Urban civilization rose in Southern Mesopotamia on the back of tides

- A newly published study challenges long-held assumptions about the origins of urban civilization in ancient Mesopotamia, suggesting that the rise of Sumer was driven by the dynamic interplay of rivers, tides, and sediments at the head of the Persian Gulf.

Published today in PLOS ONE, the study, Morphodynamic Foundations of Sumer, is led by Liviu Giosan, Senior Scientist Emeritus in Geology & Geophysics at the Woods Hole Oceanographic Institution (WHOI), and Reed Goodman, Assistant Professor of Environmental Social Science at Baruch Institute of Social Ecology and Forest Science (BICEFS), Clemson University.

The research introduces a novel paleoenvironmental model in which tidal dynamics influenced the earliest development of agriculture and sociopolitical complexity in Sumer. Results are a contribution to the long-running Lagash Archaeological Project, a collaboration led by Iraqi archaeologists and Penn Museum at the University of Pennsylvania.

“Our results show that Sumer was literally and culturally built on the rhythms of water,” said Giosan. “The cyclical patterns of tides together with delta morphodynamics -how the form or shape of a landscape changes over time due to dynamic processes - were deeply woven into the myths, innovations, and daily lives of the Sumerians.”

Sumer was an ancient civilization located in southern Mesopotamia, in what is now modern-day Iraq. It is often considered the cradle of civilization due to its numerous innovations, including the invention of writing, the wheel, and organized intensive agriculture. Sumerian society was structured into city-states like Ur, Uruk, or Lagash, each with its own ruler and religious institutions.

The study shows that from about 7000 to 5000 years ago, the Persian Gulf extended farther inland, and tides pushed freshwater twice daily far into the lower reaches of the Tigris and Euphrates. The scholars propose that the early communities must have harnessed this dependable hydrology using short canals to irrigate crops and date groves, enabling high-yield agriculture without the need for large-scale infrastructure.

As rivers built deltas at the head of the Gulf, tidal access to the interior was cut off. The resulting loss of tides likely triggered an ecological and economic crisis—one that required an ambitious societal response. The extensive works for irrigation and flood protection that followed ultimately came to define the golden age of Sumer.

“We often picture ancient landscapes as static,” says Goodman. “But the Mesopotamian delta was anything but. Its restless, shifting land demanded ingenuity and cooperation, sparking some of history’s first intensive farming and pioneering bold social experiments.”

Beyond the environmental drivers, the study also explores the cultural impacts of this watery foundation, connecting the flood myths of Mesopotamia and the water-centered Sumerian pantheon.

“The radical conclusions of this study are clear in what we’re finding at Lagash,” adds Holly Pittman, Director of the Penn Museum’s Lagash Archaeological Project. “Rapid environmental change fostered inequality, political consolidation, and the ideologies of the world’s first urban society.”

Using ancient environmental and landscape data, new samples from the archaeological site of ancient Lagash, and detailed satellite maps, the authors were able to recreate what the coast of Sumer looked like long ago and imagine how its inhabitants responded to its shape-shifting nature.

“Our work highlights both the opportunities and perils of social reinvention in the face of severe environmental crisis,” concluded Giosan. “Beyond this modern lesson, it is always surprising to find real history hidden in myth — and truly interdisciplinary research like ours can help uncover it.” 

Earliest evidence discovered of interbreeding between Homo sapiens and Neanderthals

 

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Credit: Tel Aviv University

A Scientific First: Early Biological Connections Between Neanderthals and

Homo sapiens

 

Global Breakthrough in a Prehistoric Cave in Israel:

Earliest evidence discovered of interbreeding between Homo sapiens and Neanderthals

 

The skeleton belongs to a five-year-old child who lived 140,000 years ago

 

 

Caption

The skull of Skhul I child showing cranial curvature typical of Homo sapiens.

Credit

Tel Aviv UniversityResearch team: “This discovery reveals the world’s earliest known human fossil showing morphological traits of both of these human groups, which until recently were considered two separate human species. The current study shows that the five-year-old child’s skeleton is the result of continuous genetic infiltration from the local—and older—Neanderthal population into the Homo sapiens population.”

