EXCAVATIONS IN KENYA SHEDDING LIGHT ON EARLY TOOL MAKING AND HABITATS

A team of scientists at the site of Olorgesailie in the East African Rift Valley of south central Kenya, Africa, are uncovering stone tools and geological clues that may hold some answers as well as raise new questions about the evolution of early human stone toolmaking and use and the environment in which the early humans lived up to 1.2 million years ago.

Led by Dr. Rick Potts of the Smithsonian Institution's Human Origins Program and in conjunction with the National Museums of Kenya, the current efforts involve a multidisciplinary team of scientists focusing on two separate but related sites in the Olorgesailie region that have recently produced abundant evidence of early human activity likely associated with Homo erectus, an extinct ancestral human that lived in the area between 1.2 and 490,000 years ago, and later early human activity that produced a more sophisticated industry of stone tools.

Like Olduvai Gorge, Koobi Fora, and Hadar, the Olorgesailie region has long been a focus of research related to human origins. Featuring ancient sediments laid down and altered or formed over millions of years as a result of geologic activity associated with the surrounding Rift Valley as well as shifting climates, its exposed sediment beds have yielded an abundance of fossils and stone tools.
that have afforded scientists a rich array of data for studying the
emergence and habitat of these early humans.

Olorgesailie is most noted for the numerous Acheulean stone handaxes, defining one of the largest single assemblages of handaxes in the world. In addition, in June of 2003, a team led by Potts discovered a human frontal skull bone dated to between 900,000 and 970,000 years old, identified as classifiable to Homo erectus. It was
found about 1.5 km from deposits of stone handaxes found in the same layer as the fossil discovery.

Working in the shadow of an ancient volcano a short distance from their field camp, the research team has been uncovering a wealth of stone artifacts and fossil remains of animals that they hope will give them a clearer picture of life for the early humans that walked this terrain and managed to survive or adapt to a fluctuating climate and geological landscape.

One site, an elephant butchery site where 990,000-year-old fossilized elephant bones have been excavated (referred to as Site 15), yielded not only fossilized bones with cut marks, but also more than 2300 stone tools surrounding the bones. More recently, the fossil bones of zebra and antelope, as well as stone flakes, boulders and hand-sized hammerstones (stones with depressions) were found at the site. Study of phytoliths (microscopic fossilized plant remains) found embedded on the hammerstones
revealed that they were used as anvils for crushing plants, possibly for eating. Overall analysis of the finds at this site has revealed that it may have been a drying wetland environment of reeds and other marsh plants where early humans found animals to butcher for their meat and bone marrow.

The second site, called "BOK-2" has yielded Middle Stone Age (MSA) stone points found within younger layers dating from 493,000 to 220,000 years ago. The most
recent excavation there in July, 2011 uncovered more than 150 stone artifacts concentrated in a one meter square -- the densest assemblage ever found at this site. MSA stone tools are considered to be representative of a more sophisticated and diverse stone tool technology characterized by small obsidian points and retouched flakes, a package of implements that enabled greater effectiveness and efficiency in the early human hunt for and preparation of food.

These discoveries are considered significant for a number of reasons, not the least of which is that they seem to predate similar MSA stone tool assemblages found in other parts of Africa and the world that are dated to around 285,000 to 125,000 years ago. More surprising still were excavations at Olorgesailie in 2010 at a 625,000-year-old site, producing nearly one thousand stone tools, some of which showed evidence that early humans were striking small blades from carefully prepared stone cores, a technique not known to be generally used until the later, MSA period.

Says Potts of these finds, "they indicate that even during the handaxe period, early humans were beginning to hit upon a new way of knapping stone. This new approach to toolmaking involved making smaller flakes by carefully planning how you strike one stone against another.........So here's the question we are testing in our excavations: Could it be that stone tools in the layers at Olorgesailie tell us about the oldest known transition from handaxes to the Middle Stone Age? We'll need a lot of digging and evidence to know this for sure".[1]

Farther west of Olorgesailie, another related story has been unfolding. For the past decade, Potts has also been co-directing work at a site called Kanjera South on the Homa Peninsula, a land mass that extends off the southern shore of the Winam Gulf, part of Lake Victoria. Here, he and project leader Dr. Thomas Plummer of Queens College in New York have excavated stone tools and butchered animal bones associated with some of the oldest humans to have lived in a grassland environment, dating from 1.9 to 2.0 million years ago.

