LIDAR Shows Purépecha Empire City Angamuco had as Many Buildings as Manhattan

When researchers surveyed the ruins of a Purépecha Empire city in Mexico the old-fashioned way a decade ago, it took them two seasons to explore two square kilometres. Good thing they decided to use LiDAR, because the city called Angamuco turned out bigger than they previously thought. LiDAR gave the researchers the power to see underneath the lava that covers Angamuco. Thanks to the laser technology, they now know that the city occupied 26 square kilometers of land instead of 13 square kilometers. Colorado State University archaeologist Chris Fisher is presenting that finding and all the latest info on his team's study at the ongoing American Association for the Advancement of Science conference in Austin.

"That is a huge area with a lot of people and a lot of architectural foundations that are represented," Fisher told The Guardian. According to their estimates, the city had around 1,500 structures per square kilometer of land. "If you do the maths," he added, "all of a sudden you are talking about 40,000 building foundations up there, which is [about] the same number of building foundations that are on the island of Manhattan." Further, LiDAR also led to the discovery that the city had an unusual layout, with big structures like pyramids and open plazas situated around the edges rather than in the center.

The Purépecha people existed at the same time as the Aztecs. While they are nowhere near as popular as their rivals, they were still a major civilization and had an imperial capital called Tzintzuntzan in western Mexico. Based on the team's LiDAR scans, though, Angamuco is even bigger Tzintzuntzan. It likely wasn't as densely populated, but Fisher said it's now the biggest city in western Mexico during that period that we know of.

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A new Cenrosaurine Ceratopsian From Campanian Cretaceous Mexico

A Centrosaurine (Dinosauria: Ceratopsia) from the Aguja Formation (Late Campanian) of Northern Coahuila, Mexico

Authors:

Rivera-Silva et al

Abstract:

While centrosaurines and ceratopsids in general are abundant in the Late Campanian of northern Laramidia, they are much less commonly found in southern Laramidia. This has supported hypotheses of dinosaur provinciality and endemism in the Late Cretaceous with the delineation of at least two separate faunal zones, north and south Laramidia. There have been 12 genera of centrosaurines recognized from northern Laramidia while two genera, Diabloceratops and Nasutoceratops, have been named from southern Laramidia. We present an osteological description and taphonomic outline for a new centrosaurine ceratopsid from the Aguja Formation of northern Coahuila, Mexico that is not currently diagnosable to the generic level, but likely represents a new taxon. Further, we have included three-dimensional surface scans of all material attributed to this animal. Considering the large number of centrosaurines from northern Laramidia, it is likely that cladistic analyses are biased towards this faunal zone. New findings of southern centrosaurines are needed to correct this bias. This discovery expands the range of centrosaurines south to Coahuila, Mexico and adds new information to better characterize the morphology and taxonomy of centrosaurines from southern Laramidia and their evolution in comparison to their northern counterparts.

Late Pleistocene Quaternary Horses in Mexico had a Very Adaptable Diet, More Than Modern Horses

Dietary adaptability of Late Pleistocene Equus from West Central Mexico

Authors:

Marín-Leyva et al

Abstract:

Most of the Pleistocene species of Equus from Mexico have been considered to be grazers and highly specialized on the basis of their craniodental features, and therefore analogous to their modern relatives from an ecological point of view. Here we rely on dental wear analyses of three different species of Rancholabrean Equus that exhibit differences in limb proportions and body mass and occurred in two different habitats in order to test whether species exhibited more heterogeneous dietary capabilities compared to modern horses. Overall, and although our analyses show grazer lifestyles, there is a significant degree of dietary variability among taxa according to the site, apparently as a response to differences in climate and environmental conditions, with intermediate feeding preferences on the basis of the last items consumed during the last days prior to death in some cases. Accordingly, fossil Equus might have been more sensitive to different environments and diverse in terms of dietary preferences, thus incorporating a higher proportion of browse vegetation if necessary, than their modern relatives. These results highlight the dietary plasticity of certain fossil species, and evidence the caution that should be paid when reconstructing the ecology of fossil species using their modern relatives as analogs.

