• Robot finds mysterious spheres in ancient temple

    DMC, INAH/M. Marat

    The archaeologists used a 3-foot-long, remote-controlled robot which was able to explore the last part of the tunnel.

    By Rossella Lorenzi, Discovery.com

    Hundreds of mysterious spheres lie beneath the Temple of the Feathered Serpent, an ancient six-level step pyramid just 30 miles from Mexico City.

    The enigmatic spheres were found during an archaeological dig using a camera-equipped robot at one of the most important buildings in the pre-Hispanic city of Teotihuacan.

    "They look like yellow spheres, but we do not know their meaning. It's an unprecedented discovery," said Jorge Zavala, an archaeologist at Mexico's National Anthropology and History Institute.

    PHOTOS: The Temple of the Feathered Serpent

    The Mesoamerican ruins of Teotihuacan, a World Heritage Site, represent one of the largest urban centers of the ancient world. Thought to have been established around 100 B.C., the pyramid-filled city had more than 100,000 inhabitants at its peak, but was abandoned for mysterious reasons around 700 A.D. — long before the Aztecs arrived in the 1300s.

    The excavation at the temple focused on a 330-foot-long tunnel which runs under the structure. The conduit was discovered in 2003 when heavy rain uncovered a hole a few feet from the pyramid.

    Exploring the tunnel, which was deliberately filled with debris and ruins by the Teotihuacan people, required several years of preliminary work and planning.

    "Finally, a few months ago we found two side chambers at 72 and 74 meters (236 and 242 feet) from the entrance. We called them North Chamber and South Chamber,” archaeologist Sergio Gómez Chávez, director of the Tlalocan Project, told Discovery News.

    The archaeologists explored the tunnel with a remote-controlled robot called Tlaloc II-TC, which has an infrared camera and a laser scanner that generates 3-D visualization of the spaces beneath the temple.

    "The robot was able to enter in the part of the tunnel which has not yet been excavated yet and found three chambers between 100 and 110 meters (328 and 360 feet) from the entrance," Gómez Chávez said.

    The mysterious spheres lay in both the north and south chambers. Ranging from 1.5 to 5 inches, the objects have a core of clay and are covered with a yellow material called jarosite.

    DMC, INAH/M. Marat

    The Temple of the Feathered Serpent, also known as the Temple of Quetzalcoatl, is a six-level pyramid decorated with snake-like creatures.

    "This material is formed by the oxidation of pyrite, which is a metallic ore," Gómez Chávez said. "It means that in pre-hispanic times they appeared as if they were metallic spheres. There are hundreds of these in the south chamber."

    According to George Cowgill, professor emeritus at Arizona State University and the author of several publications on Teotihuacan, the spheres are a fascinating find.

    "Pyrite was certainly used by the Teotihuacanos and other ancient Mesoamerican societies," Cowgill told Discovery News. "Originally the spheres would have shown brilliantly. They are indeed unique, but I have no idea what they mean."

    NEWS: Maya Observatory Hints at Origin of Civilization

    Even the walls and ceiling of both chambers were covered with a mineral powder composed of magnetite, pyrite and hematite which provided a special brightness to the place.

    "We believe that high-ranking people, priests or even rulers, went down to the tunnel to perform rituals," Gómez Chávez said.

    Indeed the archaeologists found many offerings, including pottery and wooden masks covered with inlaid rock crystal, jade and quartz — all dating from around 100 A.D.

    Gómez Chávez and his team now look forward to the next phase of the project — exploring the last part of the tunnel and three chambers which archaeologists have seen through the robot cameras.

    "The tunnel is in pristine condition, untouched for almost two millennia," said Ng “TC” Tze Chuen, an independent researcher who worked on the design of the Tláloc II-TC robot. "Can you can imagine what can be found inside?"

    Ng, who helped create the Djedi robot that explored Egypt's Great Pyramid in 2010, believes the Mexican tunnel might lead to one of the most significant archaeological finds in Teotihuacan.

    "The results are very encouraging indeed," he said.

    According to Gómez Chávez, the tunnel was sealed twice by the Teotihuacan people. Thick walls, erected to block access, were demolished about 1,800 years ago in order to deposit something very important in the central chamber at the end of the tunnel.

    "Maybe in this place," Gómez Chávez said, "we will find the remains of those who ruled Teotihuacan.”

