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Post by brobear on Apr 22, 2020 2:25:52 GMT -5
Continued: Unpartitioned and partitioned phylogenetic analyses in maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference of phylogeny. In partitioned analyses every partition was allowed to evolve under a separate unlinked GTR+Γ substitution model and distinct base frequencies in ML and Bayesian inference of phylogeny.  |
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Post by brobear on Apr 22, 2020 5:38:59 GMT -5
www.livescience.com/42342-tiny-carnivore-ancestor-discovered.html Lions, tigers, bears and even loyal pups and playful kitties all come from the same line of carnivorous mammals, a lineage whose origins are lost in time. Now, scientists have discovered one of the earliest ancestors of all modern carnivores in Belgium. The new species, Dormaalocyon latouri, was a 2-pound (1 kilogram) tree-dweller that likely fed on even smaller mammals and insects. "It wasn't frightening. It wasn't dreadful," said study researcher Floréal Solé, a paleontologist at the Royal Belgian Institute of Natural Sciences in Brussels. What it was, Solé said, is a clue to the beginnings of today's toothy beasts. "It is one of the oldest carnivorous mammals which is related to present-day carnivores," Solé told LiveScience. 
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Post by brobear on Apr 23, 2020 2:31:10 GMT -5
sciencepress.mnhn.fr/en/periodiques/geodiversitas/35/4/ursidae-mammalia-carnivora-de-l-oligocene-superieur-des-phosphorites-du-quercy-avec-une-revision-du-genre-cephalogale-geoffroy-1862 Ursidae (Mammalia, Carnivora) from the Late Oligocene of the "Phosphorites du Quercy" (France) and a reappraisal of the genus Cephalogale Geoffroy, 1862 Published on 27 December 2013 Many karstic fissure fillings from the Quercy (France) constitute fossil bearing localities which give an exceptional open laboratory for the study of evolution of vertebrates and especially mammals from the Eocene to the Early Miocene. A couple of localities from the Late Oligocene (MP 28 = 24.9-24.5 Ma) have yielded, among several taxa, the best sample ever found of a hemicyonine ursid. This sample corresponds to a new species and allows a reappraisal of several other species belonging to lineages attributed to a new tribe (Cephalogalini n. tr.). The latter occupied in Europe along the Oligocene and the lower Miocene some canid-like ecological niches. This tribe was replaced at the end of the Lower Miocene by the Hemicyonini, another tribe of Hemicyoninae (Ursidae). 
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Post by brobear on Apr 23, 2020 2:39:20 GMT -5
A quote from the opening post - page #1: SUBFAMILY HEMICYONINAE It is believed that bears evolved from the canid line during the late Oligocene and early Miocene (Kurten 1966). The change from canids to ursids left a fossil record relatively rich with intermediate genera and this has led to various opinions on where to differentiate the 2 families. *Note: Scientific classification is often a matter of professional opinion. In my "non-professional" opinion, there were bear-dogs and dog-bears; neither of which were true-bears. Kolponomos, Indarctos, Agriotherium, and Ailuropoda were primitive bears related ( IMO ) to true-bears as the baboons are related the the great apes. I view both the Tremarctinae and the Ursinae as true-bears with the Tremarctinae being bears and the Ursinae being real bears. -Just my opinions.  |
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Post by tom on Apr 23, 2020 17:09:53 GMT -5
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Post by brobear on Apr 24, 2020 6:42:18 GMT -5
en.wikipedia.org/wiki/Cephalogale Cephalogale: Cephalogale is an extinct genus of hemicyonine bear which lived in the Oligocene and Early Miocene epochs in North America and Europe. It lived from around 28.4—20.0 Mya. Before it was reconsidered to be close to the ancestry of hemicyonines, Cephalogale was once considered to be an ancestor of all bears.
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Post by brobear on Jun 7, 2020 4:01:31 GMT -5
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Post by brobear on Jun 7, 2020 4:07:43 GMT -5
Above: Figure 5: The phylogenetic relationships of crown and stem bears based on taxonomy and morphological data. The resolution of monophyletic clades is based on well-supported previous analyses. Monophyletic clades are indicated with labeled circles. In addition to the root node (R), there are 5 nodes defining clades containing both fossil and extant species. The origin of the tree is indicated with a red square. The time of this node represents the start of the diversification process that generated these linages. The extant lineages are shown with heavy, solid lines and the fossil lineages are dotted lines.
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Post by OldGreenGrolar on Jun 7, 2020 4:09:01 GMT -5
That is a great chart. It brings good clarity to these who are interested in bears. |
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Post by brobear on Dec 4, 2020 2:06:36 GMT -5
*From page #1, first post: 5 subfamilies:
(1) Hemicyoninae, (2) Agriotheriinae, (3) Tremarctinae, (4) Ursinae, and (5) Ailuropodidae.
