Prehistoric saber-tooth marsupial Thylacosmilus, new research


This December 2017 video says about itself:

Thylacosmilus || A Jaguar sized Saber-tooth Marsupial relative from South America

Thylacosmilus is an extinct genus of saber-toothed metatherian that inhabited South America from the Late Miocene to Pliocene epochs.

Though Thylacosmilus is one of several predatory mammal genera typically called “saber-toothed cats”, it was not a felid placentalian, but a sparassodont, a group closely related to marsupials, and only superficially resembled other saber-toothed mammals due to convergent evolution.

Remains of this animal have been found primarily in Catamarca, Entre Ríos, and La Pampa Provinces in northern Argentina.

Thylacosmilus was described and named by Elmer S. Riggs in 1933. He named two species, T. atrox and T. lentis.

Thylacosmilus had large, saber-like canines. The roots of these canines grew throughout the animal’s life, growing in an arc up the maxilla and above the orbits. Its cervical vertebrae were very strong and to some extent resembled the vertebrae of Machairodontinae.

Body mass estimates of Thylacosmilus suggest this animal weighed between 80 to 120 kilograms (180 to 260 lb), and one estimate suggesting up to 150 kg (330 lb), about the same size as a modern jaguar. This would make it one of the largest known carnivorous metatherians.

Recent comparative biomechanical analysis have estimated the bite force of T. atrox starting at maximum gape at 38 newtons (8.5 lbf), much weaker than that of a leopard, suggesting its jaw muscles had an insignificant role in the dispatch of prey.

Its skull was similar to that of Smilodon in that it was much better adapted to withstand loads applied by the neck musculature.

Based on studies of its habitat, Thylacosmilus is believed to have hunted in savanna-like or sparsely forested areas, avoiding the more open plains where it would have faced competition with the more successful and aggressive Phorusrhacids it shared its environment with.

Although older references have often stated that Thylacosmilus became extinct due to competition with the “more competitive” saber-toothed cat Smilodon during the Great American Interchange, newer studies have shown this is not the case.

Thylacosmilus died out during the Pliocene (3.6–2.58 mya) whereas saber-toothed cats are not known from South America until the Middle Pleistocene (781-126,000 years ago).

As a result, the last appearance of Thylacosmilus is separated from the first appearance of Smilodon by over one and a half million years.

From the University of Bristol in England:

Bizarre saber-tooth predator from South America was no saber-tooth cat

June 26, 2020

A new study led by researchers from the University of Bristol has shown that not all saber-tooths were fearsome predators.

Saber-tooth cats, such as the North American species Smilodon fatalis, are among the most iconic fossil animals with a reputation for being fierce predators. However, saber-tooths came in all shapes and sizes and nearly a hundred different saber-tooths are known to science so far.

Thylacosmilus atrox (which means ‘terrible pouched knife’) is a well-known animal that lived around five million years ago in Argentina.

A jaguar-sized marsupial, it is popularly known as the ‘marsupial saber-tooth’, compared with the sabertoothed cats elsewhere in the world, and it is often presented as a classic case of convergent evolution — where animals appear similar in form despite having very different evolutionary relationships (such as marsupial flying possums and placental flying squirrels — both, of course, being gliders rather than true fliers).

Thylacosmilus had huge, ever-growing canines, leading people to speculate that it was an even more vicious predator than the placental carnivores it superficially resembled such as Smilodon.

But was it really a fierce predator like the extinct placental saber-toothed cats, which seem to have been much like modern cats but with a different mode of killing their prey?

An international team of researchers, led by Professor Christine Janis from Bristol’s School of Earth Sciences, have performed a series of studies on the skull and teeth of this animal and have come to a different conclusion. Their findings are published in the journal PeerJ.

Professor Janis said: “The title of this paper, ‘An Eye for a Tooth’, sums up how we think this animal has been perceived.

“It has impressive canines, for sure: but if you look at the whole picture of its anatomy, lots of things simply don’t add up. For example, it just about lacks incisors, which big cats today use to get meat off the bone, and its lower jaws were not fused together.

“In addition, the canines of Thylacosmilus were different from the teeth of other saber-toothed mammals, being triangular in shape like a claw rather than flat like a blade.”

A statistical study, comparing aspects of the skull and teeth of Thylacosmilus with both present-day big cats and a diversity of extinct saber-toothed cats, confirmed suspicions about the differences from its placental supposed counterparts.

