New giant sloth species discovery in Mexico


This video says about itself:

Fossil of New Giant Sloth Species Found in Underwater Cave | National Geographic

31 August 2017

In an underwater cave in the Yucatán in Mexico lie the well-preserved remains of an ancient giant sloth.

The new species is from the late Pleistocene. Its scientific name is Xibalbaonyx oviceps. Its scientific description is here.

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Woolly rhinos, why extinct?


This 2013 video is called The End of the Woolly Rhino – Ice Age Giants – Episode 3 Preview – BBC.

From ScienceDaily:

Woolly rhino neck ribs provide clues about their decline and eventual extinction

Fossils point to rare condition in the extinct species, possibly caused by inbreeding and harsh conditions during pregnancy. Monitoring vertebrae in modern rhinos could indicate the level of extinction risk

August 29, 2017

Summary: A study reports on the incidence of abnormal cervical (neck) vertebrae in woolly rhinos, which strongly suggests a vulnerable condition in the species. Given the considerable birth defects that are associated with this condition, the researchers argue it is very possible that developmental abnormalities contributed towards the eventual extinction of these late Pleistocene rhinos.

Researchers from the Naturalis Biodiversity Center in Leiden examined woolly rhino and modern rhino neck vertebrae from several European and American museum collections and noticed that the remains of woolly rhinos from the North Sea often possess a ‘cervical’ (neck) rib — in contrast to modern rhinos.

The study, published in the open access journal PeerJ today, reports on the incidence of abnormal cervical vertebrae in woolly rhinos, which strongly suggests a vulnerable condition in the species. Given the considerable birth defects that are associated with this condition, the researchers argue it is very possible that developmental abnormalities contributed towards the eventual extinction of these late Pleistocene rhinos.

In modern animals, the presence of a ‘cervical rib’ (a rib attached to a cervical vertebra) is an unusual event, and is cause for further investigation. Though the rib itself is relatively harmless, this condition is often associated with inbreeding and adverse environmental conditions during pregnancy.

Frietson Galis, one of the authors of the peer-reviewed study, found a remarkably high percentage of these neck ribs in the woolly mammoth, published in a previous study.

“This aroused our curiosity to also check the woolly rhino, a species that, like the woolly mammoth lived during the late Pleistocene and similarly died out,” said Alexandra van der Geer, one of the authors of the study. “The woolly rhino bones were all dredged from the North Sea and river deltas in the Netherlands. We knew these were just about the last rhinos living there, so we suspected something could be wrong here as well. Our work now shows that there was indeed a problem in the woolly rhino population.”

The absence of cervical ribs in the modern sample is by no means evidence that rhino populations today are healthy. Museum collections are based on rhino specimens that were collected at least five decades ago. Rhinoceros numbers are dwindling extremely fast, especially the last two decades, resulting in near extinction for some species and the total extinction of the western black rhinoceros.

“Our study suggests that monitoring the health of the vertebrae in rhinos has the potential to timely detect developmental errors that indicate the level of extinction risk,” said Frietson Galis.

What Stone Age humans ate


This video says about itself:

26 June 2014

According to the oldest fossil evidence of human feces ever discovered, the extinct species known as Neanderthals probably ate vegetables. Researchers from the University of La Laguna on the Canary Islands in Spain, working along with the Massachusetts Institute of Technology, analyzed fossil samples that include 50 thousand year-old feces from a Neanderthal campfire site close to Alicante, on the coast of the Mediterranean Sea.

Data from the study shows that the Neanderthal diet was mostly meat, but the fossil evidence indicates also the presence of plants in their excrement.

Ainara Sistiaga, a PhD student at the University of La Laguna is quoted as saying: “If you find it in the faeces, you are sure that it was ingested. This molecular fossil is perfect to try to know the proportion of both food sources in a Neanderthal meal.”

Neanderthals are modern humans’ closest extinct relative living between 250 thousand to 40 thousand years ago, and some experts believe that Neanderthals interbred with Homo sapiens before they became extinct.

Experts say that the prehistoric human diet probably varied quite a bit by region and availability, so it is plausible that some populations of Neanderthals ate plants and vegetables.

