New Fossils of Crocodilian, Hippo-Like Species from Panama
Mar. 5, 2013 — University of Florida paleontologists have discovered remarkably well-preserved fossils of two crocodilians and a mammal previously unknown to science during recent Panama Canal excavations that began in 2009.
The two new ancient extinct alligator-like animals and an extinct hippo-like species inhabited Central America during the Miocene about 20 million years ago. The research expands the range of ancient animals in the subtropics — some of the most diverse areas today about which little is known historically because lush vegetation prevents paleontological excavations — and may be used to better understand how climate change affects species dispersal today. The two studies appear online today in the same issue of the Journal of Vertebrate Paleontology.
The fossils shed new light on scientists’ understanding of species distribution because they represent a time before the formation of the Isthmus of Panama, when the continents of North and South America were separated by oceanic waters.
“In part we are trying to understand how ecosystems have responded to animals moving long distances and across geographic barriers in the past,” said study co-author Jonathan Bloch, associate curator of vertebrate paleontology at the Florida Museum of Natural History on the UF campus. “It’s a testing ground for things like invasive species — if you have things that migrated from one place into another in the past, then potentially you have the ability to look at what impact a new species might have on an ecosystem in the future.”
The research was funded by the National Science Foundation Panama Canal Partnerships in International Research and Education project, which supports paleontological excavation of the canal during construction expected to continue through 2014.
“We’re very fortunate we could get the funding for PIRE to take advantage of this opportunity — we’re getting to sample these areas that are completely unsampled,” said Alex Hastings, lead author of the crocodilian study and a visiting instructor at Georgia Southern University who conducted the research for the project as a UF graduate student.
Researchers analyzed all known crocodilian fossils from the Panama Canal, including the oldest records of Central American caimans, which are cousins of alligators. The more primitive species, named Culebrasuchus mesoamericanus, may represent an evolutionary transition between caimans and alligators, Hastings said.
“You mix an alligator and one of the more primitive caimans and you end up with this caiman that has a much flatter snout, making it more like an alligator,” Hastings said. “Before this, there were no fossil crocodilian skulls known from Central America.”
Christopher Brochu, an assistant professor of vertebrate paleontology in the department of geoscience at the University of Iowa, said “the caiman fossil record is tantalizing,” and the new data shows there is still a long way to go before researchers understand the group.
“The fossils that are in this paper are from a later time period, but some of them appear to be earlier-branching groups, which could be very important,” said Brochu, who was not involved with the study. “The problem is, because we know so little about early caiman history, it’s very difficult to tell where these later forms actually go on the family tree.”
The new mammal species researchers described is an anthracothere, Arretotherium meridionale, an even-toed hooved mammal previously thought to be related to living hippos and intensively studied on the basis of its hypothetical relationship with whales. About the size of a cow, the mammal would have lived in a semi-aquatic environment in Central America, said lead author and UF graduate student Aldo Rincon.
“With the evolution of new terrestrial corridors like this peninsula connecting North America with Central America, this is one of the most amazing examples of the different kind of paths land animals can take,” Rincon said. “Somehow this anthracothere is similar to anthracotheres from other continents like northern Africa and northeastern Asia.”
Researchers also name a second crocodilian species, Centenariosuchus gilmorei, after Charles Gilmore, who first reported evidence of crocodilian fossils collected during construction of the canal 100 years ago. The genus is named in honor of the canal’s centennial in 2014.
Researchers will continue excavating deposits from the Panama Canal during construction to widen and straighten the channel and build new locks. The project is funded by a $3.8 million NSF grant to develop partnerships between the U.S. and Panama and engage the next generation of scientists in paleontological and geological discoveries along the canal.
Study co-authors include Bruce MacFadden of UF and Carlos Jaramillo of the Smithsonian Tropical Research Institute.
Feeding Limbs and Nervous System of One of Earth’s Earliest Animals Discovered
Feb. 27, 2013 — An extraordinary find allowing scientists to see through the head of the ‘fuxianhuiid’ arthropod has revealed one of the earliest evolutionary examples of limbs used for feeding, along with the oldest nervous system to stretch beyond the head in fossil record.