Co-author Borja Figueirido of the University of Málaga (Spain) added: “The skull superficially looks rather like that of a saber-toothed placental.

“But if you actually quantify things, it becomes clear that Thylacosmilus’ skull was different in many details from any known carnivorous mammal, past or present.”

Detailed biomechanical studies comparing the skulls of Thylacosmilus and Smilodon, simulating performance under different conditions, were also revealing.

Stephan Lautenschlager from the University of Birmingham, the contributing author on the paper who performed these analyses, said: “Previous studies by other researchers have shown Thylacosmilus to have had a weaker bite than Smilodon.

“But what we can show is there was probably a difference in behaviour between the two species: Thylacosmilus’ skull and canines are weaker in a stabbing action than those of Smilodon, but are stronger in a ‘pull-back’ type of action. This suggests that Thylacosmilus was not using its canines to kill with, but perhaps instead to open carcasses.”

Finally, the other teeth of Thylacosmilus also pose problems for the interpretation of this animal as a cat-like predator, whether saber-toothed or not. Besides the puzzling lack of incisors, the molars are small, and did not wear down along the sides as seen in an animal feeding on meat.

Larisa DeSantis from Vanderbilt University (USA), who conducted a detailed dental study, added: “The molars tend to wear flat from the top, rather like you see in a bone crusher.

“But if you examine the detailed microwear on tooth surfaces, it’s clear that it was eating soft food. Its wear is most similar to that of cheetahs which eat from fresh carcasses and suggests an even softer diet than fed to captive lions.

“Thylacosmilus was not a bone-crusher and may have instead specialised on internal organs.”

Professor Janis said: “It’s a bit of a mystery as to what this animal was actually doing but it’s clear that it wasn’t just a marsupial version of a saber-toothed cat like Smilodon.

“In addition to the differences in the skull and the teeth, it was also short-legged and stiff-backed, and lacked retractile claws, so it would have had difficulties in pursuing its prey, pouncing on it and holding on to it. I suspect it was some sort of specialised scavenger.

“It may have employed those canines to open carcasses and perhaps also used a big tongue to help extract the innards: other mammals that have lost the incisors, like walruses and anteaters, also have big tongues that they use in feeding.”

When Thylacosmilus lived on the plains of Argentina five million years ago, it would have inhabited a very different type of ecosystem to any modern one. Then the big predators were huge flightless birds, the “terror birds” or phorusrachiformes, now all extinct. Life in the past may have been very different to the present day.

Borja Figueirido added: “In Africa today it’s the mammals who are the killers and the big birds, like vultures, are the scavengers. But perhaps five million years ago in Argentina it was the other way around, and it was the mammals who were the scavengers.”

Fossil monk seal discovery in Australia


This 6 April 2020 video says about itself:

A very rare fossil was found on a beach near Portland Victoria in 1998, It took years to identify the true identity if the specimen. It was from a now long-extinct group of seals now no longer found in Australia and it shed a light on to what Australia’s coastline might have looked like 3 million years ago.

To find out more about the tooth go here.

Read more here.

From Monash University in Australia:

Tooth be told: Earless seals existed in ancient Australia

April 3, 2020

A fossilised seal tooth found on a Victorian beach could hold the key to uncovering the history and geography of earless seals that graced Australia’s shores three million years ago.

This prehistoric specimen is only the second earless seal fossil ever discovered in Australia, and proves the country’s local fur seals and sea lions were preceded by a group of sea mammals, known as monachines, now long extinct in Australia.

The study also highlights the current dangers of climate change to Earth’s existing wildlife, with falling sea levels likely to have played a role in the extinction of these ancient seals.

The history of this rare specimen was published today (Friday 3 April) in the Journal of Vertebrate Paleontology by a team of scientists from Monash University’s School of Biological Sciences and Department of Anatomy and Developmental Biology, and Museums Victoria, led by PhD candidate James Rule.

“This tooth, roughly three million years old, tells a story similar to what occurred in South Africa and South America in the past. Earless monachine seals used to dominate southern beaches and waters, and then suddenly disappeared, with eared seals replacing them,” Mr Rule said.

“Since seal fossils are rare globally, this discovery makes a vital contribution to our understanding of this iconic group of sea mammals.”

An Australian citizen scientist and amateur fossil collector discovered the tooth while strolling along the beach at Portland, western Victoria.

