palaeontology – Page 3 – Carbon Chemist

Tiny arm bone belonged to smallest ancient human ever found

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Credit: Yousuke Kaifu

A 700,000-year-old arm bone found on an Indonesian island is shedding light on the evolution of Homo floresiensis¹ — an ancient relative of modern humans nicknamed hobbit owing to its small stature.

At just 88 millimetres long, the arm bone fragment belonged to the smallest adult hominin ever found. The discovery, published on 6 August in Nature Communications, supports the idea that H. floresiensis’ ancestors evolved into a much smaller species just a few thousand years after arriving on the remote island of Flores in what is now Indonesia.

The discovery of Homo floresiensis: Tales of the hobbit

Island dwarfism — the process by which animals evolve a smaller body size as a result of being isolated on an island — has happened frequently throughout evolutionary time. But before the discovery of H. floresiensis, reported in 2004²^,³, “no one thought it could happen to humans”, says study co-author Yousuke Kaifu, an anthropologist at the University of Tokyo.

The suggestion that H. floresiensis’ ancestors developed dwarfism so rapidly after arriving on the island is “surprising, but also exciting”, he adds.

Island effect

Species that find themselves trapped on an island often undergo massive changes to adapt to their new environment. Mammoths, deer and other animals that have ended up on islands have all shrunk — possibly because there is less food available or because there are fewer threats from predators, says Kaifu.

Scientists suspect that something similar might have happened to the ancestors of H. floresiensis. One working theory of how the species came to be is that a group of ancient humans — possibly the larger Homo erectus — washed up on Flores Island after a tsunami or large storm. The first H. floresiensis site to be found contained fossils dating to around 60,000 years ago⁴, just a few thousand years before the species went extinct. But tools found on the island suggest that hominins arrived there much earlier, around one million years ago⁵.

What these early settlers looked like — including how tall they were — remained mysterious for years. The first clues that early versions of H. floresiensis might also have been small began to emerge in the mid-2010s, when a dig at another site uncovered unusually small jawbones and teeth dating to about 700,000 years ago⁶. But inferring body size from teeth or facial bones tends to be imperfect, says Karen Baab, a palaeoanthropologist at Midwestern University in Glendale, Arizona. To get a more reliable measure, researchers needed bones from limbs or other parts of the skeleton.

Credit: Yousuke Kaifu

A breakthrough came in 2015, when the team was reconstructing fragmented bones in the laboratory and realized that some broken pieces belonged to a humerus — the bone that connects the shoulder to the elbow. The fossil was missing both end pieces but could still provide some clues to the size of the ancient human it belonged to.

Adult bone

The size of the humerus indicated that its owner was tiny — but it could have belonged to a child rather than an adult. In the latest study, Kaifu and his team examined a slither of the bone under a microscope to investigate this possibility. The structure of the bone indicated that it belonged to a fully grown adult.

‘Hobbit’ relatives found after ten-year hunt

The arm bone is 9–16% smaller and thinner than those belonging to the 60,000-year-old H. floresiensis specimen, confirming that its owner was “at least as small” as later members of the species, says Baab. The researchers estimate that this individual would have been no more than 108 centimetres tall.

The findings suggest that H. floresiensis had evolved to be shorter within 300,000 years of the species’ ancestors arriving on the island. Cranial fossils of H. floresiensis suggest that their brains, too, shrank during that time. The rapid emergence of a new body type reveals the many pathways that human evolution can take, says Kaifu. “We think it was destiny [for humans] to become clever,” he says. “Flores tells us that there are other ways for humans to be.”

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August 6, 2024
Is that a durian? No, it’s a weird ancient mollusc

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The complete Shishania aculeata fossil resembles a durian fruit (left); its spines (right) are made of an organic compound called chitin.Credit: G Zhang/L Parry

From much-maligned garden slugs and snails to tool-using octopuses and bivalves such as clams and oysters, molluscs are among the most diverse animal groups on the planet. But their origins are a mystery.

A newly found mollusc fossil — which resembles a durian fruit sliced in half — offers clues as to what the earliest species looked like. “They were this sort of weird, spiny slug,” says Luke Parry, a palaeontologist at the University of Oxford, UK, who is part of the team that described the roughly 510-million-year-old fossils in Science on 1 August¹.

‘Touch-taste’: how the octopus repurposed its nervous system to hunt

Like many other animal groups, molluscs exploded in diversity during the Cambrian period, 539 million to 485 million years ago, and nearly all the groups found on Earth now emerged during this time.

