Paleontology news

The landscape of Central Africa 65 million years ago was a low-elevation tropical belt, but the jury is still out on whether the region's mammals browsed and hunted beneath the canopy of a lush rainforest. The scientific evidence for a tropical rainforest at that time is weak and far from convincing, says paleobotanist Bonnie F. Jacobs at Southern Methodist University in Dallas.

Many Cenozoic mysteries remain to be solved

The rainforest mystery is characteristic of the scientific uncertainty and unknowns surrounding Africa's ancient flora during the period called the Cenozoic. There are large gaps in the fossil record, says Jacobs, a co-author of "A Review of the Cenozoic Vegetation History of Africa." She is an associate professor in SMU's Roy M. Huffington Department of Earth Sciences.

The review, a chapter in "Cenozoic Mammals of Africa" (University of California Press, 2010), is the first of its kind since 1978 to review and interpret the Cenozoic paleobotanical record of Africa with paleogeographic maps showing paleobotanical site distributions through time. Jacobs co-authored the paper with Aaron D. Pan, a paleobotanist at the Fort Worth Museum of Science and History, and Christopher R. Scotese, in the Earth Sciences Department at the University of Texas at Arlington.

The 1008-page "Cenozoic Mammals of Africa" is the first comprehensive scientific reference of its kind since 1978, comprising 48 chapters by 64 experts. The volume summarizes and interprets the published fossil research to date of Africa's mammals, tectonics, geography, climate and flora of the past 65 million years.

Details sparse, but big picture emerges for past 65 million years

Paleobotanical data for Africa are generally meager and uneven for the Cenozoic, according to Jacobs and her co-authors.

In an original series of maps, they chart each Cenozoic Africa paleobotanical locale described in the published research to date. There are a mere 82 sites in all. Most of the sites date to 50 million years ago. Fewer date to 20 million, 30 million, 10 million and — perhaps most important — 2 million years ago, when the human family was evolving.

"Africa is disappointingly undersampled," say Jacobs and her colleagues. "This vast continent, roughly three times the area of the United States, has so far been documented by only a handful of Paleogene plant and vertebrate localities, and it has a Neogene record heavily biased toward the depositional basins of the East African Rift."

Shift from descriptive to analytic approach driven by holistic view

For a continent so important for its role in the evolution of mammals, the scarcity of plant fossil data stands in sharp contrast.

"As impressive as is the contemporary mammalian diversity of Africa, it is dwarfed by that of the Cenozoic," write the volume's editors, paleozoologist Lars Werdelin, the Swedish Museum of Natural History, and paleontologist William Joseph Sanders, the University of Michigan. Africa today represents 20 percent of the world's land mass, is the only continent to occupy both the north and south temperate zones, and is home now to more than 1,100 mammalian species, they write in the introduction.

Africa's paleobotanical record is key to a holistic understanding of ancient mammals, says H.B.S. Cooke in the preface. A mammal expert, Cooke was editor of the earlier 1978 scientific reference, "Evolution of African Mammals" (Harvard University Press).

"Most striking over the past years has been a shift in studying fossils from a largely descriptive taxonomy to a more analytical approach, including consideration of faunal associations, their distribution in time and space, and the environmental and climatic factors that prevailed and changed through time," Cooke writes in the preface to the new book. " … African prehistory has become more a study of paleobiology than mere paleontology."

To view a map or images of Cenozoic leaf fossils from Jacobs' field work in Africa go to SMU Research on flickr.

More scientific exploration needed to fill gaps

Scientific exploration to learn more about Africa's ancient vegetation is on the increase, say Jacobs and her co-authors. That should start to fill gaps in understanding, including the mystery of Africa's palms.

While palm trees are common in wet tropical forests worldwide, that's not the case in Africa today. Palm trees have not been found in abundance in Africa for the past 24 million years, regardless of whether the regional vegetation was forest, say the authors. Oddly, though, abundant palm samples have been found in some African locations dating between 65 million and 25 million years ago, including at Chilga in Ethiopia by Jacobs and Pan.

The implications of that difference are significant for the various endemic mammals of that time, many of which were absent by 23 million years ago, say the authors.

"We are fortunate that the sampling scale of most fossil localities is at the plant community level, and larger-scale changes took place one community at a time," they write. "Thus, as Africa becomes better sampled, the uneven record will ultimately become a more complete narrative of dynamic change at the community and ecosystem levels."

esciencenews.com

Radio carbon analysis of site in Winchester provides date range of AD 960-1030 – preceding Norman conquest.

A number of other artefacts, pits, and postholes relate to the same time, including what appears to be a large sunken structure underneath a medieval infirmary.

Most historians and archaeologists had believed hospitals in Britain only dated from after the Norman conquest of 1066.

"This is an important archaeological development," said Dr Simon Roffey from the University of Winchester, which conducted the dig.