From the Senckenberg Research Institute and Natural History Museum in Germany:

On the early human’s menu: Mammoth and plenty of raw vegetables

Early modern humans consumed more plants than Neanderthals but ate very little fish

August 4, 2017

Senckenberg scientists have studied the diet of anatomically modern humans. With their recent study, published in the journal Scientific Reports, they were able to refute the theory that the diet of early representatives of Homo sapiens was more flexible than that of Neanderthals. Just like the Neanderthals, our ancestors had mainly mammoth and plants on their plates — the researchers were unable to document fish as part of their diet. Therefore, the international team assumes that the displacement of the Neanderthals was the result of direct competition.

The first representatives of Homo sapiens colonized Europe around 43,000 years ago, replacing the Neanderthals there approximately 3,000 years later. “Many studies examine the question of what led to this displacement — one hypothesis postulates that the diet of the anatomically modern humans was more diverse and flexible and often included fish,” explains Prof. Dr. Hervé Bocherens of the Senckenberg Center for Human Evolution and Palaeoenvironment (HEP) at the University of Tübingen.

Together with his colleague, Dr. Dorothée Drucker, the biogeologist from Tübingen now set out to get to the bottom of this hypothesis. In conjunction with an international team, he studied the dietary habits of early modern man on the basis of the oldest know fossils from the Buran Kaya caves on the Crimean Peninsula in the Ukraine. “In the course of this study, we examined the finds of early humans in the context of the local fauna,” explains Drucker, and she continues, “Until now, all analyses of the diet of early modern humans were based on isolated discoveries; therefore, they are very difficult to interpret.”

In order to reconstruct our ancestor’s menu — despite the lack of a fossil dietary record — the team around the scientists from Tübingen measured the percentage of stable carbon and nitrogen isotopes in the bones of the early humans and the locally present potential prey animals such as saiga, horses, and deer. In addition, they also analyzed the nitrogen-15 content of individual amino acids, making it possible to not only determine the origin, but also the proportion of the nitrogen. “Our results reveal a very high proportion of the nitrogen isotope 15N in early modern humans,” adds Bocherens, and he continues, “However, contrary to our previous assumptions, these do not originate from the consumption of fish products, but primarily from mammoths.”

And yet another result came as a surprise for the scientists: The proportion of plants in the diet of the anatomically modern humans was significantly higher than in comparable Neanderthal finds — mammoths, on the other hand, appear to have been one of the primary sources of meat in both species.

“According to our results, Neanderthals and the early modern humans were in direct competition in regard to their diet, as well — and it appears that the Neanderthals drew the short straw in this contest,” adds Drucker in conclusion.

This video says about itself:

1 December 2009

Natural History Museum scientists, working as part of the Gibraltar Caves Project, excavated and studied remains of shellfish and other marine animals such as dolphins from two caves in Gibraltar where Neanderthals once lived and have discovered that Neanderthal diets were more like those of early modern humans than previously thought.

Little boy discovers extinct elephant fossil


This video from the USA says about itself:

9-Year-Old Boy Literally Stumbled On A 1.2 Million-Year-Old Stegomastodon Skull

19 July 2017

A 9-year-old boy who was out hiking with his family last November accidentally discovered a rare prehistoric stegomastodon skull in New Mexico’s Las Cruces desert.

From National Geographic in the USA:

Boy Found Million-Year-Old Fossil by Tripping Over It

While walking through the desert near Las Cruces, New Mexico, a now 10-year-old boy stumbled over one of the state’s rarest finds.

Boy Trips While Hiking, Discovers Million-Year-Old Fossil

By Sarah Gibbens

PUBLISHED July 19, 2017

“There are more fossils than I’ll ever be able to count in New Mexico,” said Spencer Lucas, curator of paleontology at the New Mexico Museum of Natural History and Science.

Lucas was commenting on the recent excavation of a fossil found near the Las Cruces, New Mexico, desert last November.

While exploring the region’s Organ Mountains with his parents and two brothers, then 9-year-old Jude Sparks tripped over something protruding from the earth.

In an interview with El Paso ABC affiliate KVIA, Sparks told reporters he immediately revealed the find to his brother, Hunter.

“Hunter said it was just a big fat rotten cow. I didn’t know what it was. I just knew it wasn’t usual.”

