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Running Hyena - Chasmaporthetes spp.
#1
Running Hyena - Chasmaporthetes spp.

Fossil range: Late Miocene–Late Pleistocene

Scientific classification 
Kingdom: Animalia 
Phylum: Chordata 
Class: Mammalia 
Order: Carnivora 
Family: Hyaenidae 
Genus: †Chasmaporthetes
Type Species: Chasmaporthetes ossifragus 
Chasmaporthetes lunensis 
Chasmaporthetes honanensis 
Chasmaporthetes borissiaki
Chasmaporthetes australis 
Chasmaporthetes exitelus


[Image: chasmaporthetes1.jpg]

Chasmaporthetes, also known as Hunting or Running Hyena, is an extinct genus of hyena endemic to North America, Africa, and Asia during the Pliocene-Pleistocene epochs, living from 4.9 mya—780,000 years ago, existing for approximately 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. The species C. ossifragus was the only hyena to cross the Bering land bridge into the Americas, and ranged over what is now Arizona and Mexico during Blancan and early Irvingtonian Land Mammal Ages, between 5 to 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 coursorial 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.

Taxonomy and etymology
Chasmaporthetes was named by Hay (1921). Its type is Chasmaporthetes ossifragus. It was assigned to Hyaenidae by Hay (1921), Geraads (1997) and Flynn (1998).

Its name means "he who saw the canyon", referring to the fact that it was the only one of its kind to cross the Bering land bridge.

[Image: anton-hunting-hyena.jpg]


Anatomy and paleoecology
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. It is likely that Chasmaporthetes probably 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 indicate that Chasmaporthetes was likely hypercarnivorous rather than durophagus as its modern cousins (excluding the aardwolf) are.


[Image: 250px-Chasmaportethes_lunensis.JPG] 
[Image: wildcat10-CougarHuntingDeer.jpg]
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  • Claudiu Constantin Nicolaescu
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Scalesofanubis Wrote:http://www.wired.com/wiredscience/2011/0...he-canyon/

The Hyena Who Saw the Canyon

BY BRIAN SWITEK03.07.117:46 PM

Quote:“Has the Earth’s sixth mass extinction already arrived?” This question – the title of a review published in last week’s Nature – immediately sparked a flurry of news reports about an impending ecological catastrophe on a scale not seen in 65 million years. We are not witnessing a die-off as severe as any of the “Big Five” prehistoric cataclysms just yet, but the continued, gradual loss of threatened species is bringing us ever closer to the tipping point. We can either take action and stave off this large-scale disaster, or simply wait for it to happen.

Of course, extinction is the inevitable fate of every species. Species do not only disappear during worldwide disasters. Extinction greatly outpaces the origin of new species on a global scale during rare crises, but the character of life on earth is constantly shifting as some lineages dwindle as others speciate and continue to change.

You do not need to look very far back into the fossil record to appreciate the ongoing ebb and flow of life. When I traveled through Utah and Wyoming for the first time in the summer of 2009, I saw the iconic elk, pronghorn, bison, and bears that symbolize the American wilderness. But these animals are only the inheritors of a landscape that has been inhabited by a changing cast of megamammals for millions of years. The great mammoths, ground sloths, deep-snouted bears, and sabercats of Pleistocene North America represent a lost world that disappeared only yesterday in geological terms, but they, too, were preceded by what we might perceive as strange assemblages of creatures, including North America’s only hyena.


In 1901, workmen at the Val Verde Copper Mines in Anita, Arizona were prospecting around an ancient limestone fissure when they discovered a cache of ancient mammal bones. The fragments were badly broken, but the bone material itself was well-preserved, and a number of specimens were soon collected by B.C. Bicknell. The site also piqued the interest of globe-trotting fossil hunter Barnum Brown, who collected a few additional specimens in 1904. Pieces of prehistoric horses and camels were found among those of pronghorn, squirrels, groundhogs, and pocket gophers, as well as what appeared to be jaw fragments from a large cat.

It would take a decade and a half for the Anita bones to be fully described. Brown had intended to do it himself – he even sent for the specimens Bicknell had collected – but he never got around to it. Eventually the bones were given to what is now the Smithsonian National Museum of Natural History, where Oliver Perry Hay finally reported on them in 1921.