But this rapid pace of change makes it difficult to determine the characteristics of early molluscs, says Parry. “Just from looking at a modern clam and a modern octopus, it’s sort of hard to envision what their common ancestor might have looked like.”

The durian-fruit-like mollusc fossils, a couple of centimetres in diameter, were discovered on a road-building site in Kunming, China. Study co-author Guangxu Zhang, a palaeontologist at Yunnan University in Kunming who was then doing his PhD, thought the first specimen he found resembled a rotting plastic bag. “It wasn’t immediately important or striking,” says his adviser, Xiaoya Ma, a palaeontologist at the University of Exeter in Penryn, UK, who is also a co-author of the study.

An artist’s reconstruction of the Shishania aculeata mollusc.Credit: Reconstruction by M. Cawthorne

But further, better-preserved specimens revealed the creature’s soft underside, including features found in modern molluscs, such as a foot. The mollusc’s topside was covered in hollow spines made of chitin — an organic compound that also forms insect exoskeletons. The researchers named the species Shishania aculeata, after accomplished Yunnan province geologist Shishan Zhang, who is now 87.

These bizarre ancient species are rewriting animal evolution

Hollow chitinous spines in early molluscs such as Shishania probably gave rise to calcium carbonate ‘spicules’ found in modern molluscs called chitons. The spines also seem to share an origin with chitinous bristles covering segmented worms in a distantly related invertebrate group called annelids.

“This is really another piece in the jigsaw puzzle,” says palaeobiologist Mark Sutton at Imperial College London. “It helps nail down our ideas about molluscan evolution and we’re finally getting a coherent story.”

The spines, which might also have been sense organs, probably helped Shishania and other early molluscs to avoid predators as they crept along Cambrian sea floor, says Parry. “The fact that we have any of these fossils is pretty amazing.”

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August 1, 2024
Organ systems of a Cambrian euarthropod larva

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Woolly mammoth DNA exceptionally preserved in freeze-dried ‘jerky’

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Legs of a juvenile female woolly mammoth named Yuka — The legs of a 39,000-year-old woolly mammoth

Love Dalén/Stockholm University

A woolly mammoth that died 52,000 years ago is so well preserved that it is possible both to read its full genome and to reconstruct the three-dimensional structure of its chromosomes – information that can provide unprecedented details about how the animal’s genes behaved during its life. The extraordinary feat was possible because the animal’s remains were naturally freeze-dried, preserving its DNA in a glass-like state.

Scientists found the mammoth remains in a cave in Siberia in 2018 where they had been preserved in the permafrost. The mammoth’s tissues were dry, “but not as dry as commercial beef jerky”, says Olga Dudchenko at Baylor College of Medicine in Texas, “and it was actually woolly”. Eager to see what genetic information they could glean, Dudchenko and her colleagues sampled flesh behind the mammoth’s ear and sequenced the DNA.

Because molecules of DNA begin to break down when an animal dies, scientists have previously only been able to find tiny snippets of the woolly mammoth genome – but to the researchers’ surprise, the animal’s chromosomes were perfectly preserved. “This does not match with anything that we have analysed before that was 52,000 years old, so that was very surprising,” says Juan Antonio Rodríguez at the University of Copenhagen in Denmark, a member of the research team.

They also found that the mammoth had 28 pairs of chromosomes – the same number as their closest living relative, the Asian elephant. The chromosomes’ three-dimensional structure was also preserved, which helps distinguish active genes from inactive ones. The researchers found, for example, that the gene responsible for hair growth was more active in the mammoth than in elephants, explaining their shaggy coats. The researchers also analysed a DNA sample from a 39,000-year-old mammoth (see picture above) and found its genome was preserved in a similarly exceptional state.

Identifying which genes are active in woolly mammoths versus elephants may boost so-called de-extinction efforts, says Hendrik Poinar at McMaster University in Canada, who was not involved in the work. “To get as close to a real mammoth as possible, one needs to know how the [genetic] architecture differs from an Asian elephant,” he says. Understanding which genes to tweak – such as those that produce lots of hair – could help create more realistic-looking and sounding animals that closely resemble the ancient pachyderms, though they would not be true woolly mammoths.