Precolumbian Mexican City of Teotihuacan may Have Kept Carnivores Captive

From Roman gladiatorial combat to Egyptian animal mummies, capturing and manipulating wild carnivores has long been a way for humans to demonstrate state or individual power. Historians and scientists alike have attempted to determine when humans first began to use carnivores to establish their place on the social ladder, one of the earliest examples being Moctezuma's 14th century zoo at the Aztec capital of Tenochtitlan. A recent PLOS ONE study, however, reveals evidence from the ruins of the Mexican city of Teotihuacan that may push back the date of captivating carnivores by 1000 years.

Between the first and sixth centuries A.D., Teotihuacan was one of the largest and most powerful urban cities in Mesoamerica and was home to at least 25,000 people. When the city reached the height of its influence around 1300-1500 A.D., its architects designed massive temples to show off the city's power. The ruins of three of these incredible temples still stand: the Temple of Quetzalcoatl, the Pyramid of the Sun, and the Pyramid of the Moon.

During excavations from 1998-2004, the authors of this study found rare artifacts and human and animal remains in chambers in the Pyramids of the Sun and the Moon. The authors focused the present study on the 194 animal remains, as they are evidence of one of the largest known animal sacrifices in Mesoamerica.

Of particular interest to the authors were the remains of carnivores like wolves, eagles, jaguars, and pumas, as we have little information about how humans related to carnivores prior to Montezuma's zoo in Tenochtitlan. Using isotope analysis and visual inspection of the bones, the authors were able to draw possible conclusions about the relationship between the carnivores in the chamber and the ancient inhabitants of Teotihuacan.

Visual examination of the animal skeletons suggested that some of the carnivores were kept in captivity. The authors found bone breaks and stress characteristic of captive animals – for example, three eagle skeletons showed stress on the lower part of the legs, where they may have been tied to a perch. Other deformities in the animal skeletons, such as bone fusion or abnormal growth, were evidence of infection, which typically only occur when animals are kept in close together in captivity.

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The Dinosaur Graveyards at Las Águilas, Mexico Were a Campanian Cretaceous River Delta Environment

Age and depositional environment of the “dinosaur graveyard” at Las Águilas, southern Coahuila, NE Mexico

Authors:

Vogt et al

Abstract:

Here we provide a detailed description of the upper Campanian sediment succession at Las Águilas, southern Coahuila, northeastern Mexico, including the first absolute age dating for this interval, paleoenvironmental reconstructions and taphonomic observations on the abundant dinosaur remains at the locality. Stratigraphic investigations of the dinosaur-bearing succession at the Las Águilas vertebrate fossil area near Porvenir de Jalpa reveal a diverse vertebrate assemblage, including dinosaurs, crocodilians and turtles. New findings in adjacent sites include eusuchian crocodylomorphs, four different kinds of turtles, dromaeosaurids, lambeosaurines, pterosaurs and elasmosaurid plesiosaurs. Strontium isotope measurements on fossil oyster shells provide an absolute age of 73 ± 1 Ma for the lower part of the Las Águilas section. The locality is thus of late Campanian age. The vertebrate, invertebrate and plant materials as well as the sediment structures observed in a 50 m thick predominantly siliciclastic succession of the Cerro del Pueblo Formation suggest deposition in an extensive delta plain environment. The facies succession indicates a short-termed cyclicity of limnic, brackish and shallow marine environments during the late Campanian–early Maastrichtian Cerro del Pueblo Formation with numerous layers containing dinosaur fossil remains.