 

An international study led by researchers from Tel Aviv University and the French National Centre for Scientific Research provides the first scientific evidence that Neanderthals and Homo sapiens had biological and social relations, and even interbred for the first time, in the Land of Israel. The research team found a combination of Neanderthal and Homo sapiens traits in the skeleton of a five-year-old child discovered about 90 years ago in the Skhul Cave on Mount Carmel. The fossil, estimated to be about 140,000 years old, is the earliest human fossil in the world to display morphological features of both of these human groups, which until recently were considered two separate species. The study was led by Prof. Israel Hershkovitz of the Gray Faculty of Medical and Health Sciences at Tel Aviv University and Anne Dambricourt-Malassé of the French National Centre for Scientific Research. The findings of this historic discovery were published in the journal l’Anthropologie.

Research Video

“Genetic studies over the past decade have shown that these two groups exchanged genes,” explains Prof. Hershkovitz. “Even today, 40,000 years after the last Neanderthals disappeared, part of our genome—2 to 6 percent—is of Neanderthal origin. But these gene exchanges took place much later, between 60,000 to 40,000 years ago. Here, we are dealing with a human fossil that is 140,000 years old. In our study, we show that the child’s skull, which in its overall shape resembles that of Homo sapiens—especially in the curvature of the skull vault—has an intracranial blood supply system, a lower jaw, and an inner ear structure typical of Neanderthals.”

 

For years, Neanderthals were thought to be a group that evolved in Europe, migrating to the Land of Israel only about 70,000 years ago, following the advance of European glaciers. In a groundbreaking 2021 study published in the prestigious journal Science, Prof. Hershkovitz and his colleagues showed that early Neanderthals lived in the Land of Israel as early as 400,000 years ago. This human type, which Prof. Hershkovitz called “Nesher Ramla Homo” (after the archaeological site near the Nesher Ramla factory where it was found), encountered Homo sapiens groups that began leaving Africa about 200,000 years ago—and, according to the current study’s findings, interbred with them. The child from the Skhul Cave is the earliest fossil evidence in the world of the social and biological ties forged between these two populations over thousands of years. The local Neanderthals eventually disappeared when they were absorbed into the Homo sapiens population, much like the later European Neanderthals.

 

The researchers reached these conclusions after conducting a series of advanced tests on the fossil. First, they scanned the skull and jaw using micro-CT technology at the Shmunis Family Anthropology Institute at Tel Aviv University, creating an accurate three-dimensional model from the scans. This enabled them to perform a complex morphological analysis of the anatomical structures (including non-visible structures such as the inner ear) and compare them to various hominid populations. To study the structure of the blood vessels surrounding the brain, they also created an accurate 3D reconstruction of the inside of the skull.

 

“The fossil we studied is the earliest known physical evidence of mating between Neanderthals and Homo sapiens,” says Prof. Hershkovitz. “In 1998, a skeleton of a child was discovered in Portugal that showed traits of both of these human groups. But that skeleton, nicknamed the ‘Lapedo Valley Child,’ dates back to 28,000 years ago—more than 100,000 years after the Skhul child. Traditionally, anthropologists have attributed the fossils discovered in the Skhul Cave, along with fossils from the Qafzeh Cave near Nazareth, to an early group of Homo sapiens. The current study reveals that at least some of the fossils from the Skhul Cave are the result of continuous genetic infiltration from the local—and older—Neanderthal population into the Homo sapiens population.”

 

Link to the article:

https://www.sciencedirect.com/science/article/pii/S0003552125000366?via%3Dihub

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Rare Gold Coin of Queen Berenice II of Egypt, about 2,200 years old, discovered in the City of David

A very rare gold coin, bearing the portrait of the Egyptian Queen Berenice II, was discovered in the Givati Parking Lot excavations in the City of David National Park, conducted by the Israel Antiquities Authority. The coin is a small quarter-drachma made of pure gold (99.3%), dated to 241–246 BCE, during the reign of her husband, Ptolemy III. Only about 20 such coins are known worldwide, and this is the first ever discovered in a proper archaeological context.

The obverse shows Berenice as a Hellenistic queen, with a diadem, veil, and necklace. The reverse depicts a cornucopia, symbol of prosperity and fertility, flanked by two stars, with the Greek inscription “of Queen Berenice.”

The coin was found while sifting soil by Rivka Langler, a young excavator at the Givati site: “I was sifting the soil when suddenly I saw something shiny. At first I couldn’t believe it, but then I realized it was a gold coin. Within seconds I was running in excitement across the excavation. I’ve been digging here for two years, and now I finally found gold!”

“As far as we know, the coin is the only one of its kind discovered outside Egypt, the center of Ptolemaic rule,” say Dr. Robert Kool, Head of Numismatics at the Israel Antiquities Authority, and Dr. Haim Gitler, Chief Curator of Archaeology and Numismatics at the Israel Museum. “Berenice appears not only as the king’s consort, but possibly as a ruler in her own right. This is among the earliest cases of a Ptolemaic queen depicted on a coin with her title during her lifetime.”