  • Mini-robot finds surprise in Mexico's ancient Temple of Quetzalcoatl

    Researchers lowered a robot with a camera into a tunnel under Mexico's Teotihuacan and have discovered three ancient chambers under the pyramid. NBCNews.com's Dara Brown reports.

    By Alan Boyle, Science Editor, NBC News


    A diminutive robot helped researchers make a substantial discovery during preliminary tests conducted in a tunnel running under the Temple of Quetzalcoatl at the archaeological site of Teotihuacan, the team said Monday.

    The team expected to find only one chamber in the last section of the tunnel — but instead, they found three, team leader Sergio Gomez said in a report published by the Mexican newspaper El Universal. The chambers are thought to have been used by Teotihuacan's rulers roughly 2,000 years ago for royal ceremonies or burials, but they're so choked with mud and rubble that they haven't been explored in modern times.

    Henry Romero / Reuters

    A worker from the National Institute of Anthropology and History walks next to a robot used to explore ruins at the entrance of a tunnel in the archaeological area of the Quetzalcoatl Temple, near the Pyramid of the Sun at the Teotihuacan archaeological site.

    That's where the 3-foot-long (1-meter-long) robot known as Tlaloc II-TC comes in: The robot is designed to drive through the tight spaces leading to the back of the tunnel beneath the Temple of Quetzalcoatl, also known as the Temple of the Feathered Serpent. It's equipped with a video camera as well as mechanical arms to clear obstacles.

    The current project follows up on an earlier round of robotic exploration by Tlaloc II-TC's predecessor, Tlaloc I, in 2010. (Tlaloc was the Aztec god of rain.)

    In 2010, Gomez said there was a "high possibility that in this place, in the central chamber, we can find the remains of those who ruled Teotihuacan." The city was once an influential center of Mesoamerican culture, but little is known about its rulers. Archaeologists have not yet found any depictions of a ruler, or any tomb of a monarch.

    El Universal quoted Gomez as saying that the configuration of the space beneath the temple appears to be similar to that of the tunnel running beneath Teotihuacan's Pyramid of the Sun, where four chambers were explored in the 1970s. About 76 meters (250 feet) of the Quetzalcoatl tunnel have already been uncovered, leaving 30 meters (100 feet) or so in the last section. After a round of robotic reconnaissance, archaeologists intend to clear out that section for exploration.

    Henry Romero / Reuters

    Visitors look on at the archaeological area of the Temple of Quetzalcoatl, near the Pyramid of the Sun at the Teotihuacan archaeological site, about 60 kilometesr (37 miles) north of Mexico City.

    Henry Romero / Reuters

    Archaeologist Sergio Gomez from the National Institute of Anthropology and History speaks to the media during a news conference in the archaeological area of the Temple of Quetzalcoatl on Monday. A remote-controlled robot has relayed back video images of what appears to be three ancient chambers beneath the temple.

    From Aug. 4, 2010: A tunnel is discovered beneath temple ruins in Teotihuacan, Mexico, that experts believe lead to tombs and an underground city dating back to 100 B.C. TODAY.com's Dara Brown reports.

    More about Mexican archaeology:

    Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

  • 300 B.C. Mexican temple hints at human sacrifice

    Courtesy of Charles Spencer and Elsa Redmond

    An oblique aerial view of El Palenque's temple precinct, facing southwest toward a public plaza. Three temples linked by enclosure walls face the public plaza. Behind them are two priests' residences, located in the left foreground of of this view. Also visible is the entrance to the masonry-lined tunnel behind central temple.

    By Stephanie Pappas
    LiveScience

    A newly discovered temple complex in the Valley of Oaxaca, Mexico, reveals hints of a specialized hierarchy of priests — who may have committed human sacrifice.

    The evidence of such sacrifice is far from conclusive, but researchers did uncover a human tooth and part of what may be a human limb bone from a temple room scattered with animal sacrifice remains and obsidian blades. The temple dates back to 300 B.C. or so, when it was in use by the Zapotec civilization of what is now Oaxaca. 

    Archaeologists have been excavating a site in the valley called El Palenque for years. The site is the center of what was once an independent mini-state. Between 1997 and 2000, the researchers found and studied the remains of a 9,150-square-foot (850 square meters) palace complex complete with a plaza on the north side of the site. Radiocarbon dating and copious ash reveal that the palace burned down sometime around 60 B.C. or so. [See Images of the Ancient Temple Site]

    Now, the archaeologists have unearthed an even larger complex of buildings on the east side of El Palenque. The walled-off area appears to be a temple complex, consisting of a main temple flanked by two smaller temple buildings. There are also at least two residences, probably for priests, as well as a number of fireboxes where offerings may have been made. 