But it wasn’t until he donated the fossil to Museums Victoria many years later that it was found to have been a tooth from an extinct group of earless seals.

The research team compared the tooth to other pinnipeds — a group that includes earless seals, fur seals, sea lions and the walrus.

They found the tooth possessed characteristics of monachines and shed light on how these seals lived and what they ate.

“This seal lived in shallow waters close to the shore, likely hunting fish and squid. As monachines cannot use their limbs to walk on land, it would have required flat, sandy beaches when it came ashore to rest,” Mr Rule said.

Researchers believe drastic changes in the Earth’s climate fundamentally altered Australia’s environment by eliminating the beaches used by earless seals to rest.

“These changes in the past have led to the extinction of Australia’s ancient earless seals,” Dr David Hocking, co-author and Research Fellow in Monash University’s School of Biological Sciences, said.

“Our living fur seals and sea lions will likely face similar challenges as the Earth continues to warm, with melting polar ice leading to rising sea levels.

“Over time, this may lead to the eventual loss of islands that these species currently rely upon to rest and raise their young.”

Extinct animals from Turkey, new species discoveries


This video from the USA says about itself:

Cancellaria conradiana gastropod fossil part two October 24 2019

Research shows it to be a Pliocene snail shell 5.333 Million years old to 2.58 million years old. The earth was cooling down the ice sheets were moving South and fauna migrated away from the ice sheets.

During my 16 December 2019 visit to Naturalis museum, I found about new fossil discoveries/

At the Live Science Lab, I met researcher Eelco Kruidenier. With the help of a microscope and a computer, he studied gravel from a valley in a mountain area east of Izmir in Turkey.

That gravel was about 2-3 million years old: from the late Pliocene and early Pleistocene eras. Back then, these valleys were freshwater lakes. The gravel contains lots of fossils of animals which lived then in or around these lakes. Eg, many shells of freshwater snails. Many of these shells are smaller than one millimetre, even adult snails. So, one really needs the microscope to discover them among the gravel. Every now and then, Mr Kruidenier discovered another shell and put it aside.

There are also fossils from many other animal species: bones of small mammals like mice, reptiles and amphibians. It looks like the overwhelming majority of the animals are both extinct species and new to science.

Naturalis does its research on this Turkish gravel jointly with other museums and universities, eg, in Turkey, Germany, Italy and the Netherlands. If, eg, in Naturalis, reptile fossils are found in the gravel, then the University of Florence in Italy is contacted, as they specialize in reptiles from that era.

Mr Kuidenier had previously done research on small mammals of the Gargano peninsula in Italy. During the Miocene and Pliocene, Gargano was an island; which led to evolution of endemic species, like a giant hedgehog and giant birds of prey.

United States diver discovers megalodon shark teeth


This 5 October 2019 video from South Carolina in the USA says about itself:

I found huge megalodon shark teeth while scuba diving in the Cooper River. Huge thanks to Captain Alan Devier for putting us onto an amazing site. This was a very exciting diving adventure! I can’t wait to do this again! Who else enjoys finding shark teeth?

Australopithecus anamensis discovery in Ethiopia


This 28 August 2019 video says about itself:

MRD cranium – the face of Australopithecus anamensis

In the Woranso-Mille area, Afar, Ethiopia, a 3.8-million-year-old hominin fossil cranium was discovered. Researchers lead by Dr. Yohannes Haile-Selassie (Cleveland Museum of Natural History/Case Western Reserve University) conclude that the fossil cranium MRD-VP-1/1 belongs to the species Australopithecus anamensis.

From the Max Planck Institute for Evolutionary Anthropology in Germany:

A face for Lucy’s ancestor

August 28, 2019

Summary: Researchers have discovered a remarkably complete 3.8-million-year-old cranium of Australopithecus anamensis at Woranso-Mille in Ethiopia. The 3.8 million-year-old fossil cranium represents a time interval between 4.1 and 3.6 million years ago.

Australopithecus anamensis is the earliest-known species of Australopithecus and widely accepted as the progenitor of ‘Lucy‘s’ species, Australopithecus afarensis. Until now, A. anamensis was known mainly from jaws and teeth. Yohannes Haile-Selassie of the Cleveland Museum of Natural History, Stephanie Melillo of the Max Planck Institute for Evolutionary Anthropology and their colleagues have discovered the first cranium of A. anamensis at the paleontological site of Woranso-Mille, in the Afar Region of Ethiopia.

