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Post by Gorilla king on Jul 5, 2021 17:25:22 GMT -5
Can being vegan make you go EXTINCT? Picky prehistoric cave bear's diet caused it to die out
Weighing more than half a ton and equipped with huge teeth capable of crushing bones, the prehistoric cave bear would seem equipped to be a top Ice Age predator. But new research suggests these enormous bears may actually have been absurdly picky eaters that survived on a largely vegan diet. The findings provide new clues for what led these beasts to die out around 25,000 years ago during the last glacial period.
While most modern bears are omnivorous, consuming everything from tiny berries to fish and deer, analysis of bones from extinct cave bears has revealed that they stuck to a strictly plant-based diet. Using cave bear bones found at the Goyet Cave in Belgium, a team of international researchers managed to reconstruct the bears' diet. Specifically, they looked at the isotope composition of collagen in the bones. Collagen - a protein that makes up the scaffolding of most tissues including bones, teeth, tendons and skin - is made up of amino acids that vary according to an animal's diet. The analysis eventually revealed cave bears lived on subsisted on a rigidly vegan diet. Even bear cubs that had been suckling milk showed a vegan-like collagen make-up due to their mother's dietary regime.
'Similar to today's giant panda, the cave bears were therefore extremely inflexible in regard to their food,' said lead researcher Professor Hervé Bocherens, from the Senckenberg Center for Human Evolution and Palaeoenvironment at the University of Tübingen in Germany. 'We assume that this unbalanced diet, in combination with the reduced supply of plants during the last ice age, ultimately led to the cave bear's extinction.'
Cave bears first appeared in Europe around 400,000 years ago. Measuring up to 11 feet (3.5m) long and 5.5 feet tall at the shoulder (1.7m) they were formidable animals. They earned their name as many remains of these beasts have been found in caves. However, they are only thought to have hibernated in caverns and spent most of their time roaming searching for food. 'We believe that the reliance on a purely vegan diet was a crucial reason for the cave bear's extinction,' Professor Bocherens added, whose work is published in the Journal of Quaternary Science. The team is now hoping to study cave bear bones from other areas in order to confirm their hypothesis. 'We now intend to examine additional cave bear bones from various European locations with this new method, as well as conducting controlled feeding experiments with modern bears, in order to further solidify our proposition,' Professor Bocherens explained.
www.dailymail.co.uk/sciencetech/article-3759796/Can-vegan-make-EXTINCT-Picky-prehistoric-cave-bear-s-diet-caused-die-out.html
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Post by Gorilla king on Jul 5, 2021 17:34:48 GMT -5
Cave bear is the common name for a large bear, Ursus spelaeus, that lived in Europe during the Pleistocene about 250,000 years ago and became extinct at the end of the last ice age about 12,000 years ago. Both the common name, cave bear, and the scientific name, spelaeus, derive from the fact that fossils of this species were found mostly in caves, suggesting that this species spent more time in caves than the related brown bear, which only uses caves for hibernation. As a result of its habitat, Ursus spelaeus is the species of macro fauna that has resulted in the largest amount of Pleistocene fossils in caves (Orlando et al. 2002).Human beings have long been fascinated by their own history, and cave bears have shared part of that history, living at the same time as modern human beings (Homo sapiens sapiens) and the Neanderthals. Many mysteries remain about the cave bear and about its interaction with humans, which remain active foci of human inquiry, including the employment of new technologies such as DNA analysis (Noonan et al. 2005).
