The Ursidae Family Allen Wilson 7-29-08 Dr. McCall.

The Ursidae FamilyThe Ursidae FamilyAllen WilsonAllen Wilson

7-29-087-29-08Dr. McCallDr. McCall

TaxonomyTaxonomy

Kingdom: Kingdom: AnimaliaAnimalia Phylum: Phylum: ChordataChordata Class: Class: MammaliaMammalia Order: Order: CarnivoraCarnivora

• Suborder: Suborder: CaniformiaCaniformia Family: Family: UrsidaeUrsidae

• Subfamily: Subfamily: AilurinaeAilurinae (Panda bear) (Panda bear) Subfamily: Subfamily: UrsinaeUrsinae (The other 7 species of (The other 7 species of

bear bear

Evolutionary Divergence of Evolutionary Divergence of UrsidaeUrsidae

Origins of this family can be traced to Paractis Origins of this family can be traced to Paractis (very small, skull 7 cm.)(very small, skull 7 cm.)

Paractis first occurred in North America during Paractis first occurred in North America during the Late Eocene, but not found in Eurasia and the Late Eocene, but not found in Eurasia and Africa until MioceneAfrica until Miocene

However, suggestions leads to speculation that However, suggestions leads to speculation that earlier ursids in Asia, during Eocene, gave rise to earlier ursids in Asia, during Eocene, gave rise to Paractis in North America, although no fossils of Paractis in North America, although no fossils of Paractis have been found in East Asia Paractis have been found in East Asia

This migration may have occurred via a major This migration may have occurred via a major sea-level lowstand 37 million years agosea-level lowstand 37 million years ago

Evolution of Ursidae (cont.)Evolution of Ursidae (cont.)

The most primitive ursid was Cephalogale, The most primitive ursid was Cephalogale, a raccoon-sized, dog like creaturea raccoon-sized, dog like creature

Cephalogale first appeared in the Cephalogale first appeared in the Oligocene to early Miocene in EuropeOligocene to early Miocene in Europe

Cephalogale gave rise to early bears Cephalogale gave rise to early bears (Ursavus) in Europe(Ursavus) in Europe

Ursavus radiated into Asia and gave rise to Ursavus radiated into Asia and gave rise to the first true bears (Ursus) in Europe or the first true bears (Ursus) in Europe or Asia about 5 million years agoAsia about 5 million years ago

Cephalogale jawCephalogale jaw

More Evolution!More Evolution! Ursids became very diversified in the Ursids became very diversified in the

Oligocene in AsiaOligocene in Asia Four species are found in Asia correlating Four species are found in Asia correlating

to this time, three are found commonly in to this time, three are found commonly in Europe, but one is endemic to Asia Europe, but one is endemic to Asia (suggesting speciation)(suggesting speciation)

Migration of most early ursids to North Migration of most early ursids to North America is suggested to occur during the America is suggested to occur during the late Oligocene and early Miocenelate Oligocene and early Miocene

True bears (Ursus) migrated during the True bears (Ursus) migrated during the Pliocene about 4 million years agoPliocene about 4 million years ago

Ursidae family treeUrsidae family tree

Ursidae GeneraUrsidae Genera

Tremarctos including Spectacled Tremarctos including Spectacled bearbear

Ailuropoda including the Giant PandaAiluropoda including the Giant Panda Ursus including American Black Bear, Ursus including American Black Bear,

Asiatic black bear, polar bear, brown Asiatic black bear, polar bear, brown bear, Malaysian sun bear, and sloth bear, Malaysian sun bear, and sloth bearbear

Urisidae phylogenyUrisidae phylogeny

Species of Ursidae familySpecies of Ursidae family

· · American Black Bear (American Black Bear (UrsusUrsus americanusamericanus)) · · Asiatic Black Bear (Asiatic Black Bear (UrsusUrsus thibetanusthibetanus)) · Brown bear (· Brown bear (Ursus arctosUrsus arctos) ) · Giant Panda (· Giant Panda (Ailuropoda melanoleucaAiluropoda melanoleuca) ) · Polar Bear (· Polar Bear (Ursus maritimusUrsus maritimus) ) · Sloth Bear (· Sloth Bear (Melursus ursinusMelursus ursinus) ) · Spectacled Bear (· Spectacled Bear (Tremarctos ornatusTremarctos ornatus) ) · Sun Bear (· Sun Bear (Helarctos malayanusHelarctos malayanus) )

Giant PandaGiant Panda

Ailuropoda diverged from the Ursavus Ailuropoda diverged from the Ursavus group between 18-22 million years agogroup between 18-22 million years ago

The Giant Panda was the first modern bear The Giant Panda was the first modern bear to arise from this groupto arise from this group