Until now, all fossils found of this extremely early soft-bodied animal featured heads covered by a wide shell or ‘carapace’, obscuring underlying contents from detailed study.
But a new fossil-rich site in South China has been found to contain arthropod examples where the carapace has literally been ‘flipped’ over before fossilisation — allowing scientists to examine the fuxianhuiid head to an unprecedented extent.
The study, published today in Nature, highlights the discovery of previously controversial limbs under the head, used to shovel sediment into the mouth as the fuxianhuiid crawled across the seabed, millions of years before creatures emerged from the oceans.
Scientists say that this could be the earliest and simplest example of manipulative limbs used for feeding purposes, hinting at the adaptive ability that made arthropods so successful and abundant — evolving into the insects, spiders and crustaceans we know today.
Using a feeding technique scientist’s call ‘detritus sweep-feeding’, fuxianhuiids developed the limbs to push seafloor sediment into the mouth in order to filter it for organic matter — such as traces of decomposed seaweed — which constituted the creatures’ food.
Fossils also revealed the oldest nervous system on record that is ‘post-cephalic’ — or beyond the head — consisting of only a single stark string in what was a very basic form of early life compared to today.
“Since biologists rely heavily on organisation of head appendages to classify arthropod groups, such as insects and spiders, our study provides a crucial reference point for reconstructing the evolutionary history and relationships of the most diverse and abundant animals on Earth,” said Javier Ortega-Hernández, from Cambridge’s Department of Earth Sciences, who produced the research with Dr Nicholas Butterfield and colleagues from Yunnan University in Kunming, South China. “This is as early as we can currently see into arthropod limb development.”
Fuxianhuiids existed around 520 million years ago, roughly 50 million years before primordial land animals crawled from the sea, and would have been one of the first examples of complex animal life — likely to have evolved from creatures resembling worms with legs. Arthropods were the first jointed animals, enabling them to crawl.
Fuxianhuiid arthropods would have spent most of their time grazing on the sea floor, using these newly discovered limbs to plow sediment into their mouths. They could probably also use their bodies to swim for short distances, like tadpole shrimps.
The fossils date from the early part of the event known as the ‘Cambrian explosion’, when life on Earth went from multi-cellular organisms we know very little about to a relatively sudden and wide spread explosion of diverse marine animals — the first recognisable evolutionary step for the animal kingdom we know today.
“These fossils are our best window to see the most primitive state of animals as we know them — including us,” said Ortega-Hernández. “Before that there is no clear indication in the fossil record of whether something was an animal or a plant — but we are still filling in the details, of which this is an important one.”
While still a mystery, theories about the cause of the ‘Cambrian Explosion’ include possible correlations with oxygen rises, spikes in oceanic nutrient concentration, and genetic complexity reaching critical mass.
But the new site in South China where these fossils were found could prove to be key in uncovering ever more information about this pivotal period in the history of life on Earth. The Xiaoshiba ‘biota’ — that is the collection of all organisms preserved in the new locality — in China’s Yunnan Province is similar to the world-famous Chengjiang biota, which provided many of the best arthropod fossil records to date.
“The Xiaoshiba biota is amazingly rich in such extraordinary fossils of early organisms,” said Ortega-Hernández. “Over 50 specimens of fuxianhuiids have been found in just over a year, whereas previous areas considered fossil rich such as Chengjiang it took years — even decades — to build up such a collection.”
“So much material is so well preserved. There’s massive potential for Xiaoshiba to become a huge deal for new discoveries in early animal evolution.”
Evolution and the Ice Age
Feb. 26, 2013 — Dr John Stewart has made important contributions to a growing body of work that shows how the evolution of ecosystems has to be taken into account when speculating between different geological eras. Go back to the time of the dinosaurs or to the single-celled organisms at the origins of life, and it is obvious that ecosystems existing more than 65 million years ago and around four billion years ago cannot be simply surmised from those of today.