But how did this DNA stay intact for more than 50,000 years without unravelling? The researchers credit the ideal conditions of the cave, which simultaneously chilled and desiccated the animal. “The sample lost much of its water into the cold and dry Siberian winter,” says Dudchenko. She adds that a broadly similar drying process occurs during the production of foods like prosciutto.

To check their theory, the researchers put fresh and freeze-dried beef liver through a series of tough tests. After three days at room temperature, the DNA in the fresh beef was in fragments. But the freeze-dried stuff kept its chromosome structure on the nanometre scale even after a year. “At that point, we were like, okay, time doesn’t kill it – what does?” says Dudchenko.

So they fired a shotgun at the mock mammoth jerky, ran over it with a car and had a former professional baseball player throw a fastball at it, all to try to destroy its DNA. Each time, the dried beef liver shattered into small pieces but maintained its microscopic structure, preserving the DNA inside. “We found out that it works – it survives,” says Rodríguez.

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July 11, 2024

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In two separate expeditions 150 years ago, soldiers, scientists and mineral prospectors entered the lands of Lakotan people. This was just six years after the United States had formally recognized Lakotan sovereignty in the region.

In July 1874 — in the better known of the two expeditions — an ambitious young lieutenant colonel named George Armstrong Custer led more than 1,000 heavily armed troops into the Black Hills, a mountain range in what is now western South Dakota and eastern Wyoming. The official aim of the expedition was to map the area and find a suitable location to build a military fort, “to take the hostile backbone out of these unruly savages”, according to a high-ranking army commander¹. But Custer had also recruited a team of geologists, mineral prospectors and journalists to accompany his soldiers, in the hope of precipitating a gold rush.

The second expedition was led by Othniel Charles Marsh, a pre-eminent palaeontologist at Yale University in New Haven, Connecticut. In November that year, Marsh unearthed two tonnes of prehistoric fossils and shipped them to the Yale Peabody Museum of Natural History.

Scientific societies have a part to play in repatriating fossils

Custer’s expedition is often used to demonstrate the ruthless tactics deployed by the United States to colonize Native American lands. Marsh’s venture is generally seen in a more benign light, as an effort to further humanity’s understanding of Earth’s history. But a closer look at what happened in 1874, and in the years that followed, reveals that Marsh also contributed to the dispossession of Native American people. He extracted countless specimens from Lakotan lands without permission. When he shipped the fossils to Connecticut, most of the Lakotan meanings and stories tied to them were stripped away. Perhaps most egregiously, Marsh’s specimens were subsequently used to support an erroneous, racist theory of evolutionary progress that was deployed to justify the imperial expansion of the United States.

Around the world, archaeologists and anthropologists have taken steps to confront the darker side of their disciplines’ histories. In the United States, as of this January, federal law mandates that museums obtain “free, prior, and informed consent” from lineal descendants, American Indian Tribes and Native Hawaiian organizations before they exhibit human remains or cultural items (see go.nature.com/3wcvcvh). A similar reckoning for the Earth sciences — including a rethink of where and how natural history collections are curated — could help to rebuild Indigenous communities’ trust in science globally. It could also promote a greater diversity of perspectives on the natural world.

Material motives

According to Lakotan people (the Native American Nation now has more than 115,000 citizens), they have always lived in Paha Sapa, as they call the Black Hills. When strangers first started entering their hunting grounds — often in search of material wealth — Lakotans exchanged animal pelts with them for weapons and other goods. But over time, the flow of migrants led to rising tensions, particularly around the hunting of buffalo (Bison bison)².

Lakotan people were not just dependent on the buffalo for their livelihoods; they also viewed them as relatives. Whereas the region’s Indigenous people agreed not to hunt animals beyond what was needed, migrants began slaughtering buffalo on a massive scale, in part to limit the power and mobility of the Indigenous groups.

A portrait of Red Cloud and Othniel Charles Marsh taken in 1883. — Othniel Charles Marsh (left) posing with Mahpiya Luta in a photographer’s studio.Credit: National Portrait Gallery, Smithsonian Institution

Hoping to curb the influx of migrants, a leader named Mahpiya Luta (Red Cloud), the head of a group of Lakotan people called the Oglala, forged a powerful alliance with the Cheyenne and Arapaho peoples, two other Native American Nations. When it became clear that the United States was failing to prevail on the battlefield, the federal government sued for peace and convened a treaty council in 1868 at Fort Laramie, in present-day Wyoming. After this meeting, the United States agreed to recognize Lakotan sovereignty in a swathe of territory about the size of Spain. This region, covering portions of what is now South Dakota, North Dakota, Montana, Wyoming and Nebraska, includes the Black Hills and the White River Badlands, a geological formation that is rich in vertebrate fossils, which range from 27 million to 37 million years old.