According to excavation directors Dr. Yiftah Shalev (IAA) and Efrat Bocher (CSAJ), the discovery challenges the long-held view that Jerusalem after 586 BCE was a small, poor town. Instead, the coin – with other finds from the mid-3rd century BCE – shows Jerusalem was recovering, renewing ties with major political, economic, and cultural centers of the time 

A rare lead weight inscribed with the name of an official in the Hellenistic administration

A rare lead weight, bearing an inscription from about 2,150 years ago and preserved in excellent condition, was seized in Jerusalem in an operation by the Theft Prevention Unit of the Israel Antiquities Authority. The inscription – “Heliodorus son of Apollonios, Agoranomos” – records the name of the official responsible for regulating weights and measures. It is dated to year 165, during the Hellenistic rule in the Land of Israel. Alongside the inscription, a depiction of a dolphin appears, the meaning of which is still under study, with the hope of identifying the city from which the weight originated.

The weight was seized in an antiquities shop in Jerusalem, following intelligence information received by the Israel Antiquities Authority’s Theft Prevention Unit. Inspectors of the Authority questioned the shop owner in an attempt to trace the middlemen and looters who had removed the weight from its archaeological context.

The role of the Agoranomos was to supervise weights and measures and to prevent fraud in trade – and indeed, the weight is precise: one Mina, the standard unit of weight in that period, equal to one hundred Greek drachmas.

According to Ido Zangen of the Israel Antiquities Authority, “The Greek names of Heliodorus and his father, Apollonios, attest to a Hellenized population. Both names are connected to the Greek sun gods – Helios and Apollo – and indicate a cultural-religious affinity with the Hellenistic culture that ruled the region at that time. These names were especially common in Idumea, where the local god ‘Qos’ was identified with the Greek sun gods.”

According to Ilan Haddad, Head of Antiquities Trade Supervision at the Israel Antiquities Authority, “The removal of an archaeological artifact from its site without a proper excavation results in the loss of invaluable historical information. Had we found the artifact in its precise archaeological context, it could have enriched our historical knowledge significantly״.

Ancient humans transported stones over long distances 600,000 years earlier than previously thought

 

To craft early tools, ancient human relatives transported stones over long distances 600,000 years earlier than previously thought

Stone tools unearthed in Kenya reveal that hominins regularly moved raw materials several miles

Peer-Reviewed Publication

Smithsonian

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Oldowan stone tools made from a variety of raw materials sourced more than 6 miles away from where they were found in southwestern Kenya.

Durable and versatile tools like these were crafted from special stone materials collected up to eight miles away, according to new research led by scientists at the Smithsonian’s National Museum of Natural History, Cleveland Museum of Natural History and Queens College. Their findings, published Aug. 15 in the journal Science Advances, push back the earliest known evidence of ancient humans transporting resources over long distances by some 600,000 years.

The development of the Oldowan toolkit made it possible for early humans to consume large prey. Around three million years ago, ancient hominins began refining their toolmaking, using hammerstones to strike stone cores and create sharp-edged flakes. By pounding, slicing and scraping, these stone tools could process and refine a greater variety of plant and animal materials.

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Credit: E.M Finestone, J.S. Oliver, Homa Peninsula Paleoanthropology Project

In southwestern Kenya more than 2.6 million years ago, ancient humans wielded an array of stone tools—known collectively as the Oldowan toolkit—to pound plant material and carve up large prey such as hippopotamuses.

These durable and versatile tools were crafted from special stone materials collected up to eight miles away, according to new research led by scientists at the Smithsonian’s National Museum of Natural History, Cleveland Museum of Natural History and Queens College. Their findings, published Aug. 15 in the journal Science Advances, push back the earliest known evidence of ancient humans transporting resources over long distances by some 600,000 years.

“People often focus on the tools themselves, but the real innovation of the Oldowan may actually be the transport of resources from one place to another,” said Rick Potts, the senior author of the study and the National Museum of Natural History’s Peter Buck Chair of Human Origins. “The knowledge and intent to bring stone material to rich food sources was apparently an integral part of toolmaking behavior at the outset of the Oldowan.”