Although the most drastic evolutionary changes occur over long spans of time, the effects can be seen relatively recently, argues Dr Stewart.
Stewart has studied the interaction between ancient ecosystems — paleoecology — and evolution of humans and other organisms over the past 100,000 years, undertaking everything from excavating cave sites in Belgium to exploring the desert of Abu Dhabi.
In one milestone collaborative study, Dr Stewart has taken existing knowledge of the geographical spread of plant and animal species throughout the warming and cooling of the Ice Ages to provide insights into human origins, including the evolution and extinction of Neanderthals.
He has also examined the rise of the ‘first Europeans’, along with the Denisovans — a newly discovered group — mysterious cousins of the Neanderthals, who occupied a vast realm stretching from the chill expanse of Siberia to the tropical forests of Indonesia.
The key insight in this work, conducted alongside Prof Chris Stringer of London’s Natural History Museum, came from understanding the important role of the refuge taken by a species from harsher conditions — known as a refugium — which has a tremendous influence on the evolutionary future of the species. Once the climate changes again, for instance as ice sheets melt, these refuges can expand or connect up again.
But, of course, there’s a twist. Evolution has also had a huge influence. The inhabitants are not the same as the original populations as a result of genetic mutations. The time spent apart in refuge generally serves to splinter a once unified species.
Previous research into hedgehogs, polar bears and other animals suggest that, even once an Ice Age ends and the different populations start intermingling again, they never really merge back together as a single group. This process drives important evolutionary changes, which can ultimately lead to the origins of a new species.
Ultimately, this explains why Homo sapiens are still here and our archaic human cousins went extinct some 30,000 years ago: our ancestors chose the right refuge to wait out the Ice Age.
Today, Dr Stewart’s work has shifted away from fossil remains to ancient DNA. Traditionally insights into the evolution of species have come from fossils, but we now know that the genetic changes that underlie a major change in body shape can be minor.
“The most exciting development in my field has been the ability to analyse ancient DNA, which has begun to allow us to see evolution happening over the last several dozen thousand years,” explains Dr Stewart.
His claim that climate change caused the Neanderthals’ demise is supported by work by Love Dalén at the Swedish Museum of Natural History in Stockholm, who has looked at the genes in 13 Neanderthal fossils found in southern Europe and western Asia.
All Neanderthal fossils more than 48,000 years old, and those found in Asia, had a higher level of genetic diversity than later European fossils, suggesting that the Neanderthals probably went through an evolutionary ‘bottleneck’ where a significant percentage of them perished.
When a bottleneck occurs, the remaining individuals are often a much less diverse group, which makes it more difficult for them to evolve and adapt to a changing environment.
Dr Stewart, who is doing DNA studies in collaboration with teams at the Natural History Museum in Stockholm and the Universities of York and Royal Holloway, is now focusing on using genetics to elucidate the evolution of a wide range of creatures.
He has conducted recent studies at the cave site of Trou Al’Wesse, a refugium once occupied by Neanderthals, in Belgium. He is studying how animal populations changed as a result of Ice Age climate change to understand the evolutionary processes that have taken place over the last 50,000 years.
But his work is not confined to the past. It informs the present too. Recently there had been a proposal to eradicate the Eagle Owl because it killed other birds, such as hen harriers, and was not thought to be a native species. But Dr Stewart’s studies of fossils and more recent archaeological records revealed the bird, or something like it, has been present in Britain for up to 700,000 years. The plan to cull the birds has now been abandoned.
And his research can help us predict the future. The fear is that our ever-expanding impact on the planet will trigger ecological collapse. But the only way to know for sure is to look back into the past.
“By studying how organisms have reacted to past climate change,” explains Dr Stewart, “we can learn lessons about what may take place due to human-caused global warming.”
Ancient Fossilized Sea Creatures Yield Oldest Biomolecules Isolated Directly from a Fossil
Feb. 18, 2013 — Though scientists have long believed that complex organic molecules couldn’t survive fossilization, some 350-million-year-old remains of aquatic sea creatures uncovered in Ohio, Indiana, and Iowa have challenged that assumption.
