The oldest parasite DNA ever recorded has been found in the ancient, desiccated faeces of a puma. A team of Argentinian scientists from the National Council of Scientific and Technical Research (CONICET) made the discovery after studying a coprolite taken from a rock-shelter in the country's mountainous Catamarca Province, where the remains of now extinct megafauna have previously been recovered in stratigraphic excavations.
A parasite that plagues many of today’s domestic dogs and cats rumbled the bowels of a puma 17,000 years ago [Credit: SandmanXX, iStock]
Radiocarbon dating revealed that the coprolite and thus the parasitic roundworm eggs preserved inside dated back to between 16,570 and 17,000 years ago, towards the end of the last Ice Age.
At that time, the area around the shelter at Penas de las Trampas in the southern Andean Puna was thought to have been wetter than today, making it a suitable habitat for megafauna like giant ground sloths, and also smaller herbivores like American horses and South American camelids which the pumas may have preyed on.
Ancient mitochondrial DNA analysis was used to confirm the coprolite came from a Puma (Puma concolor) and that the eggs belonged to Toxascaris leonina, a species of roundworm still commonly found in the digestive systems of modern day cats, dogs and foxes.
The study, published in the journal Parasitology, explains that the extremely dry, cold and salty conditions which took hold at the Penas de las Trampas site since the onset of the Holocene would have helped to reduce the breakdown of the DNA, allowing it to be preserved.
Led by Romina Petrigh and Martin Fugassa, the study was carried out by an interdisciplinary team including archaeologists and biologists and is part of a project that views ancient faeces as important paleobiological reservoirs.
Dr Petrigh, from the National University of Mar del Plata and CONICET, said: "While we have found evidence of parasites in coprolites before, those remains were much more recent, dating back only a few thousand years. The latest find shows that these roundworms were infecting the fauna of South America before the arrival of the first humans in the area around 11,000 years ago."
A Toxascaris leonina egg (left, scale bar 20 micrometers) and the puma feces (right, scale bar 20 millimeters) from the study [Credit: Petrigh et al. 2019]
She added: "I was very happy when I discovered how old this DNA was. It's difficult to recover DNA of such an old age as it usually suffers damage over time. Our working conditions had to be extremely controlled to avoid contamination with modern DNA, so we used special decontaminated reagents and disposable supplies. Several experiments were performed to authenticate the DNA sequences obtained and the efforts of the team of researchers who participated was essential."
The discovery marks a number of firsts: it represents the oldest record of an ancient DNA sequence for a gastrointestinal nematode parasite of wild mammals, the oldest molecular parasite record worldwide, and also a new maximum age for the recovery of old DNA of this origin.
For Dr Petrigh, the findings also cast light on both the past and the present. She said: "This work confirms the presence of T. leonina in prehistoric times, presumably even before that of humans in the region, and it represents the oldest record in the world. The common interpretation is that the presence of T. leonina in American wild carnivores today is a consequence of their contact with domestic dogs or cats, but that should no longer be assumed as the only possible explanation.
"Our aDNA studies have also confirmed the presence of pumas in the southern Puna at the end of the Pleistocene. This has significant implications for the natural history of the region, as well as for inferring the ecological context immediately before -- as far as is known -- the first human explorers ventured into the area."
She added: "The large number of eggs of T. leonina and its larva state in the puma coprolite analysed here indicate the high infective capacity of this parasite, involving a high risk for carnivores and for humans."
Short-tailed opossums are cute little marsupials which live in South America, but a new discovery shows they had a fierce fossil relative.
Reconstruction of Sparassocynus feeding on a small rodent [Credit: Velizar Simeonovski]
In a paper just published, a joint British and Argentinian research team have shown that a weasel-like carnivorous marsupial called Sparassocynus, is an extinct carnivorous relative of short-tailed opossums. Remains of Sparassocynus have been known for over a century, but its evolutionary relationships have been uncertain until now.