The tools belonged to the Oldowan industry, a comparatively simple stone tool technology and the earliest known stone tool system attributed to hominins. The Oldowan was first discovered during the 1930's by Louis S.B. Leakey at Olduvai Gorge. Analysis of the variety of materials from which the stone tools were created provided evidence that suggested that the raw materials were obtained at distances of up to 13 kilometers from the point at which they were last deposited in the form of tools. This established the longest distance at which hominins, or early humans, have transported materials for toolmaking from one point to another.

What has distinguished these excavations perhaps more than any other in the past is this research team's "paleolandscape approach" to investigation and excavation, providing a means to place their site finds within a much broader context so that they can be understood and interpreted more meaningfully within the geologic and climatological environment within which they existed. Because of this, the stone tool artifacts and fossils become stars on a bigger stage.

The excavations and research at Olorgesailie and Kanjera South are expected to continue for years into the future, with plans to share the experience with the public through ongoing updates to the Smithsonian Human Origins Program website. Interested readers and the public are invited to read more about these specific discoveries and much more at the Smithsonian Human Origins Program's Olorgesailie Field Blog.

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MARYLAND (US) SITE DATED TO 9,270 YEARS AGO

Three years of digging at a prehistoric Indian site in Anne Arundel County has unearthed the oldest structures and human habitations in Maryland and is making this bluff above the Patuxent River one of the most important archaeological sites in the Mid-Atlantic.

Last week, archaeologists learned from carbon-14 dating that a stone hearth they uncovered this summer was last used 9,290 years ago. That makes the site, called Pig Point, twice as old as the earliest carbon-dated human habitation found previously in Maryland.

Yet the carbon-14 date is just the latest in a series of extraordinary discoveries at the South County site that are drawing the interest of archaeologists from throughout the region.

Beginning in 2009, the team led by Anne Arundel County archaeologist Al Luckenbach has found oval patterns of wigwam post holes dating from 800 to 3,000 years ago, the oldest human structures ever found in Maryland.

They have found highly decorated pottery, tools of stone and bone, personal ornaments, copper beads from the Great Lakes, exotic tools and ceramics from the Ohio and Delaware valleys, fossil shark teeth from Southern Maryland and shells from the ocean beaches.

Luckenbach's team is still finding evidence of human occupations from the Early Archaic period, 10,000 to 8,000 years ago. As they dig even deeper into the bluff, and back in time, the next period they would reach is the "Paleo Indian" or "Clovis" time, roughly 10,000 to 20,000 years ago. Last year, neighbors showed Luckenbach several fluted Clovis spear points they picked up in a field at the foot of the bluff. So his team is now on the lookout for more Paleo-Indian artifacts in their excavations, finds they could document and date.

Setting aside the extraordinary artifacts, archaeologists say Pig Point is most unique and valuable because of its nearly 10,000-year record of continuous human habitation. At Pig Point, the tools, ceramics, food waste and traces of wigwams have
been repeatedly buried by fresh deposits of soil, probably washed down from higher on the bluff. That has left a continuous record, 6 or 7 feet deep, with the oldest occupations at the bottom of the layer cake, and the most recent at the top. And carbon-14 dates from many of the 13 layers have confirmed their ages. "The whole sequence [of C-14 dates] fit the way they should," Curry said. "It's very clear that the 6 feet of sediment is undisturbed."

Based on the unique and exotic artifacts he's recovered at Pig Point, Luckenbach believes the area may have been an important junction for trade, cultural and perhaps religious exchange between the Ohio Valley and the Atlantic coast, and still other cultures to the north and south.

Despite financial woes at both the state and county levels, the work has continued for three seasons, funded by Anne Arundel County and grants from the Maryland Historical Trust, as well as private donations. County staff, volunteers and college interns from at least four states have dug two days a week, every week, from April to the first frost.

http://www.baltimoresun.com/news/maryland/bs-md-pig-point-archaeology-20110814,0,3824207.story

ROMAN AMPHITHEATER FOUND NEAR YORK IN NORTHERN ENGLAND

The lost amphitheater of northern England has been found on a Yorkshire hilltop in a discovery with major implications for the study of Roman Britain.