Time period, range, and habitatThe cave bear, Ursus spelaeus, was prominent during the Pleistocene. The Pleistocene epoch of the geologic timescale is the period from 1,808,000 to 11,550 years Before Present (BP). The Pleistocene follows the Pliocene epoch and is followed by the Holocene epoch. The end of the Pleistocene corresponds with the end of the Paleolithic age used in archaeology. Cave bears inhabited Europe and the Near East since the Riss glacial period, 250,000 years ago (Orlando et al. 2002). They became extinct approximately 12,000 years ago, at the end of the last glacial period (Orlando et al. 2002).The cave bear's range stretched across Europe, from Spain to Eurasia, from Italy and Greece to Belgium, the Netherlands and possibly Great Britain, across a portion of Germany, through Poland, then south into Hungary, Romania, and parts of Russia. There have been no traces of cave bears living in northern Britain, Scandinavia, or the Baltic countries, which were covered in extensive glaciers at the time. The largest numbers of cave bear remains have been found in Austria, Switzerland, southern Germany, northern Italy, northern Spain, Croatia, Hungary, and Romania. The huge number of bones found in south, central, and east Europe has led some scientists to think that Europe may have once had literal herds of cave bears. Some, however, point out that though some caves have thousands of bones, they were accumulated over a period of 100,000 years or more, thus requiring only two deaths in a cave per year to account for the large numbers (Bieder 2005).The cave bear inhabited low mountainous areas, especially in regions rich in limestone caves. They seemed to avoid open plains, preferring forested or forest-edged terrains (Bieder 2005).Many caves in Europe have skeletons of cave bears on display, for example the Heinrichshöhle in Hemer or the Dechenhöhle in Iserlohn, Germany. In Romania, there is a cave called Peştera Urşilor (bears' cave) where numerous cave bear skeletons were discovered.
Anatomy
The cave bear was a massive bear, characterized by a very broad, domed skull with a steep forehead, unlike the more gradual sloping forehead in skulls of modern bears. Cave bears of the last ice age lacked the usual two to three premolars present in other bears; to compensate, the last molar is very elongated, with supplementary cusps (Altabadia).The cave bear's stout body had long thighs, massive shins, and in-turning feet, making it similar in skeletal structure to the grizzly bear. The average weight for males is estimated to have been 400 kilograms (880 pounds) (Brown 1993). Certain experts suggest greater weights of 500-600 kilograms (1,102-1,323 pounds) (Pastoureau 2007). The modern brown bear, Ursus arctos, weighs between 130 and 700 kilograms (286-1540 pounds), with the larger populations matching the polar bear, Ursus maritimus (300 to 600 kilograms) (660 to 1320 pounds) as the largest extant bear.Males were larger than females. About ninety percent of cave bear skeletons in museums are male, due to a misconception that the female skeletons were merely "dwarfs." Cave bears grew larger during glaciations and smaller during interglacials, probably to adjust heat loss rate (MacDonald 1992).
Dietary habitsThe dietary habits of cave bears—whether largely vegetarian, or also carnivores or scavengers—is unsettled.The morphological features of chewing apparatus of cave bears suggest herbivorous behavior, rather than predatory behavior, and important adaptations to a tough vegetarian diet (Pinto Llona 2006). On the other hand, comparison with extant European brown bears, Ursus arctos, in terms of gross-wear features on the teeth, suggests that tubers were absent from the cave bear diet and not responsible for the extreme wear seen in cave bear teeth (Pinto Llona 2006). Dental Microwear Analysis (DMA), comparing diet-related microscopic dental wear features of brown bears, whose diet is known, with cave bears suggests that the cave bear dietary behavior included a greater consumption of bone versus that of brown bears.Results obtained on the stable isotopic yield of cave bear bones also are interpreted as indicators of a largely vegetarian diet, and one even more vegetarian than contemporary herbivorous taxa (Bocherens et al. 1994; Pinto Llona 2006). The bones of central and western European cave bears matched those of vegetarians in having low levels of nitrogen-15, which is accumulated by meat eaters. However, several cave bear sites in the Peştera cu Oase in the southwestern tip of the Carpathian mountains have shown that the cave bears of that region may have been largely carnivorous, due to higher levels of nitrogen-15 in their bones (Choi 2008). Nitrogen-15 is accumulated by animals and, thus, carnivores, which eat animals, accumulate more nitrogen-15 in their bodies than do herbivores.Carnivorous behavior is also evident from very large cave bear tooth marks on young cave bear skulls in Yarimburgaz Cave in western Turkey (Choi 2008).Taphonomic analysis of modifications on cave bear bones produced by carnivores suggests that in addition to their herbivorous and carnivorous behaviors, cave bears actively scavenged on the carcasses of their con-specifics (Pinto Llona 2006).It is possible that different populations of cave bears had different dietary habits, including possible bear-bear cannibalism (Choi 2008) and cannibalistic scavenging behavior. In the case of the central and western European populations, whose bones lacked an identifiable isotopic signature of nitrogen-15, it is possible that cannibalistic scavenging behavior may have been quite limited, relative to the more dominant vegetarian diet, leaving no trace (Pinto Llona 2006).
