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The Ursidae Family Allen Wilson 7-29-08 Dr. McCall
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Taxonomy Kingdom: Animalia Kingdom: Animalia Phylum: Chordata Phylum: Chordata Class: Mammalia Class: Mammalia Order: Carnivora Order: Carnivora Suborder: CaniformiaSuborder: Caniformia Family: Ursidae Family: Ursidae Subfamily: Ailurinae (Panda bear)Subfamily: Ailurinae (Panda bear) Subfamily: Ursinae (The other 7 species of bear Subfamily: Ursinae (The other 7 species of bear
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Evolutionary Divergence of Ursidae Evolutionary Divergence of Ursidae Origins of this family can be traced to Paractis (very small, skull 7 cm.) Origins of this family can be traced to Paractis (very small, skull 7 cm.) Paractis first occurred in North America during the Late Eocene, but not found in Eurasia and Africa until Miocene Paractis first occurred in North America during the Late Eocene, but not found in Eurasia and Africa until Miocene However, suggestions leads to speculation that earlier ursids in Asia, during Eocene, gave rise to Paractis in North America, although no fossils of Paractis have been found in East Asia However, suggestions leads to speculation that earlier ursids in Asia, during Eocene, gave rise to Paractis in North America, although no fossils of Paractis have been found in East Asia This migration may have occurred via a major sea-level lowstand 37 million years ago This migration may have occurred via a major sea-level lowstand 37 million years ago
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Evolution of Ursidae (cont.) The most primitive ursid was Cephalogale, a raccoon-sized, dog like creature The most primitive ursid was Cephalogale, a raccoon-sized, dog like creature Cephalogale first appeared in the Oligocene to early Miocene in Europe Cephalogale first appeared in the Oligocene to early Miocene in Europe Cephalogale gave rise to early bears (Ursavus) in Europe Cephalogale gave rise to early bears (Ursavus) in Europe Ursavus radiated into Asia and gave rise to the first true bears (Ursus) in Europe or Asia about 5 million years ago Ursavus radiated into Asia and gave rise to the first true bears (Ursus) in Europe or Asia about 5 million years ago
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Cephalogale jaw
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More Evolution! Ursids became very diversified in the Oligocene in Asia Ursids became very diversified in the Oligocene in Asia Four species are found in Asia correlating to this time, three are found commonly in Europe, but one is endemic to Asia (suggesting speciation) Four species are found in Asia correlating to this time, three are found commonly in Europe, but one is endemic to Asia (suggesting speciation) Migration of most early ursids to North America is suggested to occur during the late Oligocene and early Miocene Migration of most early ursids to North America is suggested to occur during the late Oligocene and early Miocene True bears (Ursus) migrated during the Pliocene about 4 million years ago True bears (Ursus) migrated during the Pliocene about 4 million years ago
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Ursidae family tree
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Ursidae Genera Tremarctos including Spectacled bear Tremarctos including Spectacled bear Ailuropoda including the Giant Panda Ailuropoda including the Giant Panda Ursus including American Black Bear, Asiatic black bear, polar bear, brown bear, Malaysian sun bear, and sloth bear Ursus including American Black Bear, Asiatic black bear, polar bear, brown bear, Malaysian sun bear, and sloth bear
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Urisidae phylogeny
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Species of Ursidae family · American Black Bear (Ursus americanus) · American Black Bear (Ursus americanus)American Black Bear (Ursus americanus)American Black Bear (Ursus americanus) · Asiatic Black Bear (Ursus thibetanus) · Asiatic Black Bear (Ursus thibetanus)Asiatic Black Bear (Ursus thibetanus)Asiatic Black Bear (Ursus thibetanus) · Brown bear (Ursus arctos) · Brown bear (Ursus arctos)Brown bear (Ursus arctos)Brown bear (Ursus arctos) · Giant Panda (Ailuropoda melanoleuca) · Giant Panda (Ailuropoda melanoleuca)Giant Panda (Ailuropoda melanoleuca)Giant Panda (Ailuropoda melanoleuca) · Polar Bear (Ursus maritimus) · Polar Bear (Ursus maritimus)Polar Bear (Ursus maritimus)Polar Bear (Ursus maritimus) · Sloth Bear (Melursus ursinus) · Sloth Bear (Melursus ursinus)Sloth Bear (Melursus ursinus)Sloth Bear (Melursus ursinus) · Spectacled Bear (Tremarctos ornatus) · Spectacled Bear (Tremarctos ornatus)Spectacled Bear (Tremarctos ornatus)Spectacled Bear (Tremarctos ornatus) · Sun Bear (Helarctos malayanus) · Sun Bear (Helarctos malayanus)Sun Bear (Helarctos malayanus)Sun Bear (Helarctos malayanus)
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Giant Panda Ailuropoda diverged from the Ursavus group between 18-22 million years ago Ailuropoda diverged from the Ursavus group between 18-22 million years ago The Giant Panda was the first modern bear to arise from this group The Giant Panda was the first modern bear to arise from this group The range of this group exhibits little migration from their evolutionary home in Asia, probably due to a localized food source The range of this group exhibits little migration from their evolutionary home in Asia, probably due to a localized food source Only 700-1000 exist in wild Only 700-1000 exist in wild
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Giant Panda Range
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Giant Panda