The new study, published in the Journal of Mammalian Evolution, by Dr. Robin Beck, a mammal systematist at the University of Salford, and MatÃas Taglioretti, a palaeontologist at the Museo Municipal de Ciencias Naturales 'Lorenzo Scaglia' in Argentina, focused on a recently discovered four-million-year-old skull of Sparassocynus that provides key new information on the animal.
The skull was found in 2012 by Taglioretti and colleagues in a fossil deposit in cliffs along the Atlantic coast of Argentina, near the city of Mar del Plata.
Four million year old skull of Sparassocynus juvenile from the Chapadmalal Formation near Mar del Plata, eastern Argentina [Credit: Robin Beck]
Dr. Beck said: "As soon as MatÃas showed me the skull, I knew it was really important. It's almost perfectly preserved, and it's not fully grown (it still has its baby teeth), so it preserves a lot of features that are not visible in other specimens."
By comparing over a hundred different anatomical characteristics, and incorporating DNA evidence from living species, Beck and Taglioretti showed that Sparassocynus is an extinct member of the opossum family, and is most closely related to short-tailed opossums.
"This might seem surprising", said Beck "because Sparassocynus was clearly a carnivore that would probably have eaten rodents and other small vertebrates, whereas short-tailed opossums are about five times smaller and mainly eat insects, but they share some unusual features that indicate a close relationship."
Sparassocynus survived in South America until about 2.5 million years ago, when it may have been driven extinct by the arrival of weasels from North America. There are over 100 species of opossum still alive today in South America, of which 24 are short-tailed opossums.
The team of the Paleontological Museum of San Pedro found an extinct condor that exceeded 3.50 meters in length with its wings open, much more than the current Andean condor. Its fossil remains are about 10 thousand years old.
The current Andean condor has an average wingspan of about 3 meters while this extinct condor had an extension of more than three and a half meters [Credit: Agency CTyS-UNLaM]
The discovery occurred 12 kilometers south of the Buenos Aires city of San Pedro. Dr. Federico Agnolin, researcher at the Argentine Museum of Natural Sciences (MACN), Felix de Azara Foundation and CONICET, said that "it is an exceptional finding, since it is the record of a new species of giant bird that flew over the province of Buenos Aires at the end of the Pleistocene".
The current Andean condor has an average wingspan of about 3 meters while this extinct condor had an extension of more than three and a half meters.
"The ulna and radius found, belonging to the right wing, are much more robust than the Vultur gryphus, popularly known as the Andean condor, so we estimate that its body mass was much higher, although the study has just begun", Agnolin added to the Agency CTyS-UNLaM.
The director of the Museum of San Pedro Jose Luis Aguilar commented that "the weight of this great bird was probably between 18 and 20 kilos, while the Andean condor has a body mass between 12 and 15 kilos."
Credit: Agency CTyS-UNLaM
The discovery was made by a team from the San Pedro Museum made up of Jose Luis Aguilar, Julio Simonini, Javier Saucedo, Matias Swistun, Bruno Zarlenga and Bruno Rolfo in the La Paloma establishment of the cereal company Ramon Rosa SA. "In that place, the rains generate cuts in the ground, which allows us to observe ancient sediments from the Lujanenese Age," Aguilar said.
This gigantic new condor (which still has no name) lived accompanied by other scavenger birds such as giant caranchos, vultures and jotes. However, since birds have hollow bones, there are very few remains preserved.
Dr. Agnolin affirmed that he has just begun the study of this new specimen. "It is a relevant finding and it shows us that the condors were much more diverse at that time and that they also inhabited the Pampean region, while at present they can be seen in the Andean region, in the north of Argentina and, even, up to in the province of Cordoba".
Director Jose Luis Aguilar revealed to the Agency CTyS-UNLaM that "together with the remains of the giant condor, its was discovered the upper jaw of a juvenile peccary, that is, of a very small piglet, and the pelvis of a turtle".