In the new Scientific Advances study led by Emma Finestone, the Robert J. and Linnet E. Fritz Endowed Chair of Human Origins at the Cleveland Museum of Natural History, Finestone and Potts worked with several colleagues to analyze stone tools uncovered on Kenya’s Homa Peninsula, a fossil-rich region that juts out into the eastern margins of Lake Victoria. Potts first surveyed the region’s fossil sites in 1985. In the years since, he has worked closely with colleagues at the National Museums of Kenya to excavate the area’s gullies as part of the ongoing Homa Peninsula Paleoanthropology Project, which Potts co-directs with Queens College professor Thomas Plummer, another co-author of the new paper. Finestone joined the project in 2012, when she began working with Plummer to reconstruct hominin tool behavior on the Homa Peninsula and understand how toolmakers moved around the landscape.

One of the peninsula’s most significant sites is known as Nyayanga and contains archaeological finds dating back some three million years. A series of recent excavations yielded a trove of stone tools and hundreds of butchered hippopotamus bones. In a 2023 paper, Plummer, Potts, Finestone and their colleagues posited that these bones represent the oldest known evidence of ancient hominins using stone tools to butcher large animals.

“Hominins were using stone tools for a variety of pounding and cutting tasks, including processing plant and animal foods and working wood,” Plummer said. “The diversity of activities that used stone tools suggests that even at this early stage of cultural development stone tools enhanced the adaptability of the hominins using them.”

The development of the Oldowan toolkit made it possible for early humans to consume large prey. Around three million years ago, ancient hominins began refining their toolmaking, using hammerstones to strike stone cores and create sharp-edged flakes. By pounding, slicing and scraping, these stone tools could process and refine a greater variety of plant and animal materials.

Finding the right rocks was vital. Oldowan tools needed to be fashioned from stones that were strong yet brittle enough to easily flake. However, the local rocks at Nyayanga are relatively soft, and would produce cutting tools that would quickly dull and pounding tools that would be more likely to shatter. Like using a flimsy plastic knife trying to cut through a well-done steak, these stones would have been of little use for pounding tough plants or breaking animal bones.

As a result, hominins at Nyayanga appear to have brought in stronger stones from other areas. The researchers analyzed the geochemistry of hundreds of stone cores and flakes found at Nyayanga that date back at least 2.6 million years. They discovered that these tools were crafted from volcanic rocks like rhyolite and metamorphic rocks like quartzite. The scientists surveyed local geology and discovered that these rock types were common in drainage basins several miles east of the Homa Peninsula.

According to Finestone, Nyayanga stones are significantly older than other known examples of ancient stone transport. Previously, the oldest evidence of hominins moving rocks over significant distances was a 2-million-year-old site known as Kanjera South that is also located on the Homa Peninsula.

“It’s surprising because the Nyayanga assemblage is early in the Oldowan and we previously thought that longer transport distances may have been related to changes that happened in our more recent evolutionary history,” she said.

The distance ancient hominins traveled for stones analyzed in this study is also noteworthy. While many nonhuman primates carry food and rocks, they only utilize materials that are nearby. Some, like chimpanzees, are known to transport stones over short distances. But the hominins at Nyayanga appear to have consistently procured material from over six miles away.

The ability to transport resources is a major milestone in human evolution. According to Potts, it exhibits ancient hominins’ ability to plan ahead and assess the requirements for processing food. It also illustrates an ability to mentally map their environment and remember locations with high-quality rocks.

“The mental maps of the oldest known hominins to persistently make stone tools well surpassed their immediate surroundings, even surpassing a few miles,” Potts said.

Once ancient hominins brought their lithic haul back to Nyayanga, they fashioned the stones into flakes and cores. But the identity of these toolmakers remains elusive. At the oldest hippo butchery site, the team discovered a molar tooth from a hominin in the genus Paranthropus, a group that sported strong skulls and teeth to grind tough material. Another Paranthropus tooth was found nearby on the surface of the same geological bed. The existence of Paranthropus teeth alongside Oldowan stone tools hints that these hominins may have used stone tools like their close evolutionary relatives in the genus Homo.

However, the case is far from closed.

“Unless you find a hominin fossil actually holding a tool, you won’t be able to say definitively which species are making which stone tool assemblages,” Finestone said. “But I think that the research at Nyayanga suggests that there is a greater diversity of hominins making early stone tools than previously thought.”

The artifacts at Nyayanga also underscore that ancient humans have transported raw materials to fuel technological innovations for millions of years.

“Humans have always relied on tools to solve adaptive challenges," Finestone said. “By understanding how this relationship began, we can better see our connection to it today—especially as we face new challenges in a world shaped by technology."