MortalityCave bear longevity is unknown, though it has been estimated that they seldom exceeded 20 years of age (Bieder 2005).Some cave bear bones show signs of numerous different ailments, including fusion of the spine, bone tumors, cavities, tooth resorption, necrosis (particularly in younger specimens), nematodes, osteomyelitis, periostitis, rickets, and kidney stones (Brown 1993). Male cave bear skeletons have been found with broken baculums, probably due to fighting during breeding season (Bjorn 1968). Death during hibernation is considered to have been a common end for cave bears, mainly befalling specimens that failed ecologically during the summer season through inexperience, sickness, or old age (Bjorn 1968).Paleontologists doubt adult cave bears had any natural predators, save for pack hunting wolves and cave hyenas, which would probably have attacked sick or infirm specimens (Bieder 2005). Cave hyenas are thought to be responsible for the dis-articulation and destruction of some cave bear skeletons. Such large carcasses would have been an optimal food resource for the hyenas, especially at the end of the winter, when food was scarce (Diedrich and Zak 2006).
Evolution and extinction
The cave bear is thought to be descended from the plio-pleistocene Etruscan bear (Ursus etruscus) through the Deninger's bear (Ursus deningeri) of the Pleistocene half a million years ago.Cave bears found in different regions vary in age and evolutionary advancement, thus facilitating investigations into their development. The three anterior premolars were gradually reduced, then disappeared. In a fourth of the skulls found in the Conturines, the third premolar is still present, while the other more evolved specimens elsewhere lack it. The fourth premolar developed into a molar. The last remaining premolar became conjugated with the true molars, enlarging the crown and granting it more cusps and cutting borders. This phenomenon known as molarization improved the mastication capacities of the molars, facilitating the processing of tough vegetation. This allowed the cave bear to gain more energy for hibernation while eating less than its ancestors (Altabadia). Molecular phylogenetic analysis of mtDNA suggests that cave bears and brown bears separated from a common ancestor about 1.2 to 1.6 million years ago (Orlando et al. 2002).Experts generally agree on the time of the extinction of the cave bear—about 12,000 years ago at the end of the late glacial period (Orlando et al. 2002)—but they remain in dispute about the causes of the extinction. Some have proposed that the bears' large size and lack of natural predators caused them to degenerate as a species, while others claim that habitat loss due to climate change was responsible for the extinction. Yet another group of experts disputes this claim, as the cave bears had earlier survived multiple episodes of climate change. In their key article on ancient DNA and the population genetics of the cave bear, Orlando et al. (2002) note that climatic changes may have altered the bears' genetic diversity profiles in ways that pushed the bears to their extinction. They note that the cave bear started to become extinct during cold climatic conditions accompanied by an observed simultaneous and significant loss of genetic diversity.Overhunting by humans has been largely dismissed due to the fact that human populations at the time were too small to pose a serious threat to the cave bears' survival, though there is proof that the two species may have competed for living space in caves. One theory proposed by late paleontologist Bjorn Kurten states that the cave bear populations were fragmented and under stress even before the advent of the glaciers (Bieder 2005).
Cave bear worshipCollections of bear bones at several widely dispersed sites suggest that Neanderthals may have worshiped cave bears, especially at Drachenlock, in Switzerland, where a stone chest was discovered with a number of bear skulls stacked upon it. Neanderthals, who also inhabited the entrance of the cave, are believed to have built it. A massive stone slab covered the top of the structure. At the cave entrance, seven bear skulls were arranged with their muzzles facing the cave entrance, while still deeper in the cave, a further six bear skulls were lodged in niches along the wall. Next to these remains were bundles of limb bones belonging to different bears. Consequently, it was at this site that the supposed symbol of the "Cult of the Cave Bear" was found. This consisted of the skull of a three-year-old bear pierced in the cheek area by the leg-bone of younger bear. The arrangement of these bones of different bears are not believed to have happened by chance.A similar phenomenon was encountered in Regourdou, southern France. A rectangular pit contained the remains of at least twenty bears, covered by a massive stone slab. The remains of a Neanderthal lay nearby in another stone pit, with various objects, including a bear humerus, a scraper, a core, and some flakes, which were interpreted as grave offerings.The unusual finding in a deep chamber of Basua Cave in Savona, Italy, is thought to be related to cave bear worship, as there is a vaguely zoomorphic stalagmite surrounded by clay pellets. It was apparently used by Neanderthals for a ceremony, the fact that bear bones lay scattered on the floor further suggested that this was likely to have had some sort of ritual purpose (de al Cova).