Researchers Nicolas Chimento from MACN and German Gasparini from the La Plata Museum collaborated to identify the remains of these two animals found near the condor.
Aguilar said that these two animals could have been part of the diet of the giant condor: "We hope to confirm it when they finish analyzing the remains under the microscope; we see that the surface of the remains of the peccary and the turtle differs in appearance with that of the bones of the condor, which is why we believe that it has been eroded by the gastric juices of the bird".
In the presentation of this finding, the Museum of San Pedro will feature a life-size sculpture of this giant condor. The work was made by paleoartist Miguel Lugo, from the city of Ramallo, commissioned by the Municipality of San Pedro.
Personnel from the Samuel Lafone Quevedo Archaeological Museum of the Andalgala department in Argentina have discovered a storage jar containing the remains of a child.
Credit: El Ancasti
The discovery was made in the Agrotechnical School "Dr. Rodolfo Moran", located in the Huaco district, while works were being carried out on the grounds of the educational establishment.
According to the museum staff, the jar was in a good state of preservation and is believed to be between 650 to 900 years old.
Inside the jar were the remains of small child between 5 and 11 years of age at the time of burial. The body was placed in the foetal position or seated in the jar.
Next to the jar the archaeologists found a nativity cup and a small bowl (puco), presumably left as 'gifts' for the infant.
The finds were taken to the museum for further analysis.
One of the world's most important plant families has a history extending much farther south than any live or fossil specimen previously recorded, as shown by chinquapin fruit and leaf fossils unearthed in Patagonia, Argentina, according to researchers.
Discovery photo of the mature Castanopsis fruiting spike fossil with four nuts enclosed in scaly cupules, showing the part and counterpart on the split surface at Laguna del Hunco [Credit: Peter Wilf, Penn State University]
"The oak and beech family is recognized everywhere as one of the most important plant groups and has always been considered northern," said Peter Wilf, professor of geosciences and associate in the Earth and Environmental Systems Institute, Penn State. "We're adding a huge spatial dimension to the history of the Fagaceae family, and that's exciting." The plant family also includes chestnuts and the closely related chinquapins.
Common in the Northern Hemisphere and Asian tropics, Fagaceae cross the equator only in Southeast Asia, and even there just barely. The latest study, published in Science, extends the family's biogeographical history and suggests a Gondwanan supercontinent legacy in Asian rainforests larger than previously thought.
The researchers first found fossils resembling some oak leaves, with straight secondary veins and one tooth per secondary vein, at Laguna del Hunco, Chubut province. The leaves comprise about 10 percent of the thousands of 52-million-year-old leaf fossils, representing almost 200 species, found at the site over two decades in a long-term project between Penn State, Cornell University and Museo Paleontológico Egidio Feruglio (MEF), Trelew, Argentina.
Detail of the mature Castanopsis fruiting spike fossil with four nuts, dark and turned to coal, enclosed in scaly cupules. Cupule at top is splitting open [Credit: Peter Wilf, Penn State University]
For years the researchers hesitated to classify the leaves, because paleobotanist Edward Berry had assigned similar fossils to another family, and any claim of Fagaceae at so remote a location would require much more supporting evidence.
Later, the team unearthed rare fruit fossils -- two fruit clusters, one with more than 110 immature fruits -- at the site and compared them to living relatives. They found that these were fossils of ancient Castanopsis, an Asian chinquapin that today dominates the biodiverse, lower elevation mountain rainforests of Southeast Asia.
"One of the first clues was a little lip where the fruit is splitting open," Wilf said. "I recognized this lip as being similar to the fruit of the Japanese chinquapin. Then I realized there's a nut inside."
