Found 75 Million Years After Death
Wednesday, August 27, 2008
A turtle that toddled alongside the dinosaurs died just days before laying a clutch of eggs. Now, about 75 million years later, paleontologists are announcing their find of the fossilized mother-to-be and the eggs tucked inside her body.
Scientists from the Royal Tyrrell Museum of Palaeontology in Canada discovered the turtle in 1999 in a mud-filled channel in the badlands of southeastern Alberta. Then, in 2005, University of Calgary scientists found a nest of 26 eggs laid by another female of the same species in the same region.
Both specimens, described this week in the journal Biology Letters, belong to an extinct turtle in the Adocus genus, a large river turtle that resembles today’s slider and cooter turtles.
The pregnant turtle represents the first fossil turtle to be unearthed with eggs still inside the body cavity, the scientists say.
“Although it is relatively rare to find the eggs and babies of extinct animals, it is even rarer to find them inside the body of the mother,” said researcher Darla Zelenitsky, a geoscientist at the University of Calgary in Alberta, who was also involved in the first discovery of a dinosaur with eggs inside its body.
It was almost by accident that scientists realized that the fossil turtle had been pregnant.
“The reason we knew she was pregnant was because when the fossil was found the body was broken,” Zelenitsky told LiveScience, “so there was egg shell on the ground just below the fossil, it was falling out of the body.”
The team spotted at least five crushed eggs within the body of the fossilized female, and computed tomography (CT) scans revealed more eggs hidden beneath the turtle’s shell. The turtle, estimated to be about 16 inches (40 cm) long, could have produced about 20 eggs.
When still intact, the eggs would have been spherical and about 1.5 inches (4 cm) in diameter. The eggs from the nearby nest were about the same size and shape. Both sets of eggs also had extremely thick and hard shells, especially compared with most modern turtles whose shells are either thinner or soft.
The thick eggshell may have evolved to protect the eggs from drying out or from voracious predators that lived during the Age of Dinosaurs.
The pregnant turtle and nest specimens, the researchers say, shed light on the evolution of reproductive traits of modern turtles.
“Based on these fossils, we have determined that the ancestor of living hidden-necked turtles, which are most of today’s turtles and tortoises, laid a large number of eggs and had hard, rigid shells,” said François Therrien, the Museum’s Curator of Dinosaur Palaeoecology, who worked on the turtle report in the journal.
http://gauntlet.ucalgary.ca/story/12654 (see for pictures)
|Pregnant turtle fossil find unique
Lethbridge Herald - 28 ago 2008
By Jeff Wiebe That was Alberta, 75 million years ago. It was also home to the Adocus turtle, and the fossil of one such animal was revealed to the public …
è stato segnalato un importante ritrovamento di impronte di due baby sauropodi in Korea (Euiseong County, North Gyeongsang Province) in strati risalneti al Cretaceo e datati a 100 milioni di anni fa.
Al di là del valore intrinseco della scoperta, questa può avere anche un importante significato nel campo della paleobiologia dei sauropodi visto che rappresenta un ulteriore conferma al comportamento sociale degli stessi e può avvalorare l’ipotesi di un periodo di vita in cui i baby sauropodi vivevano da soli prima di entrare nel branco.
The world’s largest fossil of a playground of baby dinosaurs going back over 100 million years has been found in Korea. The Natural Heritage Center under the National Research Institute of Cultural Heritage announced Thursday that it found the fossil trackway of two baby dinosaurs dating back to 110 million years in Euiseong County, North Gyeongsang Province. It is from the Cretaceous period of the Mesozoic Era.
There are a total of 61 footprints of two baby Sauropoda stretching over 4.25 m, making them the largest fossil trackway of baby dinosaurs in the world to date, according the Cultural Heritage Administration. Sauropoda were large, long-necked herbivores that walked on four legs.