www.newworldencyclopedia.org/entry/Cave_bear
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Post by Gorilla king on Jul 5, 2021 17:48:34 GMT -5
Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (Ursus spelaeus) Abstract and Figures
The proposed dietary pattern of extinct Late Pleistocene cave bears (Ursus spelaeus Rosenmüller, 1794) has become controversial, as some authors have suggested that they were strictly vegetarian, whereas others maintain they were omnivores that at times ate large amounts of animal protein. We evaluated these alternatives by compiling stable isotope data of carbon (δ13C) and nitrogen (δ15N) from the bone collagen of adult European cave bears from the Late Pleistocene (Marine Isotopic Stage 3). The data include previously published analyses and additional data from the southeastern European (Carpathian) sites of Cioclovina, Muierii, Oase, and Urşilor. The cave bear isotopic values from bone collagen were compared with those from hair keratin occurring in grizzly bears (Ursus arctos horribilis Ord, 1815) collected from 1989 to 2009 in the western United States (Yellowstone National Park). The Yellowstone bears have access to a wide diversity of plants and animals, such that their diets can range from vegetarian to carnivorous. Thus, there was considerable δ13C and δ15N variation among the grizzly bear isotopic values, and the cave bear isotopic variation was encompassed within the overall grizzly bear isotopic distribution. More importantly, the δ15N distributions, reflecting principally trophic level, were not different between the cave bears and the grizzly bears; the cave bear values are, on average, slightly higher or lower than those of the grizzly bears, depending on the criteria for inclusion in the comparisons. It is therefore no longer appropriate to view Late Pleistocene cave bears as strictly or even predominantly vegetarian but as flexible omnivores within their diverse communities.
www.researchgate.net/publication/263414302_Isotopic_evidence_for_dietary_flexibility_among_European_Late_Pleistocene_cave_bears_Ursus_spelaeus
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Post by Gorilla king on Jul 5, 2021 17:50:32 GMT -5
Extinct vegetarian cave bear diet mystery unravelled
During the Late Pleistocene period (between 125,000 to 12,000 years ago) two bear species roamed Europe: omnivorous brown bears (Ursus arctos) and the extinct mostly vegetarian cave bear (Ursus spelaeus).
Until now, very little is known about the dietary evolution of the cave bear and how it became a vegetarian, as the fossils of the direct ancestor, the Deninger's bear (Ursus deningeri), are extremely scarce.
However, a paper published in the journal Historical Biology, sheds new light on this. A research team from Germany and Spain found that Deninger's bear likely had a similar diet to its descendant -- the classic cave bear -- as new analysis shows a distinct morphology in the cranium, mandible and teeth, which has been related to its dietary specialization of a larger consumption of vegetal matter.
To understand the evolution of the cave bear lineage, the researchers micro-CT scanned the rare fossils and digitally removed the sediments so as not to risk damaging the fossils. Using sophisticated statistical methods, called geometric morphometrics, the researchers compared the three-dimensional shape of the mandibles and skull of Deninger's bear with that of classic cave bears and modern bears.
"The analyses showed that Deninger's bear had very similarly shaped mandibles and skull to the classic cave bear," explains Anneke van Heteren, lead-author of the study and Head of the Mammalogy section at the Bavarian State Collection of Zoology. This implies that they were adapted to the same food types and were primarily vegetarian.
"There is an ongoing discussion on the extent to which the classic cave bear was a vegetarian. And, this is especially why the new information on the diet of its direct ancestor is so important, because it teaches us that a differentiation between the diet of cave bears and brown bears was already established by 500 thousand years ago and likely earlier," says Mikel Arlegi, doctoral candidate at the Universities of the Basque Country and Bordeaux and co-author of the study.
Interestingly, researchers also found there are shape differences between the Deninger's bears from the Iberian Peninsula and those from the rest of Europe, which are unlikely to be related to diet.
They have come up with three possibilities to explain these differences: 1) the Iberian bears are chronologically younger than the rest, 2) the Pyrenees, acting as natural barrier, resulted in some genetic differentiation between the Iberian bears and those from the rest of Europe, 3) there were multiple lineages, with either just one leading to the classic cave bear, or each lineage leading to a different group of cave bears.