Detail of a single immature fruit of living Castanopsis acuminatissima, New Guinea, showing scaly surface and preservation of three slender styles (pollen-receiving organs) at top [Credit: Peter Wilf, Penn State University]
The nuts are fully encased in a scaly outer covering, or cupule, that splits open when the fruits mature. The cupules are arranged on a spike-like fruiting axis, and the young nuts retain delicate parts from their flowering stage. Their features are just like the living Castanopsis, Wilf said, and the fruits confirm that the leaves are Fagaceae.
"This is the first confirmed evidence that Fagaceae, considered restricted to the Northern Hemisphere, was in the Southern Hemisphere," said Maria Gandolfo, associate professor, Cornell University. "This is remarkable and allows us to rethink the origins of the fossil flora."
The fossils date to the early Eocene 52.2 million years ago. They are the only fossilized or living Fagaceae ever found south of the Malay Archipelago, the island chain just north of Australia.
Large fossil Fagaceae leaf from Laguna del Hunco with well-preserved details [Credit: Peter Wilf, Penn State University]
During the globally warm early Eocene there was no polar ice, and South America, Antarctica and Australia had not completely separated, comprising the final stage of the Gondwanan supercontinent. The researchers think animals had helped disperse the chinquapin's ancestors from North to South America at an earlier time. The plants thrived in the wet Patagonian rainforest, whose closest modern analog is the mountain rainforests of New Guinea.
The chinquapins may have also ranged into then-adjacent Antarctica and on to Australia, said Wilf. Castanopsis may have survived in Australia until the continent collided with Southeast Asia, where today chinquapins are keystone species, providing forest structure and food and habitat for birds, insects and mammals.
The Laguna del Hunco fossil site in Chubut, Patagonian Argentina. Paleontologists at centre of frame are collecting diverse plant fossils, including abundant leaves of Fagaceae [Credit: Peter Wilf, Penn State University]
"We're finding, in the same rocks as Castanopsis, fossils of many other plants that live with it today in New Guinea and elsewhere, including ferns, conifers and flowering plants," said Wilf. "You can trace some of the associations with Castanopsis seen in Eocene Argentina to southern China and beyond."
Today, Castanopsis plays an important role in intercepting year-round mountain precipitation that delivers clean water for drinking, fishing and agriculture to more than half a billion people and sustains diverse freshwater and coastal ecosystems. However, humans are clearing these rainforests for timber, development and crop cultivation, and modern climate change is increasing droughts and fire frequency.
"These plants are adaptable if given time and space," Wilf said, adding Castanopsis' trek from Patagonia to Southeast Asia occurred over millions of years and thousands of miles. "But the pace of change today is hundreds of times faster than in geologic time. The animals that depend on these plants are adaptable only to the extent that the plants are, and we are one of the animals that depend on this system. If we lose mountain rainforests, really fast we lose reliable water flows for agriculture, clean coral reefs offshore, biodiversity and much more."
Chinquapin fossils found in Patagonia, Argentina are 52.2 million years old and represent
the earliest fruit of this family of trees and were found south of the tropics
[Credit: Strategic Communications, Penn State University]
This study has implications for extinction in the face of climate change, according to Kevin Nixon, professor and L.H. Bailey Hortorium curator, Cornell University. He said Castanopsis went extinct in Patagonia due to a major extinction caused by the slow cooling and drying of the climate that occurred with the glaciation of Antarctica and the rise of the Andes.
"Those kinds of climate changes can have massive effects on biodiversity," Nixon said. "The relevance of understanding this is we can start to look at extinction processes. The better we can understand what causes extinction, the better we can deal with it."
More than a hundred pre-Columbian treasures including clay idols and textiles from the Inca Empire have been returned to Peru from the United States and Argentina.