The 3.8 million-year-old fossil cranium represents a time interval between 4.1 and 3.6 million years ago, when A. anamensis gave rise to A. afarensis. Researchers used morphological features of the cranium to identify which species the fossil represents. “Features of the upper jaw and canine tooth were fundamental in determining that MRD was attributable to A. anamensis”, said Melillo. “It is good to finally be able to put a face to the name.” The MRD cranium, together with other fossils previously known from the Afar, show that A. anamensis and A. afarensis co-existed for approximately 100,000 years. This temporal overlap challenges the widely-accepted idea of a linear transition between these two early human ancestors. Haile-Selassie said: “This is a game-changer in our understanding of human evolution during the Pliocene.”

Working for the past 15 years at the site, the team discovered the cranium (MRD-VP-1/1, here referred to as “MRD”) in February 2016. In the years following their discovery, paleoanthropologists of the project conducted extensive analyses of MRD, while project geologists worked on determining the age and context of the specimen. The results of the team’s findings are published online in two papers in the international scientific journal Nature.

Discovery of the cranium

The Woranso-Mille project has been conducting field research in the central Afar region of Ethiopia since 2004. The project has collected more than 12,600 fossil specimens representing about 85 mammalian species. The fossil collection includes about 230 fossil hominin specimens dating to between more than 3.8 and about 3.0 million years ago. The first piece of MRD, the upper jaw, was found by Ali Bereino (a local Afar worker) on February 10, 2016 at a locality known as Miro Dora, Mille district of the Afar Regional State. The specimen was exposed on the surface and further investigation of the area resulted in the recovery of the rest of the cranium. “I couldn’t believe my eyes when I spotted the rest of the cranium. It was a eureka moment and a dream come true,” said Haile-Selassie.

Geology and age determination

In a companion paper published in the same issue of Nature, Beverly Saylor of Case Western Reserve University and her colleagues determined the age of the fossil as 3.8 million years by dating minerals in layers of volcanic rocks nearby. They mapped the dated levels to the fossil site using field observations and the chemistry and magnetic properties of rock layers. Saylor and her colleagues combined the field observations with analysis of microscopic biological remains to reconstruct the landscape, vegetation and hydrology where MRD died.

MRD was found in the sandy deposits of a delta where a river entered a lake. The river likely originated in the highlands of the Ethiopian plateau while the lake developed at lower elevations where rift activity caused the Earth surface to stretch and thin, creating the lowlands of the Afar region. Fossil pollen grains and chemical remains of fossil plant and algae that are preserved in the lake and delta sediments provide clues about the ancient environmental conditions. Specifically they indicate that the watershed of the lake was mostly dry but that there were also forested areas on the shores of the delta or along the side the river that fed the delta and lake system. “MRD lived near a large lake in a region that was dry. We’re eager to conduct more work in these deposits to understand the environment of the MRD specimen, the relationship to climate change and how it affected human evolution, if at all,” said Naomi Levin, a co-author on the study from University of Michigan.

A new face in the crowd

Australopithecus anamensis is the oldest known member of the genus Australopithecus. Due to the cranium’s rare near-complete state, the researchers identified never-before-seen facial features in the species. “MRD has a mix of primitive and derived facial and cranial features that I didn’t expect to see on a single individual,” Haile-Selassie said. Some characteristics were shared with later species, while others had more in common with those of even older and more primitive early human ancestor groups such as Ardipithecus and Sahelanthropus. “Until now, we had a big gap between the earliest-known human ancestors, which are about 6 million years old, and species like ‘Lucy’, which are two to three million years old. One of the most exciting aspects of this discovery is how it bridges the morphological space between these two groups,” said Melillo.

Branching out

Among the most important findings was the team’s conclusion that A. anamensis and its descendant species, the well-known A. afarensis, coexisted for a period of at least 100,000 years. This finding contradicts the long-held notion of an anagenetic relationship between these two taxa, instead supporting a branching pattern of evolution. Melillo explains: “We used to think that A. anamensis gradually turned into A. afarensis over time. We still think that these two species had an ancestor-descendent relationship, but this new discovery suggests that the two species were actually living together in the Afar for quite some time. It changes our understanding of the evolutionary process and brings up new questions — were these animals competing for food or space?”