"However, more fossils are necessary to test these three hypotheses," Asier Gómez-Olivencia, Ikerbasque Researcher at the University of the Basque Country said. www.sciencedaily.com/releases/2018/07/180728083510.htm
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Post by Gorilla king on Jul 5, 2021 17:52:18 GMT -5
The European Cave Bear or Ursus spelaeus existed during two different ice ages and is one of the best known mammals of the Ice Age. It is believed to have evolved from the Etruscan Bear (possibly Ursus deningeri) and lived from 5.3 million years ago to about 10,000 years ago. The cave bear's lifespan is believed to have been 20 years or less. The name spelaeus was taken from the ancient Roman word spelaio meaning cave. It was given to Ursus spelaeus, because most of the cave bear's remains have been found in caves.
HABITAT The cave bear inhabited parts of Austria, Switzerland, Spain, France, Netherlands, Germany, Italy, Croatia, Greece, Poland, Hungary, Romania, Greece, and Russia. It prefered low mountainous forested areas. It is not known for sure whether they visited caves on a regular basis or if they used them only for hibernation.
CHARACTERISTICS The cave bear had a heavily built body with a large head, domed skull, steep forehead, and small eyes. Male cave bears weighed on average from 900 to 1100 pounds with females about half that weight. However, overtime, cave bears varied much in size. They grew much larger during glaciations (ice ages) and then smaller during interglacials (between ice ages) to adjust to the climate. The build of its body was similar to that of a grizzly bear.
DIET Though studies have shown the diet of many cave bears had been mainly herbivorous, the reason for that is very possibly because of its prey having died off from the climate change. It may have also had to compete for food with other animals.
EXTINCTION Most cave bears seem to have died off well before the Weichselian glaciation, but survivors lasted in parts of Europe up to the end of the last ice age. Timing suggests that the cave bear's habitat loss was due to climate change about 27,800 years ago, during the last Glacial Maximum. However, a combination of reasons are believed to have led to the bear's extinction. Many of the bear's remains have been found to be diseased. This could have been caused by a drastic change in diet forced on by the change in climate. The estimated time of the bear's extinction varies from 27,800 years ago to 8,000 years ago.www.bearsoftheworld.net/ursus_spelaeus.asp
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Post by Gorilla king on Jul 5, 2021 17:53:40 GMT -5
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Post by Gorilla king on Jul 5, 2021 17:55:26 GMT -5
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Post by Gorilla king on Jul 5, 2021 23:32:06 GMT -5
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Post by Gorilla king on Jul 5, 2021 23:34:52 GMT -5
European Cave Bears Had Pure Herbivorous Diet
May 26, 2020 by Natali Anderson
An isotopic analysis of fossil collagen from the bones collected in three Romanian caves indicates that the cave bear (Ursus spelaeus), an extinct species of bear that lived 300,000-25,000 years ago in Europe, the Mediterranean and Asia, was exclusively herbivorous.
The cave bear was a very large type of bear that formed the sister lineage of living brown bears and polar bears.
The animal lived during the Pleistocene epoch and became extinct approximately 25,000 years ago.
It was 2.7-3.5 m (8.9-11.5 feet) long and up to 1.7 m (5.6 feet) at the shoulder, and has a mass between 225 and 500 kg.
Dietary habits of the cave bear has widely been debated as different paleobiological studies produced different dietary inferences for the animal, ranging from carnivory to pure herbivory.
“It comes as big surprise that these animals — despite their size and the fact they lived in a cold and dry environment — exclusively subsisted on plants,” said senior author Professor Herve Bocherens, a researcher in the Senckenberg Center for Human Evolution and Palaeoenvironment and the Department of Geosciences, Biogeology at the University of Tübingen.
“While this vegetarian lifestyle has already been proven for the vast majority of cave bears in Europe, fossil discoveries from Romania gave rise to a lively scientific discussion as to whether cave bears in that region may also have fed on meat.”
For the study, Professor Bocherens and colleagues used 20,000 to 49,000-year-old skeletal remains of six adult cave bears from the three Romanian cave sites: Măgura, Cioclovina and Răsuflătoarei.