Custer’s expedition six years later almost immediately attracted countless migrants to the treaty lands. In August 1874, before Custer’s scientists had even finished their work, expedition journalists dispatched several reports to newspapers across the United States touting the region’s rich mineral resources. As well as making front-page headlines in newspapers such as the New York Tribune, Custer’s exploits were publicized in books, pamphlets, maps and advertisements. Some of the most sensational reports were printed by the US Land Office, as well as by railroad companies that sought to profit from westward migration.

For Marsh, it wasn’t rumours of the Black Hills’ rich mineral deposits that drew him to the region, but reports from military surveyors of a “vast deposit of fossil remains” in northern Nebraska³.

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Custer had actually invited Marsh to join his July expedition. But Marsh had declined, sending his most promising student, George Bird Grinnell, instead. Later that year, however, Marsh set out for the treaty lands. When he arrived at the Red Cloud Agency, a military post where the US government distributed money and supplies to Indigenous people, Marsh found that the assembled Indigenous groups were highly suspicious of his interest in fossils. According to a 22 December 1874 article in the New York Tribune, a meeting was convened during which White Tail, one of the Lakotan leaders, “sprang at once to his feet”, declaring “that the proposed bone-seeking was merely a ruse to begin digging for gold and invading the Black Hills”.

After a tense and protracted negotiation, Red Cloud agreed to let Marsh enter the Badlands as long as he was escorted by Lakotan guides, and as long as he promised to tell federal officials in Washington DC that a government officer in charge of the Red Cloud Agency was distributing poor-quality supplies and embezzling funds. According to the Tribune article, Marsh accepted, but when it became clear that the Lakotans were growing increasingly suspicious of his true motives, he resolved to leave for the White River Badlands without his guides, under the cover of darkness.

Over the next few days, Marsh and his military escort excavated cartloads of fossils — including the massive remains of extinct ungulates that Marsh named Brontotheriidae — all under the watchful eye of Lakotan warriors who had quickly realized what he was up to. Writing in the 17 November 1874 edition of the New York Tribune, a newspaper journalist even joked that “the search for fossils instead of that for gold may unlock the gates of the Black Hills”.

Plains Bison (buffalo) with mountains behind them as they graze in Badlands National Park, South Dakota — Lakotan people depended on the hunting of buffalo for food and pelts.Credit: Mark Newman/Getty

Marsh was not the only scientist to extract knowledge and research materials from Lakotan treaty lands. Many fossils have been taken from the region over the years, often without permission⁴. After the initial discoveries of 1874, Marsh sent his assistant John Bell Hatcher to find more specimens for the Peabody Museum. Over the next several decades, scientists from the American Museum of Natural History in New York City also collected specimens in the treaty lands, resulting in the publication in 1929 of a massive treatise on the region’s extinct ungulates by the museum’s president, Henry Fairfield Osborn⁵. But Marsh’s findings helped to support the imperial expansion of the United States in a more insidious way, too.

According to Marsh and his colleagues, extinction had a role in evolutionary advancement by creating ecological space for new and more advanced lineages. This idea — that certain less-evolved races are doomed to extinction, known as ‘racial senescence’ — was widely embraced by intellectual elites at the time. And it was used to support claims that North America’s Indigenous nations were naturally destined to disappear⁶. In other words, a speculative theory about evolution bolstered by fossils extracted — illegally — from treaty lands was invoked to justify the dispossession of those same lands by portraying their original inhabitants as naturally doomed to extinction.

Genuine collaborations

Today, the involvement of scientists such as Marsh in the colonization of North America is rarely discussed. A recently renovated exhibition about vertebrate fossils at the Peabody Museum, for instance, acknowledges the historical tensions between scientists and Native American people. But it also suggests that a more collaborative relationship existed between Marsh and Lakotan people than the evidence indicates. For example, one sign explains that Marsh was inspired by Lakotan stories about thunder beings (Wakiŋyaŋ) when he decided to use the Greek word for thunder beast to name the extinct ungulates he had excavated ‘brontotheres’. Wakiŋyaŋ are bird-like spirits whose conflict with ancient monsters called uŋhcegila is often used by Lakotan people to explain the abundance of fossils in the White River Badlands.