The spindly animals with feathery arms — called crinoids, but better known today by the plant-like name “sea lily” — appear to have been buried alive in storms during the Carboniferous Period, when North America was covered with vast inland seas. Buried quickly and isolated from the water above by layers of fine-grained sediment, their porous skeletons gradually filled with minerals, but some of the pores containing organic molecules were sealed intact.
That’s the conclusion of Ohio State University geologists, who extracted the molecules directly from individual crinoid fossils in the laboratory, and determined that different species of crinoid contained different molecules. The results will appear in the March issue of the journal Geology.
William Ausich, professor in the School of Earth Sciences at Ohio State and co-author of the paper, explained why the organic molecules are special.
“There are lots of fragmented biological molecules — we call them biomarkers — scattered in the rock everywhere. They’re the remains of ancient plant and animal life, all broken up and mixed together,” he said. “But this is the oldest example where anyone has found biomarkers inside a particular complete fossil. We can say with confidence that these organic molecules came from the individual animals whose remains we tested.”
The molecules appear to be aromatic compounds called quinones, which are found in modern crinoids and other animals. Quinones sometimes function as pigments or as toxins to discourage predators.
Lead author Christina O’Malley, who completed this work to earn her doctoral degree, first began the study when she noticed something strange about some crinoids that had perished side by side and become preserved in the same piece of rock: the different species were preserved in different colors.
In one rock sample used in the study, one crinoid species appears a light bluish-gray, while another appears dark gray and yet another more of a creamy white. All stand out from the color of the rock they were buried in. The researchers have since found similar fossil deposits from around the Midwest.
“People noticed the color differences 100 years ago, but no one ever investigated it,” O’Malley said. “The analytical tools were not available to do this kind of work as they are today.”
O’Malley isolated the molecules by grinding up small bits of fossil and dissolving them into a solution. Then she injected a tiny sample of the solution into a machine called a gas chromatograph mass spectrometer. The machine vaporized the solution so that a magnet could separate individual molecules based on electric charge and mass. Computer software identified the molecules as similar to quinones.
Then, with study co-author and Ohio State geochemist Yu-Ping Chin, she compared the organic molecules from the fossils with the molecules that are common in living crinoids today. Just as the researchers suspected, quinone-like molecules occur in both living crinoids and their fossilized ancestors.
Though different colored fossils contained different quinones, the researchers cautioned that there’s no way to tell whether the quinones functioned as pigments, or that the preserved colors as they appear today were similar to the colors that the crinoids had in life.
Part of why the crinoids were so well preserved has to do with the structure of their skeletons, the researchers said. Like sand dollars, crinoids have skin on top of a hard calcite shell. In the case of crinoids, their long bodies are made up of thousands of stacked calcite rings, and each ring is a single large calcite crystal that contains pores filled with living tissue. When a crinoid dies, the tissue will start to decay, but calcite will precipitate into the pores, and calcite is stable over geologic time. Thus, organic matter may become sealed whole within the rock.
“We think that rock fills in the skeleton according to how the crystals are oriented. So it’s possible to find large crystals filled in such a way that they have organic matter still trapped inside,” Ausich said.
The location of the fossils was also key to their preservation. In the flat American Midwest, the rocks weren’t pushed up into mountain chains or heated by volcanism, so from the Ohio State geologists’ perspective, they are pristine.
Their next challenge is to identify the exact type of quinone molecules they found, and determine how much information about individual species can be gleaned from them.
“These molecules are not DNA, and they’ll never be as good as DNA as a means to define evolutionary relationships, but they could still be useful,” Ausich said. “We suspect that there’s some kind of biological signal there — we just need to figure out how specific it is before we can use it as a means to track different species.”
This research was sponsored by the National Science Foundation and the Geological Society of America.
Jurassic Records Warn of Risk to Marine Life from Global Warming
Feb. 19, 2013 — The risk posed by global warming and rising ocean temperatures to the future health of the world’s marine ecosystem has been highlighted by scientists studying fossil records.