“Well-preserved bone specimens of cave bears from these three sites allowed us to examine the feeding behavior of the individuals from this region,” the researchers said.
They analyzed the nitrogen isotope values of amino acids in the bone collagen from the cave bear specimens.
“We measured special amino acids in the fossil bone collagen and subsequently compared the values with those from other cave bear bones as well as typical carnivores and herbivores; in our case, a lion and a horse,” Professor Bocherens added.
“Our results show that Romanian cave bears subsisted on an exclusively vegetarian diet before they became extinct about 25,000 years ago.”
The study was published in the journal Scientific Reports.
www.sci-news.com/paleontology/herbivorous-cave-bears-08466.html
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Post by Gorilla king on Jul 5, 2021 23:41:24 GMT -5
FIRST EVER PRESERVED GROWN UP CAVE BEAR-EVEN ITS NOSE IS INTACT-UNHEARTHED ON THE ARTIC ISLAND
Separately at least one preserved carcass of a cave bear cub found on the mainland of Yakutia, with scientists hopeful of obtaining its DNA.
More details of the finds are to be announced soon.
Until now only the bones of cave bears have been discovered.
The new finds are of ‘world importance’, according to one of Russia’s leading experts on extinct Ice Age species.
Scientist Lena Grigorieva said of the island discovery of the adult beast: 'Today this is the first and only find of its kind - a whole bear carcass with soft tissues.
'It is completely preserved, with all internal organs in place including even its nose.
“Previously, only skulls and bones were found. This find is of great importance for the whole world.’
First ever preserved grown up cave bear - even its nose is intact - unearthed on Bolshoy Lyakhovsky island, with at least one preserved carcass of a cave bear cub found on the mainland of Yakutia. Pictures: NEFU
The remains were found by reindeer herders on the island and the remains will be analysed by scientists at the North-Eastern Federal University (NEFU) in Yakutsk, which is at the forefront of research into extinct woolly mammoths and rhinos.
Russian and foreign colleagues will be invited to join the study.
The cave bear (Ursus spelaeus) is a prehistoric species or subspecies that lived in Eurasia in the Middle and Late Pleistocene period and became extinct about 15,000 years ago.
According to the rough preliminary suggestions the bear could live in Karginsky interglacial (this was the period between 22,000 and 39,500 years).
'It is necessary to carry out radiocarbon analysis to determine the precise age of the bear,’ said senior researcher Maxim Cheprasov from the Mammoth Museum laboratory in Yakutsk.
The finder transferred the right to research to the scientists of NEFU, he said.
Bolshoy Lyakhovsky Island, or Great Lyakhovsky, is the largest of the Lyakhovsky Islands belonging to the New Siberian Islands archipelago between the Laptev Sea and the East Siberian Sea in northern Russia. Picture: Alexander Oboimov
'A scientific programme for its comprehensive study will be prepared. We will have to study the carcass of a bear using all modern scientific research methods - molecular genetic, cellular, microbiological and others.
'The research is planned on as large a scale as in the study of the famous Malolyakhovsky mammoth,’ said Dr Grigorieva, leading researcher of the International Centre for Collective Use of Molecular Paleontology at the NEFU’s Institute of Applied Ecology of the North.
Recent years have seen major discoveries of mammoths, woolly rhinos, Ice Age foal, several puppies and Cave Lion cubs as the permafrost melts in Siberia.