Most of the initial identifications Brown had made in his notes turned out to be correct. The mammals appeared to represent a time in the not-too-distant past when forms still living in North America today mixed with lineages that have since been extirpated. What stood out were two parts of “cat” jaw that didn’t correspond to any known feline. With the exception of a tiny part of a molar, the crowns of the teeth were entirely gone, but together the two pieces comprised most of the mandible of a carnivorous mammal. Though this was not much to work with, Hay was able to determine that the jaw had belonged to a hyena – a type of carnivore never before found in North America – and he named it Chasmaporthetes ossifragus.”The name of this [genus] makes allusion to the Grand Canyon,” Hay wrote, “whose beginning this animal may have witnessed.”

Yet Chasmaporthetes was not unique to North America. The species Hay described – C. ossifragus – turned up in deposits between 3 and 1.5 million years old at other sites in Mexico, the American southwest, and Florida, but other species of the same genus were also discovered in Europe, Africa and Asia. Rather than being entirely unique to North America, Chasmaporthetes had initially evolved elsewhere and eventually spread over the Bering Land Bridge into North America. It was a long-lived variety of hyena that was just part of a radiation of now-extinct forms.

Although Africa’s spotted hyena is the most iconic member of the group, there are three other species of living hyena: the striped hyena, the brown hyena, and the aardwolf. They are all that’s left of a once-more widespread and diverse lineage that traces back about 20 million years to small, civet-like forms such as Plioviverrops. Now, based upon appearances alone, it might seem reasonable to lump all four modern hyenas into a single evolutionary subgroup tied together by common ancestry, but this wouldn’t be right. The aardwolf, a strange and small hyena that primarily eats termites, is actually a relatively distant cousin of other modern hyenas and represents what some of the early members of the group may have been like. Likewise, the extinct giant Pachycrocuta was a closer relative of the spotted hyena than the striped and brown hyenas, and there was an entire array of extinct forms with no living representatives. Chasmaporthetes was among these now-extinct hyena lineages, and it was significantly different from the hyenas we know today.

Chasmaporthetes has often been called the “hunting hyena.” By itself, this isn’t a very helpful moniker. Despite their reputation as scavengers, for example, spotted hyenas actually obtain much of their meat through hunting, with carrion making up as little as five percent of their diet in some populations. Even so, the nickname is meant to highlight the long-legged and relatively graceful build of Chasmaporthetes. This was a hyena well-adapted to running and chasing down prey.

For decades, most of what was hypothesized about the North American hyena was based on Chasmaporthetes specimens found elsewhere. Jaw fragments and teeth were all that had been recovered in the southwest and Mexico. This changed in 1981, when Annalisa Berta described parts of the skull and limbs of the hyena found in Florida. No single skeleton was found, but by looking at the accumulated pieces Berta determined that the Florida hyenas had strongly-muscled, flexible upper arms and long, slightly curved tibiae which indicated that the hyenas had very powerful hindlimbs. The fact that premolars of Chasmaporthetes resembled the meat-slicing teeth of the spotted hyena rather than the crushers of the brown and striped hyenas was taken as an indication that it was more of a predator than a scavenger, and a fleet-footed one at that.

Though the North American Chasmaporthetes specimens were differentiated from other species by their relatively robust limbs, deep lower jaws, and slightly curved tooth rows, their general anatomy was consistent with finds in the Old World. These hyenas were hunters that ran down their prey. This might have put them in competition with speedy cats that evolved about 1.8 million years ago – namely North America’s false cheetah Miracinonyx – but some researchers stressed caution in drawing conclusions about diet on the basis on anatomy alone. In a 1994 paper about Chasmaporthetes and Hyaenictis, paleontologists Lars Werdelin, Alan Turner, and Nikos Solounias wrote:

"It should be noted, however, that our suggestion of adaptations towards a cursorial and active hunting mode of life for Chasmaporthetes does not mean that it did not scavenge, nor that it was necessarily in competition with extremely cursorial hunters such as Acinonyx [true cheetahs] and Miracinonyx. However, relative to other hyaenas[,] it has clearly evolved in that direction."

Although many researchers stressed that the cheek teeth of the several Chasmaporthetes species were better suited to shearing than crushing, this did not mean that the hyenas were incapable of cracking bone. After all, modern spotted hyenas are formidable hunters as well as accomplished bone-crackers, and a complete skull of the European species C. lunensis found in Spain exhibited patterns of tooth wear consistent with breaking open bones. Much like the modern spotted hyena, Chasmaporthetes was a hunter that could make full use of a carcass, as well as scavenge when the opportunity presented itself.