Researchers at Plymouth University believe that findings from fieldwork along the North Yorkshire coast reveal strong parallels between the Early Jurassic era of 180 million years ago and current climate predictions over the next century.
Through geology and palaeontology, they’ve shown how higher temperatures and lower oxygen levels caused drastic changes to marine communities, and that while the Jurassic seas eventually recovered from the effects of global warming, the marine ecosystems that returned were noticeably different from before.
The results of the Natural Environment Research Council-funded project are revealed for the first time in this month’s PLOS ONE scientific journal.
Professor Richard Twitchett, from the University’s School of Geography, Earth and Environmental Sciences, and a member of its Marine Institute, said: “Our study of fossil marine ecosystems shows that if global warming is severe enough and lasts long enough it may cause the extinction of marine life, which irreversibly changes the composition of marine ecosystems.”
Professor Twitchett, with Plymouth colleagues Dr Silvia Danise and Dr Marie-Emilie Clemence, undertook fieldwork between Whitby and Staithes, studying the different sedimentary rocks and the marine fossils they contained. This provided information about the environmental conditions on the sea floor at the time the rocks were laid down.
The researchers, working with Dr Crispin Little from the University of Leeds, were then able to correlate the ecological data with published data on changes in temperature, sea level and oxygen concentrations.
Dr Danise said: “Back in the laboratory, we broke down the samples and identified all of the fossils, recording their relative abundance much like a marine biologist would do when sampling a modern environment. Then we ran the ecological analyses to determine how the marine seafloor community changed through time.”
The team found a ‘dead zone’ recorded in the rock, which showed virtually no signs of life and contained no fossils. This was followed by evidence of a return to life, but with new species recorded.
Professor Twitchett added: “The results show in unprecedented detail how the fossil Jurassic communities changed dramatically in response to a rise in sea level and temperature and a decline in oxygen levels.
“Patterns of change suffered by these Jurassic ecosystems closely mirror the changes that happen when modern marine communities are exposed to declining levels of oxygen. Similar ecological stages can be recognised in the fossil and modern communities despite differences in the species present and the scale of the studies.”
The NERC project – ‘The evolution of modern marine ecosystems: environmental controls on their structure and function’ – runs until March 2015, and is one of four funded under their Coevolution of Life and the Planet research programme.
Ice Age Extinction Shaped Australian Plant Diversity
Feb. 12, 2013 — Researchers have shown that part of Australia’s rich plant diversity was wiped out by the ice ages, demonstrating that extinction, probably more than evolution, influences biodiversity.
The research led by the University of Melbourne and University of Tasmania has shown that plant diversity in South East Australia was as rich as some of the most diverse places in the world, and that most of these species went extinct during the ice ages, probably about one million years ago.
The team’s work was recently published in the Proceedings of the National Academy of Sciences.
Dr Sniderman of the University of Melbourne’s School of Earth Sciences said the findings show extinction is just as important to diversity of organisms as evolution.
“Traditionally scientists believed some places have more species than others because species evolved more rapidly in these places. We have overthrown this theory, which emphasizes evolution, by showing that extinction may be more important, ” he said.
The study compared two regions of Southern Australia and South Africa.
“South-western Australia has a huge diversity of tough-leaved shrubs and trees such as eucalypts, Banksia, Grevilleas and Acacias, making it one of the most biodiverse places on Earth,” Dr Sniderman said.
“The southern tip of South Africa is even richer, with astonishing numbers of similar kinds of plants like proteas and ericas.”
Scientists have long maintained that this diversity is somehow related to the poor soils and dry summers of these places.
For the study researchers analysed plant fossils that accumulated in an ancient lake in South Eastern Australia. They found the region had at least as many tough-leaved plants 1.5 million years ago as Western Australia and South Africa do today.
The results were entirely unexpected.
“As Australia dried out over the past several million years, rainforest plants largely disappeared from most of the continent,” said Dr Sniderman
“It has been thought that this drying trend allowed Australia’s characteristic tough-leaved plants to expand and became more diverse. We have shown that the climate variability of the ice ages not only drove rainforest plants to extinction but also a remarkable number of tough-leaved, shrubby plants,” he said. Dr Greg Jordan of the School of Plant Sciences at the University of Tasmanian said not only has the study overturned current thought on the role of extinction in plant diversity, it has implications for understanding how Australian plant diversity will deal with current and future climate change.