"Historically, it has always been assumed that hospitals were a post-conquest phenomenon, the majority founded from the late 11th century onwards.

"However, our excavations have revealed a range of buildings and, more significantly, convincing evidence for a foundation in the 10th century.

"Our excavations at St Mary Magdalen offer an intriguing insight into a little known aspect of the history of both Winchester and England. It is undoubtedly a site of national importance."

Among the earliest known hospitals in the UK is Harbledown in Canterbury, founded by Lanfranc in the 1070s, following the Norman conquest.

Professor Nicholas Orme, a leading researcher on medieval hospitals, added: "I have only studied the documentary evidence but I could not find any such evidence for a hospital before 1066 except perhaps as an activity within a monastery or minster.

"A late Anglo-Saxon hospital would surely be a first for archaeology and indeed for history."

Winchester was the capital of England throughout a large part of the Anglo-Saxon period and after the Norman conquest. The capital was moved to London from the Hampshire city in the 12th century.

guardian.co.uk

Paleontologists have discovered a new species of dinosaur with a softball-sized lump of solid bone on top of its skull, according to a paper published in the April issue of the journal Cretaceous Research. The species was a plant-eating dinosaur about as big as a medium-sized dog that lived 70 to 80 million years ago, said Nicholas Longrich of Yale University, lead author of the paper. The team discovered two skull fragments in Big Bend National Park in southwest Texas in 2008. They compared them to dozens of fossils from related species found in Canada and Montana before confirming that the fossils represented a new genus of pachycephalosaur, a group of bipedal, thick-skulled dinosaurs.

The discovery of the new species lends further weight to the idea, which has gained popularity in recent years, that dinosaurs found in Canada and the northern United States were distinct from their southern neighbors.

"Instead of roaming across the North American continent, we see pockets of different dinosaurs that are pretty isolated from one another," Longrich said. "Every time we get good fossils from Texas, they end up looking very different from those to the north."

Because fossils from the Big Bend region are rare and tend to be poorly preserved, scientists do not have a complete picture of the different species that once inhabited the area, Longrich said.

But the team may have uncovered an important piece of the puzzle with their discovery. They found that this particular group of dinosaurs, which was previously thought to have originated in Asia, likely evolved in North America.

Longrich expects more related species to be discovered in the future as fossils from the Texas site and elsewhere continue to be examined.

"I think we underestimate how many different species there were," he says.

Yale University

A new study led by Ohio University scientists suggests that early Native Americans left a bigger carbon footprint than previously thought, providing more evidence that humans impacted global climate long before the modern industrial era. Chemical analysis of a stalagmite found in the mountainous Buckeye Creek basin of West Virginia suggests that native people contributed a significant level of greenhouse gases to the atmosphere through land use practices. The early Native Americans burned trees to actively manage the forests to yield the nuts and fruit that were a large part of their diets.

Initially, Springer and research collaborators from University of Texas at Arlington and University of Minnesota were studying historic drought cycles in North America using carbon isotopes in stalagmites. To their surprise, the carbon record contained evidence of a major change in the local ecosystem beginning at 100 B.C. This intrigued the team because an archeological excavation in a nearby cave had yielded evidence of a Native American community there 2,000 years ago.

Springer recruited two Ohio University graduate students to examine stream sediments, and with the help of Harold Rowe of University of Texas at Arlington, the team found very high levels of charcoal beginning 2,000 years ago, as well as a carbon isotope history similar to the stalagmite.

This evidence suggests that Native Americans significantly altered the local ecosystem by clearing and burning forests, probably to make fields and enhance the growth of nut trees, Springer said. This picture conflicts with the popular notion that early Native Americans had little impact on North American landscapes. They were better land stewards than the European colonialists who followed, he said, but they apparently cleared more land and burned more forest than previously thought.

"Long before we were burning fossil fuels, we were already pumping greenhouse gasses into the atmosphere. It wasn't at the same level as today, but it sets the stage," Springer said.

This long-ago land clearing would have impacted global climate, Springer added. Ongoing clearing and burning of the Amazon rainforest, for example, is one of the world's largest sources of greenhouse gas emissions. Prehistoric burning by Native Americans was less intense, but a non-trivial source of greenhouse gases to the atmosphere, he said.

Ohio University

The new T. rex has ferociously large teeth lining a single jaw. But its length is less than 2 inches. Tyrannobdella rex, which means tyrant leech king, is a new species of blood sucker that lives in the remote parts of the Upper Amazon. Although its regular host remains unknown, it was discovered three years ago in Perú when a 44.5 millimeter leech was plucked from the nose of a girl who had recently been bathing in a river. The new species, described in PLoS ONE, has led to revising the group of leeches that has a habit of feeding from body orifices of mammals. "Because of our analysis of morphology and DNA, we think that Tyrannobdella rex is most closely related to another leech that gets into the mouths of livestock in Mexico," says Anna Phillips, a graduate student affiliated with the American Museum of Natural History and the first author of the paper. "We think the leech could feed on aquatic mammals, from their noses and mouths for example, where they could stay for weeks at a time."