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In our view, Earth scientists and natural history museums should foster further conversations about the ways in which their disciplines and institutions are entangled with the violent history of colonialism. Some have already begun to take important steps in this direction. The Natural History Museum in Berlin, for example, has created an interdisciplinary research centre, involving historians, anthropologists and natural scientists, to explore the provenance of its collections.

We encourage more interdisciplinary research of this kind. More museums and universities should create scholarships to make their collections easily accessible to students and researchers from the lands from which they were extracted. Furthermore, scientists could do much more to forge reciprocal relationships with people on whose lands they wish to work — for instance, by discussing potential collaborations with local partners before submitting a funding proposal. Finally, we think that where and how natural history collections are curated should be re-evaluated.

There are clear legal arguments for repatriating fossils extracted from the White River Badlands. The 1868 Treaty of Fort Laramie — which, according to a 1980 ruling by the US Supreme Court, remains in effect — explicitly sets aside the lands around the Black Hills for the “absolute and undisturbed use and occupation” of Lakotan people (see go.nature.com/4ar2cat). Why should this language not cover the extraction of specimens?

Angela Babby, “The Race for Paha Sapa”, Vitreous enameled glass and mortar on tile board showing land, sky and various animals. — Legends around the fossils include stories about a great race involving animals.Credit: Angela Babby

Implicitly or explicitly, it is often assumed that because Earth sciences deal with rocks and fossils, rather than with artefacts or human remains, they should not be held to the same ethical standards as anthropology and archaeology. In 1999, for example, under the Native American Graves Protection and Repatriation Act (NAGPRA), the Confederated Tribes of the Grand Ronde Community of Oregon asked for the return of a sacred meteorite called Tomanowos, or ‘sky person’. Describing the specimen as “a feature of the landscape”, the American Museum of Natural History denied the tribe’s claim and filed a federal lawsuit in 2000 to clarify that “NAGPRA does not cover this type of object”⁷. In support, an editorial in The New York Times stated that the meteorite “is a celestial object” that “belongs to us all, and is best left in the custody of the museum”. Similar arguments are often made for fossils that pre-date the evolution of humans⁸.

This line of reasoning overlooks the very different relationships between nature and culture, prehistory and the present that characterize the cosmology of Lakotans and many other Indigenous cultures worldwide.

The Lakotan creation story — the narrative of how Lakotan people came to be, passed down through generations — begins with Iŋyaŋ (stone). Iŋyaŋ existed before there was anything else, but he wanted something over which he could exercise his power. So he opened his veins and spread his blood in a great disk all around himself to create Maka (Earth). Because Iŋyaŋ was unable to staunch the flow of blood, his body became brittle and dry, and he was scattered all over Maka. From this initial sacrifice, everything else followed, including the sky, the Sun, the Moon, the plants and the animals⁹.

Del Iron Cloud, "Arriving for the Great Race", Acrylic painting of various dinosaurs and a buffalo in a field. — All animals came together for the start of the great race, according to legend.Credit: Del Iron Cloud

According to Luther Standing Bear, who worked to uphold Lakotan culture and sovereignty in the late nineteenth century, the creation story reminds Lakotans that they came from Maka, which in turn provides “the foundation for the love they bore for earth and all the things of the earth”¹⁰. These teachings are reinforced by ceremonies, such as the sweat lodge, a ritual that involves pouring water over hot stones while offering prayers to Tuŋkasila (grandfather or creator). As Albert White Hat, a respected teacher of Lakotan language and culture, explains¹¹: “Whether it’s the spirit of the eagle, or the coyote, or the spider, whatever spirit comes in the lodge, I address them as Tuŋkasila … because they represent the beginning of time until today. And they are my relatives, they are dear to me.”

The Lakotan saying Mitakuye Oyasiŋ, or ‘We are all related’, extends beyond humans to encompass everything in the treaty lands — including plants and animals, stones, the sky, fossils, thunderstorms and Earth itself. All are part of a complex network of relationships forged out of mutual dependence and reciprocity. In our view, museums have an ethical duty to return fossils extracted from the White River Badlands, not just because of the 1868 agreement, but because fossils are an integral part of the system of relationships that brings order to all life in the treaty lands.

Diverse world views

The realization that extractive capitalism is unsustainable is leading to a growing interest in how Lakotans and other Indigenous people relate to Earth². By partnering with Native American Nations to build museums on tribal lands, institutions such as the Peabody Museum could help to develop exhibits that present a much richer picture of the stories, meanings and interpretations tied to fossils than is currently possible.