Discovery confirms early species of hominins co-existed in Ethiopia

 

New findings document the geological age, context and anatomy of hominin fossils discovered at the Ledi-Geraru Research Project, Ethiopia

While we know much of the story of how humans evolved, the puzzle is still missing critical pieces. For example, fossil evidence for human evolution between 2 and 3 million years ago is patchy. It’s frustrating because we know that the branch of the hominin family tree that includes humans, or Homo sapiens, appears in the fossil record for the first time in this period.  

Today, Homo sapiens (which anthropologists shorten to Homo), is the only hominin species alive. But in the past, Homo wasn’t alone. We coexisted and competed with other branches of the human family tree. Research supported by the National Science Foundation and the Leakey Foundation and published in Nature now fills in a piece of the ongoing evolutionary puzzle, placing two early species of hominin side-by-side. 

A team working in the Afar Region of Ethiopia, at the site of Ledi-Geraru, reports hominin fossils that date between 2.6 and 3.0 million years old. Lucas Delezene, an associate professor of anthropology at the University of Arkansas, was second author on a paper that incorporated the work of more than 20 researchers from North America, Africa and Europe. 

The team found fossils of Homo that confirm the earliest evidence for the human lineage at 2.8 million years ago as well as evidence of Homo at 2.6 million years ago, solidifying the antiquity of Homo. Unexpectedly, the team also found evidence that Homo overlapped at the site with a different type of hominin, Australopithecus, at 2.6 million years ago.  

This was a surprise because Australopithecus was thought to be extinct in the area by about 3 million years ago. The famous Australopithecus fossil known as Lucy was found at a nearby site, but her species disappeared from the fossil record at 3 million years ago.  

“People often think evolution is a linear progression,” explains Delezene, “like the March of Progress, but in reality humans are only one species that make up a twig of a bigger family tree — it’s quite bushy and what we found is another twig that was previously unknown. The idea that Homo appears and immediately spreads around the planet and replaces all other hominin species is not accurate. Homo lived side-by-side with many other hominin species throughout Africa. What’s neat is that Homo overlaps with different hominin species in different places.” 

For example, from southern Ethiopia to southern Africa, the earliest species of Homo overlapped with a hominin known as Paranthropus, which is well known for its massive teeth and chewing muscles and a diet reliant on grass in some parts of its range. However, in the Afar Region of Ethiopia, no Paranthropus fossils have ever been found.  

Instead, the team working at Ledi-Geraru found that Homo overlap with a different type of hominin, Australopithecus. How all of these hominin species divided up resources is the question of ongoing research. Did Homo nod to the other hominin species on their way to hunting and gathering in the morning, or did the various species consume similar resources? Did Homo eat the same things in Ethiopia where it coexisted with Australopithecus as it did in the south where it coexisted with Paranthropus, or was its diet flexible?  

We know that Homo eventually becomes a culturally reliant tool user and occasionally consumed meat. But the oldest Homo fossils at Ledi-Geraru predate any evidence of tool manufacture or meat consumption. Did Homo evolve those traits to avoid competing with other hominin species? Competition among these various hominin species likely set the stage for the evolution of the traits that ultimately made humans a globally widespread and successful species. 

The fossils published in the Nature paper are all teeth. Teeth are often the best-preserved fossils because their enamel coating provides better protection from the ravages of time and the elements.  

Delezene, a hominin dental expert, says, “When we get down to the picky details, the teeth of Homo and Australopithecus look different. The differences are subtle, but once you see them, you can't unsee them. They're very consistent.” 

While the new fossils fill in a piece of the puzzle, there is still a long way to go before we have a complete picture of human evolution. While there is evidence for the teeth of early Homo and the new Australopithecus, the team doesn’t know what their heads or the rest of their bodies looked like. The multi-national collaboration, done in partnership with the local community of Afar people, will continue its work looking for more fossils, ideally with continued funding.  

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Journal

Nature

DOI

10.1038/s41586-025-09390-4 

Stalagmites in Mexican caves reveal duration and severity of drought during the Maya collapse

 

Peer-Reviewed Publication

University of Cambridge

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Tourists explore the ‘Dome of the Cathedral’, the largest chamber in Grutas Tzabnah (Yucatán, Mexico), and the origin of Tzab06-1. The artificial well ‘La Noria’ now illuminates the cave. 

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Credit: Mark Brenner

A drought lasting 13 years and several others that each lasted over three years may have contributed to the collapse of the Classic Maya civilisation, chemical fingerprints from a stalagmite in a Mexican cave have revealed.