The new genus and species, Tyrannobdella rex, has led to a revision of the phylogenetic relationships among several leech families. Both morphological and genetic data show that this species is most closely related to Pintobdella chiapasensis, a leech from Chiapas that is typically hosted by tapir but also infests cows. Part of the research for this paper involved a Mexican expedition by Phillips and Oceguera-Figueroa to gather new specimens for DNA analysis. Close by on the phylogenetic tree, this group is related to leeches found in India and Taiwan like Dinobdella ferox, the terrible, ferocious leech that is well-known for feeding on mucus membranes and getting into various human orifices. All of these species, and others from Mexico, Africa, and the Middle East, make up the family Praobdellidae, a group of leeches that seems to share this feeding behavior and which can pose a risk to human health in certain parts of the world.

The evolutionary relationship among leeches that currently inhabit distant regions suggests that the common ancestor of this group must have lived when the continents were pressed together into a single land mass, before Pangaea broke up.

"We named it Tyrannobdella rex because of its enormous teeth. Besides, the earliest species in this family of these leeches no-doubt shared an environment with dinosaurs about 200 million years ago when some ancestor of our T. rex may have been up that other T. rex's nose," says Siddall. "The new T. rex joins four other species that use this abbreviated name, including two Miocene fossils (a snail and a scarab beetle), a living Malaysian formicid ant, and, of course, the infamous Cretaceous theropod dinosaur that was described in 1905 by an earlier curator of the American Museum of Natural History."

American Museum of Natural History

The study reveals for the first time how Archimylacris eggintoni's physical traits helped it to thrive on the floor of Earth's early forests. The fossils of these creatures are normally between 2cm and 9cm in length and approximately 4cm in width.

The lead author of the study, Mr Russell Garwood, a PhD student from the Department of Earth Science and Engineering at Imperial College London, says, "The Carboniferous period is sometimes referred to as the age of the cockroach because fossils of Archimylacris eggintoni and its relatives are amongst the most common insects from this time period. They are found all over the world. People joke about it being impossible to kill cockroaches and our 3D model almost brings this one back to life. Thanks to our 3D modelling process, we can see how Archimylacris eggintoni's limbs were well adapted for all terrains, as it was not only adept in the air but also very agile on the ground."

sciencecodex.com

Dr Robyn Pickering of the School of Earth Sciences at the University of Melbourne who was one a team of international and Australian scientists to accurately date the sediments surrounding the fossils says, "We are now able to fill in the gap of what happened 2 million years ago in the beginnings of our species."

"It has never been clear where our own genus Homo came from – this new discovery, Australopithecus sediba could answer these questions," she says.

Researchers say this species appears to be a transitional form, maybe the best yet found, between early australopithecines and early members of the genus Homo, thereby replacing other candidates such as Homo habilis (the tool making 'handy' man from east Africa) as the distant ancestor of Homo sapien.

The Sediba fossils are exceptionally well preserved, and therefore provide a unique insight in the period when the earliest members of our genus evolved.

Sediments from surrounding and supporting the fossils were analysed by several research teams.

Using a state-of-the-art uranium lead dating technique, conducted independently and in parallel by Dr Pickering at the University of Melbourne and her former PhD supervisor Professor Jan Kramers from the University of Bern in Switzerland, they produced an identical age result confirming the sediment was close to 2 million years old.

"Together with palaeomagnetic dating of the sediments more closely surrounding the fossils by Andy Herries of UNSW and our team of colleagues led by Professor Paul Dirks from the University of Townsville, we were collectively able to provide an age of 1.95-1.78 million years for the fossils," Dr Pickering says.

"This is the first time, in relation to these renowned caves in South Africa, that we have been able to achieve such high-quality age control."

"Knowing how old these early human (hominin) fossils are, is critical to our knowledge of where this newly found species fits into our family tree," she says.

Associate Professor Jon Woodhead, who heads the Isotope Geosciences laboratory in the School of Earth Sciences at the University of Melbourne, noted "This is a highly significant find and I congratulate Robyn and her colleagues on their discovery."

"Only very recently have we been able to develop the technologies required to allow precise dating of cave sediments such as those found in intimate association with these new fossils."

"This really is the beginning of a 'new era' as such methods have much to contribute to studies of global climate change, biodiversity and, in this case, human evolution."

"The University of Melbourne is a world leader in this area and we are proud to have been able to contribute to this important discovery."

University of Melbourne

"One possibility is that these differences are evidence of a powerful selection process, through which the Stone Age hunter-gatherers' genes were lost due to some significant advantage associated with the capacity to digest milk," says Anna Linderholm. "The other possibility is that we simply are not descended from this group of Stone Age people."

The capacity to consume unprocessed milk into adulthood is regarded as having been of great significance for human prehistory.