“The species that went extinct in SE Australia during the ice ages were likely to be the ones most sensitive to rapid climate change, meaning that the species that now grow in eastern Australia may be more capable of tolerating rapid changes than predicted by current science,” he said.
“However, the species in hotspots of diversity like Western Australia may be much more sensitive to future climate change, because they have been protected from past climate changes.”
The study was done in collaboration with the Nelson Mandela Metropolitan University in South Africa.
Ancient Insects Shed Light On Biodiversity
Simon Fraser University evolutionary biologists Bruce Archibald and Rolf Mathewes, and Brandon University biologist David Greenwood, have discovered that modern tropical mountains’ diversity patterns extended up into Canada about 50 million years ago.
Their findings confirm an influential theory about change in modern species diversity across mountains, and provide evidence that global biodiversity was greater in ancient times than now. The scientific journal Palaeogeography, Palaeoclimatology, Palaeoecology has published their research.
About 45 years ago, an evolutionary biologist at the University of Pennsylvania theorized that change in species from site to site across mountain ranges in the tropics should be greater than in temperate latitudes.
Daniel Janzen reasoned that the great difference between summer and winter in temperate latitudes (high seasonality) offers a wide window to migrate across mountainous regions. The small difference in the tropics (low seasonality) allows a very narrow opportunity, annually. Consequently, communities across tropical mountains should have fewer of the same species. Many studies examining modern communities support this theory.
Archibald, Mathewes and Greenwood realized that fossil beds across a thousand kilometres of the ancient mountains of British Columbia and Washington provided a unique lens through which to deepen evaluation of this theory.
Fifty million years ago, when these fossil beds were laid down, the world had low seasonality outside of the tropics, right to the poles. Because of this, if Janzen’s theory is right, the pattern of biodiversity that he described in modern tropical mountains should have extended well into higher latitudes.
“We found that insect species changed greatly across British Columbia’s and Washington State’s ancient mountain ranges, like in the modern tropics,” Archibald says, “exactly as Janzen’s seasonality hypothesis predicted.
This implies that it’s the particular seasonality now found in the modern tropics, not where that climate is situated globally, that affects this biodiversity pattern.” He adds: “Sometimes it helps to look to the ancient past to better understand how things work today.”
The findings also bolster the idea that ancient Earth was a much more diverse world than now with many more species.
New Kind of Extinct Flying Reptile Discovered
Feb. 4, 2013 — A new kind of pterosaur, a flying reptile from the time of the dinosaurs, has been identified by scientists from the Transylvanian Museum Society in Romania, the University of Southampton in the UK and the Museau Nacional in Rio de Janiero, Brazil.
The fossilised bones come from the Late Cretaceous rocks of Sebeş-Glod in the Transylvanian Basin, Romania, which are approximately 68 million years old. The Transylvanian Basin is world-famous for its many Late Cretaceous fossils, including dinosaurs of many kinds, as well as fossilised mammals, turtles, lizards and ancient relatives of crocodiles.
A paper on the new species, named Eurazhdarcho langendorfensis has been published in the online journal PLoS ONE. Dr Darren Naish, from the University of Southampton’s Vertebrate Palaeontology Research Group, who helped identify the new species, says: “Eurazhdarcho belong to a group of pterosaurs called the azhdarchids. These were long-necked, long-beaked pterosaurs whose wings were strongly adapted for a soaring lifestyle. Several features of their wing and hind limb bones show that they could fold their wings up and walk on all fours when needed.
“With a three-metre wingspan, Eurazhdarcho would have been large, but not gigantic. This is true of many of the animals so far discovered in Romania; they were often unusually small compared to their relatives elsewhere.”
The discovery is the most complete example of an azhdarchid found in Europe so far and its discovery supports a long-argued theory about the behaviour of these types of creatures.