This conclusion is based on the assignment of the 3.8-million-year-old MRD to A. anamensis and the 3.9-million-year-old hominin cranial fragment commonly known as the Belohdelie frontal, to A. afarensis. The Belohdelie frontal was discovered in the Middle Awash of Ethiopia by a team of paleontologists in 1981, but its taxonomic status has been questioned in the intervening years.

The new MRD cranium enabled the researchers to characterize frontal morphology in A. anamensis for the first time and to recognize that these features differed from the morphology common to the Belohdelie frontal and to other cranial specimens already known for Lucy’s species. As a result, the new study confirms that the Belohdelie frontal belonged to an individual of Lucy’s species. This identification extends the earliest record of A. afarensis back to 3.9 million years ago, while the discovery of MRD nudges the last appearance date of A. anamensis forward to 3.8 million years — indicating the overlap period of at least 100,000 years.

Smallest African monkey fossil discovered in Kenya


This 16 July 2019 video says about itself:

Researchers working in Kenya have found a 4.2 million-year-old fossil of a miniature monkey which only weighed one kilogram.

From the University of Arkansas in the USA:

Fossil of smallest old world monkey species discovered in Kenya

Research team discovered Nanopithecus browni near Kanapoi, Kenya, far from the habitat of other guenons

July 15, 2019

Researchers from the National Museums of Kenya, University of Arkansas, University of Missouri and Duke University have announced the discovery of a tiny monkey that lived in Kenya 4.2 million years ago.

Nanopithecus browni was the same size as a modern talapoin monkey, the smallest living Old World monkey species that weighs only 2 to 3 pounds, about the size of a cottontail rabbit. Talapoins are part of a large group of monkeys called guenons, which are commonplace and widespread across Africa today. Most species are several times larger in size than Nanopithecus browni.

Guenon evolution is poorly understood but thought to be driven by changes in forest habitats, with the distribution of modern species reflecting the breakup and re-convergence of ancient forests. Talapoins live only in West Central Africa, are confined to tropical forests, and are thought to be dwarfed from a larger ancestor in response to life in woody, swampy habitats.

Nanopithecus browni, though, was found in Kenya on the eastern side of the continent, at a site called Kanapoi. The Kanapoi habitat was dry and covered with grasslands and open forests — a very different place from the tropical forests of Cameroon and Gabon in West Central Africa. It is also at Kanapoi where remains of some of the earliest human ancestors, Australopithecus anamensis, have been found and would have lived alongside Nanopithecus browni.

Nanopithecus browni is the second oldest guenon found so far, just younger than the guenon single tooth found 10 years ago on the Arabian Peninsula. The ancient date, combined with a habitat so different and so far away from that of modern talapoins, reveals a much more complex evolution of guenon monkeys than previously thought. This new enigmatic member of the primate family reveals that dwarfing occurred far longer ago than scientists suspected and may have happened more than once, and in very different habitats perhaps for different reasons.

Nanopithecus browni was discovered by the West Turkana Paleo Project, led by Fredrick Kyalo Manthi of the National Museums of Kenya, with project co-leaders Carol Ward of the University of Missouri and Michael Plavcan of the University of Arkansas. The fossils were analyzed in collaboration with Richard Kay of Duke University.

The fossil is housed at the National Museums of Kenya. The researchers published their findings in the Journal of Human Evolution.

“The discovery of Nanopithecus browni reaffirms Kenya’s contribution to understanding the evolution and diversity of Pliocene fauna and the environmental contexts in which they lived,” said Manthi. “Environmental changes during the Plio-Pleistocene may have influenced the present-day distribution of guenons.”

Nanopithecus browni is named after the late Francis Brown of the University of Utah for his contribution to understanding the geological history of the Omo-Turkana Basin within which the Kanapoi site is located.

Megalodon and great white shark updates


Megalodon extinction timeline, credit: Robert Boessenecker

From the University of Wisconsin Oshkosh in the USA:

Giant ‘megalodon‘ shark extinct earlier than previously thought

Prehistoric beast not killed off by a supernova

February 13, 2019

Summary: ‘Megalodon‘ — a giant predatory shark that has inspired numerous documentaries, books and blockbuster movies — likely went extinct at least one million years earlier than previously thought, according to new research. This is a substantial adjustment as it means that O. megalodon likely went extinct long before a suite of strange seals, walruses, sea cows, porpoises, dolphins and whales all disappeared sometime about 1-2.5 million years ago.