Tototlmimus packardensis: an new Ornithomimid Dinosaur From Upper Cretaceous Mexico

A new ornithomimid dinosaur from the Upper Cretaceous Packard Shale formation (Cabullona Group) Sonora, México

Authors:

Serrano-Brañas et al

Abstract:

New ornithomimid material discovered from the Upper Cretaceous Packard Shale Formation, (Cabullona Group) of Sonora, Mexico is described. The material includes a partial skeleton, which is assigned to a new genus and species, Tototlmimus packardensis. This new taxon differs from other ornithomimids in having five unique characteristics that separate it from other Northamerican ornithomimids: (1) a distinctively articulation between metatarsals, where the distal ends of metatarsals II and IV contact directly with the distal facet of metatarsal III; (2) a metatarsal III with a weakly ginglymoid distal articular face; (3) the medial and lateral sides of metatarsal III are shaped into the form of metatarsals II and IV, so all distal ends fit together when they articulate; (4) an asymmetrical and narrow pedal ungual with shallow grooves in both medial and lateral sides; and finally, (5) the presence of a deep sulcus on the ventromedial edge, close to the articular end. Phylogenetic analysis suggests that Tototlmimus packardensis corresponds to a derived ornithomimid included in the Northamerican clade, forming a monophyly with Ornithomimus. Tototlmimus packardensis is the first definitive ornithomimid described for Mexico, and represents one of the southernmost occurrences in the Western Interior Basin of North America.

Crazy Thought: The Border Patrol Should get the 141 Predator Drones to be Retired by 2018

The United States Air Force is going to be retiring the MQ-1 Predator drone from service by the end of 2018.  This will bring an end to a long service for the drone for the past twenty years.  The USAF plans to simply place them drones out in the boneyard and leave them there in a nonflyable storage, stripped of parts and rusting away.

Is this really the best idea?  The drones have life time left in them, but they are obsolete as far as frontline service goes.

Some asked if the US Army should take the drones: the army doesn't want them.  The Navy doesn't want them either: they are working on the far higher end UCLASS.

There is one more place these could end up: the Department of Homeland Security.  I'm generally not much of a fan of the department, to be honest, but there are parts of it which are useful.  The Coast Guard, for example.  I do have a love-hate, emphasis on the latter, relationship with the Border Patrol.  However, with all the stupid talk of building a wall between us and Mexico, and the failed attempt at the "smart border," I wondered if you could use those 141 drones to patrol the Mexican border.

The first problem is the fact the video feed of the Predator is like looking through a soda straw when you want to be looking at a wide area if you are going to be enforcing the border.  because of this, the Predators and Reapers have not been that effective at patrolling the border.  

There is a solution, but it will cost more money.  That would be the ARGUS-IS pod designed for the Predator and Reaper drones.  Without sacrificing the ability to zoom in to look at specific targets, the Predators would have an area of 100 square km (39 square miles, 6 1/4 miles on a side) it would be watching.

Secondly, with 141 drones, you (at most) can have one third of them in the air at a time.  Minor maintenance and refueling will take out some and others will need major maintenance.  This leaves us with 47 Predators in the air at a time max.

With the border 1989 miles long, roughly, each drone would be responsible for 43 miles.  At any given moment, only 6.25 miles are being observed.  However, the Predator cruises at roughly 90 mph.  If you assume a circuit of 90 miles around (43 miles each way with a 1 mile overlap between the Predator tracks and a 1 mile turn, so to speak), then the Predator will sweep every half hour and be observing any particular spot for roughly 4 minutes.

25 or 26 minutes is pretty long if there is a car on road.  However, for looking for people on foot, piece of cake.  Likewise, if you consider, the evidence of places being used by cars or whatnot will also be observed.  Even vehicles on rough terrain could be caught, actually.

This would mean the 9 Reapers DHS already has could be placed on the border for specific areas which might be of interest without interrupting the normal patrols.  And the Reapers can be tasked for the Coast Guard, etc. when not on special tasking on the USA/USM border.

It seems doable.  On the technical and operational side.  However, this is really a money problem.  The DHS would need to set up at airports along the border.  Probably every hundred or two hundred miles.  That's 10 to 20 airports.  It also means procuring the 141 ARGUS-IS pods.  it also means the data produced would need to be archived and then accessible for analysis.  Each ARGUS produces over a petabyte per day.  This means 47 PB per day 365 days per year: 17.6 exabytes for a year's worth of data which would need to be on disk.  A five year period would need a massive tape library.  It would also need a massive computer center for the analysis of that data.  Plus the sudden surge in drone mechanics and pilots.  And security.  I am sure there are plenty of countries who'd be tempted to make off with an ARGUS pod and the border patrol is not the US Army....and the US Army has munitions swiped and stolen.  I'd guess you'd have a billion dollar program to build up and then half that to run it.