Dr Gareth Dyke, Senior Lecturer in Vertebrate Palaeontology, based at the National Oceanography Centre Southampton says: “Experts have argued for years over the lifestyle and behaviour of azhdarchids. It has been suggested that they grabbed prey from the water while in flight, that they patrolled wetlands and hunted in a heron or stork-like fashion, or that they were like gigantic sandpipers, hunting by pushing their long bills into mud.
“One of the newest ideas is that azhdarchids walked through forests, plains and other places in search of small animal prey. Eurazhdarcho supports this view of azhdarchids, since these fossils come from an inland, continental environment where there were forests and plains as well as large, meandering rivers and swampy regions.”
Fossils from the region show that there were several places where both giant azhdarchids and small azhdarchids lived side by side. Eurazhdarcho’s discovery indicates that there were many different animals hunting different prey in the region at the same time, demonstrating a much more complicated picture of the Late Cretaceous world than first thought.
Features of Southeast European Human Ancestors Influenced by Lack of Episodic Glaciations
Feb. 6, 2013 — A fragment of human lower jaw recovered from a Serbian cave is the oldest human ancestor found in this part of Europe, who probably evolved under different conditions than populations that inhabited more western parts of the continent at the same time, according to research published Feb. 6 in the open access journal PLOS ONE.
The research was carried out by William Jack Rink of McMaster University, Canada, and the international team under the direction of Dušan Mihailović, University of Belgrade, Serbia, and Mirjana Roksandic, University of Winnipeg, Canada.
The fossil was found to be at least 397,000 years old and possibly older than 525,000 years old, a time when distinctly Neandertal traits began to appear in Europe. The evolution of these traits was strongly influenced by periodic isolation of groups of individuals, caused by episodic formation of glaciers. Humans in southeastern Europe were never geographically isolated from Asia and Africa by glaciers, and according to the authors, this resulted in different evolutionary forces acting on early human populations in this region.
Roksandic explains that their study confirms the importance of southeast Europe as a ‘gate to the continent’ and one of the three main areas where humans, plants and animals sought refuge during glaciations in prehistoric times. She adds, “We have very few fossils of hominins in general from this time, a period that was critical for shaping the appearance and evolution of uniquely human morphology and behaviors.”
Previous Unknown Fossilized Fox Species Found
Jan. 23, 2013 — Researchers from Wits University, the University of Johannesburg and international scientists have announced the discovery of a 2-million-year-old fossil fox at Malapa, South Africa, in the Cradle of Humankind World Heritage Site.
In an article published in the journal Transactions of the Royal Society of South Africa, the researchers describe the previously unknown species of fox named Vulpes Skinneri — named in honour of the recently deceased world renowned South African mammalogist and ecologist, Prof. John Skinner of the University of Pretoria.
The site of Malapa has, since its discovery in 2008, yielded one of the most extraordinary fossil assemblages in the African record, including skeletons of a new species of human ancestor named Australopithecus sediba, first described in 2010.
The new fox fossils consist of a mandible and parts of the skeleton and can be distinguished from any living or extinct form of fox known to science based on proportions of its teeth and other aspects of its anatomy.
Dr. Brian Kuhn of Wits’ Institute for Human Evolution (IHE) and the School of GeoSciences, an author on the paper and head of the Malapa carnivore studies explains: “It’s exciting to see a new fossil fox. The ancestry of foxes is perhaps the most poorly known among African carnivores and to see a potential ancestral form of living foxes is wonderful.”
Prof. Lee Berger, also of the IHE and School of GeoSciences, author on the paper and Director of the Malapa project notes: “Malapa continues to reveal this extraordinary record of past life and as important as the human ancestors are from the site, the site’s contribution to our understanding of the evolution of modern African mammals through wonderful specimens like this fox is of equal import. Who knows what we will find next?.”
The entire team has expressed their privilege in naming the new species after “John Skinner, one of the great names in the study of African mammals and particularly carnivores. We (the authors) think that John would be pleased, and it is fitting that this rare little find would carry his name forever.”