The find was in fact not a big fat rotten cow but a stegomastodon, an ancient, primitive mammal that lived an estimated 1.2 million years ago. (Stegomastodons were early tuskers from the animal family Gomphotheres, a distant cousin of ancient mammoths and modern day elephants.)

Later that night, Jude’s parents reached out to New Mexico State University Professor Peter Houde, who they discovered from a previous interview he gave on similar subjects. Houde and the Sparks family returned to the discovery site, finding an entire skull.

After securing funding, finding volunteers, and coordinating when the dig would take place, the university team and the Sparks family returned to the site to excavate the remains. A week after careful excavation, the fragile pieces, which Houde described as “egg-shell thin” to National Geographic.

Houde hopes the fossil will eventually be available for exhibit.

The Fossil State

This isn’t the first time a stegomastodon has been found in New Mexico. In 2014, a bachelor party stumbled across a nearly intact fossil that was collected by the New Mexico Natural History Museum.

Coming across a stegomastodon fossil is considered a rare find. Lucas explained that fossils like those belonging to mammoths are relatively abundant in western portions of North America but for reasons not quite known, stegomastodons are less frequently found. According to Lucas, only a couple hundred have been found in the world.

One theory for why stegomastodons went extinct correlates to the arrival of mammoths.

Lucas’s theory is that the ancient animals couldn’t compete with mammoths. Both animals grazed on their surroundings, and could have competed for resources.

Houde theorized that climate change could have caused the animal’s demise.

“They existed during a time when it was wetter and cooler,” said Houde. “Las Cruces is now a desert.”

Researchers don’t know how many fossils lie buried in the desert, but if they’re to be found anywhere in America, the southwest is a likely location. The region’s naturally dry, rocky terrain create conditions needed to preserve bones for millions of years.

In interviews with local news, the Sparks family speculated that the recent rains in the area before the discovery might have helped to expose the fossil. Lucas agreed that this was well within the realm of possibility. He says that as rain erodes more sediment, discoveries are always possible.

“Erosion is a paleontologist’s best friend.”

Earliest Australians earlier than thought


This video says about itself:

Australian Cave Painting Found To Be One of World’s Oldest

18 June 2012

An archaeologist discovered an aboriginal cave painting in the Australian outback that was created 28,000 years ago.

Bryce Barker, from the University of Southern Queensland, originally made the find last year. Because most rock art is made with mineral paint, it’s difficult to get an accurate measure of age. But Barker’s find at the Nawarla Gabarnmang cave dwelling was created using charcoal, so he was able to employ radiocarbon dating, which gave him the astonishing age of the art—now believed to be one of the oldest in the world.

Spain’s El Castillo still has seniority over Australia’s find by about 12,000 years. But the Australian shelter may have had dwellers—if not decorations—for just as long.

From the University of Washington in the USA:

Artifacts suggest humans arrived in Australia earlier than thought

July 19, 2017

Summary: Archeologists have found and dated artifacts in northern Australia that indicate humans arrived there about 65,000 years ago — more than 10,000 years earlier than previously thought.

When and how the first humans made their way to Australia has been an evolving story.

While it is accepted that humans appeared in Africa some 200,000 years ago, scientists in recent years have placed the approximate date of human settlement in Australia further and further back in time, as part of ongoing questions about the timing, the routes and the means of migration out of Africa.

Now, a team of researchers, including a faculty member and seven students from the University of Washington, has found and dated artifacts in northern Australia that indicate humans arrived there about 65,000 years ago — more than 10,000 years earlier than previously thought. A paper published July 20 in the journal Nature describes dating techniques and artifact finds at Madjedbebe, a longtime site of archaeological research, that could inform other theories about the emergence of early humans and their coexistence with wildlife on the Australian continent.

The new date makes a difference, co-author and UW associate professor of anthropology Ben Marwick said. Against the backdrop of theories that place humans in Australia anywhere between 47,000 and 60,000 years ago, the concept of earlier settlement calls into question the argument that humans caused the extinction of unique megafauna such as giant kangaroos, wombats and tortoises more than 45,000 years ago.

“Previously it was thought that humans arrived and hunted them out or disturbed their habits, leading to extinction, but these dates confirm that people arrived so far before that they wouldn’t be the central cause of the death of megafauna,” Marwick said. “It shifts the idea of humans charging into the landscape and killing off the megafauna. It moves toward a vision of humans moving in and coexisting, which is quite a different view of human evolution.”