"This capacity is closely associated with the transition from hunter-gatherer to agricultural societies," says Anders Götherström of the Department of Evolutionary Biology at Uppsala University.

He serves as coordinator of LeCHE (Lactase persistence and the early Cultural History of Europe), an EU-funded research project focusing on the significance of milk for European prehistory.

"In the present case, we are inclined to believe that the findings are indicative of what we call "gene flow," in other words, migration to the region at some later time of some new group of people, with whom we are genetically similar," he says. "This accords with the results of previous studies."

The researchers' current work involves investigating the genetic makeup of the earliest agriculturalists in Scandinavia, with an eye to potential answers to questions about our ancestors.

Uppsala University

In the ruins of a city that was once Rome's neighbor, archaeologists last summer found a 1,000-pound lead coffin. Who or what is inside is still a mystery, said Nicola Terrenato, the University of Michigan professor of classical studies who leads the project---the largest American dig in Italy in the past 50 years.

"We're very excited about this find," Terrenato said. "Romans as a rule were not buried in coffins to begin with and when they did use coffins, they were mostly wooden. There are only a handful of other examples from Italy of lead coffins from this age---the second, third or fourth century A.D. We know of virtually no others in this region."

This one is especially unusual because of its size.

"It's a sheet of lead folded onto itself an inch thick," he said. "A thousand pounds of metal is an enormous amount of wealth in this era. To waste so much of it in a burial is pretty unusual."

Was the deceased a soldier? A gladiator? A bishop? All are possibilities, some more remote than others, Terrenato said. Researchers will do their best to examine the bones and any "grave goods" or Christian symbols inside the container in an effort to make a determination.

"It's hard to predict what's inside, because it's the only example of its kind in the area," Terrenato said. "I'm trying to keep my hopes within reason."

Human remains encased in lead coffins tend to be well preserved, if difficult to get to. Researchers want to avoid breaking into the coffin. The amount of force necessary to break through the lead would likely damage the contents. Instead, they will first use thermography and endoscopy. Thermography involves heating the coffin by a few degrees and monitoring the thermal response. Bones and any artifacts buried with them would have different thermal responses, Terrenato said. Endoscopy involves inserting a small camera into the coffin. But how well that works depends on how much dirt has found its way into the container over the centuries.

If these approaches fail, the researchers could turn to an MRI scan---an expensive option that would involve hauling the half-ton casket to a hospital.

The dig that unearthed this find started in summer 2009 and continues through 2013. Each year, around 75 researchers from around the nation and world, including a dozen U-M undergraduate students, spend two months on the project at the ancient city of Gabii (pronounced "gabby").

The site of Gabii, situated on undeveloped land 11 miles east of Rome in modern-day Lazio, was a major city that pre-dates Rome but seems to have waned as the Roman Empire grew.

Studying Gabii gives researchers a glimpse into pre-Roman life and offers clues to how early Italian cities formed. It also allows them broader access to more substantial archaeological layers or strata. In Rome, layers of civilization were built on top of each other, and archaeologists are not able or allowed to disturb them.

"In Rome, so often, there's something in the way, so we have to get lucky," Terrenato said. "In Gabii, they should all be lucky spots because there's nothing in the way."

Indeed, Terrenato and others were surprised to find something as significant as this coffin so soon.

"The finding of the lead coffin was exhilarating," said Allison Zarbo, a senior art history major who graduates this spring.

Zarbo didn't mind that after the researchers dug up the coffin once, they had to pile the dirt back on to hide it from looters overnight.

"The fact that we had to fill the hole was not so much of a burden as a relief!" Zarbo said. "For academia to lose priceless artifacts that have been found fully in context would be very damaging to our potential knowledge."

Students spent most of their time pick-axing, shoveling, and manning the wheelbarrows, said Bailey Benson, a junior who is double majoring in classical archaeology and art history.

"By the end of the day, not even a 20-minute shower can remove all the dirt and grime you get covered in," Benson said. "It's hard but satisfying work. How many people can say they uncovered an ancient burial?"

University of Michigan

"Blindsnakes are not very pretty, are rarely noticed, and are often mistaken for earthworms," admits Blair Hedges, professor of biology at Penn State University. "Nonetheless, they tell a very interesting evolutionary story." Hedges and Nicolas Vidal, of the Muséum National d'Histoire Naturelle in Paris, are co-leaders of the team that discovered that blindsnakes are one of the few groups of organisms that inhabited Madagascar when it broke from India about 100 million years ago and are still living today. The results of their study will be published in the 31 March 2010 issue of the Royal Society journal Biology Letters. Blindsnakes comprise about 260 different species and form the largest group of the world's worm-like snakes -- scolecophidians. These burrowing animals typically are found in southern continents and tropical islands, but occur on all continents except Antarctica. They have reduced vision -- which is why they are called "blind" -- and they feed on social insects including termites and ants. Because there are almost no known fossil blindsnakes, their evolution has been difficult to piece together. Also, because of their underground lifestyle, scientists have long wondered how they managed to spread from continent to continent.