You'd have your border fence though and it'd probably cause less environmental problems and cost less.

1700 year Old PreColumbian Pyramid Comparable to El Mirador in MExico

Researchers discover immense pyramid in Mexico, larger than Teotihuacan’s Pyramid of the Sun. Researchers in Mexico have discovered a Pyramid that, according to initial measurements, is larger than the Great Pyramid of the Sun in Teotihuacan. Initial excavations were done in 2010.

The Pyramid, 75 meters in height, was explored by specialists from the National Institute of Anthropology and History (INAH) on the acropolis of Tonina, Chiapas, estimated to be around 1700 years old.

Emiliano Gallaga, director of the archaeological zone, explained that work has been done in the last two years, and by means of a “three-dimensional, researchers verified that in the northeastern part of the site, stands one of the largest construction in Mesoamerica, comparable in size only to great Mayan cities like Tikal and El Mirador in Guatemala.

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Zaha Hadid's Plans for a 981 Unit Apartment Complex in Monterrey, Mexico

Zaha Hadid Architects (ZHA) has unveiled a luxury apartment building planned for Huajuco Canyon, Monterrey, Mexico. The original brief for the Esfera City Center project demanded 12 residential towers. But presumably an architect with Hadid's clout can choose to do what she thinks best, and she designed a nine-story complex comprising a total of 981 apartments spread over 136,000 sq m (1,463,891 sq ft) instead.

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Immigration to America From China, India Over Take Mexico

During my adult life, the main source of immigration to the U.S. has always been Mexico. Thus, I was surprised to see that for 2013, immigration from China and India exceeded that from Mexico. The data comes from analysts at the US Census Bureau, Eric B. Jensen, Anthony Knapp, C. Peter Borsella, and Kathleen Nestor, and presented at a recent conference under the title, "The Place-of-Birth Composition of Immigrants to the United States: 2000 to 2013."

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Teotihuacan's Collapse due to Internal Strife?

The demise of Mexico's enigmatic pre-Hispanic city of Teotihuacan stemmed from a conflict among the civilization's elite classes, with buildings set ablaze in the clash, according to a study.

The famed pyramids of the Sun and Moon are among the majestic structures that remain at the tourist site near Mexico City, centuries after Teotihuacan's population vanished.

What caused the civilization to abandon the sprawling city in the 7th century has been the subject of many studies, with political, economic and social problems believed to be behind the exodus.

Linda Manzanilla, an anthropologist at the National Autonomous University of Mexico, now says the collapse was the result of a confrontation between the city's rulers and an "intermediate elite" comprised of entrepreneurs.

The governing class ruled like a "corporate organization" that distributed power among each other, without dynasties or kings -- unlike the Mayan civilization elsewhere in Mexico.

The city, which at some point housed 125,000 people, was divided into neighborhoods where "mid-rank nobles who acted like entrepreneurs" competed to show off the best luxury goods, she told AFP.

"They competed among themselves to bring raw materials, and luxury goods from distant regions, and demonstrate the most attractive and rarest items," said Manzanilla.

This rivalry gave rise to tensions within the city, said Manzanilla, whose conclusions were published in the Proceedings of the National Academy of Sciences in the United States.

The clash, she said, finally took place when "the governing elite realized that the neighborhood elites around the center of the city were getting richer and functioning in an autonomous way."

"They tried to take control, but it was too late," the researcher said.

Around 550 A.D., the revolt of the neighborhood entrepreneur led to the destruction of the Street of the Dead, which is now a major tourist site, and the main buildings of the ruling elite.