Centuries of speculation have ended with a printout from geomagnetic scanners which reveals a great tiered bank of seats below curving hummocks in a field now frequented only by a herd of cattle. Crowning the summit of Studforth Hill, the oval arena would have combined spectacles and entertainments with a magnificent 360-degree view, making it the equivalent of a national theater of the north.

The find by Cambridge University archaeologists – led by a young woman who grew up locally and was told the amphitheater legend by her grandfather – seals the importance in Roman times of the small village of Aldborough, between Harrogate and York.

It also adds to growing evidence that Britannia Inferior, as the northern province was known, was busier, more prosperous and cultured than previously thought. There have been a relative shortage of digs and studies of civilian sites in the area, compared with hundreds in Britannia Superior, today's south.

"Its discovery leaves little doubt that Isurium Brigantium, as Aldborough was called in Roman times, was the civil capital of the Britons known as Brigantes, effectively the population between Derbyshire and Hadrian's Wall," said Martin Millett, professor of classical archaeology at Cambridge.

The sweeping curve of the amphitheatre, which crowns a long series of discoveries at Aldborough, lay hidden because of changing fashions in archaeology, shortage of money for excavations and pressure for resources to go elsewhere.

The breakthrough came with geomagnetic and ground radar in which more than a square mile of cottages and pasture were turned into a grid, which Ferraby, Millett and volunteer students paced with handheld scanners and others examined on a machine akin to a lawnmower. They called locals to a packed meeting this week to announce the amphitheater had at last been tracked down.

Most of the tiered seats were quarried or hacked out centuries ago, but the high bank which forms the crown of Studforth Hill hides the surviving section. The geomagnetic scan detected a large mass of material and then tiering, which is crudely reflected by ridges in the grassy surface until it disappears under a small copse.

"We don't yet know whether the seats are stone, which would have been the best quality, or a mixture of timber and compacted earth which has been found at other sites in the UK," said Ferraby. "But there are at least four rows and an extra ridge of land behind the trees suggests that there may have been a fifth. Whatever the material, it would have been an imposing building."

The Cambridge team is now completing its geophysical survey of the Roman town's entire site, which will be analyzed for possible excavation points, possibly including the amphitheater, if funding can be found.

EXCITING NEWS ABOUT ROCK ART IN THE SOUTHWEST --PETROGLYPHS OF MAMMOTHS FOUND IN UTAH

Rock art specialists Ekkehart Malotki and Henry Wallace report the discovery of portrayals of mammoths and a possible bison at the Upper Sand Island rock art site along the San Juan River in southeastern Utah (USA), most likely dating between 13,000 and 11,000 BP (before present). Until now, no unambiguously ancient rock art imagery of Ice Age megafauna has been found in North America.

The now generally accepted notion is that there were multiple waves of immigrants prior to Clovis (circa 13,500 BP). Icons of the Ice Age, mammoths were extinct at the latest by 10,800 BP. However, most ancient recognizable and datable art in the American West is almost exclusively non-iconic, with a overwhelming bias for abstract-geometric motifs.

The Upper Sand Island rock art site extends intermittently for several hundred meters along the vertical Navajo Sandstone cliffs bordering the flood-plain of the San Juan River. Consisting exclusively of petroglyphs, the site was first recorded in 1985. With the exception of a brief paper, none of the different rock art styles, occurring in multiple clusters at the site, have been described. The image of one supposed mammoth was known to some archaeologists and rock art enthusiasts, but because of its difficult access - on a vertical cliff face several meters above ground level - it was never scientifically investigated and its authenticity remained in question.

The lines of the mammoth and bison images are both pecked and ground. Some portions of the design follow natural microscopic fissures in the cliff face. That the artist chose this location, and drew the most diagnostic portions of the creature following a natural feature of the rock, demonstrates that the artist saw the likeness of the mammoth in the rock prior to making the image.

Closely associated with the mammoth is a much larger image that suggests a bison, which partially overlaps the dorsal ridge of the underlying mammoth. Their placement some 5m above the remnants of an ancient gravel bar, which in turn rises an additional 7 to 8m above the current floodplain, betrays the panel's deep antiquity. At the time of its manufacture, the artist's access to the rock face must have been facilitated by a considerably higher ground level.

The authentication of two petroglyph depictions of mammoths along Utah's San Juan River clearly confirms the consensus of Late Pleistocene researchers that Paleo-american humans lived side by side with now-extinct megafauna in the fossil- and archaeologically-rich region of south-eastern Utah.

