Three ancestral groups gave rise to the diverse people of South Asia today.

Mary Doggett/Alamy Stock Photo

South Asians are descended from a mix of farmers, herders, and hunter-gatherers, ancient DNA reveals

Sul-asiáticos são descendentes de uma mistura de agricultores, pastores e caçadores-coletores, DNA antigo revela

By Lizzie WadeApr. 18, 2018 , 3:00 PM

AUSTIN—Today, the population of South Asia is divided into dozens of ethnic, linguistic, and religious groups that live side by side—but not always in harmony. A contentious border separates India and Pakistan; political movements draw stark lines between India’s Muslim and Hindu populations. Groups don’t mix much, as people tend to marry those who share their ethnicity and tongue.

Now, a study of the first ancient DNA recovered from South Asia shows that populations there mingled repeatedly thousands of years ago. Nearly all of the Indian subcontinent’s ethnic and linguistic groups are the product of three ancient Eurasian populations who met and mixed: local hunter-gatherers, Middle Eastern farmers, and Central Asian herders. Three similar groups also mingled in ancient Europe, giving the two subcontinents surprisingly parallel histories.
The study, presented here last week at the meeting of the American Association of Physical Anthropologists and in a preprint on the bioRxiv server, sheds light on where these populations came from and when they arrived in South Asia. It also strengthens the claim that Proto-Indo-European (PIE)—the ancestral language that gave rise to modern languages from English to Russian to Hindi—originated on the steppes of Asia.

Agora, um estudo do primeiro DNA antigo recuperado do sul da Ásia mostra que as populações ali se misturavam repetidamente há milhares de anos. Quase todos os grupos étnicos e linguísticos do subcontinente indiano são o produto de três antigas populações eurasianas que conheceram e misturaram: caçadores-coletores locais, agricultores do Oriente Médio e pastores da Ásia Central. Três grupos semelhantes também se misturaram na Europa antiga, dando aos dois subcontinentes histórias surpreendentemente paralelas.

O estudo, apresentado na semana passada na reunião da Associação Americana de Antropólogos Físicos e em uma pré-impressão no servidor bioRxiv, esclarece de onde essas populações vieram e quando chegaram ao sul da Ásia. 
Também reforça a afirmação de que o proto-indo-europeu (PIE) - a língua ancestral que originou as línguas modernas, do inglês ao russo e ao hindi - originou-se nas estepes da Ásia.

“It’s first-rate work,” says Partha Majumder, a geneticist at the National Institute of Biomedical Genomics in Kalyani, India. He found hints of similar genetic patterns in his previous studies, but the addition of ancient DNA makes the new conclusions stronger, he says. “It’s absolutely stunning.”
Priya Moorjani, a geneticist at the University of California, Berkeley, studies how South Asian populations relate to each other and to others around the world.

In previous work, she analyzed the genomes of nearly 600 modern Indians and Pakistanis from 73 ethnolinguistic groups in South Asia. Her team found that almost all people living in India today carry ancestry from two ancient populations: Ancestral North Indians, who were more related to people from Central Asia, the Middle East, the Caucasus, and Europe; and Ancestral South Indians, who were more related to indigenous groups living in the subcontinent today. But without DNA from ancient people, Moorjani couldn’t be sure who gave rise to those ancestral populations, or when.

Moorjani, David Reich of Harvard University, and Kumarasamy Thangaraj of the Centre for Cellular and Molecular Biology in Hyderabad, India, spent years searching for ancient DNA in South Asia, where hot climates might degrade it. Finally, their team recovered and analyzed ancient genomes from 65 individuals who lived in northern Pakistan between 1200 B.C.E. and 1 C.E. They also analyzed 132 ancient genomes from Iran and southern Central Asia, and 165 from the steppes of Kazakhstan and Russia, and compared them with published ancient and modern genomes. These data allowed them to reconstruct when different populations arrived in South Asia and how they interacted.