Mutations in the genes record the history of these blurry-eyed serpents. The genetic research reveals that the original stock of worm-like snakes arose on Gondwana, the ancient southern supercontinent. The initial split occurred about 155 million years ago as Gondwana divided into East Gondwana (the landmasses of Antarctica, India, Madagascar, and Australia) and West Gondwana (the landmasses of South America and Africa). The residents of East Gondwana -- the blindsnakes -- then diverged into several lineages including a new family named in this study and found only on Madagascar. Later, East Gondwana further divided into a new paleolandmass -- called by the researchers "Indigascar" (India plus Madagascar) -- and another comprised of Australia and Antarctica. The research suggests that the new family on Madagascar arose as a result of the break-up of the Indigascar landmass about 94 million years ago.

Madagascar's long isolation has led to the evolution of many unique endemic animals including this family of blindsnakes, various lemurs, and other rare mammals. Unfortunately, both the animals and plants of Madagascar are now endangered by habitat loss. Says team member Miguel Vences, a professor at the Technical University of Braunschweig, Germany, and authority on the biodiversity of Madagascar, "Finding such ancient roots for a group of animals in Madagascar gives us even more reason to protect their rapidly declining habitat."

If blindsnakes got their start on Indigascar, leaving an endemic living family as evidence on Madagascar, how did they get to all of those other places in the world that they occupy today -- Europe, Asia, Australia, Africa, and the Americas?

The phylogeny constructed by the Hedges and Vidal team shows a series of diversifications within the blindsnakes, outside of Madagascar, that occurred between 63 and 59 million years ago. The period of greatest diversification coincided with a time of low sea levels, when connections between continents were forming and the dispersal of such unlikely animals by floating on flotsam was easier. Blindsnakes must have moved either out of Africa via Europe and Asia -- the ancient northern supercontinent Laurasia -- or out of India and then from southeast Asia to Australia at about 28 million years ago. Since there were no land connections between Asia and Australia at this time, these blindsnakes could have reached Australia only by crossing the ocean on floating flotsam. After that point, the splits within the blindsnakes probably occurred because they were following the evolution and spread of their prey -- ants and termites -- in various geographic regions.

Floating across oceans seems an unlikely mechanism for a burrowing animal to spread to new continents, but there is a second instance of ocean crossing by blindsnakes among the groups left on West Gondwana: West Gondwana broke up about 100 million years ago, making Africa and South America separate continents, but the genetic split between African and South American blindsnakes occurred only at about 63 million years ago. This finding shows that blindsnakes probably were confined to Africa when West Gondwana broke up and only later traveled to South America -- and still later to the West Indies -- by floating across the Atlantic from east to west.

This journey has rarely been documented. Only six or seven other vertebrates are thought to have crossed the Atlantic in a westward direction. However, the crossing would have taken no more than six months and might not have been too difficult for blindsnakes, which have a relatively low need for food and may have been floating on vegetation rafts along with their insect prey.

"Some scientists have argued that oceanic dispersal is an unlikely way for burrowing organisms to become distributed around the world," observes Hedges. "Our data now reinforce the message that such 'unlikely' events nonetheless happened in evolutionary history."

Penn State

A large red granite false door from the tomb of an ancient queen's powerful vizier has been discovered in Luxor, Egypt's culture minister said on Monday.

The door, 1.75 metres (5.7 feet) high and 50 cm (19 inches) thick, is engraved with religious texts and various titles used by User, including mayor of the city, vizier and prince, antiquities chief Zahi Hawass was quoted as saying.

"The newly discovered door was reused during the Roman period. It was removed from the tomb of User and used in the wall of a Roman structure," said Mansur Boraik, who headed the excavation mission.

Hatshepsut, who ruled Egypt between 1479 BC and 1458 BC, was the longest reigning female pharaoh.

QMI

According to Dr Roger Benson of the Department of Earth Sciences at the University of Cambridge, who identified the find: "The bone is unambiguously identifiable as a tyrannosaur because these dinosaurs have very distinctive hip bones."

The discovery lays to rest the belief held by some scientists that tyrannosaurs never made it to the southern continents.

"This is an exciting discovery because tyrannosaur fossils had only ever been found in the northern hemisphere before and some scientists thought tyrannosaurs never made it down south.

"Although we only have one bone, it shows that 110 million years ago small tyrannosaurs like ours might have been found worldwide. This find has major significance for our knowledge of how this group of dinosaurs evolved." says Dr Benson.

Dr Paul Barrett, Palaeontologist at the Natural History Museum, London and member of the research team commented: "The absence of tyrannosauroids from the southern continents was becoming more and more anomalous as representatives of other 'northern' dinosaur groups started to show up in the south. This find shows that tyrannosauroids were able to reach these areas early in their evolutionary history and also hints at the possibility that others remain to be discovered in Africa, South America and India."