Edited from Rock Art Research, 2011 - Volume 28, Number 2
http://www.stonepages.com/docs/malotki-wallace.pdf
[13 images]

IOWA (USA) 7,000 YEAR OLD SITE UNCOVERED

University of Iowa archaeologists announced the discovery of a 7,000-year-old archaeological site in Des Moines (Iowa, USA). The site, nicknamed 'the Palace' because of its size and preservation, yielded the remains of two humans, a woman and an infant, that are the oldest human bones to be found in the state.

"This site is important because it was intensively occupied and very quickly river floods sealed the deposits and very quickly preserved items that otherwise could have been lost" according to State Archaeologist John Doershuk. Because so many items were found together at the site - archaeologists gathered more than 6,000 artifacts - it helps researchers put into context the information they learn about how the villagers lived, what they ate and how they were developing as a people, Doershuk added.

Construction work was ongoing at the site, when workers moving dirt noted charcoal and burned earth stains, Doershuk said. The Office of the State Archaeologist, was called to the site in December 2010 to monitor the work and investigate interesting findings. Archaeologists worked through May to collect as much information and as many artifacts as possible before construction work had to return to that portion of the site.

They found the remnants of four oval-shaped deposits, possibly houses, as large as 800 square feet with hearths. "It became clear very quickly that the site was something spectacular - something none of us had seen before or probably will ever again, as well-preserved house deposits of this age are extremely rare west of the Mississippi River Valley," Bill Whittaker, a project archaeologist who co-directed the dig, said.

The burial pit was discovered in March, about six or seven feet below the ground surface. Items were found in the grave along with the remains, including a spear point. The age of the site was determined by radiocarbon dating based on wood charcoal from the burial feature and also the spear point found there, by matching it to the time frame of other similar artifacts found in the Midwest, Doershuk said.

The crew also used laser technology to map more than 12,000 archaeological data points so they can develop 3-D models of the site with computer software.

"The field work is done... but we have at least a year's worth of analysis and writing and comparative work," Doershuk said. "All the artifacts will be officially stored at the archaeological depository at our office at UI, but we'll probably loan them out for display at the State Historical Museum in Des Moines and other locales.

While construction at the site continues, there is adjacent, unexcavated land that researchers believe will yield more archaeological finds, and they are working on a preservation plan.

Edited from The Gazette (18 August 2011), Press-Citizen.com (19 August 2011)
http://tinyurl.com/3ps7ngn
[1 image, 1 video]
http://tinyurl.com/3tbewpb

DENISOVIANS -- NEANDERTHALS -- LINKED TO MODERN PEOPLE

An international team of scientists has identified a previously shadowy human group known as the Denisovans as cousins to Neanderthals who lived in Asia from roughly 400,000 to 50,000 years ago and interbred with the ancestors of today’s inhabitants of New Guinea.

All the Denisovans have left behind are a broken finger bone and a wisdom tooth in a Siberian cave. But the scientists have succeeded in extracting the entire genome of the Denisovans from these scant remains. An analysis of this ancient DNA reveals that the genomes of people from New Guinea contain 4.8 percent Denisovan DNA.

An earlier, incomplete analysis of Denisovan DNA had placed the group as more distant from both Neanderthals and humans. On the basis of the new findings, the scientists propose that the ancestors of Neanderthals and Denisovans emerged from Africa half a million years ago. The Neanderthals spread westward, settling in the Near East and Europe. The Denisovans headed east. Some 50,000 years ago, they interbred with humans expanding from Africa along the coast of South Asia, bequeathing some of their DNA to them.

“It’s an incredibly exciting finding,” said Carlos Bustamante, a Stanford University geneticist who was not involved in the research.

The research was led by Svante Paabo, a geneticist at the Max Planck Institute for Evolutionary Anthropology in Liepzig, Germany. Dr. Paabo and his colleagues have pioneered methods for rescuing fragments of ancient DNA from fossils and stitching them together. In May, for example, they published a complete Neanderthal genome.

The stocky, barrel-chested Neanderthals left a fossil record stretching from about 240,000 to 30,000 years ago in Europe, the Near East and Russia. Analyzing the Neanderthal genome, Dr. Paabo and his colleagues concluded that humans and Neanderthals descended from common ancestors that lived 600,000 years ago.