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Climate Change's Impact on PreColumbian Cantona, Mexico

Cultural implications of late Holocene climate change in the Cuenca Oriental, Mexico

Authors:

Bhattacharya et al

Abstract:

There is currently no consensus on the importance of climate change in Mesoamerican prehistory. Some invoke drought as a causal factor in major cultural transitions, including the abandonment of many sites at 900 CE, while others conclude that cultural factors were more important. This lack of agreement reflects the fact that the history of climate change in many regions of Mesoamerica is poorly understood. We present paleolimnological evidence suggesting that climate change was important in the abandonment of Cantona between 900 CE and 1050 CE. At its peak, Cantona was one of the largest cities in pre-Columbian Mesoamerica, with a population of 90,000 inhabitants. The site is located in the Cuenca Oriental, a semiarid basin east of Mexico City. We developed a subcentennial reconstruction of regional climate from a nearby maar lake, Aljojuca. The modern climatology of the region suggests that sediments record changes in summer monsoonal precipitation. Elemental geochemistry (X-ray fluorescence) and δ18O from authigenic calcite indicate a centennial-scale arid interval between 500 CE and 1150 CE, overlaid on a long-term drying trend. Comparison of this record to Cantona’s chronology suggests that both the city’s peak population and its abandonment occurred during this arid period. The human response to climate change most likely resulted from the interplay of environmental and political factors. During earlier periods of Cantona’s history, increasing aridity and political unrest may have actually increased the city’s importance. However, by 1050 CE, this extended arid period, possibly combined with regional political change, contributed to the city’s abandonment.

Cretaceous–Paleogene Boundary Section Found in Campeche Escarpment

Cretaceous–Paleogene boundary exposed: Campeche Escarpment, Gulf of Mexico

Authors:

Paull et al

Abstract:

We present the first multibeam bathymetric maps of the Campeche Escarpment, a Mesozoic carbonate platform in the Gulf of Mexico, which represents the closest Cretaceous–Paleogene (K-Pg) boundary outcrops to the Chicxulub impact structure. The impact of an extraterrestrial-body ~ 65 million years ago on top of this platform is implicated in the end of the Cretaceous mass extinction and caused the largest debris flow yet described on Earth, which is found across the floor of the Gulf of Mexico and the Caribbean Sea. The location of the K-Pg boundary has been identified in the escarpment face by combining the new multibeam data with existing information from boreholes. The boundary is represented by an abrupt change in gradient on the escarpment face. The morphology of the escarpment combined with seismic data reveals that a significant amount of material is missing from the face, which failed catastrophically due to seismic shaking produced by the impact. The escarpment face is inferred to be an important source for the extensive debris flows triggered by the impact, whose deposits are found throughout much of the Gulf of Mexico.

Paleoclimate Evidence From Campanian Cretaceous Mexico

Wood Anatomy Reveals High Theoretical Hydraulic Conductivity and Low Resistance to Vessel Implosion in a Cretaceous Fossil Forest from Northern Mexico

Authors:

Martínez-Cabrera et al

Abstract:

The Olmos Formation (upper Campanian), with over 60 angiosperm leaf morphotypes, is Mexico's richest Cretaceous flora. Paleoclimate leaf physiognomy estimates indicate that the Olmos paleoforest grew under wet and warm conditions, similar to those present in modern tropical rainforests. Leaf surface area, tree size and climate reconstructions suggest that this was a highly productive system. Efficient carbon fixation requires hydraulic efficiency to meet the evaporative demands of the photosynthetic surface, but it comes at the expense of increased risk of drought-induced cavitation. Here we tested the hypothesis that the Olmos paleoforest had high hydraulic efficiency, but was prone to cavitation. We characterized the hydraulic properties of the Olmos paleoforest using theoretical conductivity (Ks), vessel composition (S) and vessel fraction (F), and measured drought resistance using vessel implosion resistance and the water potential at which there is 50% loss of hydraulic conductivity (P50). We found that the Olmos paleoforest had high hydraulic efficiency, similar to that present in several extant tropical-wet or semi-deciduous forest communities. Remarkably, the fossil flora had the lowest , which, together with low median P50 (−1.9 MPa), indicate that the Olmos paleoforest species were extremely vulnerable to drought-induced cavitation. Our findings support paleoclimate inferences from leaf physiognomy and paleoclimatic models suggesting it represented a highly productive wet tropical rainforest. Our results also indicate that the Olmos Formation plants had a large range of water conduction strategies, but more restricted variation in cavitation resistance. These straightforward methods for measuring hydraulic properties, used herein for the first time, can provide useful information on the ecological strategies of paleofloras and on temporal shifts in ecological function of fossil forests chronosequences.