The bone would have come from an animal about three metres long and weighing around 80 kg, similar to a human, and would have had the large head and small arms that make tyrannosaurs so distinctive.

The newly identified dinosaur, known as NMV P186069, was much smaller than T. rex, which was 12 metres long and weighed around four tonnes. Giant size like this only evolved late in the tyrannosaur lineage.

Compared with T. rex, which lived about 70 million years ago at the end of Cretaceous period, NMV P186069 lived earlier during the Cretaceous, around 110 million years ago.

During the time of the dinosaurs the continents gradually went from a single supercontinent towards something like their present-day arrangement. This tyrannosaur is from the mid-stages of this continental break-up, when the southern continents of South America, Antarctica, Africa and Australia had separated from the northern continents, but had not separated from each other.

While answering the question of whether or not tyrannosaurs lived in both the southern and northern hemispheres, the new find leaves another, deeper mystery: why did tyrannosaurs evolve into giant predators such as T. rex only in the northern hemisphere?

According to Dr Benson: "It is difficult to explain why different groups succeeded in the north and the south if they originally existed in both places. What we need to know now is just how diverse the early radiation of tyrannosaurs was, why they went extinct, leaving only giant-sized, short-armed species like T. rex, and how successful they might have been in the southern hemisphere. We can only answer these questions with new discoveries."

The paper is published today in Science.

University of Cambridge

In the '80s, Spanish researchers found the first fossils of Cloudina in Spain, a small fossil of tubular appearance and one of the first animals that developed an external skeleton between 550 and 543 million years ago. Now palaeontologists from the University of Extremadura have discovered a new species, Cloudina carinata, the fossil of which has preserved its tridimensional shape. "Cloudina carinata is characterised by its elaborate ornamentation and complexity of the shells and tube that are formed when inserted", Iván Cortijo, main author and researcher in the Area of Palaeontology at the University of Extremadura, describes to SINC.

The fossils have been found in the archaeological site El Membrillar (Badajoz), one of the few sites in Europe where remains of Cloudina can be found. "The specimens display exceptional preservation, they appear preserved in three dimensions, and show their original form and numerous details of the shells", Cortijo points out.

The discovery of new species of Cloudina is important "for understanding the early evolution of animals", states Cortijo, who adds that "its importance for understanding the origin of skeletons is indisputable". Despite the fact that its relation to other groups of animals is uncertain, Cloudina has been compared to cnidaria (medusas and corals) and annelida (polychaeta sea worms, earthworms and leeches).

According to the research team, the study of fossils from the Ediacaran period (between 630 and 540 million years ago) and of other fossils from the early Cambrian (540 million years ago) reveals the path followed by evolution at a crucial moment in the history of life, when the first animals appeared. This first evolutionary radiation of animals reached its apex in the so-called "great Cambrian explosion" or "Big-Bang of evolution".

In search of Cloudina

In the '70s specimens of Cloudina were discovered for the first time in Namibia and later they were discovered in Oman, southern China and the south-east of the USA. According to scientists, it is a fossil indicative of the terminal Ediacaran, which marks the end of the Proterozoic eon, and gives way to the Phanerozoic, when the great radiation of animals began.

In Spain Cloudina was discovered in the '80s thanks to Teodoro Palacios, director of the research group Palaeontology and Stratigraphy of the Neoproterozoic and Palaeozoic at the University of Extremadura.

FECYT - Spanish Foundation for Science and Technology

In the latest use of DNA to investigate the story of humankind, scientists have decoded genetic material from an unidentified human ancestor that lived in Siberia and concluded it might be a new member of the human family tree.

Instead, it suggests the Siberian species lineage split off from the branch leading to moderns and Neanderthals a million years ago, the researchers calculated. And they said that doesn't seem to match the history of human ancestors previously known from fossils.

So the Siberian species may be brand new, although the scientists cautioned that they're not ready to make that claim yet.

Other experts agreed that while the Siberian species may be new, the case is far from proven.

"We really don't know," said Ian Tattersall of the American Museum of Natural History in New York, who wasn't involved in the new research.

But "the human family tree has got a lot of branchings. It's entirely plausible there are a lot of branches out there we don't know about."

The discovery "is like many new finds," said Eric Delson of Lehman College of the City University of New York, who didn't participate in the new work. "You say, `I think this is different, but I'm not sure.' And then you look for more material and you try to make better comparisons."

The researchers, who say the Siberian species is not a direct ancestor of modern-day people, hope further genetic analysis will show if it's a new species. Some experts are skeptical about whether such analysis will resolve that.

In any case, the finding emphasizes that quite unlike the present day, anatomically modern humans have often lived alongside their evolutionary relatives, one expert said.