    Sacrificial site
    The whole complex measures almost 54,000 square feet (5,000 square meters), and the main temple alone has a 4,090-square-foot (380 square meters) footprint.

    The main room of the main temple was scattered with artifacts, including shell, mica and alabaster ornaments, researchers reported Monday in the journal Proceedings of the National Academy of Sciences. The archaeologists also found ceramic vessels and whistles, as well as incense braziers. Obsidian blades and lances suggest that the priests engaged in ritual bloodletting and animal sacrifice, as did the remains of turkeys, doves and other animals in the temple hearth.

    It was in this room that the human tooth and possible human limb bone were discovered, though researchers can't say for certain whether those bones were a sign of human sacrifice at the temple.

    The main temple also contained a kitchen much larger than those found in households in El Palenque, suggesting that cooks whipped up meals for large groups in this spot. Behind the temple were several cell-like rooms, perhaps places for priests-in-training or low-ranking priests to sleep.

    Hierarchy of priests
    Also behind the temple, archaeologists turned up two buildings that appear to be priestly residences. These buildings were earthen-floored and thick-walled, with firepits inside that are characteristic of El Palenque homes. Unlike other homes in the city, though, these probably priestly digs revealed few utilitarian jars, griddles and grinding stones — but there were many serving plates. The artifacts suggest that priests didn't cook their own food, but were served meals in their quarters by temple servants or staff.

    Like the palace, the temple complex has been burned and appears to have fallen out of use by the end of the first century B.C or the first century A.D., making it the oldest temple discovered yet in the Valley of Oaxaca. Among the remaining mysteries of the site is a hastily buried body found in one of the temple's fireboxes.

    According to the researchers, the skeleton was found "in a cramped position that resulted in the skull resting at the firebox's southeast corner and a knee poking about its northwest corner." 

    Follow Stephanie Pappas on Twitter and Google+. Follow us @livescience, Facebook and Google+. Original article on LiveScience.com.

    Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

  • Scientists see ominous decline in Mexico's Monarch butterflies

    Marco Ugarte / AP file

    A monarch butterfly sits on a tree trunk at the Sierra Chincua Sanctuary in Mexico.

    By Mark Stevenson, The Associated Press

    MEXICO CITY —The amount of Monarch butterflies wintering in Mexico dropped 59 percent this year, falling to the lowest level since comparable record-keeping began 20 years ago, scientists reported Wednesday.

    It was the third straight year of declines for the orange-and-black butterflies that migrate from the United States and Canada to spend the winter in mountaintop fir forests in central Mexico. Six of the last seven years have shown drops, and there are now only one-fifteenth as many butterflies as there were in 1997.

    The decline now marks a statistical long-term trend and can no longer be seen as a combination of yearly or seasonal events, the experts said.

    But they differed on the possible causes.

    Who's at fault?
    Illegal logging in the reserve established in the Monarch wintering grounds was long thought to contribute, but such logging has been vastly reduced by increased protection, enforcement and alternative development programs in Mexico.

    The World Wildlife Fund, one of the groups that sponsored the butterfly census, blamed climate conditions and agricultural practices, especially the use of pesticides that kill off the Monarchs' main food source, milkweed. The butterflies breed and live in the north in the summer, and migrate to Mexico in the winter.

    "The decrease of Monarch butterflies ... probably is due to the negative effects of reduction in milkweed and extreme variation in the United States and Canada," the fund and its partner organizations said in a statement.

    Omar Vidal, the World Wildlife Fund director in Mexico, said: "The conservation of the Monarch butterfly is a shared responsibility between Mexico, the United States and Canada. By protecting the reserves and having practically eliminated large-scale illegal logging, Mexico has done its part.

    "It is now necessary for the United States and Canada to do their part and protect the butterflies' habitat in their territories," Vidal said.

    Debate over logging
    Logging was once considered the main threat to the reserve, located west of Mexico City. At its peak in 2005, logging devastated as many as 1,140 acres (461 hectares) annually in the reserve, which covers 193,000 acres (56,259-hectares). But a 2012 aerial survey showed almost no detectable logging, the first time that logging had not been found in detectable amounts since the mountaintop forests were declared a nature reserve in 2000.

    Lincoln Brower, a leading entomologist at Sweet Briar College in Virginia, said in a statement that "the report of the dwindling Monarch butterfly winter residence in Mexico is ominous."

