Triceratops Was A Social Animal, Group Of Dinosaur Fossils Suggests

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ScienceDaily (Mar. 24, 2009) — Until now, Triceratops was thought to be unusual among its ceratopsid relatives. While many ceratopsids—a common group of herbivorous dinosaurs that lived toward the end of the Cretaceous—have been found in enormous bonebed deposits of multiple individuals, all known Triceratops (over 50 in total) fossils have been solitary individuals.

But a new discovery of a jumble of at least three juveniles the badlands of the north-central United States suggests that the three-horned dinosaurs were not only social animals, but may have exhibited unique gregarious groupings of juveniles.
"This is very thrilling," says Stephen Brusatte, an affiliate of the American Museum of Natural History and a doctoral student at Columbia University. "We can say something about how these dinosaurs lived. Interestingly, what we've found seems to be a larger pattern among many dinosaurs that juveniles lived and traveled together in groups."
In 2005, Brusatte and colleagues found and excavated a site that contained multiple Triceratops juveniles in 66-million-year-old rocks in southeastern Montana. The geological evidence suggests that at least three juveniles were deposited at the same time by a localized flood, and this suggests that they were probably living together when disaster struck. This find indicates that Triceratops juveniles congregated in small herds, a social behavior increasingly identified in other dinosaur groups, such as Psittacosaurus, a small cousin of Triceratops that lived in Asia.
"We don't know why they were grouped together or how much time they spent together," says Joshua Mathews of the Burpee Museum of Natural History and Northern Illinois University, who led the project. "Herding together could have been for protection, and our guess is that this wasn't something they did full time."
The site was discovered in 2005 by Burpee Museum volunteer Helmuth Redschlag. Redschlag, a devoted fan of The Simpsons television program, named the bonebed the "Homer Site."
"It's kind of fitting that these big, bulky, plodding Triceratops are named after Homer Simpson," says Brusatte. "But more than anything, we were able to find something shockingly unexpected, even though there are more Triceratops skeletons than [there are of] nearly any other dinosaur, and southeastern Montana has been combed for fossils for hundreds of years." Excavation at the Homer Site is ongoing, and the Burpee Museum team expects to find additional fossils of Triceratops juveniles.
The research is published in the current issue of the Journal of Vertebrate Paleontology. In addition to Matthews and Brusatte, Scott Williams and Michael Henderson, also of the Burpee Museum of Natural History and Northern Illinois University, are authors.
Adapted from materials provided by American Museum of Natural History, via EurekAlert!, a service of AAAS.

Fossil Fragments Reveal 500-million-year-old Monster Predator

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ScienceDaily (Mar. 21, 2009) — Hurdia victoria was originally described in 1912 as a crustacean-like animal. Now, researchers from Uppsala University and colleagues reveal it to be just one part of a complex and remarkable new animal that has an important story to tell about the origin of the largest group of living animals, the arthropods.

The fossil fragments puzzled together come from the famous 505 million year old Burgess Shale, a UNESCO World Heritage Site in British Columbia, Canada. Uppsala researchers Allison Daley and Graham Budd at the Department of Earth Sciences, together with colleagues in Canada and Britain, describe the convoluted history and unique body construction of the newly-reconstructed Hurdia victoria, which would have been a formidable predator in its time.
Although the first fragments were described nearly one hundred years ago, they were assumed to be part of a crustacean-like animal. It was not then realised that other parts of the animal were also in collections, but had been described independently as jellyfish, sea cucumbers and other arthropods. However, collecting expeditions from in the 1990s uncovered more complete specimens and hundreds of isolated pieces that led to the first hints that Hurdia was more than it seemed. The last piece of the puzzle was found when the best-preserved specimen turned up in the old collections at the Smithsonian National Museum of Natural History, Washington DC. This specimen was first classified as an arthropod in the 1970s and 80s, and then as an unusual specimen of the famous monster predator Anomalocaris.
The new description of Hurdia shows that it is indeed related to Anomalocaris. Like Anomalocaris, Hurdia had a segmented body with a head bearing a pair of spinous claws and a circular jaw structure with many teeth. But it differs from Anomalocaris by the possession of a huge three-part carapace that projects out from the front of the animal's head.
"This structure is unlike anything seen in other fossil or living arthropods," says Ph.D. student Allison Daley, who has been studying the fossils for three years as part of her doctoral thesis.
"The use of the large carapace extending from the front of its head is a mystery. In many animals, a shell or carapace is used to protect the soft-parts of the body, as you would see in a crab or lobster, but this structure in Hurdia is empty and does not cover or protect the rest of the body. We can only guess at what its function might have been."
Hurdia and Anomalocaris are both early offshoots of the evolutionary lineage that led to the arthropods, the large modern group that contains the insects, crustaceans, spiders, millipedes and centipedes. They reveal details of the origins of important features that define the modern arthropods such as their head structures and limbs. As well as its bizarre frontal carapace, Hurdia reveals exquisite details of the gills associated with the body, some of the best preserved in the fossil record.
"Most of the body is covered in the gills, which were probably necessary to provide oxygen to such a large, actively swimming animal," says Allison Daley.
Journal reference:
Allison Daley, Graham Budd, Jean-Bernard Caron, Gregory Edgecombe and Desmond Collins. The Burgess Shale anomalocaridid Hurdia and its significance for early euarthropod evolution. Science, 20th March 2009
Adapted from materials provided by Uppsala University.