A detailed analysis of oxygen isotopes in the stalagmite allowed a team of researchers, led by the University of Cambridge, to determine rainfall levels for individual wet and dry seasons between 871 and 1021 CE, which overlaps with the Terminal Classic period of Maya civilisation. This is the first time it has been possible to isolate rainfall conditions for individual wet and dry seasons during the Terminal Classic, the time of societal decline historically referred to as the Maya collapse.

During the Terminal Classic, limestone Maya cities in the south were abandoned and dynasties were ended, as one of the ancient world’s great civilisations shifted north and lost much of its political and economic power.

The data contained within the stalagmite, from a cave in the Yucatán, showed that there were eight wet season droughts that lasted for at least three years during this period, with the longest drought lasting for 13 consecutive years.

This climate data aligns with existing historical and archaeological evidence: construction of monuments and political activity at several major northern Maya sites, including the famous city of Chichén Itzá, stopped at different times during this period of climate stress.

The accurately and precisely dated droughts provide a new framework for fine-grained analysis of the timing and dynamics of human-climate interactions in the region. The results are reported in the journal Science Advances.

“This period in Maya history has been a cause of fascination for centuries,” said lead author Dr Daniel H. James, who conducted the research while a PhD student at Cambridge’s Department of Earth Sciences. “There have been multiple theories as to what caused the collapse, such as changing trade routes, war or severe drought, based on the archaeological evidence the Maya left behind. But in the past few decades, we’ve started to learn quite a lot about what happened to the Maya and why, by combining the archaeological data with quantifiable climate evidence.”

Starting in the 1990s, researchers began to piece together climate records with those left by the Maya, such as the dates they recorded on key monuments, to show that a series of droughts during the Terminal Classic was a likely contributor to the massive socio-political upheaval in Maya society.

Now, James and his co-authors from the UK, US and Mexico have used the chemical fingerprints contained in stalagmites from a cave in the northern Yucatán to bring those droughts into much sharper focus.

Stalagmites form when water drips from the ceiling of a cave, and the minerals contained in the water grow into large deposits on the cave floor. By dating and analysing the layers of oxygen isotopes within the stalagmite, the researchers extracted highly detailed information about the climate in the Terminal Classic period. Earlier research has measured the oxygen isotopes contained in lake sediment to determine the severity of drought, but lake sediment does not contain enough detail to pinpoint climate conditions in any given year at a particular site.

“It hasn’t been possible to directly compare the history of individual Maya sites with what we previously knew about the climate record,” said James, who is now a postdoctoral researcher at University College London (UCL). “Lake sediment is great when you want to look at the big picture, but stalagmites allow us to access the fine-grained detail that we’ve been missing.”

Earlier research on stalagmites has determined annual average rainfall amounts during the Terminal Classic, but the Cambridge-led team have now been able to go further, and isolate information from individual wet and dry seasons, thanks to relatively thick (about 1mm) annual layers in the stalagmite used in this study. The specific oxygen isotopes in each layer are a proxy for wet season drought.

“Knowing the annual average rainfall doesn’t tell you as much as knowing what each individual wet season was like,” said James. “Being able to isolate the wet season allows us to accurately track the duration of wet season drought, which is what determines if crops succeed or fail.”

According to the information contained in the stalagmite, there were eight wet season droughts lasting for at least three years between 871 and 1021 CE. The longest drought of the period lasted for 13 years. Even with the water management techniques that the Maya had, a drought that long would have had major impacts on society.

The climate information contained in the stalagmite lines up with the dates inscribed by the Maya on their monuments. In the periods of prolonged and severe drought, date inscription at sites such as Chichén Itzá stopped entirely.

“This doesn’t necessarily mean that the Maya abandoned Chichén Itzá during these periods of severe drought, but it’s likely that they had more immediate things to worry about than constructing monuments, such as whether the crops they relied on would succeed or not,” said James.

The researchers say that stalagmites from this and other caves in the region could be vital in putting the puzzle of the Terminal Classic period together.

“In addition to what stalagmites can tell us about this period in Maya history, they might also be able to tell us about the frequency and severity of tropical storms, for instance,” said James. “As a case study for fine-grained comparisons between climate and historical data, it’s exciting being able to apply methods usually associated with the deeper past to relatively recent history.”

The research was supported in part by the National Geographic Society and the Leverhulme Trust.

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Journal

Science Advances

DOI

10.1126/sciadv.adw7661