Since 1973, digs at Madjedbebe, a rock shelter in Australia’s Northern Territory, have unearthed more than 10,000 stone tools, ochres, plant remains and bones. Following the more recent excavations in 2012 and 2015, a University of Queensland-led research team, which included the UW, evaluated artifacts found in various layers of settlement using radiocarbon dating and optical stimulated luminescence (OSL).

The new research involved extensive cooperation with the local Aboriginal community, Marwick added. The Gundjeihmi Aboriginal Corporation, representing the Mirarr people, joined much of the excavation and reviewed the findings, Marwick said. Researchers had both a memorandum of understanding and a contract with the community, which gave control to the Mirarr as senior custodians, oversight of the excavation and curation of the finds. The Mirarr were interested in supporting new research into the age of the site and in knowing more about the early human occupants, particularly given environmental threats posed by nearby modern-day mining activities.

Noteworthy among the artifacts found were ochre “crayons” and other pigments, what are believed to be the world’s oldest edge-ground hatchets, and evidence that these early humans ground seeds and processed plants. The pigments indicate the use of paint for symbolic and artistic expression, while the tools may have been used to cut bark or food from trees.

Labs in Australia used OSL to identify the age range, Marwick explained. Radiocarbon dating, which requires a certain level of carbon in a substance, can analyze organic materials up to about 45,000 or 50,000 years old. But OSL is used on minerals to date, say, the last time a sand grain was exposed to sunlight — helpful in determining when an artifact was buried — up to 100,000 years ago or more. That process measured thousands of sand grains individually so as to establish more precise ages.

The UW researchers worked in the geoarchaeology lab on the Seattle campus, testing sediment samples that Marwick helped excavate at Madjedbebe. One graduate student and six undergraduate students studied the properties of hundreds of dirt samples to try to picture the time in which the ancient Australian humans lived.

Using a scanning electron microscope, the students examined the composition of the sediment layers, the size of the grains of dirt and any microscopic plant matter. For another test, the students baked soil samples at various temperatures, then measured the mass of each sample, said UW doctoral student Gayoung Park, another author on the paper. Because organic matter turns into gases at high heat, a loss of mass indicated how much matter was in a given sample. This helped create a picture of the environments across the sedimentary layers of the site. The team found that when these human ancestors arrived, northern Australia was wetter and colder.

“Together, we were working on establishing questions: What kind of environments did these people live in? What was the climate like? Were there any disturbances to the site, and were artifacts mixed up from different ages?” Marwick said. “I’m proud of being able to involve UW students in this research in a really substantial way.”

One of the authors, Mara Page, was a senior double-majoring in archaeology and Earth and space sciences when she joined the project. She analyzed stable carbon isotopes found in sediment, which can reveal the types of plants present in the past and the kinds of environments they lived in. She determined that the vegetation at Madjedbebe remained stable during the time of human occupation, which suggests that there was no major environmental change that might have prompted humans to leave the area.

“I feel that I contributed something important by being able to rule something out of the story we were telling,” Page explained.

By placing the date of Australian settlement at around 65,000 years ago, researchers confirm some of the shifting theories about when the first humans left Africa. A common view is that humans moved into Asia 80,000 years ago, and if they migrated to Australia some to 15,000 years later, it means those ancestors co-existed with another early human in Asia, Homo florensiensis. It also means that these early Australians preceded early Europeans, who are believed to have entered that continent 45,000 years ago. A related question is whether these early human species left Africa at one time, gradually spreading the population through Asia, Europe and Australia, or whether there were multiple waves of migration.

In recent years, new evidence, obtained through DNA testing of a 90-year-old hair sample of an Aboriginal Australian man, suggests Australia was settled as far back as 70,000 years ago.

Marwick believes the Madjedbebe results, because they rely on so many artifacts and intensive analysis of sediment samples, confirm that early humans occupied Australia at least 65,000 years ago and support the theory that Homo sapiens, the species of modern-day humans, evolved in Africa before dispersing to other continents. The findings also suggest Homo sapiens’ predecessors, Neanderthals and Denisovans, overlapped with humans for a long period of time, and suggest a larger role for Australia, and the Eastern Hemisphere in general, in the story of humankind.