Byzantine Period Church With Beautiful Mosaics Discovered

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ScienceDaily (Mar. 20, 2009) — A church that dates to the Byzantine period which is paved with breathtakingly beautiful mosaics and a dedicatory inscription was exposed in an archaeological excavation the Israel Antiquities Authority is conducting near Moshav Nes-Harim, 5 kilometers east of Bet Shemesh (at the site of Horvat A-Diri), in the wake of plans to enlarge the moshav.

According to archaeologist Daniel Ein Mor, director of the excavation on behalf of the Israel Antiquities Authority, “The site was surrounded by a small forest of oak trees and is covered with farming terraces that were cultivated by the residents of Nes-Harim. Prior to the excavation we discerned unusually large quantities of pottery sherds from the Byzantine period and thousands of mosaic tesserae that were scattered across the surface level”.
The excavation seems to have revealed the very center of the site, which extends across an area of approximately 15 dunams, along the slope of a spur that descends toward Nahal Dolev.
During the first season of excavation (November 2008) the church’s narthex (the broad entrance at the front of the church’s nave) was exposed in which there was a carpet of polychrome mosaics that was adorned with geometric patterns of intertwined rhomboids separated by flower bud motifs. Unfortunately, at the conclusion of the excavation this mosaic was defaced and almost completely destroyed by unknown vandals. During that excavation season a complex wine press was partly exposed that consists of at least two upper treading floors and elongated, well-plastered arched cells below them that were probably meant to facilitate the preliminary fermentation there of the must. Part of the main work surface, which was paved with large coarse tesserae, was exposed at the foot of these cells. A complex wine press of this kind is indicative of a wine making industry at the site; this find is in keeping with the presence here of a church and is consistent with our knowledge about Byzantine monasteries in the region during this period (sixth-seventh centuries CE).
Other parts of the church were revealed in the current excavation season. The area of the apse was almost entirely exposed, as were other parts of the southern aisle.
Two rooms that are adjacent to the northern and southern sides of the church were also uncovered. In the southern room a mosaic pavement was exposed that is decorated with intertwined patterns of different size concentric circles. The mosaic also includes a dedicatory inscription written in ancient Greek that was deciphered by Dr. Leah Di Signi of the Hebrew University of Jerusalem:
O Lord God of saint Theodorus, protect Antonius and Theodosia the illustres (illustres - a title used to distinguish high nobility in the Byzantine period) [- - - ] Theophylactus and John the priest (or priests). [Remember o Lord] Mary and John who have offe[red - - ] in the 6th indiction. Lord, have pity of Stephen.
Various phases that were used after the church was abandoned in the later part of the Byzantine period were discerned elsewhere in the structure. The mosaic floor was completely destroyed in different places and the area inside the church was put to secondary use. Industrial installations that are ascribed to the same phase were found which attest to the functional change the building underwent during the end of the Byzantine period-beginning of the Early Islamic period (seventh century CE).
According to Daniel Ein Mor, “We know of other Byzantine churches and sites that are believed to be Byzantine monasteries, which are located in the surrounding region. The excavation at Nes-Harim supplements our knowledge about the nature of the Christian-Byzantine settlement in the rural areas between the main cities in this part of the country during the Byzantine period, among them Bet Guvrin, Emmaus and Jerusalem”.
Adapted from materials provided by Israel Antiquities Authority.