But paleontologists have been able to do more than propose hypotheses on the gross anatomy of the Chasmaporthetes bones alone. The rediscovery of the skull from Spain – which had been found in the 1970′s and studied by Dolores Soria for her doctoral thesis before fading from view until 2007 – finally provided scientists with an opportunity to see what kind of stresses and strains the hyena’s skull was capable of withstanding. Paleontologists have carried out these tests for a variety of bone-crunching mammals over the years, and so there was already plenty to compare the C. lunensis skull with.

Zhijie Tseng, Mauricio Antón, and Manuel Salesa published the results of their study in Paleobiology earlier this year. Like many other bone-cracking carnivorans, the skull of Chasmaporthetes exhibited a mosaic of features that gave it a powerful bite – a short snout, massive premolars, a large sagittal crest on the top of the skull for muscle attachment, deep lower jaws, and teeth modified at the microscopic level to resist fracturing. These traits are present to relatively lesser or greater degrees among carnivorous mammals adapted to crack bones, but the scientists proposed that the skull of Chasmaporthetes would have had suffered greater stress while breaking through bone than the skull of a modern spotted hyena.

The scientists turned out to be wrong. Based upon the computerized models created for the study, Tseng and colleagues concluded that the skull of “Chasmaporthetes was just as adapted for handling stress incurred during bone-cracking behavior as the modern Crocuta [spotted hyena].” Yet this does not necessarily mean that the extinct hyena hunted and fed in the exact same way that spotted hyenas do. Chasmaporthetes still had comparatively slender teeth better suited to cutting through fresh than breaking through bone, and so the authors of the paper suggest that the stress-absorbing features of the skull might be adaptations to withstanding forces generated by struggling prey. The way the hyenas caught prey has to be taken into account, and future studies that model stresses created by prey may help scientists identify skull characteristics related to hunting rather than fracturing bone. Chasmaporthetes certainly could have been a competent bone-cracker, but whether the anatomy of its skull can be attributed to this kind of behavior is another question.

Unfortunately, no one has yet found a complete skull from an American hyena. Perhaps some lucky paleontologist will, but, for now, the skull from Spain provides the best available information about the possible feeding habits of these “hunting hyenas.” I can only imagine a pack of Chasmaporthetes chasing down a prehistoric pronghorn through the grasslands – a scene that still echoes in Africa, but occurred during a distant part of North America’s prehistory.

Rashido Wrote:Analysis of a Chasmaporthetes lunensis skull:

http://digital.csic.es/bitstream/10261/22443/1/31.pdf

Vita Wrote:Document Description
Fossil species of the family Hyaenidae represent a wide range of ecomorphological diversity not observed in living representatives of this carnivoran group. Among them, the cursorial meat-and-bone specialists are of particular interest not only because they were the most cursorial of the hyaenids, but also because they were the only members of this family to spread into the New World. Here we conduct a functional morphological analysis of the cranium of the cursorial meat-and-bone specialist Chasmaporthetes lunensis by using finite element modeling to compare it with the living Crocuta crocuta, a well-known bone-cracking carnivoran.

Link for download (PDF)


http://pdfcast.org/pdf/the-evolution-of-...he-plio-pl

The evolution of the bone-cracking model in carnivorans: cranial functional morphology of the Plio-Pleistocene cursorial hyaenid Chasmaporthetes lunensis (Mammalia: Carnivora)


Some interesting points:

"The cranium of C. lunensis is not differentially adapted for stress dissipation
between the bone-cracking and meat-shearing teeth. A smaller occlusal surface on the more slender P3
cusp of C. lunensis allowed this species to use less bite force to crack a comparably-sized bone relative
to C. crocuta, but higher muscle masses in the latter probably allow it to process larger food items.
We
use two indices, the stress slope and the bone-cracking index, to show that C. lunensis has a welladapted
cranium for stress dissipation given its size, but the main stresses placed on its cranium
might have been more from subduing prey and less from cracking bones."

"Previous studies have provided definitions
of the mosaic of morphological features to be
expected in a bone-cracking carnivoran."

For example:

"The skull displays a prominent
sagittal crest that rises behind the orbits,
giving the skull a dome-like profile, also
reflecting the expansion of attachment area
of the temporalis muscle, the primary jaw
adductor muscle; in addition, the dome shape
appears to strengthen the skull by dissipating
compressive forces that occur during bonecracking

(Werdelin 1989)."