Em trabalhos anteriores, ela analisou os genomas de quase 600 indianos modernos e paquistaneses de 73 grupos etnolinguísticos no sul da Ásia. Sua equipe descobriu que quase todas as pessoas que vivem na Índia hoje são ancestrais de duas populações antigas: os índios do norte ancestrais, que estavam mais relacionados com pessoas da Ásia Central, Oriente Médio, Cáucaso e Europa; e os índios do sul ancestrais, que estavam mais relacionados aos grupos indígenas que vivem no subcontinente hoje. Mas sem DNA de pessoas antigas, Moorjani não podia ter certeza de quem deu origem a essas populações ancestrais, ou quando.

 Moorjani, David Reich, da Universidade de Harvard, e Kumarasamy Thangaraj, do Centro de Biologia Celular e Molecular, em Hyderabad, Índia, passaram anos procurando DNA antigo no sul da Ásia, onde climas quentes poderiam degradá-lo. Finalmente, sua equipe recuperou e analisou genomas antigos de 65 indivíduos que viviam no norte do Paquistão entre 1200 a.C.E. e 1 C.E. Eles também analisaram 132 genomas antigos do Irã e do sul da Ásia Central, e 165 das estepes do Cazaquistão e Rússia, e os compararam com genomas antigos e modernos publicados. Esses dados permitiram que eles se reconstruissem quando diferentes populações chegavam ao sul da Ásia e como interagiam.



Between 4700 and 3000 B.C.E., farmers from Iran mixed with hunter-gatherers indigenous to South Asia, Moorjani said. This combination of ancestries was found in the DNA of skeletal remains from sites in Turkmenistan and Iran known to have been in contact with the Indus Valley civilization, which thrived in Pakistan and northwest India starting around 3300 B.C.E. The researchers dub this population “Indus periphery.” The 65 ancient people from Pakistan also show this combination, although they all lived after the Indus civilization declined. The researchers suspect that “Indus periphery” people actually may have been the founders of Indus society, although without ancient DNA from Indus Valley burials, they can’t be sure.




Entre 4700 e 3000 aC, os agricultores do Irã misturaram-se com caçadores-coletores nativos do sul da Ásia, disse Moorjani. Essa combinação de ancestrais foi encontrada no DNA de restos de esqueletos de locais no Turcomenistão e no Irã, conhecidos por terem estado em contato com a civilização do Vale do Indo, que floresceu no Paquistão e no noroeste da Índia a partir de 3300 aC. Os pesquisadores apelidaram essa população de "periferia do Indus". Os 65 povos antigos do Paquistão também mostram essa combinação, embora todos tenham vivido depois que a civilização do Indo declinou. Os pesquisadores suspeitam que as pessoas da “periferia do Indus” na verdade podem ter sido as fundadoras da sociedade Indus, embora sem DNA antigo dos enterros do Indus Valley, eles não podem ter certeza.


Still, Moorjani’s team sees this ancient mixture of Iranian farmers and South Asian hunter-gatherers all over South Asia today. As the Indus Valley civilization declined after 1300 B.C.E., some Indus periphery individuals moved south to mix with indigenous populations there, forming the Ancestral South Indian population, which today is more prominent in people who speak Dravidian languages such as Tamil and Kannada, and in those belonging to lower castes.

Ainda assim, a equipe de Moorjani vê essa antiga mistura de fazendeiros iranianos e caçadores-coletores do sul da Ásia em todo o sul da Ásia hoje. Como a civilização do Vale do Indo declinou depois de 1300 aC, alguns indivíduos da periferia do Indo se mudaram para o sul para se misturar com populações indígenas, formando a população do sul da Índia, que hoje é mais proeminente em pessoas que falam línguas dravídicas, como Tamil e Kannada. pertencente a castas inferiores.

Meanwhile, herders from the Eurasian steppe moved into the northern part of the subcontinent and mixed with Indus periphery people still there, forming the Ancestral North Indian population. Today, people who belong to higher castes and those who speak Indo-European languages such as Hindi and Urdu tend to have more of this ancestry. Shortly after, these two already mixed groups mixed with each other, giving rise to the populations living in India today.