But the scientists also found that 2.5 percent of the Neanderthal genome is more similar to the DNA of living Europeans and Asians than to African DNA. From this evidence they concluded that Neanderthals interbred with humans soon after they emerged from Africa roughly 50,000 years ago.

Dr. Paabo’s success with European Neanderthal fossils inspired him and his colleagues to look farther afield. They began to work with Anatoli Derevianko of the Russian Academy of Sciences, who explores Siberian caves in search of fossils of hominins (species more closely related to living humans than to chimpanzees, our closest living relatives).

Last year, Dr. Derevianko and his colleagues sent Dr. Paabo a nondescript fragment of a finger bone from a cave called Denisova. Dr. Derevianko thought that the
fossil, which is at least 50,000 years old, might have belonged to one of the earliest humans to live in Siberia.

Dr. Paabo and his colleagues isolated a small bundle of DNA from the bone’s mitochondria, the energy-generating structures within our cells. Dr. Paabo and his colleagues were surprised to discover that the Denisova DNA was markedly different from that of either humans or Neanderthals. “It was a great shock to us that it was distinct from those groups,” Dr. Paabo said in an interview.

Dr. Paabo and his colleagues immediately set about to collect all the DNA in the Denisova finger bone. Once they had sequenced its genome, they sent the data to researchers at Harvard Medical School and the Broad Institute in Cambridge, Mass., to compare with other species.

The Massachusetts scientists concluded that the finger bone belonged to a hominin branch that split from the ancestors of Neanderthals roughly 400,000 years ago. Dr. Paabo and his colleagues have named this lineage the Denisovans.

Next, the researchers looked for evidence of interbreeding. Nick Patterson, a Broad Institute geneticist, compared the Denisovan genome to the complete genomes of five people, from South Africa, Nigeria, China, France and Papua New Guinea. To his astonishment, a sizable chunk of the Denisova genome resembled parts of the New Guinea DNA.

“The correct reaction when you get a surprising result is, ‘What am I doing wrong?’ ” said Dr. Patterson. To see if the result was an error, he and his colleagues sequenced the genomes of seven more people, including another individual from New Guinea and one from the neighboring island of Bougainville. But even in the new analysis, the Denisovan DNA still turned up in the New Guinea and Bougainville genomes.

If the Denisovans did indeed have a range spreading from Siberia to South Asia, they must have been a remarkably successful kind of human. And yet, despite having the entire genome of a Denisovan, Dr. Paabo cannot say much yet about what they were like. “By sequencing my complete genome, there’s very little you could predict about what I look like or how I behave,” he said.

One solid clue to what the Denisovans looked like emerged in January. Dr. Paabo and his team had flown to Novosibirsk to share their initial results with Dr. Derevianko. Dr. Derevianko then presented them with a wisdom tooth from Denisova.

That match offers some hope that if researchers can find the same kind of tooth on a fossil skull, or perhaps even a complete skeleton, they’ll be able to see what these ghostly cousins and ancestors looked like in real life.

Dr. Bustamante also thinks that other cases of interbreeding are yet to be discovered. “There’s a lot of possibility out there,” he said. “But the only way to get at them is to sequence more of these ancient genomes.”

ENGLAND'S WESTERN-MOST ROMAN TOWN UNCOVERED

A chance discovery of coins has led to the bigger find of a Roman town, further west than it was previously thought Romans had settled in England.The town was found under fields a number of miles west of Exeter, Devon. Nearly 100 Roman coins were initially uncovered there by two amateur archaeological enthusiasts.

It had been thought that fierce resistance from local tribes to Roman culture stopped the Romans from moving so far into the county. Sam Moorhead, national finds adviser for Iron Age and Roman coins for the PAS at the British Museum, said it was one of the most significant Roman discoveries in the country for many decades.

After the coins were unearthed by the local men out using metal detectors, Danielle Wootton, the University of Exeter's liaison officer for the Portable Antiquities Scheme (PAS), which looks after antiquities found by the public, was tasked with investigating further. After carrying out a geophysical survey last summer, she said she was astonished to find evidence of a huge landscape, including at least 13 round-houses, quarry pits and track-ways covering at least 13 fields, the first of its kind for the county. "You just don't find Roman stuff on this scale in Devon," said Ms Wootton.

She carried out a trial excavation on the site, and has already uncovered evidence of extensive trade with Europe, a road possibly linking to the major settlement at Exeter, and some intriguing structures, as well as many more coins. "This was a really exciting discovery," said Ms Wootton. But she said most exciting of all was that her team had stumbled across two burial plots that seem to be located alongside the settlement's main road.