View of one of the 130 textile and ceramic archaeological pieces belonging to the Moche, Chimu, Nazca, Chancay, Huari, Vicus, Inca and other cultures, after being successfully repatriated from the US and Argentina, on display at the Peruvian Ministry of Foreign Affairs building in Lima, on May 14, 2019. A lot of 38 pieces belonging to the Peruvian national heritage patrimony were brought with the assistance of the Phoebe A. Hearst Anthropology Museum at Berkeley University in the U.S. and a lot of 92 pieces smuggled out of Peru were also repatriated from Argentina [Credit: Cris Bouroncle/AFP]
The 130 artefacts, many of which were voluntarily returned after being illegally smuggled out of Peru, were displayed at the Ministry of Foreign Affairs building in the capital Lima on Tuesday.
The objects included decorated bowls and vases, embroidered cloths, carved wooden sculptures and painted figurines.
View of one of the 130 textile and ceramic archaeological pieces belonging to the Moche, Chimu, Nazca, Chancay, Huari, Vicus, Inca and other cultures, after being successfully repatriated from the US and Argentina, on display at the Peruvian Ministry of Foreign Affairs building in Lima, on May 14, 2019. A lot of 38 pieces belonging to the Peruvian national heritage patrimony were brought with the assistance of the Phoebe A. Hearst Anthropology Museum at Berkeley University in the U.S. and a lot of 92 pieces smuggled out of Peru were also repatriated from Argentina [Credit: Cris Bouroncle/AFP]
"Argentina (returned) a lot of 92 cultural goods and another from the United States is made up of 38 cultural assets," said a foreign ministry statement.
The US lot was repatriated with the help of an anthropology museum at the University of California, Berkeley, while 77 other objects belonged to Argentine individual collectors.
View of one of the 130 textile and ceramic archaeological pieces belonging to the Moche, Chimu, Nazca, Chancay, Huari, Vicus, Inca and other cultures, after being successfully repatriated from the US and Argentina, on display at the Peruvian Ministry of Foreign Affairs building in Lima, on May 14, 2019. A lot of 38 pieces belonging to the Peruvian national heritage patrimony were brought with the assistance of the Phoebe A. Hearst Anthropology Museum at Berkeley University in the U.S. and a lot of 92 pieces smuggled out of Peru were also repatriated from Argentina [Credit: Cris Bouroncle/AFP]
The archaeological pieces can be traced back to pre-Columbian cultures including the Moche, Chimu, Nasca, Chancay, Huari, Vicus, Lambayeque and Chincha, as well as the Inca.
The owners were approached by Peruvian authorities, who requested the objects' repatriation after identifying them as part of the nation's cultural heritage.
Cerro Blanco Volcanic Complex, located in the south of the Altiplano-Puna plateau, erupted around 4,200 years ago. But it was not an ordinary event. It was the largest eruption of the last 5,000 years in the Central Volcanic Zone of the Andes according to a new study published in the journal Estudios Geologicos. The estimated volume of ejected ash places this eruption amongst the largest eruptions of the Holocene Era (the last 11,700 years).
General view of the volcanic ash deposits of Cerro Blanco [Credit: JL Fernandez Turiel]
The research team was led by Jose Luis Fernandez Turiel, researcher at Institute of Earth Sciences Jaume Almera of the CSIC (ICTJA-CSIC). Spanish researchers from the University of Las Palmas de Gran Canaria and the Institute of Natural Resources and Agrobiology of Salamanca of the CSIC also participated in the study. They worked alongside Argentinian researchers from the National University of Mar del Plata, the National University of Tucuman and the University of Buenos Aires.
The authors of the study determined that the Cerro Blanco Volcanic Complex, located in the Argentine province of Catamarca, was the source of the thick, high-volume volcanic ash-fall deposits that are still present today in a large area of north-western Argentina. The existence of these deposits was previously known, but not their origin.
Researchers studied 62 outcrops in the area and collected more than 230 ash samples during several field campaigns. In order to determine the origin of these ash deposits, the samples were analysed and characterized by different petrological and geochemical techniques.
"Now we can confirm that the eruption of Cerro Blanco volcano was the event that produced those large Holocene ash deposits that blanketed and cover a large area of the Puna and neighbouring areas of northwestern Argentina," says Jose Luis Fernandez Turiel, leading author of the study.