What Perfumes Did Ancient Egyptians Use? Researchers Aim To Recreate 3,500-year-old Scent

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ScienceDaily (Mar. 18, 2009) — The Ancient Egyptians cherished their fragrant scents, too, as perfume flacons from this period indicate. In its permanent exhibition, Bonn University's Egyptian Museum has a particularly well preserved example on display. Screening this 3,500-year-old flacon with a computer tomograph, scientists at the university detected the desiccated residues of a fluid, which they now want to submit to further analysis. They might even succeed in reconstructing this scent.

Pharaoh Hatshepsut was a power-conscious woman who assumed the reins of government in Egypt around the year 1479 B.C. In actual fact, she was only supposed to represent her step-son Thutmose III, who was three years old at the time, until he was old enough to take over.
But the interregnum lasted 20 years. "She systematically kept Thutmose out of power," says Michael Höveler-Müller, the curator of Bonn University's Egyptian Museum.
Hatshepsut's perfume is also presumably a demonstration of her power. "We think it probable that one constituent was incense – the scent of the gods," Michael Höveler-Müller declares. This idea is not so wide of the mark, as it is a known fact that in the course of her regency Haptshepsut undertook an expedition to Punt – the modern Eritrea, and the Egyptians had been importing precious goods such as ebony, ivory, gold, and just this incense, from there since the third millennium B.C. Apparently the expedition brought back whole incense plants, which Hatshepsut then had planted in the vicinity of her funerary temple.
The filigree flacon now under examination by the researchers in Bonn bears an inscription with the name of the Pharaoh. Hence it was probably once in her possession. The vessel is exceptionally well preserved. "So we considered it might be rewarding to have it screened in the University Clinic´s Radiology Department," Höveler-Müller explains. "As far as I know this has never been done before."
This world premier will now in all probability be followed by another one: "The desiccated residues of a fluid can be clearly discerned in the x-ray photographs," the museum´s curator explains. "Our pharmacologists are now going to analyse this sediment." The results could be available in a good year´s time. If they are successful, the scientists in Bonn are even hoping to "reconstruct" the perfume so that, 3,500 years after the death of the woman amongst whose possessions it was found, the scent could then be revitalised.
Hatshepsut died in 1457 B.C. Analysis of the mummy ascribed to her showed that the ruler was apparently between 45 and 60 years of age at the end of her life; that she was also overweight, and suffering from diabetes, cancer, osteoporosis and arthritis. Obviously for reasons of security, she was laid to rest in the tomb of her wet nurse. In 1903, over 3,300 years later, the famous Egyptologist Howard Carter stumbled upon the two mummies.
However, more than 100 years were to pass before the Pharaoh´s corpse could be identified using DNA and dental analysis in the year 2007. Thutmose III, incidentally, appears not to have shed a single tear for his step-mother, as during his reign he had every image destroyed which showed her as ruler, and which could have belonged to her.
Adapted from materials provided by University of Bonn.

Teeth Of Columbus' Crew Flesh Out Tale Of New World Discovery

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ScienceDaily (Mar. 20, 2009) — The adage that dead men tell no tales has long been disproved by archaeology.