Visitors could learn, for example, how a series of uplifts followed by erosion, which extend as far back as the Precambrian period (more than 500 million years ago), helped to create the Black Hills. But they could learn about the Lakotan narrative of how the Black Hills came to be, too.

“Far back in the first sunrise of time,” Lakotan storyteller James LaPointe explains in his 1976 book, Legends of the Lakota, the treaty lands were disordered and chaotic. After much deliberation, humanity held a great race to decide who could eat whom. As the seething mass of animals raced round and round, Earth began to quiver and, with “a thunderous roar, it burst open”. As flames rose all around them, the animals “lay dead in their tracks, covered with smoldering ashes and lava”¹². As a result of all this, “there are many large bones still lying along the historic track”, including the “huge bones of Unkche Ghila, which, once upon a time, roamed these prairie lands” and “can be found in the badlands to the east and south of the Black Hills”.

As well as being repositories for repatriated specimens, museums on Indigenous lands could employ local researchers, provide educational resources for local students and develop innovative exhibitions by involving Indigenous poets and artists — ultimately providing an inclusive and informative resource for everyone.

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How I’ve helped to discover nearly 40 species in the Amazon

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“In the past, scientists thought it was impossible to find fossils in the Amazon, because the vegetation is dense and there are few exposed rock outcrops to dig into. It’s also a constantly changing landscape: specimens that become exposed on riverbanks can disappear in a rainstorm. But over the past 15 years, palaeontologists have worked smarter to find fossil evidence to reconstruct the Amazon’s past: that’s why my colleagues and I find ourselves on expeditions each August and September, when the water level drops and fossils are exposed on the riverbanks.

We have found signs of a rich variety of crocodilian species — especially from the Miocene epoch (5 million to 23 million years ago). Today, these reptiles include crocodiles, caimans, alligators and gharials; of these, alligators are the only ones never to have existed in South America.

As part of the first team of vertebrate palaeontologists based in Peru, I have participated in the discovery of 37 species in the Amazon. In 2004, we described a caiman with a shovel-like head that it would have used to excavate bivalves in muddy lake bottoms. And, in 2018, we conducted a big expedition funded by the US National Geographic Society to the Napo River, which flows into the Amazon from Ecuador. We were looking for crocodilians, but we also found a 16-million-year-old fossil of a freshwater dolphin that would have been more than 3 metres long.

In this image, I’m preparing a caiman fossil that was collected in the Amazon by an international team including French and American colleagues. I worked for hours to determine that it was roughly 40 million years old: all the caiman fossils found before that had been 13 million to 14 million years old, so this creature was even older relative to them than they are compared with us.”

This interview has been edited for length and clarity.

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June 17, 2024

Tiny great ape fossils identified as new species from Europe

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Two teeth, viewed from multiple angles, from the newly identified ancient ape Buronius manfredschmidi

Böhme et al., 2024, PLOS ONE, CC-BY 4.0

A tiny, vegetarian great ape may have lived in western Europe 11.6 million years ago. Smaller and lighter than any other known great ape, the newly discovered 10-kilogram primate was a skilled climber that probably ate leaves, says Madelaine Böhme at the University of Tübingen in Germany.

“It’s quite a small primate,” she says. “But it differs from all known fossils and, of course, all living great apes we know so far.”

About 15 million years ago, in the middle of the Miocene Epoch, hominoids – the great apes – became rarer in Africa and more abundant in Europe. While they sometimes shared habitats with other primates such as pliopithecoids – extinct cousins of apes and Old World monkeys – hominoid species didn’t appear to coexist with each other in Europe.

In 2019, Böhme and her colleagues reported the discovery of 37 bones at Bavaria’s Hammerschmiede archaeological site that appeared to come from an early bipedal ape from 11.6 million years ago, which they named Danuvius guggenmosi.

During the excavations, Böhme was surprised when she found two tiny, ape-like teeth and a kneecap in the same layer of sediment as the Danuvius fossils.

“We kept saying: ‘What is this?’” she says of these smaller fossils. “And then we decided, OK, it’s clear: this is something new.”

The fossils are too old for DNA analysis, says Böhme. So the researchers took detailed measurements of the 7-millimetre-long molar and the 16-millimetre-wide kneecap, both from a juvenile, as well as a smaller premolar fragment, which they say came from a young adult. They also calculated the thickness of the enamel and ran microscopic CT scanning of the teeth.