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Post by brobear on Jan 1, 2021 4:48:26 GMT -5
www.bearbiology.org/fileadmin/tpl/Downloads/URSUS/Vol_9/McLellan_Reiner_Vol_9.pdf A REVIEW OF BEAR EVOLUTION BRUCE MCLELLAN, Forest Sciences Research Branch, Revelstoke Forest District, RPO#3, Box 9158, Revelstoke, BC VOE 3KO DAVID C. REINER, U.S. Fish and Wildlife Service, NS 312, University of Montana, Missoula, MT Abstract. Ursidae is a young family, evolving from early canids during the late Oligocene and early Miocene, about 20-25 million years ago. The family has frequently been divided into subfamilies. Although debated, these often include: (1) Hemicyoninae, (2) Agriotheriinae, (3) Tremarctinae, (4) Ursinae, and (5) Ailuropodidae. Based on scattered literature published over the past century, we trace the evolutionary lineage of the various genera and species found in these subfamilies; most are extinct, 8 species remain. Many if not most of the relationships have been disputed for many years and we may be far from the definitive history. Speculated causes of extinction usually involved climate change and competition. Primitive man may have been the major competitor of some extinct species and modem man is definitely a major influence on bear evolution today.
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Post by brobear on Jul 1, 2021 12:52:47 GMT -5
en.wikipedia.org/wiki/Bear Bear. Bears are carnivoran mammals of the family Ursidae. They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, Europe, and Asia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails. The family Ursidae is one of nine families in the suborder Caniformia, or "doglike" carnivorans, within the order Carnivora. Bears' closest living relatives are the pinnipeds, canids, and musteloids. Modern bears comprise eight species in three subfamilies: Ailuropodinae ( monotypic with the giant panda ), Tremarctinae ( monotypic with the spectacled bear ), and Ursinae ( containing six species divided into one to three genera, depending on the authority ). Nuclear chromosome analysis show that the karyotype of the six ursine bears is nearly identical, each having 74 chromosomes (see Ursid hybrid), whereas the giant panda has 42 chromosomes and the spectacled bear 52. These smaller numbers can be explained by the fusing of some chromosomes, and the banding patterns on these match those of the ursine species, but differ from those of procyonids, which supports the inclusion of these two species in Ursidae rather than in Procyonidae, where they had been placed by some earlier authorities
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Post by brobear on Aug 18, 2021 3:49:05 GMT -5
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Post by brobear on Sept 8, 2021 4:28:21 GMT -5
northamericannature.com/how-did-bears-evolve/ Early Bears Species of bear alive today evolved from a family called Miacidae. Miacids were small, tree-climbing carnivores. Miacids lived in the Paleocene through the Eocene epochs. These early animals were small and arboreal mammals. They were known to be carnivores due to their canine and carnassial teeth. The canine teeth were used to hold prey and pierce through their skin, while the carnassial teeth were used to tear off meat. The earliest bears were similar to raccoons and were small compared to later bears. These early bears were called Parictis and lived in North America during the late Eocene. Miacids branched off into two groups about 60 million years ago. These were the cat family and the dog family. The dog family (arctoids or vulpavines) were the ancestors of bears, with today’s wild dogs being their closest relatives.
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Post by brobear on Sept 8, 2021 4:30:52 GMT -5
www.bearsinmind.org/Page/The-evolution-of-bear-species THE EVOLUTION OF BEAR SPECIES Where did the bear really come from? The evolution of bears as we know them today, started around 30 million years ago. Their ancestors evolved into a family of small mammals known as the Miacids (Miacidae). The bears, small bears and also the canines developed from the Miacids. Some of the canine species resembled bears, and we refer to them as bear dogs or Amphicyonidae. The size and appearance of the bear dog varied from small and dog-like to big and bear-like. Please see below diagram which represents this ‘evolutionary tree’. The family of real bears can ultimately be traced back to the oldest genus, the Ursavus, which was roughly the size of a sheepdog and had evolved from a canine ancestor. The bears (Ursidae) form a separate family within the order of carnivora. The bear family can be divided into three subfamilies: the giant panda (Ailuropodinae), the spectacled bear (Tremarctinae), and the real bears (Ursinae). The family of Ursinae consists of six different species, all of which have similar external characteristics like strong claws and a robust body. They also have their diet in common. Although these bears are all omnivores, their diet is mainly vegetarian. Bears live in very different regions of the world, from the North Pole to the tropical rainforests around the equator. The projects which are run by Bears in Mind focus mainly on the brown bear, but also on the Asiatic black bear, the Malayan sun bear, the spectacled bear and the sloth bear. 
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Post by OldGreenGrolar on Sept 8, 2021 9:24:51 GMT -5
Bears and raccoons seem to have similarities.
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Post by brobear on Sept 8, 2021 9:26:26 GMT -5
Bears and raccoons seem to have similarities. Yes, they are cousins.  |
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Post by OldGreenGrolar on Sept 8, 2021 9:27:32 GMT -5
Bears and raccoons seem to have similarities. Yes, they are cousins. And they are also good grapplers. Are raccoons plantigrades too? Yes they are. |
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Post by brobear on Sept 8, 2021 9:33:42 GMT -5
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Post by OldGreenGrolar on Sept 9, 2021 8:34:55 GMT -5
Gorillas are plantigrades too.
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