Field work conducted in Tafi del Valle (Tucuman, Argentina) on the ash deposits from the Cerro Blanco eruption [Credit: JL Fernandez Turiel]
The vegetal remains preserved in the sediment layers embedded below the ash deposits were dated using carbon 14. Researchers were able to establish that the eruption took place 4,200 years ago. They reconstructed the transport and the fall of the ash that created the deposits. The eruption of Cerro Blanco was so explosive that the ash was scattered over an area of about 500,000 square kilometres. Ash deposits originated by the eruption were identified and found 400 kilometres away from the volcano caldera, near the town of Santiago del Estero.
In addition, pyroclastic flows filled up the surrounding valleys with thick ignimbrite deposits, some of them located about 35 kilometres away from Cerro Blanco volcano. The emptying of the magmatic chamber caused by the eruption led to the collapse of the volcanic building and the formation of a complex volcanic caldera.
"The geodynamic context of the area determines large explosive eruptions. These are a type of eruptions characterized by rhyolitic magma, with high silica and gas content," says Francisco Jose Perez Torrado, researcher at the Institute of Environmental Studies and Natural Resources of the University of Las Palmas de Gran Canaria.
According to Perez Torrado, "the eruption was not annular, following the edge of the caldera; in this case it was focused on a point to the edge. It was an explosive eruption that pushed an ash and gas cloud at an altitude of almost 32 kilometres according to our simulations."
Location map of the Cerro Blanco Volcanic Complex [Credit: JL Fernandez Turiel]
According to the study, the volume of deposited ash in this eruption was bigger than 170 cubic kilometres which lead to the researchers to estimate that the eruption of Cerro Blanco had a Volcanic Explosivity Index (VEI) of 7. This places the Cerro Blanco eruption among the largest volcanic global events of the last 10,000 years: it is similar to the eruption that occurred in the Island of Santorini which meant the end of the Minoan civilization. Moreover the volume of magma ejected by Cerro Blanco volcano eruption doubled to the magma ejected by the eruption of the Tambora volcano in 1815, which is thought to be the cause of a global cooling (1815 is known as "the year without summer").
The present study takes its origin from a previous project conducted to determine whether the high arsenic levels in the water of the Chaco-Pampeana Plain was related to ash-fall deposits of the Central and Southern Andes Volcanic Zones. It was during this work when the team of researchers began to characterize the ashes.
"We verified that the ash from the analysed deposits in the north came mainly from a single eruption, unlike in the south, which clearly came from different volcanoes," recalls Alejandro Rodriguez Gonzalez, from the Institute of Environmental Studies and Natural Resources of the University of Las Palmas de Gran Canaria.
According to Fernandez-Turiel, "our investigation changes the model of active volcanism of the Central Andean Volcanic Zone. Until now, it was thought that volcanism worked exactly the same, like in the south: many volcanoes with many eruptions over time. What we have seen in our research is that there are few eruptions, but highly explosive and erupting large volumes of magma."
Comparative graph of the volumes of magma expelled in different volcanic eruptions [Credit: JL Fernandez Turiel/Jordi Cortes]
These findings offer researchers an excellent temporal milestone to study many geological, archaeological and paleoclimatic features, among others, which occurred around the middle Holocene in a broad geographical area of South America.
According to Norma Ratto, archaeologist at the Institute of Cultures of the University of Buenos Aires and CONICET (UBA-CONICET), "the determination of the scope and occurrence of this large eruption provides new information to interpret different aspects of hunter-gatherer societies which inhabited north-western Argentina during the Holocene, as the different occupation of the spaces, the changes in the mobility of the groups due to modification and alteration of routes that allowed the connection between different ecological environments, the changes in the ecosystems and the health of the prehispanic populations, among others topics."