Not enough excavation has been done yet to date the main occupation phase of the site, but the coins that were found range from slightly before the start of the Roman invasion up until the last in 378 AD.

The Romans reached Exeter during the invasion of Britain in AD 50-55, and a legion commanded by Vespasian built a fortress on a spur overlooking the River Exe. This legion stayed for the next 20 years before moving to Wales. A few years after the army left, Exeter was converted into a bustling Romano-British civilian settlement known as Isca Dumnoniorum with all the usual Roman public buildings, baths and forum.
It was also the principal town for the Dumnonii tribe, a native British tribe who inhabited Devon and Cornwall. It was thought that their resistance to Roman rule and influence, and any form of 'Romanisation' stopped the Roman's settling far into the south west. For a very long time, it was thought that Exeter was the limit of Roman settlement in Britain in the south west, with the rest being inhabited by local unfriendly tribes.

OLDEST STRUCTURE DISCOVERED IN MEROE, SUDAN

Hidden beneath an ancient palace in what is now central Sudan, archaeologists have discovered the oldest building in the city of Meroë, a structure that also may have housed royalty.

The capital of a vast empire that flourished around 2,000 years ago, Meroë was centered on the Nile River. At its height, the city was controlled by a dynasty of kings who ruled about 900 miles (1,500 kilometers) of territory that stretched from southern Egypt to areas south of modern-day Khartoum.

People of Meroë built palaces and small pyramids, and developed a writing system that scholars still can't fully translate today. Although Meroë has been excavated off and on for more than 150 years, archaeologists are not yet clear on how it came to be. The city seems to have emerged out of nowhere. [Image Gallery: Ancient Rock Art of Sudan]

TRIAD OF FELINES FOUND SOUTH OF MEXICO CITY -- PROBABLY OLMEC

With a little help from archaeologists, three giant cats have slunk into view after spending thousands of years underground in central Mexico.

Carved in a vaguely Olmec style into a stone monolith, the seated jaguars-or
possibly mountain lions-may have been part of a decorative hillside wall that was crawling with big-cat carvings, experts suggest.

The circa 700 B.C. carving, dubbed the "Triad of Felines" by archaeologists, was found about 60 miles (a hundred kilometers) south of Mexico City at Chalcatzingo, an archaeological site known to have had ties to the Olmec civilization.

Measuring about 5 feet (1.5 meters) tall and 3.6 feet (1.1 meters) wide, the carving was originally set within a hillside and was designed to be clearly visible from a village below, experts say.

The discovery is only the latest of about 40 large stone carvings found at Chalcatzingo since 1935-many of them depicting cats, said David Grove, an anthropologist at the University of Florida who conducted research at Chalcatzingo for 30 years beginning in the 1970s.As an example of Olmec-style art, Grove added, "Triad of Felines" is "spectacular."

It took experts months to piece together and restore the 11 fragments that make up the cat-trio carving. At the same time, the scientists are assembling a theory in which the "Triad" is itself just one piece of a larger puzzle.

"Triad of Felines" may have been part of a collection of carvings that dotted the Chalcatzingo landscape, perhaps as spiritual "billboards" along pilgrimage route, archaeologists suggest.

"One of our hypotheses is that, in the time from 800 to 500 B.C., there was a frieze along the entire Cerro Chalcatzingo," or "Chalcatzingo hill," project member Mario Cordova Tello, an archaeologist with Mexico's National Institute of Anthropology and History (INAH), said in a statement.

The Olmec occupied south-central Mexico from about 1500 to 400 B.C. and are thought by many to have had a large influence on other Mesoamerican civilizations, such as the Maya-and the people of Chalcatzingo. (Get the full story of the rise and fall of the Maya in National Geographic magazine.)

"Triad of Cats," though, is unique in depicting sitting animals, Grove said. The cats in the new carving also appear to have supernatural traits, such as flaming eyebrows and stylized mouths reminiscent of traditional Olmec masks.

"Something having to do with mythology is being expressed in these carvings
... but I am still trying to figure out exactly what it is," Grove said.
"Not a lot is known about Olmec religion."

http://news.nationalgeographic.com/news/2011/08/110801-three-cat-carving-felines-triad-olmec-mexico-science/