Enquanto isso, os pastores da estepe da Eurásia se mudaram para a parte norte do subcontinente e se misturaram com as pessoas da periferia do Indo ainda presentes, formando a população do norte da Índia. Hoje, as pessoas que pertencem a castas mais altas e as que falam línguas indo-europeias, como o hindi e o urdu, tendem a ter mais descendentes dessa ancestralidade. Pouco depois, esses dois grupos já misturados se misturaram, dando origem às populações que hoje vivem na Índia.

“Strikingly, this is very similar to the pattern we see in Europe,” Moorjani said. Around 7000 B.C.E., agriculture spread into both Europe and South Asia with farmers from Anatolia and Iran, respectively, who each mixed with local hunter-gatherer populations. After about 3000 B.C.E., Yamnaya pastoralists from the Central Asian steppe swept both east and west, into Europe and South Asia, bringing the wheel and perhaps cannabis.
Earlier genetic work had linked the arrival of these herders to the spread of Indo-European languages in Europe. But other researchers, including archaeologist Colin Renfrew of the University of Cambridge in the United Kingdom, had argued that the earlier Anatolian farmers were the original PIE speakers. The new data “make a strong case” for the Yamnaya as carriers of Indo-European languages, Renfrew says. But he still thinks Anatolian farmers could have spoken the earliest language in that family.

Surpreendentemente, isso é muito semelhante ao padrão que vemos na Europa ”, disse Moorjani. Por volta de 7000 aC, a agricultura se espalhou para a Europa e o Sul da Ásia, com agricultores da Anatólia e do Irã, respectivamente, cada um misturado com populações locais de caçadores-coletores. Após cerca de 3000 a.C.E., os pastores Yamnaya da estepe da Ásia Central varreram o leste e o oeste, para a Europa e o sul da Ásia, trazendo a roda e talvez a Cannabis.

Trabalhos genéticos anteriores ligaram a chegada desses pastores à disseminação das línguas indo-européias na Europa. Mas outros pesquisadores, incluindo o arqueólogo Colin Renfrew, da Universidade de Cambridge, no Reino Unido, argumentaram que os primeiros fazendeiros da Anatólia eram os oradores originais da TORTA. Os novos dados "fazem um caso forte" para os Yamnaya como portadores de línguas indo-européias, diz Renfrew. Mas ele ainda acha que os fazendeiros da Anatólia poderiam ter falado a primeira língua daquela família.

Posted in:

• Asia/Pacific
• Europe
• Evolution

doi:10.1126/science.aat9247

Once Written Off for Dead, the Aral Sea Is Now Full of Life

Thanks to large-scale restoration efforts, the North Aral Sea has seen a resurgence of fish—a boon to the communities that rely on it.

Omirserik Ibragimov, 25, uses a net to ice fish on the frozen surface of the North Aral Sea near Tastubek, Kazakhstan.

Photograph by Taylor Weidman

By Dene-Hern Chen

Photographs by Taylor Weidman

PUBLISHED March 16, 2018

Reporting on this story was supported by a grant from the Pulitzer Center on Crisis Reporting.

ARALSK DISTRICT, KAZAKHSTANOmirserik Ibragimov fixed his gaze on the hole he had carved out from the frozen Aral Sea. The 25-year-old’s hands moved steadily, pulling out a fishing net that he and his father had left under the solid, snow-covered surface just three days earlier.

After a minute marked by tense silence, two breams emerged from the hole. Then three pike-perches, their silver scales shimmering as they struggled against the net’s green meshing.

“Here comes the gold,” Omirserik said with a smile as he continued tugging the net. The pike-perch, with its tender flesh and few bones, is considered to be the most valuable catch, selling for roughly 650 tenge (a little over $2) for a kilogram; local fishermen refer to them as “gold fish.”

His father, Kidirbai, worked with his bare hands to free the fish, his knuckles flush from the freezing water. After gathering all their nets, their total catch of the day was about 77 pounds (35 kilograms) of pike-perch and 44 pounds (20 kilograms) of bream—a sizable haul for a few hours of work.

The fishing has improved dramatically over the past few years on the North Aral Sea, indicating restoration efforts are working.