Now, however, science is taking interrogation of the dead to new heights. In a study that promises fresh and perhaps personal insight into some of the earliest European visitors to the New World, a team or researchers from the University of Wisconsin-Madison is extracting the chemical details of life history from the teeth of crew members Christopher Columbus left on the island of Hispaniola after his second voyage to America in 1493-94.
"This is telling us about where people came from and what they ate as children," explains T. Douglas Price, a UW-Madison professor of anthropology and the leader of the team conducting an analysis of the tooth enamel of three individuals from a larger group excavated almost 20 years ago from shallow graves at the site of La Isabela, founded by Columbus.
Price and colleague James Burton, in collaboration with researchers from the Autonomous University of the Yucatan in Mexico, are attempting to flesh out the details of a colony that lasted less than five years. The human remains used in the study were buried without the formalities of coffins or shrouds, and were excavated from what was once the church graveyard of the town Columbus established. Headstones and other identifying markers have long since faded to nothing or have been lost entirely during the 500 years since the bodies were first interred.
Despite its brief existence, historians and archaeologists believe La Isabela was a substantial settlement with a church, public buildings such as a customhouse and storehouse, private dwellings and fortifications. It is also the only known settlement in America where Columbus actually lived.
Although the town has been the subject of previous archaeological studies, the work by Price, Burton and their colleague Vera Tiesler and Andrea Cucina of the Autonomous University of the Yucatan is revealing new insight into the people who lived and sailed with Columbus, and who died on the shores of a strange and exotic new world.
Histories of La Isabela, named after Spain's queen and Columbus's patron and located in what is today the Dominican Republic, suggest its population was made up only of men from the fleet of 17 vessels that comprised Columbus's second visit to the New World. But the first analysis of the remains of 20 individuals excavated two decades ago by Italian and Dominican archaeologists portray a different picture, suggesting that living among the Spaniards at La Isabela were native Taínos, women and children, and possibly individuals of African origin. If confirmed, that would put Africans in the New World as contemporaries of Columbus and decades before they were believed to have first arrived as slaves.
The study conducted by the Wisconsin researchers relied on isotopic analysis of three elements: carbon, oxygen and strontium.
Carbon isotope ratios provide reliable evidence of diet at the time an individual's adult teeth emerge in childhood. For example, people who eat maize, as opposed to those who consume wheat or rice, have different carbon isotope ratio profiles locked in their tooth enamel.
"Heavy carbon means you were eating tropical grasses such as maize, found only in the New World, or millet in Africa, neither of which was consumed in Europe" at the time, says Burton.
Oxygen isotopes provide information about water consumption and also can say something about geography as the isotopic composition of water changes in relation to latitude and proximity to the ocean. Strontium is a chemical found in bedrock and that enters the body through the food chain as nutrients pass from bedrock to soil and water and, ultimately, to plants and animals. The strontium isotopes found in tooth enamel, the most stable and durable material in the human body, thus constitute an indelible signature of where someone lived as a child.
Three of the individuals whose teeth were subjected to isotopic analysis by the Wisconsin group were males under the age of 40 and who had carbon isotope profiles far different from the rest, suggesting an Old World origin. "I would bet money this person was an African," Price says of one of the three individuals whose teeth were subjected to analysis.
It was known that Columbus had a personal African slave on his voyages of discovery. The new analysis could mean that Africans played a much larger role in the first documented explorations of America.
The strontium isotope analysis, Price notes, is not yet complete, as samples from the teeth of the presumed sailors remain to be matched with strontium profiles of Spanish soils. However, such matches could open an intriguing window to the personal identities of individuals buried in La Isabela.
"All of these sailors — their place of birth, their age — were recorded in Seville before they left on the second voyage," Price explains. "One of the things we're hoping to do with the strontium is identify individuals."
The skeletons also exhibit evidence of scurvy, a common affliction of 15th century sailors who lacked vitamin C on their long voyages, as well as signs of malnutrition and physical stress. Chronicles of the voyage noted that most of the Europeans, including Columbus himself, fell sick shortly after landfall on Hispaniola, and many subsequently died, perhaps becoming the first to be buried in the La Isabela church graveyard.
Adapted from materials provided by University of Wisconsin-Madison.

Byzantine Period Church With Beautiful Mosaics Discovered

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ScienceDaily (Mar. 15, 2009) — A church that dates to the Byzantine period which is paved with breathtakingly beautiful mosaics and a dedicatory inscription was exposed in an archaeological excavation the Israel Antiquities Authority is conducting near Moshav Nes-Harim, 5 kilometers east of Bet Shemesh (at the site of Horvat A-Diri), in the wake of plans to enlarge the moshav.