"We weren't alone," said Todd Disotell of New York University, who was familiar with the new work. "When we became modern, we didn't instantly replace everybody. There were other guys running around who survived quite well until very, very recently."

Just last month, other researchers used DNA analysis to show the genetic diversity still present in residents of Africa, the cradle of the human race. And another project produced the first genome of an ancient human — a man who lived in Greenland some 4,000 years ago.

The new work, published online Wednesday by the journal Nature, is reported by Johannes Krause and Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and others.

They describe mapping DNA from what appeared to be a youngster's pinkie finger bone, which had been recovered in 2008 from Denisova Cave in Altai Mountains of southern Siberia. They showed how it differed from DNA of 54 modern-day people and six Neanderthals.

Their analysis indicated the Siberian species last shared a common ancestor with modern humans and Neanderthals about 1 million years ago. That in turn suggested there was a previously unrecognized migration out of Africa around that time, they said.

The work decoded the complete set of DNA from mitochondria, the power plants of cells. That's different from the better-known DNA that comes from cell nuclei and determines things like eye color. Paabo said the researchers are working to decode nuclear DNA from the Siberian species. That will reveal whether it was closely related to Neanderthals or today's humans, and answer questions like whether it interbred with Neanderthals or ancestors of modern-day people, he said.

Without a completed analysis of the nuclear DNA, "we are not saying this is a new species," Paabo said, although he said that's a likely possibility.

Rick Potts, director of the Smithsonian Institution's Human Origins Program, said the Siberian find might represent Homo heidelbergensis or Homo erectus. And even analysis of the Siberian species' nuclear DNA won't show if it's distinct from those ancestors, he said.

As for the study's suggestion of a migration out of Africa about a million years ago, Potts said there's already evidence of one or two migrations around that time.

The finger bone recovered from the Siberian species is not enough for a fossil-to-fossil comparison with other ancient species to show whether it's a new species, Delson said.

He suspects it might be a descendant of Homo erectus that's already documented in some fossil remains in northern Africa and Europe. Scientists are still trying to figure out how many species of the Homo grouping those bones represent and what name or names to attach to them, he said.

Disotell said the new creature could be an early version of Homo antecessor, a forerunner of Neanderthals and modern humans known from fossils in Spain. Or, he said, it could be a new species. In fact, the eventual decision could hinge mostly on the philosophical question of just how different a creature has to be to be declared a new species, he said.

Potts said that in the new work, "what we're seeing is a really, really interesting distant echo of the DNA history of human evolution.... This is an amazingly powerful technique that these guys have. This is going to be a growth industry in the study of human evolution."

MIA

A new species of dinosaur has emerged from the rocks of southern Utah.

Named Seitaad ruessi, the species was 10-to-15 feet long and 3-to-4 feet high. It's bones were found protruding from sandstone at the base of a cliff, directly below an ancient Anasazi cliff dwelling.

No humans were around at the time of the dinosaurs, but researchers say the bones could well have been visible when the early Indians lived there.

The name Seitaad comes from the word "Seit'aad," which was a sand monster that buried its victims in dunes in Navajo legend, according to the researchers. The newly named skeleton had been swallowed by a sand dune.

So, might visible dinosaur remains have given rise to the ancient Indian monster legend?

"That's a lot of speculation, but anything's possible," said Mark Loewen, a paleontologist at the Utah Museum of Natural History and instructor in the Department of Geology and Geophysics at the University of Utah.

One of the Anasazi dwellings included a stone with a dinosaur footprint in its center, he noted.

The ruessi part of the name is in honor of poet and naturalist Everett Ruess who disappeared in southern Utah in 1934.

Understanding how dinosaurs lived in the past, how their environments changed and affected them, is important for understanding our changing world today, Loewen said.

The nearly complete skeleton is missing only its head, one toe and a lower shinbone, he said, noting erosion over the years probably accounts for the missing parts.

What the researchers have is similar to other sauropodomorphs found in South America and southern Africa, which were all vegetarians, he explained in a telephone interview. However, Seitaad did have a claw on its front limbs, which Loewen suggested was probably used for defense.

"We were absolutely shocked" by the discovery of this dinosaur, Loewen said. It was found in 2004 by a local artist studying rock paintings and the scientists went to the area immediately when they learned of it, he said. The bones were excavated the following year by Museum researchers.

While dinosaur remains have been found in other parts of Utah fossils are rare in the Navajo sandstone areas and generally have been from smaller creatures.

"This new find suggests that there may be more dinosaurs yet to be discovered in these rocks," said Joseph Sertich, co-author of the report and currently a doctoral student at New York's Stony Brook University.

news.yahoo.com

The ancient stone spheres of Costa Rica were made world-famous by the opening sequence of "Raiders of the Lost Ark," when a mockup of one of the mysterious relics nearly crushed Indiana Jones. So perhaps John Hoopes is the closest thing at the University of Kansas to the movie action hero.