Marwick, who advocates for open science, particularly in data collection and the code used to analyze it, noted that the Nature paper is also pushing new frontiers because it combines three strands of reproducibility. Researchers examined a field site that has been excavated in the past; they’ve made available their raw data and code; and they consulted an outside lab for third-party OSL verification.

Pliocene big marine life extinction discovered


This video from the USA says about itself:

Pliocene Epoch – Florida Fossils: Evolution of Life and Land

2 February 2010

This video from the Museum’s Florida Fossils exhibit describes the Pliocene Epoch, 5 million to 2 million years ago The formation of a land bridge across Panama in Central America about 3 million years ago was a major biotic event. Both North and South America had been previously isolated for millions of years. Each had evolved its own unique flora and fauna.

Contact between North and South America allowed for the overland dispersal of organisms between the two continents. Mammals living in North America invaded South America, and South American mammals moved north. The closure of the seaway between North and South America apparently resulted in extinctions of many marine organisms. However, newly formed habitats also promoted the evolution of many new species.

Produced, directed and filmed for the Florida Museum of Natural History by Wes C. Skiles/Karst Productions, Inc.

From the University of Zurich in Switzerland:

Previously unknown extinction of marine megafauna discovered

June 26, 2017

Summary: Over two million years ago, a third of the largest marine animals like sharks, whales, sea birds and sea turtles disappeared. This previously unknown extinction event not only had a considerable impact on the earth’s historical biodiversity but also on the functioning of ecosystems.

The disappearance of a large part of the terrestrial megafauna such as saber-toothed cat and the mammoth during the ice age is well known. Now, researchers at the University of Zurich and the Naturkunde Museum in Berlin have shown that a similar extinction event had taken place earlier, in the oceans.

New extinction event discovered

The international team investigated fossils of marine megafauna from the Pliocene and the Pleistocene epochs (5.3 million to around 9,700 years BC). “We were able to show that around a third of marine megafauna disappeared about three to two million years ago. Therefore, the marine megafaunal communities that humans inherited were already altered and functioning at a diminished diversity,” explains lead author Dr. Catalina Pimiento, who conducted the study at the Paleontological Institute and Museum of the University of Zurich.

Above all, the newly discovered extinction event affected marine mammals, which lost 55 per cent of their diversity. As many as 43 per cent of sea turtle species were lost, along with 35 per cent of sea birds and 9 per cent of sharks. On the other hand, the following new forms of life were to develop during the subsequent Pleistocene epoch: Around a quarter of animal species, including the polar bear Ursus [maritimus], the storm petrel Oceanodroma or the penguin Megadyptes had not existed during the Pliocene. Overall, however, earlier levels of diversity could not be reached again.

Effects on functional diversity

In order to determine the consequences of this extinction, the research team concentrated on shallow coastal shelf zones, investigating the effects that the loss of entire functional entities had on coastal ecosystems. Functional entities are groups of animals not necessarily related, but that share similar characteristics in terms of the function they play on ecosystems. The finding: Seven functional entities were lost in coastal waters during the Pliocene.

Even though the loss of seven functional entities, and one third of the species is relatively modest, this led to an important erosion of functional diversity: 17 per cent of the total diversity of ecological functions in the ecosystem disappeared and 21 per cent changed. Previously common predators vanished, while new competitors emerged and marine animals were forced to adjust. In addition, the researchers found that at the time of the extinction, coastal habitats were significantly reduced due to violent sea levels fluctuations.

Large warm-blooded marine animals are more vulnerable to global environmental changes

The researchers propose that the sudden loss of the productive coastal habitats, together with oceanographic factors such as altered sea currents, greatly contributed to these extinctions. “Our models have demonstrated that warm-blooded animals in particular were more likely to become extinct. For example, species of sea cows and baleen whales, as well as the giant shark Carcharocles megalodon disappeared,” explains Dr. Pimiento. “This study shows that marine megafauna were far more vulnerable to global environmental changes in the recent geological past than had previously been assumed.” The researcher also points to a present-day parallel: Nowadays, large marine species such as whales or seals are also highly vulnerable to human influences.