According to archaeologist Daniel Ein Mor, director of the excavation on behalf of the Israel Antiquities Authority, “The site was surrounded by a small forest of oak trees and is covered with farming terraces that were cultivated by the residents of Nes-Harim. Prior to the excavation we discerned unusually large quantities of pottery sherds from the Byzantine period and thousands of mosaic tesserae that were scattered across the surface level”.
The excavation seems to have revealed the very center of the site, which extends across an area of approximately 15 dunams, along the slope of a spur that descends toward Nahal Dolev.
During the first season of excavation (November 2008) the church’s narthex (the broad entrance at the front of the church’s nave) was exposed in which there was a carpet of polychrome mosaics that was adorned with geometric patterns of intertwined rhomboids separated by flower bud motifs. Unfortunately, at the conclusion of the excavation this mosaic was defaced and almost completely destroyed by unknown vandals. During that excavation season a complex wine press was partly exposed that consists of at least two upper treading floors and elongated, well-plastered arched cells below them that were probably meant to facilitate the preliminary fermentation there of the must. Part of the main work surface, which was paved with large coarse tesserae, was exposed at the foot of these cells. A complex wine press of this kind is indicative of a wine making industry at the site; this find is in keeping with the presence here of a church and is consistent with our knowledge about Byzantine monasteries in the region during this period (sixth-seventh centuries CE).
Other parts of the church were revealed in the current excavation season. The area of the apse was almost entirely exposed, as were other parts of the southern aisle.
Two rooms that are adjacent to the northern and southern sides of the church were also uncovered. In the southern room a mosaic pavement was exposed that is decorated with intertwined patterns of different size concentric circles. The mosaic also includes a dedicatory inscription written in ancient Greek that was deciphered by Dr. Leah Di Signi of the Hebrew University of Jerusalem:
O Lord God of saint Theodorus, protect Antonius and Theodosia the illustres (illustres - a title used to distinguish high nobility in the Byzantine period) [- - - ] Theophylactus and John the priest (or priests). [Remember o Lord] Mary and John who have offe[red - - ] in the 6th indiction. Lord, have pity of Stephen.
Various phases that were used after the church was abandoned in the later part of the Byzantine period were discerned elsewhere in the structure. The mosaic floor was completely destroyed in different places and the area inside the church was put to secondary use. Industrial installations that are ascribed to the same phase were found which attest to the functional change the building underwent during the end of the Byzantine period-beginning of the Early Islamic period (seventh century CE).
According to Daniel Ein Mor, “We know of other Byzantine churches and sites that are believed to be Byzantine monasteries, which are located in the surrounding region. The excavation at Nes-Harim supplements our knowledge about the nature of the Christian-Byzantine settlement in the rural areas between the main cities in this part of the country during the Byzantine period, among them Bet Guvrin, Emmaus and Jerusalem”.
Adapted from materials provided by Israel Antiquities Authority.

Cretaceous Octopus With Ink And Suckers -- The World's Least Likely Fossils?

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ScienceDaily (Mar. 18, 2009) — New finds of 95 million year old fossils reveal much earlier origins of modern octopuses. These are among the rarest and unlikeliest of fossils. The chances of an octopus corpse surviving long enough to be fossilized are so small that prior to this discovery only a single fossil species was known, and from fewer specimens than octopuses have legs.

Even if you have never encountered an octopus in the flesh, the eight arms, suckers, and sack-like body are almost as familiar a body-plan as the four legs, tail and head of cats and dogs. Unlike our vertebrate cousins, however, octopuses don't have a well-developed skeleton. And while this famously allows them to squeeze into spaces that a more robust animal could not, it does create problems for scientists interested in evolutionary history. When did octopuses acquire their characteristic body-plan, for example? Nobody really knows, because fossil octopuses are rarer than, well, pretty much any very rare thing you care to mention.
The body of an octopus is composed almost entirely of muscle and skin, and when an octopus dies, it quickly decays and liquefies into a slimy blob. After just a few days there will be nothing left at all. And that assumes that the fresh carcass is not consumed almost immediately by hungry scavengers. The result is that preservation of an octopus as a fossil is about as unlikely as finding a fossil sneeze, and none of the 200-300 species of octopus known today has ever been found in fossilized form. Until now, that is.
Palaeontologists have just identified three new species of fossil octopus discovered in Cretaceous rocks in Lebanon. The five specimens, described in the latest issue of the journal Palaeontology, are 95 million years old but, astonishingly, preserve the octopuses' eight arms with traces of muscles and those characteristic rows of suckers. Even traces of the ink and internal gills are present in some specimens. '
"These are sensational fossils, extraordinarily well preserved," says Dirk Fuchs of the Freie University Berlin, lead author of the report. But what surprised the scientists most was how similar the specimens are to modern octopus: "these things are 95 million years old, yet one of the fossils is almost indistinguishable from living species." This provides important evolutionary information. "The more primitive relatives of octopuses had fleshy fins along their bodies. The new fossils are so well preserved that they show, like living octopus, that they didn't have these structures." This pushes back the origins of modern octopus by tens of millions of years, and while this is scientifically significant, perhaps the most remarkable thing about these fossils is that they exist at all.
Journal reference:
Fuchs et al. New Octopods (Cephalopoda: Coleoidea) from the Late Cretaceous (Upper Cenomanian) of Hakel and Hadjoula, Lebanon. Palaeontology, 2009; 52 (1): 65 DOI: 10.1111/j.1475-4983.2008.00828.x
Adapted from materials provided by The Palaeontological Association, via EurekAlert!, a service of AAAS.