His report will help determine if sites linked to the massive orbs will be designated for preservation and promotion because of their "outstanding value to humanity."

Hoopes, who researches ancient cultures of Central and South America, is one of the world's foremost experts on the Costa Rican spheres. He explained that although the stone spheres are very old, international interest in them is still growing.

"The earliest reports of the stones come from the late 19th century, but they weren't really reported scientifically until the 1930s — so they're a relatively recent discovery," Hoopes said. "They remained unknown until the United Fruit Company began clearing land for banana plantations in southern Costa Rica."

According to Hoopes, around 300 balls are known to exist, with the largest weighing 16 tons and measuring eight feet in diameter. Many of these are clustered in Costa Rica's Diquis Delta region. Some remain pristine in the original places of discovery, but many others have been relocated or damaged due to erosion, fires and vandalism.

The KU researcher said that scientists believe the stones were first created around 600 A.D., with most dating to after 1,000 A.D. but before the Spanish conquest.

"We date the spheres by pottery styles and radiocarbon dates associated with archeological deposits found with the stone spheres," Hoopes said. "One of the problems with this methodology is that it tells you the latest use of the sphere but it doesn't tell you when it was made. These objects can be used for centuries and are still sitting where they are after a thousand years. So it's very difficult to say exactly when they were made."

Speculation and pseudoscience have plagued general understanding of the stone spheres. For instance, publications have claimed that the balls are associated with the "lost" continent of Atlantis. Others have asserted that the balls are navigational aids or relics related to Stonehenge or the massive heads on Easter Island.

"Myths are really based on a lot of very rampant speculation about imaginary ancient civilizations or visits from extraterrestrials," Hoopes said.

In reality, archaeological excavations in the 1940s found the stone balls to be linked with pottery and materials typical of pre-Columbian cultures of southern Costa Rica.

"We really don't know why they were made," Hoopes said. "The people who made them didn't leave any written records. We're left to archeological data to try to reconstruct the context. The culture of the people who made them became extinct shortly after the Spanish conquest. So, there are no myths or legends or other stories that are told by the indigenous people of Costa Rica about why they made these spheres."

Hoopes has a created a popular Web page to knock down some of the misconceptions about the spheres. He said the stones' creation, while vague, certainly had nothing to do with lost cities or space ships.

"We think the main technique that was used was pecking and grinding and hammering with stones," said Hoopes. "There are some spheres that have been found that still have the marks of the blows on them from hammer stones. We think that that's how they were formed, by hammering on big rocks and sculpting them into a spherical shape."

University of Kansas

The two PhD students, Michael Pittman from UCL (University College London) and Jonah Choiniere from George Washington University (GWU), found the dinosaur sticking out of a cliff face during a field project in Inner Mongolia, China. Their research is published online today in the journal Zootaxa.

"Jonah saw a claw protruding from the cliff face. He carefully removed it and handed it to me. We went through its features silently but he wanted my identification first. I told him it was from a carnivorous dinosaur and when he agreed I'm surprised nobody in London heard us shouting," said Michael Pittman, a PhD student in the UCL Department of Earth Sciences who was the co-discoverer of the dinosaur.

"I've always wanted to discover a dinosaur since I was a kid, and I've never given up on the idea. It was amazing that my first discovery was from a Velociraptor relative. My thesis is on the evolution and biomechanics of dinosaur tails but the carnivorous dinosaurs are my favourite and my specialty," he added.

At approximately 2.5 metres long and 25 kilograms, the researchers believe Linheraptor would have been a fast, agile predator that preyed on small horned dinosaurs related to Triceratops. Like other dromaeosaurids, it possessed a large "killing claw" on the foot, which may have been used to capture prey. Within the Dromaeosauridae family, Linheraptor is most closely related to another recently discovered species Tsaagan mangas.

Linheraptor differs from all other dromaeosaurs because of a triangular hole in front of the eye socket called the antorbital fenestra, which is a space in the skull that sinuses would have occupied. In Linheraptor this triangular hole is divided into two cavities – one of which is particularly big.

"This is a really beautiful fossil and it documents a transitional stage in dromaeosaurid evolution," said Dr. Xu Xing, Professor of Palaeontology at the Institute of Vertebrate Paleontology & Paleoanthropology (IVPP).

Linheraptor was found in rocks of the Wulansuhai Formation, part of a group of red sandstone rocks found in Inner Mongolia, China during a field expedition by the researchers in 2008. It is the fifth dromaeosaurid discovered in these rocks, which are famous for their preservation of uncrushed, complete skeletons.

The research was done as part of the Inner Mongolia Research project, led by Dr. Xu, which aims to better understand the Late Cretaceous ecosystem of Inner Mongolia, China which is analogous but less well-studied than the well known Late Cretaceous ecosytem of Outer Mongolia. The research was funded by the Geological Society of London, the US National Science Foundation, the Chinese National Science Foundation, and George Washington University.

University College London