The thin enamel, like that of gorillas, suggests a soft diet probably composed of leaves, says Böhme. The shape, thickness and ligament attachment sites of the kneecap resemble those of tree-living primates, hinting that the ape was a proficient climber.

The researchers named the new ape Buronius manfredschmidi, after the medieval name of a city near the Hammerschmiede site, and a dentist named Manfred Schmid who has been collecting fossils from the site since the 1970s.

Lack of competition for resources might explain why the Buronius and Danuvius apes could live together, says Böhme – Danuvius is thought to have eaten hard foods like nuts and possibly meat. The team cannot rule out the possibility that the larger ape, which might have been up to three times heavier, may have sometimes fed on the smaller species, she adds.

However, the three fossils might not be sufficient to make such “grandiloquent” conclusions, says Sergio Almécija at the American Museum of Natural History in New York City. “Could the smaller fossil elements belong to an infantile Danuvius individual?” he asks. “The teeth certainly look like they could be deciduous [baby teeth].”

He also wonders whether the kneecap represents the same species as the teeth. “Even though it is suggested that it belongs to a juvenile individual, its size overlaps with the lower range of adult orangutans [which are much larger apes],” says Almécija.

Clément Zanolli at the University of Bordeaux, in France, also has doubts. “It is not very clear to me if the teeth – and in particular the molar – belong to the hominoids or to another primate superfamily, the pliopithecoids.”

Böhme and her colleagues say their comparisons ruled out the possibility that the teeth are baby teeth or pliopithecoid teeth.

In any case, the possibility that two primate species shared the same habitat and perhaps even interacted with each other is a “fantastic discovery”, says Zanolli. “This shows once again that, at that time, Europe was a luxurious and hospitable place for primates to evolve.”

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June 7, 2024

Ancient geese stood 3 metres tall and weighed as much as a cow

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An artistic reconstruction of Genyornis newtoni, an ancient relative of geese

Illustration by Jacob C. Blokland

Australia’s prehistoric thunder birds – once thought to be the ancestors of emus – were, in fact, the biggest geese that ever lived.

The group has been reclassified following the analysis of a 45,000-year-old Genyornis newtoni skull found in a fossil deposit at Lake Callabonna in the South Australian desert.

The newly discovered skull is the first from the extinct species found since 1913 and the only one preserved well enough to allow detailed anatomical study. It is thought that G. newtoni weighed about 230 kilograms and stood over 2.5 metres tall.

However, its close relative, Dromornis stirtoni, reached heights well over 3 metres and weighed up to 600 kilograms, making it not just a contender for biggest bird ever, but by far the largest goose.

When the first thunder bird fossils were found in the 19th century, they were thought to be the ancestors of the ratites, which include emus, cassowaries and ostriches. Others have since argued that the group, formally called the Dromornithidae and comprising eight known species, should be categorised as land fowl, which includes chickens and pheasants.

Now, Phoebe McInerney at Flinders University in Adelaide, Australia, and her colleagues have determined that thunder birds were giant waterfowl and should be moved into the same group as geese, the Anseriformes.

The team was mainly convinced by the anatomy of the beak and skull, including the arrangement of muscles and modifications to the bone where they attach. The structure in Genyornis is near-identical to that of an old waterfowl lineage, the South American screamers. This structure is extremely complex and is unlikely to have evolved independently, says McInerney.

Artistic reconstruction of the skull of Genyornis newtoni, based on the fossil material

Illustration by Jacob C. Blokland

All the thunder birds were vegetarians, she says, though they were probably fierce creatures. “I think they would have been very tough animals,” says McInerney. “They would have been able to defend themselves and would have been quite overwhelming beasts. They would have made very deep and loud calls.”

Adam Yates at the Museum and Art Gallery of the Northern Territory, Australia, says the study is a vindication of his predecessor, Peter Murray, who proposed in the early 1990s that the thunder birds were waterfowl. “So it’s not a shock to me,” says Yates. “But a skull of Genyornis has been hard to find, so it’s great to see its skull finally revealed.”

Many thunder bird species died out prior to the arrival of humans in Australia around 65,000 years ago, with this most likely to have been due to climate change. However, G. newtoni and humans overlapped on the continent for tens of thousands of years and some researchers speculate that hunting also played a role in their demise.

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June 3, 2024