Should North America Integrate More?

NEVER have Latin American leaders talked so much about regional integration as in the past decade. They have cooked up an alphabet soup of organisations, whose chefs hold non-stop summits even as trade among them grows only slowly. But three countries in the Americas have practised integration while eschewing much of the fanfare.

Under the North American Free-Trade Agreement (NAFTA), which came into effect in January 1994, the economies of Mexico and Canada have become ever more closely entwined with that of the United States. Trade between the three has more than tripled, to $1.1 trillion in 2013, and cross-border investment has risen fourfold. Many companies now operate on a North American basis.

Yet this economic entanglement has no match in politics and policy. The Security and Prosperity Partnership of North America, set up by George W. Bush in 2005 to deepen NAFTA, was quietly downgraded four years later to a regular meeting of the three countries’ leaders. An accompanying private-sector “competitiveness council” was disbanded.

Because NAFTA is falsely blamed in the United States for a net loss of manufacturing jobs, it is a subject that Barack Obama prefers not to mention. Stephen Harper, Canada’s Conservative prime minister, hews to his country’s close bilateral relationship with the United States. Mexico’s problems with organised crime, its reputation as a source of migrants (though few now cross the border) and the fear that it might provide an access route for terrorists (though it hasn’t) make closer trilateral ties politically toxic in the other two countries.

This neglect is a missed opportunity, according to a new report* by the Council on Foreign Relations, a New York think-tank. Drawn up by a group led by Robert Zoellick, a Republican former cabinet member, and General David Petraeus, a former commander of American forces in Iraq and Afghanistan, the report makes a passionate case for North America to switch from “an afterthought” to “a central priority for US policy”.

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Did Clovis Culture Originate in Central or South America?

Of the scores of North American archaeological sites claimed to provide evidence of human hunting of now-extinct Pleistocene mammals, only about a dozen have compelling evidence of such predation. In all instances, the animals involved were mammoth and mastodon (1). In PNAS, Sanchez et al. (2) contend that a third genus of proboscidean (elephants and their near relatives), the gomphothere Cuvieronius, should be added to the small list of large mammals pursued by Clovis hunters. It is an intriguing claim; skeptics, however, might require more proof than is currently available.

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Canada and Mexico Relations in NAFTA

CANADA and Mexico share the fortune, or misfortune, of a border with the world’s most powerful country, which looks down on both of them. For 20 years, as privileged trading partners of the United States, they have had the opportunity to influence it by creating a shared vision for North America. Instead the two have bickered like rivals in a tawdry ménage a trois.

Canada plays the part of the wronged partner. It has jealously sought to protect the relationship with its neighbour, fearing that Mexico may steal its thunder. “Canada is quick to give offence and Mexico is quick to take it,” says Laura Dawson, author of a report on the bilateral relations for the Canadian Council of Chief Executives, a business group. That could be shrugged off as irrelevant in a region where the only bond that matters is with the United States. But there are economic costs for North America as a whole, including the United States, because more could be done to link supply chains and energy markets trilaterally rather than just bilaterally.

Canada was a reluctant participant in the negotiations for the North American Free Trade Agreement (NAFTA), which was launched in 1994. It agreed to join largely to safeguard the advantages it had won from a prior free-trade deal with the United States. After the terrorist attacks on September 11th 2001, efforts to strengthen NAFTA through trilateral negotiations lost momentum. Instead, the United States, Canada and Mexico have sought to tackle border and security issues bilaterally.

Relations between Canada and Mexico have become more brittle this year; the leaders of both countries have pointedly snubbed each other.