Photograph by Taylor Weidman

Just 15 years earlier, this would not have been possible. Once the world’s fourth-largest freshwater lake, with an area of some 26,000 square miles, the Aral Sea became the victim of the Soviet Union’s agricultural policies in the 1950s. Water from its two river sources—the Amu Darya and Syr Darya—was intentionally diverted for cotton cultivation. (See other rivers that have been run dry.)

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As decreasing water flow into the sea caused a rise in salinity, the abundant freshwater fish species began to die out. By the 1980s, the fishing industry in the Aralsk district—once a robust source of employment for the region—was wiped out, forcing a mass migration of people. The remaining population was hit by extreme weather, brought on by the dried-out Aral seabed, and deteriorating health.

“The people destroyed the sea and then nature took revenge on the people,” said Madi Zhasekenov, the director of the Aralsk Regional Museum and Fishermen Museum.

Ice fishing can be cold, yet lucrative, work.

Photograph by Taylor Weidman

Massive Disaster

This rapid collapse over less than three decades—which environmental scientists say is one of the planet’s worst ecological disasters—is marked today by the sea’s reduced size. Its total area of water, straddling Kazakhstan and Uzbekistan, is now a tenth of its original size. What’s left has broken into two distinct bodies: the North and South Aral Seas. In Uzbekistan, the entire eastern basin of the South Aral Sea is completely desiccated, leaving merely a single strip of water in the west. (Learn about other vanishing lakes around the world.)

But Kazakhstan’s North Aral Sea has seen a happier outcome, thanks to a nearly $86 million project financed in large part by the World Bank. Along with repairs to existing dikes around the basin to prevent spillage, an eight-mile dam was constructed just south of the Syr Darya River. Completed in the summer of 2005, this dam, named Kokaral, surpassed all expectations. It led to an 11-foot increase in water levels after just seven months—a goal that scientists initially expected would take three years.

Local people have long relied on camels as livestock, especially as fishing declined.

Photograph by Taylor Weidman

This turnaround in the North Aral Sea’s fate has meant that the fish stocks have returned to its waters, injecting new life into the local communities. Just as government policies had doomed the Aral Sea, careful planning and research helped revive at least part of it.

Kristopher White, a researcher and professor of Almaty’s KIMEP University who has studied the economic impacts of the Aral Sea’s desiccation, explained that while the sea will never return to its former size, the 18 percent increase in mass of the North Aral Sea is a testament to how political will and scientific research can benefit the environment.

“Anthropogenic ecological damage can be reversed by human intervention,” said White.

Children play on a snowdrift in Tastubek, Kazakhstan, where economic opportunities are improving with the health of the sea.

Photograph by Taylor Weidman

Optimism and Hope

At its peak in 1957, the Aral Sea produced more than 48,000 tons of fish, representing roughly 13 percent of the Soviet Union’s fish stocks. By the 1980s, due to the rising salinity of the sea, the 20 native species of fish were decimated; commercial harvests plummeted to zero by 1987. The water from the sea receded, and today, the shore is about 12 miles (20 kilometers) from Aralsk.

“The major source of employment was gone, and with it optimism and hope for the future,” said White. “And that really prevailed throughout the region until the completion of this dam.”

Workers process fish at a plant in Aralsk, Kazakhstan.

Photograph by Taylor Weidman

During those decades, flounder was the only fish that could survive the high-salinity North Aral Sea. But after the Kokaral Dam was finished, the average salinity dropped from 30 grams to 8 grams per liter, prompting the return of almost two dozen freshwater species through the Syr Darya river.

According to the Aralsk Fish Inspection Unit, fish catch in the North Aral Sea has grown six-fold since 2006, when the bulk of the 1,360 tons caught was flounder. By 2016, 7,106 tons of fish was caught, with bream being the most common, followed by roach and the sought-after pike-perch. For 2018, the fishing limit is set at 8,200 tons, said head inspector Esenbai Ensepov.

A worker prepares fish for smoking.

Photograph by Taylor Weidman

This return has brought commerce back to the inland town of Aralsk. Askar Zhumashev, 42, a supervisor at Kambala Balyk Processing Plant, said that his team processed roughly 500 tons of fish two years ago, the biggest amount since he started working there.

