Primates’ origin in North America, not Asia?


This 29 November 2018 video from the USA says about itself:

Early primate ancestor may have come from North America

A mouse-sized primate known as Teilhardina eventually gave rise to today’s monkeys, apes and humans. But one of the persistent mysteries about this distant relative of ours is where it came from. New research by University of Florida doctoral graduate Paul Morse shows that Teilhardina brandti, a species found in Wyoming, is as old or older than its Asian and European relatives, upending the prevailing hypothesis that this early primate first appeared in China.

From the Florida Museum of Natural History in the USA:

Oldest-known ancestor of modern primates may have come from North America, not Asia

November 29, 2018

Summary: A new fossil analysis suggests the earliest-known ancestor of modern primates may have come from North America, not Asia, as previously thought.

About 56 million years ago, on an Earth so warm that palm trees graced the Arctic Circle, a mouse-sized primate known as Teilhardina first curled its fingers around a branch.

The earliest-known ancestor of modern primates, Teilhardina’s close relatives would eventually give rise to today’s monkeys, apes and humans. But one of the persistent mysteries about this distant cousin of ours is where it originated.

Teilhardina (ty-hahr-DEE’-nuh) species quickly spread across the forests of Asia, Europe and North America, a range unparalleled by all other primates except humans. But where did its journey begin?

New research shows that Teilhardina brandti, a species found in Wyoming, is as old or older than its Asian and European relatives, upending the prevailing hypothesis that Teilhardina first appeared in China.

Teilhardina’s origins, however, remain a riddle.

“The scientific conclusion is ‘We just don’t know,'” said Paul Morse, the study’s lead author and a recent University of Florida doctoral graduate. “While the fossils we’ve found potentially overturn past hypotheses of where Teilhardina came from and where it migrated, they definitely don’t offer a clearer scenario.”

What is clear, Morse said, is that T. brandti had a wide variety of features, some of which are as primitive as those found in Teilhardina asiatica, its Asian cousin, previously thought to be the oldest species in the genus.

To make this determination, Morse studied 163 teeth and jaws in the most comprehensive analysis of T. brandti to date.

Teeth contain a treasure-trove of information and often preserve better than bone, thanks to their tough enamel. They can reveal clues about an animal’s evolutionary past, its size, diet and age as an individual and in geological time.

Primate teeth have particularly distinct structures that are immediately recognizable to the trained eye, said Jonathan Bloch, study co-author and curator of vertebrate paleontology at the Florida Museum of Natural History.

“Identifying differences between primate teeth is not so different from a biker recognizing that a Harley is different from a scooter or an art critic evaluating whether an image was created by Picasso or Banksy,” he said. “In detail, they are very different from each other in specific, predictable ways.”

While Teilhardina bones are very rare in the fossil record, its teeth are more plentiful — if you know how to find them. Bloch’s team of paleontologists, Morse included, have spent years combing the surface of Wyoming’s Bighorn Basin on hands and knees and then packing out 50-pound bags of soil to a river to screen wash. The remaining bits of bones and teeth — which can be smaller than a flea — are examined under a microscope back at the museum.

This painstaking search has built up the dental record of T. brandti from a single molar — used to first describe the species in 1993 — to hundreds of teeth, providing a broad look at the primate’s population-level variation.

Still, Morse and Bloch were unprepared for the peculiar variation exhibited by specimen UF 333700, a jagged piece of jaw with T. brandti teeth.

“Jon and I started arguing about the alveoli” — empty tooth sockets — “and how they didn’t look right at all,” said Morse, now a postdoctoral researcher at Duke University. “By the end of the day, we realized that specimen completely overturned both the species definition of T. asiatica and part of the rationale for why it is the oldest Teilhardina species.”

Studies based on a small number of teeth simply missed the diversity in Teilhardina’s physical characteristics, Morse said.

“There’s likely a tremendous amount of variation in the fossil record, but it’s extremely difficult to capture and measure when you have a small sample size,” he said. “That’s one of the reasons collecting additional fossils is so important.”

The analysis also reshuffled the Teilhardina family tree, reducing the number of described species from nine to six and reclassifying two species as members of a new genus, Bownonomys, named for prominent vertebrate paleontologist Thomas Bown.

But the precise ages of Teilhardina species are still impossible to pinpoint and may remain that way.

Teilhardina appeared during the geological equivalent of a flash in the pan, a brief 200,000-year period known as the Paleocene-Eocene Thermal Maximum, or PETM. This era was characterized by a massive injection of carbon into the Earth’s atmosphere, which sent global temperatures soaring. Sea levels surged by 220 feet, ecosystems were overhauled and the waters at the North Pole warmed to 74 degrees.

Scientists can use the distinct carbon signature of the PETM to locate this period in the rock record, and carbon isotopes in teeth can also be used to identify fossil animals from the era.