Lena Grigorieva, first from the left, leading researcher of the International Centre for Collective Use of Molecular Paleontology at the NEFU’s Institute of Applied Ecology of the North
siberiantimes.com/other/others/news/first-ever-preserved-grown-up-cave-bear-even-its-nose-is-intact-unearthed-on-the-arctic-island/
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Post by tyrannosaurs on Jul 7, 2021 6:11:46 GMT -5
A three-dimensional analysis of tooth-root morphology in living bears and implications for feeding behaviour in the extinct cave bear: Abstract; The morphology of both crowns and tooth-roots reflects dietary specialisation in mammalian carnivores. In this article, we analyse the tooth-root morphology of maxillary teeth from CT scans of living bears (Ursus arctos, Ursus americanus, Ursus maritimus, Ursus thibetanus, Melursus ursinus, Helarctos malayanus, Tremarctos ornatus and Ailuropoda melanoleuca) in order to make inferences about the diet and feeding behaviour of the extinct cave bear (Ursus spelaeus sensu lato). Specifically, we investigate two major mitochondrial clades of extinct cave bears recognized by previous authors: Ursus ingressus and Ursus spelaeus (U. spelaeus spelaeus, U. spelaeus ladinicus, U. spelaeus eremus). Our results indicate a close association between tooth-root surface area and feeding behaviour in all living bear species. Tooth-root surface area values of cave bears suggest that they relied more on vegetative matter than living brown bears (Ursus arctos) but subtle differences between these species/subspecies could also indicate different feeding strategies among the members of cave bear complex. www.researchgate.net/publication/328232826_A_three-dimensional_analysis_of_tooth-root_morphology_in_living_bears_and_implications_for_feeding_behaviour_in_the_extinct_cave_bear
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Post by tyrannosaurs on Jul 7, 2021 6:18:29 GMT -5
What size were Arctodus simus and Ursus spelaeus (Carnivora: Ursidae)?: Body masses of the giant short-faced bear (Arctodus simus Cope) and the cave bear (Ursus spelaeus Rosenmüller & Heinroth) were calculated with equations based on a long-bone dimensions:body mass proportion ratio in extant carnivores. Despite its more long-limbed, gracile and felid-like anatomy as compared with large extant ursids, large Arctodus specimens considerably exceeded even the largest extant ursids in mass. Large males weighed around 700—800 kg, and on rare occasions may have approached, or even exceeded one tonne. Ursus spelaeus is comparable in size to the largest extant ursids; large males weighed 400—500 kg, females 225—250 kg. Suggestions that large cave bears could reach weights of one tonne are not supported. www.jstor.org/stable/23735739
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Post by Gorilla king on Jul 7, 2021 6:23:27 GMT -5
Body size variability in cave bears from the Southern Alps
During the Last Glacial, the cave bear (Ursus spelaeus Rosenmüller, 1794) was widely spread in Europe from the Atlantic coast to the Ural Mountains. Th e vast numbers of its remains found in caves have enabled scholars to obtain a fairly complete picture of its geographical distribution, anatomy, evolution and pathology. In spite of this wealth of cave bear remains, however, many important aspects of its palaeobiology remain poorly understood. One such aspect regards the reason behind the diachronic variations in body size, which are usually linked to sexual dimorphism, polytypism, continual or clinal geographic variation and continual intraspecifi c variability. Th is paper is aimed at further clarifying the diachronic variations in cave bear body size by studying the material originating from the Southern Alps. Th e results of the study showed that oscillations in temperature and humidity might have been one of the main factors infl uencing the size variability of cave bears of each sex excavated at the studied sites, with individuals originating from colder (and possibly also damper) periods having been larger. Such a conclusion is in line with the biology of extant brown and black bears and is linked by the authors to the supposed prolongation of the energy-saving dormancy period in harsher climates.
.. These data correspond to results of the study of strontium isotope ratios ( 87 Sr/ 86 Sr) in U. spelaeus dentin and enamel (Ábelová 2006) that suggests limited movement of bears during their lifetime. This feature of behavior, which can lead to constrains of gene flow, and other environmental factors (height above sea level of habitat, orography, climate evolution), as well as evolutionary trends may act as a factors of high individual and group morphological variability of cave bears in different sites , Carlis et al. 2005, Toškan 2006, Toškan and Bona 2012, Krajcarz et al. 2016, Robu 2016, and others). ...
... Hind limbs proportions are largely uniform across mammals in comparison with the high degree of variability in forelimb proportions, which is dependent on adaptations ( Schmidt and Fischer 2009). Therefore, from an evolutionary perspective, morphology of hind paws in bears is probably more conservative, while forepaw anatomy varies greatly, depending on specific adaptations to local environmental conditions , Toškan and Bona 2012. ...