“When I was born, the sea was already gone,” said Zhumashev. “I went to the Aral Sea for the first time only two years ago. My parents used to tell me that the boats would come in and out everyday from the old port.” (Learn why a giant green lake turned red.)

Kiderbai Ibragimov, 45, prepares a fish meal at home in Tastubek.

Photograph by Taylor Weidman

Growing Prosperity—and Problems

In the winter, the village of Tastubek, about four hours from Aralsk, appears desolate. But around 10 AM every morning, the town hums to life as the fishermen begin gathering to inspect their gear and discuss the day’s plans. With the Aral Sea just an hour’s drive away, they can be back in the village by the late afternoon with a successful haul.

Kidirbai, the patriarch of the Ibragimov family, has witnessed the changing fortunes of Tastubek. He was born here in 1973. Unlike those forced to move during the bleak years, his family relied on their livestock of camels and horses for income. When he was a young boy, there were 90 houses in Tastubek.

“By the mid-90s, there were only nine houses left,” he said. This year, he counted 34, an increase from last year’s 29. The newcomers are young fishermen attempting to strike gold. “I am happy the village is growing because then maybe the government will pay more attention to us, like they would build a road or support the village,” said Kidirbai.

People wait for a train under a Soviet-era mural in Aralsk.

Photograph by Taylor Weidman

But prosperity has also generated some negative effects, like the raft of illegal fishing during the breeding season of May to July. Aldanbek Kerinov, a former taxi driver from Aralsk who started fishing full-time with his brothers seven years ago, explained that this period, well legally off limits, is considered the most bountiful because fish swim closer to the shore to lay their eggs.

“Everyone usually goes late at night, because during the day, everyone is afraid the fish inspectors will come,” he said. “There are no other jobs and fishing is the main source of income, so they will always continue to fish.”

Aldanbek was unconcerned about the impact this would have on the fisheries, as the World Bank’s second phase to the dam is touted to bring more water and thus more fish, he said. (While a plan to raise the Kokaral Dam’s walls to increase water levels has been in the works for years, a World Bank representative said that the government needs to approve the project in order for it to move forward.)

Yet the illegal fishing does worry experts like White, who points out that illicit harvests are much harder to track for management purposes. And the history of fishing has been rife with loose or no management, followed by collapse of stocks. (Learn about vanishing aquifers.)

A Muslim graveyard is seen at sunrise near Tastubek.

Photograph by Taylor Weidman

An Unpredictable Force

For Kirdirbai, the sea has been an unpredictable force in his life. In 1987, the water froze unexpectedly early in November, and his family’s fishing boat was stuck a thousand feet (300 meters) out in the sea. His father, worried about thin ice, tied a rope to himself and shuffled out from shore to retrieve it. Fourteen-year-old Kidirbai watched as his father freed the craft from the ice with a metal spike and dragged it back, without incident.

Five years later, Kidirbai was not so lucky. He and his friend were fishing in the summer when a big storm hit. The boat overturned and his friend drowned. Kidirbai, traumatized by the incident, stopped fishing for three years.

Yes, it is bad to fish during the breeding season, Kidirbai said. But after decades of poverty and harsh living, they were all hungry for prosperity. “Now the locals are thinking only about how to earn as much as possible,” he said.

His faith in the Aral Sea remains unwavering. Since the freshwater fish species have returned, Kidirbai—who could never fathom living anywhere else—is determined that his son has a future there as well.

“The sea is the source of life for us,” he said. “Next year, I am going to build a new house for him. My son will get married and he will continue fishing.”

With reporting contributions by Serik Dyussenbayev

Whence the Domestic Horse?

By Sarah C. P. WilliamsMay. 7, 2012 , 3:00 PM

Shards of pottery with traces of mare's milk, mass gravesites for horses, and drawings of horses with plows and chariots: These are some of the signs left by ancient people hinting at the importance of horses to their lives.