Mini Dinosaurs Prowled North America

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ScienceDaily (Mar. 17, 2009) — Massive predators like Albertosaurus and Tyrannosaurus rex may have been at the top of the food chain, but they were not the only meat-eating dinosaurs to roam North America, according to Canadian researchers who have discovered the smallest dinosaur species on the continent to date. Their work is also helping re-draw the picture of North America's ecosystem at the height of the dinosaur age 75 million years ago.

"Hesperonychus is currently the smallest dinosaur known from North America. But its discovery just emphasizes how little we actually know, and it raises the possibility that there are even smaller ones out there waiting to be found," said Nick Longrich, a paleontology research associate in the University of Calgary's Department of Biological Sciences. "Small carnivorous dinosaurs seemed to be completely absent from the environment, which seemed bizarre because today the small carnivores outnumber the big ones," he said. "It turns out that they were here and they played a more important role in the ecosystem than we realized. So for the past 100 years, we've completely overlooked a major part of North America's dinosaur community."
In a paper published March 16 in the scientific journal Proceedings of the National Academy of Sciences, Longrich and University of Alberta paleontologist Philip Currie describe a new genus of carnivorous dinosaur that was smaller than a modern housecat and likely hunted insects, small mammals and other prey through the swamps and forests of the late Cretaceous period in southeastern Alberta, Canada. Weighing approximately two kilograms and standing about 50 centimetres tall, Hesperonychus elizabethae resembled a miniature version of the famous bipedal predator Velociraptor, to which it was closely related. Hesperonychus ran about on two legs and had razor-like claws and an enlarged sickle-shaped claw on its second toe. It had a slender build and slender head with dagger-like teeth.
"It was half the size of a domestic cat and probably hunted and ate whatever it could for its size – insects, mammals, amphibians and maybe even baby dinosaurs," Longrich said. "It probably spent most of its time close to the ground searching through the marshes and forests that characterized the area at the end of the Cretaceous."
Fossilized remains of Hesperonychus, which means “western claw,” were collected in 1982 from several locations including Dinosaur Provincial Park. The most important specimen, a well-preserved pelvis, was recovered by legendary Alberta paleontologist Elizabeth (Betsy) Nicholls, after which the species is named. Nicholls was the curator of marine reptiles at the Royal Tyrrell Museum in Drumheller and earned her MSc and PhD degrees at U of C. She passed away in 2004. The fossils remained unstudied for 25 years until Longrich came across them in the University of Alberta’s collection in 2007. Longrich and Currie focused on fossilized claws and a well-preserved pelvis for their description.
"The claws were thought to come from juveniles- they were just so small. But when we studied the pelvis, we found the hip bones were fused, which would only have happened once the animal was fully grown", Longrich said. "Until now, the smallest carnivorous dinosaurs we have seen in North America have been about the size of a wolf. Judging by the amount of material that was collected, we believe animals the size of Hesperonychus must have been quite common on the landscape."
Currie and Longrich last year described the previous record-setting small North American dinosaur, a chicken-sized insectivore named Albertonykus borealis.
The discovery of Hesperonychus is the first sign of small carnivorous dinosaurs in North America and also extends the timeframe of small, birdlike dromaeosaurs known as the Microraptorinae in the fossil record by approximately 45 million years. Specimens from China have been found dating to 120 million years ago, while Hesperonychus appeared to have thrived until the end of dinosaur age in the late Cretaceous.
Journal reference:
Nicholas R. Longrich and Philip J. Currie. A microraptorine (Dinosauria-Dromaeosauridae) from the Late Cretaceous of North America. Proceedings of the National Academy of Sciences, 2009; DOI: 10.1073/pnas.0811664106
Adapted from materials provided by University of Calgary.

Old Soles: 800-year-old Shoe Soles Yield Clues About Preservation Of Leather

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ScienceDaily (Mar. 17, 2009) — Ancient garbage can be like gold to archaeologists. During excavation of an 800-year-old trash dump in Lyon, France, scientists discovered the archaeological equivalent of golden shoe soles: A trove of leather soles of shoes, which is helping scientists understand how leather stays preserved in wet, oxygen-free environments.