Megalodon — a giant predatory shark that has inspired numerous documentaries, books and blockbuster movies — likely went extinct at least one million years earlier than previously thought, according to new research published Feb. 13 in PeerJ — the Journal of Life and Environmental Sciences.

Earlier research, which used a worldwide sample of fossils, suggested that the 50-foot-long, giant shark Otodus megalodon went extinct 2.6 million years ago. Another recent study attempted to link this extinction (and that of other marine species) with a supernova known to have occurred at about this time.

However, a team of researchers led by vertebrate paleontologist Robert Boessenecker with the College of Charleston, Charleston, South Carolina, noted that in many places there were problems with the data regarding individual fossils in the study estimating the extinction date.

In the new study, the researchers reported every fossil occurrence of O. megalodon from the densely sampled rock record of California and Baja California (Mexico) in order to estimate the extinction.

Besides Boessenecker, the research team included Dana Ehret, of New Jersey State Museum; Douglas Long, of the California Academy of Sciences; Morgan Churchill, of the University of Wisconsin Oshkosh; Evan Martin, of the San Diego Natural History Museum; and Sarah Boessenecker, of the University of Leicester, United Kingdom.

They found that genuine fossil occurrences were present until the end of the early Pliocene epoch, 3.6 million years ago. All later fossils either had poor data provenance and likely came from other fossil sites or showed evidence of being eroded from older deposits. Until 3.6 million years ago, O. megalodon had a continuous fossil record on the West Coast.

“We used the same worldwide dataset as earlier researchers but thoroughly vetted every fossil occurrence, and found that most of the dates had several problems-fossils with dates too young or imprecise, fossils that have been misidentified, or old dates that have since been refined by improvements in geology; and we now know the specimens are much younger,” Boessenecker said.

“After making extensive adjustments to this worldwide sample and statistically re-analyzing the data, we found that the extinction of O. megalodon must have happened at least one million years earlier than previously determined.”

This is a substantial adjustment as it means that O. megalodon likely went extinct long before a suite of strange seals, walruses, sea cows, porpoises, dolphins and whales all disappeared sometime about 1-2.5 million years ago.

“The extinction of O. megalodon was previously thought to be related to this marine mass extinction-but in reality, we now know the two are not immediately related,” Boessenecker said.

It also is further unclear if this proposed mass extinction is actually an extinction, as marine mammal fossils between 1 and 2 million years old are extraordinarily rare-giving a two-million- year-long period of “wiggle room.”

“Rather, it is possible that there was a period of faunal turnover (many species becoming extinct and many new species appearing) rather than a true immediate and catastrophic extinction caused by an astronomical cataclysm like a supernova,” Boessenecker said.

The researchers speculate that competition with the newly evolved modern great white shark (Carcharodon carcharias) is a more likely reason for megalodon’s extinction.

Great whites first show up with serrated teeth about 6 million years ago and only in the Pacific; by 4 million years ago, they are finally found worldwide.

“We propose that this short overlap (3.6-4 million years ago) was sufficient time for great white sharks to spread worldwide and outcompete O. megalodon throughout its range, driving it to extinction-rather than radiation from outer space,” Boessenecker said.

A new study has documented unexpected consequences following the decline of great white sharks from an area off South Africa. The study found that the disappearance of great whites has led to the emergence of sevengill sharks, a top predator from a different habitat. A living fossil, sevengill sharks closely resemble relatives from the Jurassic period, unique for having seven gills instead of the typical five in most other sharks: here.

Prehistoric hyenas, video


This 17 January 2019 video says about itself:

Chasmaporthetes, also known as hunting or running hyena, is an extinct genus of hyenas distributed in Eurasia, North America, and Africa. It lived during the Pliocene-Pleistocene epochs, from 4.9 million to 780,000 years ago, existing for about 4.12 million years.

The genus probably arose from Eurasian Miocene hyenas such as Thalassictis or Lycyaena, with C. borissiaki being the oldest known representative. It was a fast runner and an important carnivore on 4 continents during the Pliocene.

At least nine species are currently recognised. The genus type species is Chasmaporthetes ossifragus. It was assigned to Hyaenidae by Hay (1921), Geraads (1997), and Flynn (1998).

The species C. ossifragus was the only hyena to cross the Bering land bridge into the Americas. C. ossifragus ranged over what is now Arizona and Mexico during Blancan and early Irvingtonian Land Mammal ages, between 5.0 and 1.5 million years ago.