.. It has been also found that sites of the same age are geographically grouped with regards to cave bear dental measurements. This phenomenon may be explained by regional peculiarities in the bear diet ( Taboda et al. 2001;Baryshnikov et al. 2003Baryshnikov et al. , 2004Bocherens et al. 2014;Robu et al. 2018), as well as by other environmental factors (elevation of habitat above sea level, physiography, and climate evolution; Jambre si c & Paunovi c 2002; Athen et al. 2005;de Carlis et al. 2005;To skan 2006;Rabeder et al. 2008Rabeder et al. , 2010Rabeder et al. , 2011To skan & Bona 2012;Krajcarz et al. 2016; Robu 2016), and/or by philopatria that suggests limited movement of bears during their lifetime that imposes constraints on the gene flow ( Abelov a 2006; Fortes et al. 2016). Most studies of cave bear tooth morphology and morphometry, as well as those of their skull and postcranial elements, are based on geographically restricted material. ...
www.researchgate.net/publication/273699464_Body_size_variability_in_cave_bears_from_the_Southern_Alps
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Post by tyrannosaurs on Jul 7, 2021 6:27:17 GMT -5
FIRST EVER PRESERVED GROWN UP CAVE BEAR-EVEN ITS NOSE IS INTACT-UNHEARTHED ON THE ARTIC ISLAND
Separately at least one preserved carcass of a cave bear cub found on the mainland of Yakutia, with scientists hopeful of obtaining its DNA.
More details of the finds are to be announced soon.
Until now only the bones of cave bears have been discovered.
The new finds are of ‘world importance’, according to one of Russia’s leading experts on extinct Ice Age species.
Scientist Lena Grigorieva said of the island discovery of the adult beast: 'Today this is the first and only find of its kind - a whole bear carcass with soft tissues.
'It is completely preserved, with all internal organs in place including even its nose.
“Previously, only skulls and bones were found. This find is of great importance for the whole world.’
First ever preserved grown up cave bear - even its nose is intact - unearthed on Bolshoy Lyakhovsky island, with at least one preserved carcass of a cave bear cub found on the mainland of Yakutia. Pictures: NEFU
The remains were found by reindeer herders on the island and the remains will be analysed by scientists at the North-Eastern Federal University (NEFU) in Yakutsk, which is at the forefront of research into extinct woolly mammoths and rhinos.
Russian and foreign colleagues will be invited to join the study.
The cave bear (Ursus spelaeus) is a prehistoric species or subspecies that lived in Eurasia in the Middle and Late Pleistocene period and became extinct about 15,000 years ago.
According to the rough preliminary suggestions the bear could live in Karginsky interglacial (this was the period between 22,000 and 39,500 years).
'It is necessary to carry out radiocarbon analysis to determine the precise age of the bear,’ said senior researcher Maxim Cheprasov from the Mammoth Museum laboratory in Yakutsk.
The finder transferred the right to research to the scientists of NEFU, he said.
Bolshoy Lyakhovsky Island, or Great Lyakhovsky, is the largest of the Lyakhovsky Islands belonging to the New Siberian Islands archipelago between the Laptev Sea and the East Siberian Sea in northern Russia. Picture: Alexander Oboimov
'A scientific programme for its comprehensive study will be prepared. We will have to study the carcass of a bear using all modern scientific research methods - molecular genetic, cellular, microbiological and others.
'The research is planned on as large a scale as in the study of the famous Malolyakhovsky mammoth,’ said Dr Grigorieva, leading researcher of the International Centre for Collective Use of Molecular Paleontology at the NEFU’s Institute of Applied Ecology of the North.
Recent years have seen major discoveries of mammoths, woolly rhinos, Ice Age foal, several puppies and Cave Lion cubs as the permafrost melts in Siberia.
Lena Grigorieva, first from the left, leading researcher of the International Centre for Collective Use of Molecular Paleontology at the NEFU’s Institute of Applied Ecology of the North
siberiantimes.com/other/others/news/first-ever-preserved-grown-up-cave-bear-even-its-nose-is-intact-unearthed-on-the-arctic-island/
Wow! That's just awesome! I mean, I already knew about this but I couldn't find it in my data collector. Thank you for posting it King Kodiak!
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Post by tyrannosaurs on Jul 7, 2021 6:41:39 GMT -5
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Post by tyrannosaurs on Jul 7, 2021 7:18:49 GMT -5
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Post by tyrannosaurs on Jul 7, 2021 7:21:23 GMT -5
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Post by tyrannosaurs on Jul 7, 2021 7:25:49 GMT -5
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Post by tyrannosaurs on Jul 7, 2021 7:26:51 GMT -5
Meant reply #8, my mistake...
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Post by Gorilla king on Jul 7, 2021 7:30:16 GMT -5
You mean between cave bears and lions? They go by evidence like bone marks, see reply #7.
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