    "This is not just the lowest population recorded in the 20 years for which we have records," Brower said. "It is the continuation of a statistically significant decrease in the Monarch population that began at least a decade ago."

    However, Brower differed on whether small-scale logging, the diversion of water resources and other disruptive activity in the reserves in Mexico are playing a role in the decline.

    "To blame the low numbers of monarchs solely on what is happening north of Mexico is misleading," Brower said. "Herbiciding of soybean and corn fields that kills milkweed is a serious problem, but the historical decline over the past 19 years has multiple causes.

    "All three countries need to face up to the fact that it is our collective activities that are killing the migratory phenomenon of the Monarch butterfly," he said.

    Hidden problems
    Environmentalist and writer Homero Aridjis praised Mexico for progress in reducing illegal logging, but added that "low intensity logging, not detected in satellite image analysis, continues unabated in and near critical overwintering habitats."

    The head of Mexico's nature reserves, Luis Fueyo, said there are still some problem to be solved at the wintering grounds in Mexico, including some small-scale logging and water availability. The Monarchs don't drink any water throughout their long migration until the reach Mexico, and the mountain streams in the area have been affected by drought and human use.

    The migration is an inherited trait. No butterfly lives to make the round trip. The millions of Monarchs cluster so densely on tree boughs in the reserve that researchers don't count their individual numbers but rather measure the amount of forest they cover.

    This winter, the butterflies covered just 2.93 acres (1.19 hectares), down from 7.14 acres (2.89 hectares) last year.

    Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. 

  • Mass human sacrifice? Ancient skulls discovered in Mexican field

    Christopher Morehart

    An artifact depicting Tlaloc, a pre-Columbian water god, was found at the human sacrifice site in Mexico.

    By Tia Ghose, LiveScience

    Archaeologists have unearthed a trove of skulls in Mexico that may have once belonged to human sacrifice victims. The skulls, which date between the year 600 and 850, may also shatter existing notions about the ancient culture of the area.

    The find, described in the January issue of the journal Latin American Antiquity, was located in an otherwise empty field that once held a vast lake, but was miles from the nearest major city of the day, said study co-author Christopher Morehart, an archaeologist at Georgia State University.

    "It's absolutely remarkable to think about this little nothing on the landscape having potentially evidence of the largest mass human sacrifice in ancient Mesoamerica," Morehart said.

    Middle of nowhere
    Morehart and his colleagues were using satellite imagery to map ancient canals, irrigation channels and lakes that used to surround the kingdom of Teotihuacan (home to the Pyramid of the Sun), about 30 miles (50 kilometers) from Mexico City. The vast ancient kingdom flourished from around the year 200 to 650, though who built it remains a mystery. [In Photos: Amazing Ruins of the Ancient World]

    In a now-drained lake called Lake Xaltocan, around which was essentially rural farmland at the time, Morehart stumbled upon a site with evidence of looting.

    When the team investigated, they discovered lines of human skulls with just one or two vertebra attached. To date, more than 150 skulls have been discovered there. The site also contained a shrine with incense burners, water-deity figurines and agricultural pottery, such as corncob depictions, suggesting a ritual purpose tied to local farming. [See images from the grisly excavation]

    Carbon dating suggested that the skulls were at least 1,100 years old, and the few dozen analyzed so far are mostly from men, Morehart told LiveScience. The researchers did not release photos of the skulls because the sacrifice victims may have historic ties to modern-day indigenous cultures.

    The findings shake up existing notions of the culture of the day, because the site is not associated with Teotihuacan or other regional powers, said Destiny Crider, an archaeologist at Luther College in Iowa, who was not involved in the study.

    Big event in a little place
    Human sacrifice was practiced throughout the region, both at Teotihuacan and in the later Aztec Empire, but most of those rituals happened at great pyramids within cities and were tied to state powers.

    By contrast, "this one is a big event in a little place," Crider said. 

    The shrines and the fact that sacrifice victims were mostly male suggest that they were carefully chosen, not simply the result of indiscriminate slaughter of a whole village, Crider told LiveScience.

    Many researchers believe that massive drought caused the fall of Teotihuacan and ushered in a period of warfare and political infighting as smaller regional powers sprang up, Morehart said. Crider said those tumultuous times could have spurred innovative — and bloody — practices.

    "Maybe they needed to intensify their activities because everything was changing," she said. "When things are uncertain, you try new strategies."

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    © 2012 LiveScience.com. All rights reserved.