Chasmaporthetes was one of the so-called “dog-like” hyenas (of which the aardwolf is the only survivor), a hyaenid group which, in contrast to the now more common “bone-crushing” hyenas, evolved into slender-limbed, cursorial hunters like modern canids.

The genus has entered the popular culture lexicon as a result of cryptozoologic claims, having been proposed as the likely origin of the American Shunka Warakin and the Cuitlamiztli.

Chasmaporthetes was named by Hay (1921), who noted the name to be a reference to the possibility that the beginning of the Grand Canyon was witnessed by the North American species, C. ossifragus.

The limb bones of Chasmaporthetes were long and slender like those of cheetahs, and its cheek teeth were slender and sharp-edged like those of a cat. Chasmaporthetes likely inhabited open ground and was a daytime hunter.

In Europe, the species C. lunensis competed with the giant cheetah Acinonyx pardinensis, and may have preyed on the small bourbon gazelle (Gazella borbonica) and the chamois antelope (Procamptoceras brivatense).

The North American C. ossifragus was similar in build to C. lunensis, but had slightly more robust jaws and teeth. It may have preyed on the giant marmot Paenemarmota, and competed with the far more numerous Borophagus diversidens.

A study on the genus’ premolar intercuspid notches indicated Chasmaporthetes was likely hypercarnivorous rather than durophagous as its modern cousins (excluding the aardwolf) are.

Like most of the animals of the time, reasons for its extinction are not known.

‘Apeman’ toddler foot discovery


This 2015 video is called The Evolution From Ape To Man – Full Documentary.

From Dartmouth College in the USA:

Our human ancestors walked on two feet but their children still had a backup plan

Most complete foot of ancient human child ever

July 4, 2018

More than 3 million years ago, our ancient human ancestors, including their toddler-aged children, were standing on two feet and walking upright, according to a new study published in Science Advances.

“For the first time, we have an amazing window into what walking was like for a 2½-year-old, more than 3 million years ago”, says lead author, Jeremy DeSilva, an associate professor of anthropology at Dartmouth College, who is one of the world’s foremost authorities on the feet of our earliest ancestors. “This is the most complete foot of an ancient juvenile ever discovered.”

The tiny foot, about the size of a human thumb, is part of a nearly complete 3.32-million-year-old skeleton of a young female Australopithecus afarensis discovered in 2002 in the Dikika region of Ethiopia by Zeresenay (Zeray) Alemseged, a professor of organismal biology and anatomy at the University of Chicago and senior author of the study. Alemseged is internationally known as a leading paleontologist on the study of human origins and human evolution.

“Placed at a critical time and the cusp of being human, Australopithecus afarensis was more derived than Ardipithecus (a facultative biped) but not yet an obligate strider like Homo erectus. The Dikika foot adds to the wealth of knowledge on the mosaic nature of hominin skeletal evolution” explained Alemseged.

Given that the fossil of the tiny foot is the same species as the famous Lucy fossil and was found in the same vicinity, it is not surprising that the Dikika child was erroneously labeled “Lucy’s baby” by the popular press, though this youngster lived more than 200,000 years before Lucy.

In studying the fossil foot’s remarkably preserved anatomy, the research team strived to reconstruct what life would have been like years ago for this toddler and how our ancestors survived. They examined what the foot would have been used for, how it developed and what it tells us about human evolution. The fossil record indicates that these ancient ancestors were quite good at walking on two legs. “Walking on two legs is a hallmark of being human. But, walking poorly in a landscape full of predators is a recipe for extinction”, explained DeSilva.

At 2½ years old, the Dikika child was already walking on two legs, but there are hints in the fossil foot that she was still spending time in the trees, hanging on to her mother as she foraged for food. Based on the skeletal structure of the child’s foot, specifically, the base of the big toe, the kids probably spent more time in the trees than adults. “If you were living in Africa 3 million years ago without fire, without structures, and without any means of defense, you’d better be able get up in a tree when the sun goes down”, added DeSilva. “These findings are critical for understanding the dietary and ecological adaptation of these species and are consistent with our previous research on other parts of the skeleton especially, the shoulder blade”, Alemseged noted.

See also here.

African hominid fossils show ancient steps toward a two-legged stride. New cache of Ardipithecus ramidus bones reveals advances in upright walking 4 million years ago. By Bruce Bower, 11:11am, February 22, 2019.