The range of this group exhibits little The range of this group exhibits little migration from their evolutionary home in migration from their evolutionary home in Asia, probably due to a localized food Asia, probably due to a localized food sourcesource

Only 700-1000 exist in wildOnly 700-1000 exist in wild

Giant Panda RangeGiant Panda Range

Giant PandaGiant Panda

Sloth BearsSloth Bears

Ursis ursinus radiated from the other Ursis ursinus radiated from the other ursidae family members about 7 ursidae family members about 7 million years agomillion years ago

The oldest ursis bear, and no surprise The oldest ursis bear, and no surprise that it has the farthest east that it has the farthest east distribution, not ranging much from distribution, not ranging much from its ancestral home its ancestral home

Sloth BearsSloth Bears

Malaysian sun bearMalaysian sun bear

Smallest of all the bears, consistent Smallest of all the bears, consistent with Bergmann’s rulewith Bergmann’s rule

Polar is the largest and most Polar is the largest and most northern, and sun bear is the northern, and sun bear is the smallest and near equatorsmallest and near equator

Diverged about 5 million years ago Diverged about 5 million years ago from the lineage leading to polar and from the lineage leading to polar and brown bearsbrown bears

Malaysian sun bear rangeMalaysian sun bear range

Asiatic Black BearAsiatic Black Bear

Closely related to American black Closely related to American black bear, did not migrate to North bear, did not migrate to North AmericaAmerica

Lives in Eastern Asia, inhabiting Lives in Eastern Asia, inhabiting highlands and tropical forestshighlands and tropical forests

Asiatic black bear rangeAsiatic black bear range

Asiatic Black BearAsiatic Black Bear

American Black BearAmerican Black Bear

Most closely related to Asiatic black bearMost closely related to Asiatic black bear Lineage containing these two bears split Lineage containing these two bears split

from others in the Ursidae family about 6 from others in the Ursidae family about 6 million years agomillion years ago

Within the next million years, these Within the next million years, these diverged from each otherdiverged from each other

Migrated to North America about 1-4 Migrated to North America about 1-4 million years ago from Europe or Asiamillion years ago from Europe or Asia

Two found in Meridian during the last yearTwo found in Meridian during the last year

American Black Bear: RangeAmerican Black Bear: Range

American Black BearAmerican Black Bear

Which bear has this distribution?Which bear has this distribution?

Brown or Grizzly bearBrown or Grizzly bear

Brown BearBrown Bear

There are an estimated 125-150,000 There are an estimated 125-150,000 brown bears in the wilderness today. brown bears in the wilderness today. Most are in the former U.S.S.R. Most are in the former U.S.S.R. (100,000), in Canada and (100,000), in Canada and Alaska(50,000)Alaska(50,000)

However there are isolated However there are isolated populations in rural France and Spain populations in rural France and Spain (fewer than 100) and even in Mexico(fewer than 100) and even in Mexico

North American range (past and North American range (past and present)present)

Migration (Brown bears)Migration (Brown bears)

The remote populations remaining in The remote populations remaining in Europe suggests a migration across Asia to Europe suggests a migration across Asia to North America, as suggested, during the North America, as suggested, during the PliocenePliocene

The lineage containing the ursus bears The lineage containing the ursus bears diverged about 5 million years ago.diverged about 5 million years ago.

The lineage containing the polar bear and The lineage containing the polar bear and the brown bear seems to diverge from the brown bear seems to diverge from each other about 400,000 years ago, each other about 400,000 years ago, making them close relatives (DNA testing)making them close relatives (DNA testing)

Polar bearPolar bear

Polar bearPolar bear

Closest relative to brown bearClosest relative to brown bear Most threatened due to depleting ice Most threatened due to depleting ice

packs in Articpacks in Artic Found in Northern ArticFound in Northern Artic Migration across vast ice expanses Migration across vast ice expanses

very likelyvery likely

Polar Bear RangePolar Bear Range

Spectacled bearSpectacled bear

Tramarctos diverged from the last Tramarctos diverged from the last line of the Ursavus line about 10-15 line of the Ursavus line about 10-15 million years ago million years ago

Found in Andes Mountains of South Found in Andes Mountains of South America, its main habitat is the cloud America, its main habitat is the cloud forests of the Andesforests of the Andes

It is considered threatenedIt is considered threatened

Spectacled bear Range MapSpectacled bear Range Map

How?How?

Since Gondwanaland and Laurasia Since Gondwanaland and Laurasia were already separated when these were already separated when these bears evolved, the most logical bears evolved, the most logical explanation is that the bears explanation is that the bears speciated from Northern migrant speciated from Northern migrant bears, via the Central American land bears, via the Central American land bridgebridge

Spectacled bearSpectacled bear