But putting a place and date on the domestication of horses has been a challenge for archaeologists. Now, a team of geneticists studying modern breeds of the animal has assembled an evolutionary picture of its storied past. Horses, the scientists conclude, were first domesticated 6000 years ago in the western part of the Eurasian Steppe, modern-day Ukraine and West Kazakhstan. And as the animals were domesticated, they were regularly interbred with wild horses, the researchers say.
"This is a very good paper," says biologist Michael Hofreiter of the University of York in the United Kingdom. "Nobody has applied this method of population modeling to horses before."


Throughout their history, horses have been interbred, traded between populations of people, and moved across continents. All of this makes their genetic history hard to follow. Moreover, the wild ancestor of horses, Equus ferus, is extinct, complicating researchers' efforts to compare the genetics of domestic animals with wild ones. 

Previous research nailed down a broad area—the Eurasian Steppe, which stretches from Hungary and Romania through Mongolia—as the region where horses originated and were domesticated. But earlier genetic studies relied mostly on mitochondrial DNA, which is inherited only from a mother, to try to understand horses' evolutionary history.

"The problem was that there was a lot of diversity in the mitochondrial DNA," says biologist Vera Warmuth of the University of Cambridge in the United Kingdom, the first author of the new study. And the diversity didn't group the horses into their breed or place of origin. "Every horse breed has almost all the mitochondrial lineages represented," she says.

Warmuth instead studied sequences of horse DNA inherited from both parents and known to be diverse between horse populations. She and her colleagues collected genetic samples from more than 300 horses at 12 different sites across the steppe.

Data were collected for only working animals bred within a local area, not those bred for show or appearance, to minimize any human-guided selection that would make some genes more common. Then, the researchers used computer programs designed to model the spread of a population to simulate how different locations of horse domestication and spread throughout the steppe would influence modern genetic diversity. They compared each model with the real data they had collected to see which fit best.


The best-fit model, the team reports today in the Proceedings of the National Academy of Sciences, showed the wild ancestor of domestic horses originating in eastern Eurasia 160,000 years ago and being domesticated in the western part of the Eurasian Steppe around 6000 years ago. The model also helped explain why there had been so many female lineages when previous studies had tried to rely on mitochondrial DNA. "We think that as domestic horses spread out of the western steppe, local wild females were continuously incorporated into the spreading herds," says Warmuth. The constant addition of new females made the genetic patterns—in particular, the female lineages—more complex than if the domestic population had been totally isolated.

Hofreiter is impressed. "They have still only narrowed down the domestication region to a fairly big area," he says, "but they did have enough genetic data to get a signal out of the noise."
Not all researchers are convinced, however. Archaeologist Marsha Levine of the University of Cambridge thinks using modern genetic samples to retrace horses' evolution is a dead end. "There's been mixing of cultures and mixing of horses in this region for many thousands of years," she says. "And so when you're looking at any modern horse, you just don't know where it's from."
Bringing together many kinds of evidence is what will ultimately answer the whens and wheres of horse domestication, Levine says. "What we need to be doing is using material from excavations, sequencing ancient genes, and combining that with what we know from archaeological evidence about how animals were used in the past."

Ultimately, says Hofreiter, getting to the bottom of horse domestication will reveal more than just the history of these animals. "Horse domestication has changed human cultures a lot. It has changed warfare, it has changed transportation," he says. "Studying the past of horses can tell us a lot about our own past."

Crânio de animal pré-histórico 'russo' é encontrado no Brasil

Fóssil ajuda a entender distribuição de ancestral dos mamíferos pela Terra.
É o 1º fóssil de carnívoro terrestre da Era Paleozoica na América do Sul.

Mário Barra Do G1, em São Paulo

16/01/2012 18h00 - Atualizado em 20/03/2012

 

O crânio de um ancestral dos mamíferos só encontrado antes em terras russas e africanas foi descoberto em São Gabriel, no Rio Grande do Sul, anunciaram cientistas brasileiros nesta segunda-feira (16). O fóssil é o primeiro descoberto na região de um carnívoro terrestre que teria vivido na América do Sul durante a Era Paleozoica – entre 540 milhões e 250 milhões de anos atrás.