Ancient tools and bones discovered in China by archaeologists suggest early humans left Africa and arrived in Asia earlier than previously thought: here.

Ancient fossil bear discovery in Canada


This video says about itself:

18 December 2017

Paddington‘s prehistoric ancestor, a primitive bear with a sweet tooth, has been discovered in the Arctic. Researchers identified the remains of a 3.5-million-year-old bear from a fossil-rich site in Canada’s High Arctic. The findings show that the animal is a close relative of the ancestor of modern bears, and that it also had a taste for sweet treats – shown by cavities in its teeth. They say the ancient bear may have got his bad teeth from munching on berries, rather than Paddington’s preferred sweet treat of marmalade sandwiches.

From the Natural History Museum of Los Angeles County in the USA:

Primitive fossil bear with a sweet tooth identified from Canada’s High Arctic

December 18, 2017

Researchers from the Canadian Museum of Nature and the Natural History Museum of Los Angeles County have identified remains of a 3.5-million-year-old bear from a fossil-rich site in Canada’s High Arctic. Their study shows not only that the animal is a close relative of the ancestor of modern bears — tracing its ancestry to extinct bears of similar age from East Asia — but that it also had a sweet tooth, as determined by cavities in the teeth.

The scientists identify the bear as Protarctos abstrusus, which was previously only known from a tooth found in Idaho. Showing its transitional nature, the animal was slightly smaller than a modern black bear, with a flatter head and a combination of primitive and advanced dental characters. The results are published today in the journal Scientific Reports.

“This is evidence of the most northerly record for primitive bears, and provides an idea of what the ancestor of modern bears may have looked like,” says Dr. Xiaoming Wang, lead author of the study and Head of Vertebrate Paleontology at the Natural History Museum of Los Angeles County (NHMLA). “Just as interesting is the presence of dental caries, showing that oral infections have a long evolutionary history in the animals, which can tell us about their sugary diet, presumably from berries. This is the first and earliest documented occurrence of high-calorie diet in basal bears, likely related to fat storage in preparation for the harsh Arctic winters.”

The research team, which included co-author Dr. Natalia Rybczynski, a Research Associate and paleontologist with the Canadian Museum of Nature, were able to study recovered bones from the skull, jaws and teeth, as well as parts of the skeleton from two individuals.

The bones were discovered over a 20-year period by Canadian Museum of Nature scientists, including Dr. Rybczynski, at a fossil locality on Ellesmere Island known as the Beaver Pond site. The peat deposits include fossilized plants indicative of a boreal-type wetland forest, and have yielded other fossils, including fish, beaver, small carnivores, deerlets, and a three-toed horse.

The findings show that the Ellesmere Protarctos lived in a northern boreal-type forest habitat, where there would have been 24-hour darkness in winter, as well as about six months of ice and snow.

“It is a significant find, in part because all other ancient fossil ursine bears, and even some modern bear species like the sloth bear and sun bear, are associated with lower-latitude, milder habitats,” says co-author Dr. Rybczynski. “So, the Ellesmere bear is important because it suggests that the capacity to exploit the harshest, most northern forests on the planet is not an innovation of modern grizzlies and black bears, but may have characterized the ursine lineage from its beginning.”

Dr. Wang analyzed characteristics of fossil bear remains from around the world to identify the Ellesmere remains as Protarctos and to establish its evolutionary lineage in relation to other bears. Modern bears are wide-ranging, found from equatorial to polar regions. Their ancestors, mainly found in Eurasia, date to about 5 million years ago.

Fossil records of ursine bears (all living bears plus their ancestors, except the giant panda, which is an early offshoot) are poor and their early evolution controversial. The new fossil represents one of the early immigrations from Asia to North America but it is probably not a direct ancestor to the modern American black bear.

Of further significance is that the teeth of both Protarctos individuals show signs of well-developed dental cavities, which were identified following CT scans by Stuart White, a retired professor with the UCLA School of Dentistry. The cavities underline that these ancient bears consumed large amounts of sugary foods such as berries. Indeed, berry plants are found preserved in the same Ellesmere deposits as the bear remains.

“We know that modern bears consume sugary fruits in the fall to promote fat accumulation that allows for winter survival via hibernation. The dental cavities in Protarctos suggest that consumption of sugar-rich foods like berries, in preparation for winter hibernation, developed early in the evolution of bears as a survival strategy,” explains Rybczynski.