That knowledge could aid restoration of other leather artifacts, according to a report on analysis of the old soles scheduled for the current issue of ACS' semi-monthly journal Analytical Chemistry.
In the article, Michel Bardet and colleagues point out that leather consists of collagen, a tough protein that can remain intact hundreds of thousands of years under ideal conditions. The French soles were buried in mud in the absence of oxygen — good conditions for preservation.
They used laboratory technology called nuclear magnetic resonance to compare composition of the ancient leather to modern leather. It turned out that tannin, which helps to preserve leather, had been washed out of the old soles and replaced by iron oxides. The iron oxides, which leached into the leather from surrounding soil, helped preserve the soles in the absence of tannins.
Journal reference:
Bardet et al. Nuclear Magnetic Resonance and Electron Paramagnetic Resonance as Analytical Tools To Investigate Structural Features of Archaeological Leathers. Analytical Chemistry, 2009; 81 (4): 1505 DOI: 10.1021/ac802052a
Adapted from materials provided by American Chemical Society, via EurekAlert!, a service of AAAS.

Young Dinosaurs Roamed Together, Died Together

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ScienceDaily (Mar. 16, 2009) — A herd of young birdlike dinosaurs met their death on the muddy margins of a lake some 90 million years ago, according to a team of Chinese and American paleontologists that excavated the site in the Gobi Desert in western Inner Mongolia.

The Sudden sudden death of the herd in a mud trap provides a rare snapshot of social behavior. Composed entirely of juveniles of a single species of ornithomimid dinosaur (Sinornithomimus dongi), the herd suggests that immature individuals were left to fend for themselves when adults were preoccupied with nesting or brooding.
"There were no adults or hatchlings," said Paul Sereno, professor at the University of Chicago and National Geographic Explorer-in-Residence. "These youngsters were roaming around on their own," remarked Tan Lin, from the Department of Land and Resources of Inner Mongolia.
Within an exquisite pair of the skeletons, prepared for display in Sereno's lab and airlifted back to China in late February, preserve stomach stones and the animal's' last meals are preserved.
Sereno, Tan and Zhao Xijin, professor in the Chinese Academy of Sciences, led the 2001 expedition that found the fossils. Team members also included David Varricchio of Montana State University (MSU), Jeffrey Wilson of the University of Michigan and Gabrielle Lyon of Project Exploration.
"Finding a mired herd is exceedingly rare among living animals," said Varricchio, an assistant professor of paleontology at MSU. "The best examples are from hoofed mammals," such as water buffalo in Australia or feral horses in the American West, he said.
The first bones from the dinosaur herd were spotted by a Chinese geologist in 1978 at the base of a small hill in a desolate, windswept region of the Gobi Desert. Some 20 years later, a Sino-Japanese team excavated the first skeletons, naming the dinosaur Sinornithomimus ("Chinese bird mimic").
Sereno and associates then opened an expansive quarry, following one skeleton after another deep into the base of the hill. In sum, more than 25 individuals were excavated from the site. They range in age from one to seven years, as determined by the annual growth rings in their bones.
The team meticulously recorded the position of all of the bones and the details of the rock layers to try to understand how so many animals of the same species perished in one place. The skeletons showed similar exquisite preservation and were mostly facing the same direction, suggesting that they died together and over a short interval.
The details provided key evidence of an ancient tragedy. Two of the skeletons fell one right over the other. Although most of their skeletons lay on a flat horizontal plane, their hind legs were stuck deeply in the mud below. Only their hip bones were missing, which was likely the handiwork of a scavenger working over the meatiest part of the body bodies shortly after the animals died.
"These animals died a slow death in a mud trap, their flailing only serving to attract a nearby scavenger or predator," Sereno said. Usually, weathering, scavenging or transport of bone have long erased all direct evidence of the cause of death. The site provides some of the best evidence to date of the cause of death of a dinosaur.
Plunging marks in mud surrounding the skeletons recorded their failed attempts to escape. Varricchio said he was both excited and saddened by what the excavation revealed. "I was saddened because I knew how the animals had perished. It was a strange sensation and the only time I had felt that way at a dig," he said.
In addition to herd composition and behavior, the site also provides encyclopedic knowledge of even the tiniest bones in the skull and skeleton. "We even know the size of its eyeball," Sereno said. "Sinornithomimus is destined to become one of the best- understood dinosaurs in the world."
The work was funded by the National Geographic Society and the David and Lucile Packard Foundation.
Journal reference:
David J. Varricchio, Paul C. Sereno, Zhao Xi-jin, Tan Lin Jeffrey A. Wilson, and Gabrielle H. Lyon. Mud-trapped herd captures evidence of distinctive dinosaur sociality. Acta Palaeontologica Polonica, December 2008 [link]
Adapted from materials provided by University of Chicago, via EurekAlert!, a service of AAAS.