Os chamados "terápsidos" viveram há 260 milhões de anos e se alimentavam de pequenos herbívoros.
O crânio completo encontrado tem aproximadamente 32 centímetros de comprimento e foi visto pela primeira vez em dezembro de 2008 na região dos pampas, dentro de uma fazenda. Depois de três anos de análises, os cientistas conseguiram identificar a espécie do animal e a anunciaram nesta segunda.
Para os pesquisadores responsáveis pela descoberta, as comparações com os “parentes” russos e africanos permitem estimar que o carnívoro brasileiro tinha 3 metros de extensão, pesando mais do que um leão.

O crânio encontrado na região dos pampas, no RS. (Foto: Cortesia Juan Carlos Cisneros / Divulgação)

O nome científico do bicho (Pampaphoneus biccai) significa “matador dos pampas”, explica um dos autores da descoberta, o pesquisador Juan Carlos Cisneros, da Universidade Federal do Piauí (UFPI).
O animal pertence a um grupo particular de terápsidos conhecidos como "dinocefálios". Este grupo de animais já extintos também recebeu um apelido ameaçador na tradução do latim: “cabeça terrível”.
A bravura está ligada aos ossos grossos dos dinocefálios, reforçados por rugas e cristais no crânio. “Essa característica era voltada para proteção. Algumas espécies usavam a cabeça para brigar, como fazem as cabras hoje em dia”, diz o pesquisador.
Mesmo bravos, a maior parte dos dinocefálios era herbívora. As poucas espécies carnívoras mediam até 6 metros e eram os maiores predadores terrestres na época em que P. biccai viveu.
“Carnívoros são raros. Até hoje, se você vê um documentário na África, vai ver um monte de zebra, mas poucos leões”, diz Cisneros. “Eles são limitados pelo volume de alimento disponível, há sempre menos carnívoros do que herbívoros.
Caça a fósseis
O achado foi divulgado na revista da Academia de Ciências Americana, a PNAS, nesta segunda. Cisneros já esperava encontrar fósseis no Rio Grande do Sul que fossem parecidos com os de outras partes do globo.
“A gente tinha uma suspeita de que esse animal pudesse existir no Brasil”, afirma.
Entre 2008 e 2009, a equipe de Cisneros visitou 50 localidades no país, procurando por sítios paleontológicos relevantes. Eles escolheram dez lugares, sendo que um deles rendeu a descoberta de outro animal pré-histórico, mas herbívoro: o Tiarajudens eccentricus, um terápsido com dentes no céu da boca (palato), cujo fóssil também foi achado em São Gabriel.
“Procurávamos sempre por lugares sem vegetação e, dependendo das cores observadas e da erosão no local, nós avaliamos as chances de encontrar fósseis ou não”, explica o especialista. “Essa área dos pampas gaúchos apresenta grande potencial, há rochas sedimentares ali, que cobrem os restos mortais dos seres vivos com areia e lama.”

Ilustração mostra como seria o 'Pampaphoneus biccai'. (Crédito: Voltaire Neto / Divulgação)

Passeio pela Pangeia

Cisneros defende que o estudo é uma prova da grande mobilidade dos vertebrados terrestres por todos os cantos do supercontinente Pangeia, que unia, no passado, todos os continentes atuais.
O fóssil é muito parecido com as espécies encontradas atualmente na Rússia, no Cazaquistão, na China e na África do Sul. Com a versão brasileira deste tipo de animal, especialistas acreditavam que uma distribuição mais cosmopolita dos terápsidos pode ter ocorrido muito antes do que se imaginava.
Até então, os cientistas afirmavam que este tipo de interação teria ocorrido somente mais tarde, durante o período Triássico – entre cerca de 250 milhões e 200 milhões de anos atrás.


'Pais' dos mamíferos

Apesar de serem muito parecidos com répteis, os terápsidos se encontram mais próximos dos mamíferos na arvore genealógica dos animais pré-históricos. Isso os distancia também das comparações com os dinossauros.
Os mamíferos atuais possuem ossos dentro do ouvido que participam da audição, além de dentes mais complexos, cauda menor e uma postura mais ereta. No caso de P. biccai, a semelhança com répteis aparece somente quando se leva em conta a forma como os dentes se encaixavam: os de cima entre os debaixo, como ocorre em uma boca de jacaré.