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Sloth Bears Ursis ursinus radiated from the other ursidae family members about 7 million years ago Ursis ursinus radiated from the other ursidae family members about 7 million years ago The oldest ursis bear, and no surprise that it has the farthest east distribution, not ranging much from its ancestral home The oldest ursis bear, and no surprise that it has the farthest east distribution, not ranging much from its ancestral home
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Sloth Bears
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Malaysian sun bear Smallest of all the bears, consistent with Bergmann’s rule Smallest of all the bears, consistent with Bergmann’s rule Polar is the largest and most northern, and sun bear is the smallest and near equator Polar is the largest and most northern, and sun bear is the smallest and near equator Diverged about 5 million years ago from the lineage leading to polar and brown bears Diverged about 5 million years ago from the lineage leading to polar and brown bears
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Malaysian sun bear range
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Asiatic Black Bear Closely related to American black bear, did not migrate to North America Closely related to American black bear, did not migrate to North America Lives in Eastern Asia, inhabiting highlands and tropical forests Lives in Eastern Asia, inhabiting highlands and tropical forests
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Asiatic black bear range
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Asiatic Black Bear
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American Black Bear Most closely related to Asiatic black bear Most closely related to Asiatic black bear Lineage containing these two bears split from others in the Ursidae family about 6 million years ago Lineage containing these two bears split from others in the Ursidae family about 6 million years ago Within the next million years, these diverged from each other Within the next million years, these diverged from each other Migrated to North America about 1-4 million years ago from Europe or Asia Migrated to North America about 1-4 million years ago from Europe or Asia Two found in Meridian during the last year Two found in Meridian during the last year
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American Black Bear: Range
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American Black Bear
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Which bear has this distribution?
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Brown or Grizzly bear
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Brown Bear There are an estimated 125-150,000 brown bears in the wilderness today. Most are in the former U.S.S.R. (100,000), in Canada and Alaska(50,000) There are an estimated 125-150,000 brown bears in the wilderness today. Most are in the former U.S.S.R. (100,000), in Canada and Alaska(50,000) However there are isolated populations in rural France and Spain (fewer than 100) and even in Mexico However there are isolated populations in rural France and Spain (fewer than 100) and even in Mexico
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North American range (past and present)
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Migration (Brown bears) The remote populations remaining in Europe suggests a migration across Asia to North America, as suggested, during the Pliocene The remote populations remaining in Europe suggests a migration across Asia to North America, as suggested, during the Pliocene The lineage containing the ursus bears diverged about 5 million years ago. The lineage containing the ursus bears diverged about 5 million years ago. The lineage containing the polar bear and the brown bear seems to diverge from each other about 400,000 years ago, making them close relatives (DNA testing) The lineage containing the polar bear and the brown bear seems to diverge from each other about 400,000 years ago, making them close relatives (DNA testing)
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Polar bear
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Closest relative to brown bear Closest relative to brown bear Most threatened due to depleting ice packs in Artic Most threatened due to depleting ice packs in Artic Found in Northern Artic Found in Northern Artic Migration across vast ice expanses very likely Migration across vast ice expanses very likely
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Polar Bear Range
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Spectacled bear Tramarctos diverged from the last line of the Ursavus line about 10-15 million years ago Tramarctos diverged from the last line of the Ursavus line about 10-15 million years ago Found in Andes Mountains of South America, its main habitat is the cloud forests of the Andes Found in Andes Mountains of South America, its main habitat is the cloud forests of the Andes It is considered threatened It is considered threatened
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Spectacled bear Range Map
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How? Since Gondwanaland and Laurasia were already separated when these bears evolved, the most logical explanation is that the bears speciated from Northern migrant bears, via the Central American land bridge Since Gondwanaland and Laurasia were already separated when these bears evolved, the most logical explanation is that the bears speciated from Northern migrant bears, via the Central American land bridge
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Spectacled bear
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