Preserved Shark Fossil Adds Evidence To Great White's Origins

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ScienceDaily (Mar. 13, 2009) — A new University of Florida study could help resolve a long-standing debate in shark paleontology: From which line of species did the modern great white shark evolve?

For the last 150 years, some paleontologists have concluded the great white shark, Carcharodon carcharias, is a smaller relative of the line that produced Carcharodon megalodon, the largest carnivorous fish known. Other paleontologists disagree, arguing the great white shark evolved instead from the broad-toothed mako shark. The second group contends megalodon, which grew to a length of 60 feet, should have its genus name switched to Carcharocles to reflect its different ancestry.
The study in the March 12 issue of the Journal of Vertebrate Paleontology falls squarely into the mako camp. It concludes megalodon and modern white sharks are much more distantly related than paleontologists initially believed.
"I think that this specimen will clarify things," said lead author Dana Ehret, a vertebrate paleontology graduate student at the Florida Museum of Natural History located on the UF campus. "When we only have isolated teeth to describe, it's very hard to come to a definitive conclusion."
The study is based on a remarkably well preserved 4- to 5-million-year-old fossil from Peru of an early white shark species: a complete jaw with 222 teeth intact and 45 vertebrae. Most ancient shark species are known only from isolated teeth. Based on tooth size and analysis of growth rings within the vertebrae, the shark was about 20 years old and 17 to 18 feet long, a size in the range of modern white sharks.
Having the teeth in place allows researchers to see important distinguishing characteristics that help determine a fossil's genus and species, such as whether a tooth curves toward the outside of the jaw or its midline, Ehret said. He believes the fossil belongs to a white shark species closely related to Isurus hastalis, a broad-toothed mako shark that probably grew to 27 feet long and lived 9 million to 10 million years ago.
An olive-grove farmer trained in fossil collection discovered it near his home in the desert of southern Peru in 1988. It now belongs to a private collection and was only recently pledged to the Florida Museum of Natural History.
"It's the only fossilized partial skull of a white shark that's ever been found," said Gordon Hubbell, the fossil's owner and study co-author.
Hubbell purchased the fossil from the farmer during his first trip to Peru, which coincidentally occurred only a few days after the discovery.
The specimen came from an area known as the Pisco Formation, famous for its rich fossil beds dating from the late Miocene to Pleistocene, about 1 million to 9 million years ago. The region was once a sheltered, shallow marine environment ideal for preserving skeletons. The formation has produced articulated broad-toothed mako shark skeletons as well as fossils of whales, aquatic sloths and sea turtles.
The study strengthens the evolutionary link between the extinct mako and the modern white shark, said vertebrate paleontologist Kenshu Shimada, an associate professor at DePaul University in Chicago. Shimada said paleontologists now need fossil skeletons from megalodon and a shark from the extinct Otodontidae family such as Otodus, a large prehistoric mackerel shark that lived about 40 million to 60 million years ago.
"If we can demonstrate the strong link between Carcharocles and Otodus from such skeletal remains," Shimada said, "we may be able to settle the evolutionary and taxonomic debates."
Megalodon was first classified in the same genus as the modern white shark in the 1840s based on the similarity of tooth shape and serrations specialized for eating marine mammals. Mako sharks have no serrations because they feed primarily on fish.
Ehret says the shark fossil's coarse serrations are evidence of a transition between broad-toothed mako sharks and modern white sharks.
"Here we have a shark that's gaining serrations," he said. "It's becoming a white shark, but it's not quite there yet."
The transition from megatooth sharks like megalodon to modern white sharks would require changes in body size and tooth serrations, thickness and enamel, Ehret said. By contrast, the transition from the broad-toothed mako shark to modern white sharks would require only the presence of serrations and a shift in the slant of a key tooth position.
Adapted from materials provided by University of Florida, via EurekAlert!, a service of AAAS.