"The postcranial anatomy of Chasmaporthetes
indicates that this genus evolved increasingly
cursorial limb morphology and proportions
(Berta 1981; Kurte´n and Werdelin 1988). It
also possessed premolars that were slender,
trenchant and with strong posterior accessory
cusps, a morphology that made them more
adequate for cutting flesh and skin than the
robust, conical premolars of many other
hyaenids
(Berta 1981; Khomenko 1932;
Schaub 1941; Werdelin and Solounias 1991).
This set of dental and postcranial features has
been recognized as an indication of more
actively predatory habits, and less reliance on
scavenging and bone-cracking than in modern
hyenas.
However, the functional adaptations
of the cranium are a more complex
issue. Anto´n et al. (2006) pointed out several
morphological features suggesting a less
complete adaptation of the skull for bonecracking
in Chasmaporthetes than in Crocuta
and other extreme bone-crackers, and those
observations were in line with previous work
by Kurte´n and Werdelin (1988)."
[Image: wildcat10-CougarHuntingDeer.jpg]
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  • Claudiu Constantin Nicolaescu
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#3
(06-05-2018, 10:22 PM) pid=\737' Wrote:Prehistoric Hyena’s Teeth Show Bone-Crushing Carnivore Roamed the Arctic
The only hyena to live in North America, Chasmaporthetes, had the stature of a wolf and the powerful jaws of its modern relatives
[Image: 1.jpg]

An artist’s rendering of ancient Arctic hyenas belonging to the genus Chasmaporthetes. A new study reports that two enigmatic fossil teeth found in Yukon Territory in Canada belonged to Chasmaporthetes, making the teeth the first known fossils of hyenas found in the Arctic. (Julius T. Csotonyi)
By Riley Black

smithsonian.com 
June 18, 2019 6:00AM

Over a million years ago, among the chilly grasslands of the ancient Yukon, Canada’s most northwesterly territory, an unexpected beast roamed: a hyena. More lupine in appearance than its modern relatives, but still adept at crushing bones with its powerful jaws, this "running hyena" was the only species of its family to venture out of Eurasia and spread to the Americas. Paleontologists know the prehistoric carnivore as Chasmaporthetes.

The first Chasmaporthetes fossils were named nearly a century ago from the vicinity of the Grand Canyon, and accordingly, the ancient hyena’s scientific name roughly translates to “the hyena who saw the canyon.” Since that initial discovery, additional fossils have turned up from California to Florida, from northern Mexico to Kansas, and additional species have been unearthed in Africa and Eurasia. But there was always a missing piece to the puzzle. Paleontologists found Chasmaporthetes fossils in Eurasia, and the ancient predator clearly ranged widely through southern North America, but the fossils bridging the gap in a place called Beringia, where Siberia and Alaska were once joined by a land bridge, were seemingly nowhere to be found. A newly analyzed pair of teeth is helping to fill in part of that story.
A team of paleontologists led by researchers from the University at Buffalo describe the fossils today in the journal Open Quaternary. The teeth were collected back in the 1970s, found in the Yukon’s Old Crow Basin—a place that has yielded over 50,000 vertebrate fossils representing more than 80 species. Even though the hyena teeth were known in certain paleontology circles, no formal study had ever been published. Whispers of Arctic hyenas piqued the curiosity of University at Buffalo paleontologist Jack Tseng, who over years of discussions with coauthors Lars Werdelin and Grant Zazula eventually tracked down the teeth and positively identified them. “This was classic paleo collection detective work, involving a network of collaborators and collections managers,” Tseng says.
[Image: tooth-beebe-irving-1.jpg]
This Ice Age fossil tooth—tucked away for years in the collections of the Canadian Museum of Nature—belonged to the “running hyena” Chasmaporthetes, according to a new University at Buffalo-led study. This tooth, found in 1977, and one other are the first known hyena fossils found in the Arctic. (Grant Zazula / Government of Yukon)