But among Teilhardina fossil sites across the globe, only Wyoming has the uninterrupted, neatly demarcated layers of rock that allow paleontologists to hone in on more precise dates.

“The humblest statement would be to say that these species are essentially equivalent in age,” Bloch said. “Determining which came earlier in the PETM probably surpasses the level of resolution we have in the rock record. But what we can say is that the only place where you can really establish where Teilhardina appears in this climate event with confidence is in the Bighorn Basin.”

As the Earth warmed, plants and animals expanded their ranges northward, returning south as temperatures cooled at the end of the PETM.

“This dance of plants and animals with climate change happened over vast landscapes, with forests moving from the Gulf Coast to the Rocky Mountains in just a few thousand years,” Bloch said.

Teilhardina likely tracked the shifts in its forest habitats across the land bridges that then connected North America, Greenland and Eurasia, he said.

“Teilhardina is not throwing its bag over its shoulder and walking,” he said. “Its range is shifting from one generation to the next. Over 1,000 years, you get a lot of movement, and over 2,000-3,000 years, you could easily cover continental distances.”

While it was well-suited to Earth’s hothouse environment, Teilhardina disappeared with the PETM, replaced by new and physically distinct primates. It’s a sobering reminder of what can happen to species — including humans — during periods of swift climatic changes, Bloch said.

“A changing planet has dramatic effects on biology, ecosystems and evolution. It’s part of the process that has produced the diversity of life we see today and mass extinctions of life that have happened periodically in Earth’s history,” Bloch said. “One of the unexpected results of global warming 56 million years ago is that it marks the origin of the group that ultimately led to us. How we will fare under future warming scenarios is less certain.”

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Primate evolution, video


This 16 October 2018 video says about itself:

Purgatorius, a kind of mammal called a plesiadapiform, might’ve been one of your earliest ancestors. But how did we get from a mouse-sized creature that looked more like a squirrel than a monkey — to you, a member of Homo sapiens?

Rare silky sifaka lemurs re-released in the wild


This 20 September 2018 video from Madagascar says about itself:

Incredibly Rare Silky Sifaka Lemurs Re-Released in the Wild | BBC Earth

After inspecting these rare white lemurs, the scientists free them again, and discover a pleasant surprise. Narrated by David Attenborough.

Lemur study suggests why some fruits smell so fruity. A new test with lemurs and birds suggests there’s more to fruit odors than simple ripening. By Susan Milius, 2:12pm, October 3, 2018.

Javan slow lorises freed from criminal traders


This video from Indonesia says about itself:

18 September 2018

International Animal Rescue recently released 20 Javan slow lorises in Bandung, West Java. Javan slow lorises (Nycticebus javanicus) are protected primates and yet are heavily trafficked in the wildlife trade.

Human origins, video


This 14 September 2018 video says about itself:

The story of human evolution began about 7 million years ago, when the lineages that lead to Homo sapiens and chimpanzees separated. Learn about the over 20 early human species that belong in our family tree and how the natural selection of certain physical and behavioral traits defined what it means to be human.

How human ancestors ate


This November 2011 video says about itself:

Part Ape, Part Human: The Fossils of Malapa | Nat Geo Live

Professor Lee Berger and his son stumble across an amazing find in South Africa — two-million-year-old fossils of an unknown species of ape-like creatures.

From the Max Planck Institute for Evolutionary Anthropology:

Getting to the roots of our ancient cousins’ diet

The splay of tooth roots reveals how South African hominins, Australopithecus africanus and Paranthropus robustus, chewed their food

Since the discovery of the fossil remains of Australopithecus africanus from Taung nearly a century ago, and subsequent discoveries of Paranthropus robustus, there have been disagreements about the diets of these two South African hominin species. By analyzing the splay and orientation of fossil hominin tooth roots, researchers of the MPI for Evolutionary Anthropology, the University of Chile and the University of Oxford now suggest that Paranthropus robustus had a unique way of chewing food not seen in other hominins.

Food needs to be broken down in the mouth before it can be swallowed and digested further. How this is being done depends on many factors, such as the mechanical properties of the foods and the morphology of the masticatory apparatus.

Palaeoanthropologists spend a great deal of their time reconstructing the diets of our ancestors, as diet holds the key to understanding our evolutionary history. For example, a high-quality diet (and meat-eating) likely facilitated the evolution of our large brains, whilst the lack of a nutrient-rich diet probably underlies the extinction of some other species (e.g., P. boisei). The diet of South African hominins has remained particularly controversial however.

Using non-invasive high-resolution computed tomography technology and shape analysis the authors deduced the main direction of loading during mastication (chewing) from the way the tooth roots are oriented within the jaw. By comparing the virtual reconstructions of almost 30 hominin first molars from South and East Africa they found that Australopithecus africanus had much wider splayed roots than both Paranthropus robustus and the East African Paranthropus boisei. “This is indicative of increased laterally-directed chewing loads in Australopithecus africanus, while the two Paranthropus species experienced rather vertical loads”, says Kornelius Kupczik of the Max Planck Institute for Evolutionary Anthropology.