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Natural Gas Exports to Mexico From America

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Youngest Gomphothere Site in Mexico (13.4kya) has Clovis Points (yup, they get et too)

An animal once believed to have disappeared from North America before humans ever arrived there might actually have roamed the continent longer than previously thought – and it was likely on the list of prey for some of continent's earliest humans, researchers from the University of Arizona and elsewhere have found.

Archaeologists have discovered artifacts of the prehistoric Clovis culture mingled with the bones of two gomphotheres – an ancient ancestor of the elephant – at an archaeological site in northwestern Mexico.

The discovery suggests that the Clovis – the earliest widespread group of hunter-gatherers to inhabit North America – likely hunted and ate gomphotheres. The members of the Clovis culture were already well-known as hunters of the gomphotheres' cousins, mammoths and mastodons.

Although humans were known to have hunted gomphotheres in Central America and South America, this is the first time a human-gomphothere connection has been made in North America, says archaeologist Vance Holliday, who co-authored a new paper on the findings, published this week in Proceedings of the National Academy of Sciences.

"This is the first archaeological gomphothere found in North America, and it's the only one known," said Holliday, a professor of anthropology and geology at the UA.

Holliday and colleagues from the U.S. and Mexico began excavating the skeletal remains of two juvenile gomphotheres in 2007 after ranchers alerted them that the bones had been found in northwestern Sonora, Mexico.

They didn't know at first what kind of animal they were dealing with.

"At first, just based on the size of the bone, we thought maybe it was a bison, because the extinct bison were a little bigger than our modern bison," Holliday said.

Then, in 2008, they discovered a jawbone with teeth, buried upside down in the dirt.

"We finally found the mandible, and that's what told the tale," Holliday said.

Gomphotheres were smaller than mammoths – about the same size as modern elephants. They once were widespread in North America, but until now they seemed to have disappeared from the continent's fossil record long before humans arrived in North America, which happened some 13,000 to 13,500 years ago, during the late Ice Age.

However, the bones that Holliday and his colleagues uncovered date back 13,400 years, making them the last known gomphotheres in North America.

The gomphothere remains weren't all Holliday and his colleagues unearthed at the site, which they dubbed El Fin del Mundo – Spanish for The End of the World – because of its remote location.

As their excavation of the bones progressed, they also uncovered numerous Clovis artifacts, including signature Clovis projectile points, or spear tips, as well as cutting tools and flint flakes from stone tool-making. The Clovis culture is so named for its distinctive stone tools, first discovered by archaeologists near Clovis, New Mexico, in the 1930s.

link.

And, yes, I guess it did hold up.

paper link when I see it.

The Amazon Basin Drained Through Mexico in the Norian Triassic

Early Mesozoic Southern Mexico-Amazonian connection based on U-Pb ages from detrital zircons: The La Mora Paleo-River in the Mixteca Terrane and its paleogeographic and tectonic implications

Authors:

Silva-Romo et al

Abstract:

The La Mora Formation is the oldest Mesozoic floodplain succession in the Mixteca Terrane of Southern Mexico. The presence of Amazonian detrital zircons in the La Mora Formation and in the overlying volcanic Diquiyú Unit indicates a major fluvial system that drained the Mixteca Terrane. The La Mora Paleo-River crossed the Oaxaquia microcontinent and the Mixteca Terrane prior to the breakup of Pangea, during Late Triassic-Early Jurassic time, when the Acatlán-Oaxaquia block was part of the northwestern portion of the Amazonian craton. Detrital zircons in the La Mora Formation have ages between 3307 ± 31 and 210 ± 12 Ma, which suggest that they originated in Amazonia and Southern Mexico: 33.2% of the detrital zircons have ages that are found only in Amazonian sources; whereas 66.7% of the zircons may be associated with either the Amazonian craton, the Andean basement, or Southern Mexico. We propose that the La Mora fluvial system drained the Amazon basin in a westward direction, with its mouth in central Pangea, and that it most likely fed the Tolimán submarine fan. The inferred location of the Acatlán-Oaxaquia tectonic block at the time of the La Mora fluvial system implies that the basement of Southern Mexico experienced right lateral displacement of at least 2300 km with respect to South America during the Mesozoic.