What emerges is a view of the Ice Age that’s a bit different than typical visions of woolly mammoths and Smilodon, or Saber-toothed cats. Even though artistic depictions and museum displays sometimes depict many different Ice Age species together, Chasmaporthetes arrived in the Yukon during a very specific slice of time that would look a bit less familiar to us. “There were no bison, likely no lions, no gray wolves, no muskoxen, no saiga antelope,” says Zazula, a paleontologist at Simon Fraser University. All those animals arrived in North America later. Instead, the hyena was neighbors with giant camels, horses, caribou and steppe mammoths (a different species than the more familiar woolly sort). And despite the moniker “Ice Age,” the time of Chasmaporthetes was on the green side. “There were probably a few stunted spruce trees, with swaths of steppe-tundra grasslands with shrub birch and willows,” Zazula says. Nevertheless, the high latitude of the ancient Yukon still brought protracted chills and short summers, meaning the hyenas “had to have been effective predators in the long, dark, cold Arctic winters.”
[Image: old-crow-flats-froese-1.jpg]
The Old Crow River region (Vuntut Gwitchin First Nation) in Yukon Territory in Canada is known for its rich deposits of fossils. The ancient hyena teeth are among tens of thousands of fossils recovered from the region in the last century. (Duane Froese / University of Alberta)

When Chasmaporthetes arrived in North America in the Pliocene, many of the other “classic” Pleistocene carnivores were not yet present. Gray wolves and lions wouldn’t arrive for tens of thousands of years. The hyena likely lived along cuons—relatives of today’s dholes—and scimitar-toothed cats, Zazula says, so the hyena might have lived during a window when there wasn’t too much competition for prey.
However, Chasmaporthetes did face some competition with another bone crusher. A prehistoric dog, Borophagus, overlapped with the hyena for about three million years in North America. The canid might have dominated southern habitats while Chasmaporthetes largely stayed north until Borophagus, whose name means “gluttonous eater,” went extinct. “They almost certainly were competing with bone-cracking dogs during their co-occurrence in the fossil record,” Meachen says.

The challenging Arctic landscape may have actually been an ideal place for a predator with such abilities. “In harsh environments with low abundance of prey, bone cracking was a necessary and advantageous trait to hyenas because they could gain more calories from being able to eat more of the prey,” Tseng says.

Like many Ice Age mammals, Paleontologists are still wrestling with the question of what exactly wiped out Chasmaporthetes. “Since Chasmaporthetes went extinct before the end-Pleistocene, obviously something other than that event did the deed for them,” Meachen says. The arrival of gray wolves in North America, and the profusion of native dire wolves, may have given the hyena some stiff competition, but what drove Chasmaporthetes to the brink is still an open question. “Overall, I think this is still a mystery,” Meachen says.

The loss of the continent’s bone-crushing hyena was no small matter. Even though wolves can and do crunch bones, none did so to the degree of Chasmaporthetes. The hyena played an important ecological role breaking down large carcasses out on the plains and spreading nutrients throughout their range. The loss of these carnivores, and the lack of a suitable successor, changed the nature of North America—the continent just isn’t the same without hyenas.

Read more: https://www.smithsonianmag.com/science-n...JmEFWV8.99
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  • Claudiu Constantin Nicolaescu, OldGreenVulture
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#4
Abstract and study link of above research:

Journal Reference:
Z. Jack Tseng, Grant Zazula and Lars Werdelin. 2019. First Fossils of Hyenas (Chasmaporthetes, Hyaenidae, Carnivora) from North of the Arctic Circle. Open Quaternary. 5(1) DOI: 10.5334/oq.64

Abstract
The northern region of Beringia is ecologically and biogeographically significant as a corridor for biotic dispersals between the Old and New Worlds. Large mammalian predators from Beringia are exceedingly rare in the fossil record, even though carnivore diversity in the past was much higher than it is in this region at present. Here we report the first fossils of cursorial hyenas, Chasmaporthetes, in Beringia and north of the Arctic Circle. Two isolated teeth recovered in the Old Crow Basin, Yukon Territory, Canada, were identified amongst over 50,000 known fossil mammal specimens recovered from over a century of collecting in the Old Crow Basin. These rare records fill an important intermediary locale in the more than 10,000 km geographic distance between previously known New and Old World records of this lineage. The Pleistocene age of these fossils, together with its Arctic Circle occurrence, necessitate a rethinking of the role of large-bodied hunter-scavengers in Ice Age megafaunas in North America, and the implications of lacking an important energy flow modifier in present day North American food webs.

https://www.openquaternary.com/articles/10.5334/oq.64/
[Image: wildcat10-CougarHuntingDeer.jpg]
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#5
So there are hyenas that live in the tundra as well. That's good to know.
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