Paranthropus robustus, unlike any of the other species analysed in this study, exhibits an unusual orientation, i.e. “twist”, of the tooth roots, which suggests a slight rotational and back-and-forth movement of the mandible during chewing. Other morphological traits of the P. robustus skull support this interpretation. For example, the structure of the enamel also points towards a complex, multidirectional loading, whilst their unusual microwear pattern can conceivably also be reconciled with a different jaw movement rather than by mastication of novel food sources. Evidently, it is not only what hominins ate and how hard they bit that determines its skull morphology, but also the way in which the jaws are being brought together during chewing.

The new study demonstrates that the orientation of tooth roots within the jaw has much to offer for an understanding of the dietary ecology of our ancestors and extinct cousins. “Perhaps palaeoanthropologists have not always been asking the right questions of the fossil record: rather than focusing on what our extinct cousins ate, we should equally pay attention to how they masticated their foods,” concludes Gabriele Macho of the University of Oxford.

Molar root variation in hominins is therefore telling us more than previously thought. “For me as an anatomist and a dentist, understanding how the jaws of our fossil ancestors worked is very revealing as we can eventually apply such findings to the modern human dentition to better understand pathologies such as malocclusions”, adds Viviana Toro-Ibacache from the University of Chile and one of the co-authors of the study.

New Eocene primates discovery in California


This 16 May 2018 video says about itself:

From the Fall of Dinos to the Rise of Humans

After taking you on a journey through geologic time, we’ve arrived at the Cenozoic Era. Most of the mammals and birds that you can think of appeared during this era but perhaps more importantly, the Cenozoic marks the rise of organisms that look a lot like us.

From the University of Texas at Austin in the USA:

Three previously unknown ancient primates identified

Biological anthropologists from The University of Texas at Austin have described three new species of fossil primates that were previously unknown to science. All of the new primates were residents of San Diego County at a time when southern California was filled with lush tropical forests.

Since the 1930s, numerous primate fossils have been uncovered in the sandstones and claystones that make up the Friars Formation in San Diego County. Paleontologist Stephen Walsh and fieldworkers from the San Diego Museum of Natural History (SDNHM) built up a large collection of fossil primates from the San Diego area, but Walsh was unable to describe these specimens before his death in 2007.

A decade later, UT Austin graduate student Amy Atwater and anthropology professor Chris Kirk took up the challenge, describing and naming three previously unknown omomyoid primates that lived 42 million to 46 million years ago. The researchers named these new species Ekwiiyemakius walshi, Gunnelltarsius randalli and Brontomomys cerutti.

These findings double the number of known primate genera represented in the Friars Formation and increase the total number of known omomyine primates of that period from 15 to 18.

Atwater and Kirk’s descriptions were published in the Journal of Human Evolution.

“The addition of these primates provides for a better understanding of primate richness in the middle Eocene”, said Atwater, who is now the paleontology collection manager at the Museum of the Rockies in Bozeman, Montana. “Previous research in the Rocky Mountain basins suggested the primate richness declined during this time period, but we argue that primate richness increased concurrently in other locations.”

Studying the teeth, researchers concluded the three new genera, which represent the bulk of the undescribed Friars Formation omomyoid sample at SDNHM, range in size from 113 to 796 grams and are most likely related to a group of extinct species comprising the primate subfamily Omomyinae.

“Teeth can tell us a lot about evolutionary history and give us a good handle on the size and diet of an extinct primate”, Kirk said. “Enamel is the hardest tissue in the body. And as a result, teeth are more likely to be preserved in the fossil record.”

Ekwiiyemakius walshi, the smallest of the three new species, was estimated to weigh between 113 and 125 grams — comparable in size to some modern bushbabies. It was named for Walsh, who collected and prepared many of the specimens, and also derives from the Native American Kumeyaay tribe’s place name, Ekwiiyemak — meaning “behind the clouds” — for the location of the headwaters of the San Diego and Sweetwater Rivers.

Gunnelltarsius randalli was named for Gregg Gunnell, the researchers’ late colleague and expert on Eocene mammals, and for SDNHM fossil collections manager Kesler Randall. It was estimated to weigh between 275 and 303 grams, about the size of today’s fat-tailed dwarf lemur.

Brontomomys cerutti was large compared with most other omomyoids and was estimated to weigh between 719 and 796 grams — about the size of a living sportive lemur. Due to its large size, its name derives from the Greek word brontē, or “thunder”, as well as for Richard Cerutti, the retired SDNHM paleontologist responsible for collecting many of the Brontomomys specimens.