It is a surprising accumulation of fossils that would belong to dinosaurs, giant crocodiles and mammalian ancestors. In this "bed of bones", there are skulls and dismembered parts of, at least, seven or eight individuals, although there could be many more.
The fossilised dinosaur remains discovered in western Argentina are believed to be 220 million years old [Credit: CTyS-UNLaM Agency]
Dr. Ricardo MartÃnez, a researcher at the Institute and Museum of Natural Sciences of the University of San Juan (IMCN), highlighted the CTyS-UNLaM Agency that “it is a mass of almost bone against bone, there are no sediments; it is as if they had made a well and filled it with bones”.
In 2014, IMCN investigators had also released another bonebed, but that accumulation was not at all comparable to the one announced today. “This is something impressive; it's as if, here, the carnivores had a well and were pulling the bones after the meal”, joked the paleontologist.
In times of re-releases of Pet Sematary, this finding is an increased remastering of the bed of bones found years ago in Balde de Leyes, which is another very important site located southeast of the province of San Juan. If you want, too, with an even more terrifying image.
Dr. Martinez compared: “What we find now is a true accumulation of bones, glued together, with skulls, jaws, of at least 10 different animals totally disarticulated, piled bone on bone”.
Scientists speculate the site was a former drinking hole at a time of great drought, where the creatures died of weakness [Credit: CTyS-UNLaM Agency]
The diameter of this bone bed is King size, about two meters. Meanwhile, the depth may be much greater than that of a sommier. “So far, we have managed to dig about 50 centimeters and it continue down, so it could have a depth of a meter or two, we do not know, but, with what we have seen so far, it is already impressive", pondered the chief of the IMCN paleontology area. He added: "In addition, we verify that the diameter of the accumulation grows as we move forward with the excavation”.
Dr. Cecilia Apaldetti, researcher at IMCN and CONICET, explained that the finding was made in September of last year and, now, after the summer season in which there are no campaigns because of the high temperatures and the rains, they have returned with the intention to extract the entire block.
"However, this accumulation of bones is bigger than we thought, we still can not find the base and we will return to the site in these weeks with more people and more logistics, to be able to extract the entire block, for which we must make a concrete base and, of course, we will need a crane and adequate machinery to be able to achieve it”, Apaldetti told the CTyS-UNLaM Agency.
Beyond the fact that the famous Ischigualasto basin in San Juan always surprises, researchers claim never to have seen anything like it. "It is very difficult to find a cause to this tremendous accumulation of bones”, remarked Martinez, who directs this research.
Scientists preparing the fossil bed for transporation [Credit: CTyS-UNLaM Agency]
The expert noted that, beyond the extraordinary that is this accumulation, the finding has an even greater scientific value, "because these bones belong to a time interval that is among the fauna of Los Colorados, in which there was a great abundance of herbivorous dinosaurs especially sauropodomorphs and, below, is the Ischigualasto formation that has the most primitive and ancient dinosaurs known in the world”.
But in this interval that would be about 220 million years old, many species were not known and here a lot of individuals have been found, at least seven or eight, although there may be many more.
Among these new species, there would be discinodes -predecessors of mammals the size of an ox- and other archosaurs that, surely, are unknown species that can be dinosaurs and the giant ancestors of crocodiles, for example.
The researchers run a hypothesis about the factors that would have allowed this surprising accumulation of bones worthy of the imagination of a Stephen King of the Triassic. "Our theory is that it could have been a time of great drought and there was a body of water, a small lake for example, in which the herbivores were piled up to drink and, as the water evaporated, they were weakening and they were dying in the place”.
Once dead, other animals trampled their bodies and also appeared predators that partially disintegrated their bones. "Many of the predators also died on the spot, either because of the scarcity of water or because this site became a kind of trap for them”, MartÃnez said. He added: "This is how we thought that this great accumulation of bones would have taken place that we do not yet know the depth and the extension that it has; We will know this as we move forward with the investigation”.
