Placental Carnivores: Past and Present

Placental Carnivores: Past and Present Ilse Kotzee Student # 2456349 Landscape Ecology and People University of the Western Cape

Placental Carnivore Definition: • Placental refers to a mammal who gives birth to live young, which is nourished throughout the pregnancy by placenta; a specialized organ attached to the uterus wall. (www.britannica.com/eb/article-9027844) • Carnivore refers to any animal whose diet consists mainly out of meat. (www.barteleby.com/carnivore.html ) • Presently there are about 260 placental carnivores (http://en.wikipedia.org/wiki/Carnivora)

Creodonts and Carnivores • Placental carnivores represented by two orders: • The now extinct Creodonts • The very successful true Carnivores

Creodonts • Primitive carnivorous mammals • Long and low scull with primitive brain • Head large in proportion to body • Short and heavy limbs; long tail; sharp clawed toes http://en.wikipedia.org/wiki/Creodonta Hyeanodon gigas

Carnivores • Dominated from late Eocene up to present day • Large brain case • Good sense of smell • Well developed canines • Shearing and crushing teeth • Strong body capable of powerful movement http://en.wikipedia.org/wikia/Carnivora Lion

Adaptations • Differ from insectivores in having special pairs of upper and lower carnassials • Dagger like canines used for stabbing, main weapon for killing prey • Strong incisor teeth used for nipping www.shsu.edu/~bio_mlt/Carnivor.html

Carnivore evolutionary timeline www.shsu.edu/~bio_mlt/Carnivor.html

The Oxyaenids • Characteristic long body, short limbs and very long tail • Can be compared to martens and cats of today • Diet consisted out of birds, eggs, small mammals and most likely still insects • Capable of climbing trees www.paleocene-mammals.de/predators.htm Reconstruction of the cat-like creodont Oxyaena

Resembled hyena's and dogs of present time Reached very large sizes Had longer limbs, so were better runners Active predators, able to compete with true carnivores for short time Much more abundant than Oxyaenids The Hyaenodontids

A change in temperature may have favored the early carnivores No match for the true carnivores with greater intelligence and more specializations Extinction of Creodonts

Seen as most primitive representative of True Carnivores Still had primitive features such as; a low scull, elongated body and tail, and short limbs, but larger brain Diet consisted of small animals living in dense undergrowth or in trees Resembled modern day weasels Miacids

Dominated from late Eocene till present time They are the familiar and well known dogs, cats, raccoons, bears, wolves etc. Order divided into two groups; Cannoids and Feloids Division based on anatomical differences The Fessipeds

The early Cannoids kept much of their primitive characteristics Did show some elongation of limbs and feet Carnassials more specialized for shearing then in Miacids The brain case was also bigger Super family: Canoidea

Canidae • Has long legs, of all carnivores most adapted for running • They are social hunters that rely on speed to chase and pin down prey • Possesses an elongated muzzle and bushy tail www.shsu.edu/~bio_mlt/Carnivore.html

Ursids • In the Miocene dogs started evolving into larger heavier carnivores • This could be where the ancestry of bears can be traced • Like dogs bears are very adaptable and widely distributed • Dentition more suitable for omnivory Panda

Procyonids • The Oligocene gave rise to yet another Cannoid • A small, climbing carnivore with hand like forepaws, and flexible limbs • Differs from dogs in that they walk on the soles of their feet • Like dogs they have 5 toes ending in non retractable claws Kinkajou

Mustelids • Of all carnivores this group shows the widest range of adaptive radiation • Group consists out of primitive mustelines, the mellivorines, melines, mephitines and the lutrines • Can be identified by their tapering body and short legs • Each group’s diet and behavior is equally diverse Skunk

Viverridae • Included in the Feloid carnivores , is one of the oldest carnivores still living today; the civets • They first made their appearance in the Eocene and lower Oligocene age • The small, forest living genet ‘s ancestry can be closely linked with that of the civet’s Genet

Herpestidae • Recently split from the civet stock due to technical details in anatomy • Least known and studied of all carnivores • Small carnivore, with short legs and a long tail Mongoose

Hyaenidae • Very large and heavy descendant of the civet • Hyena has heavy skull, with strong enlarged teeth for cracking bones • Legs are elongated for faster running. • Highly specialized carnassials with almost no molars Hyena

Nimravidae • The evolution of cats mirrors that of the Hyena only occurring earlier • A very successful group that very rapidly evolved into the modern day cats we know today http://images.google.co.za/images?q=carnivore+evolution&svnum

Includes the lynxes, lions, leopards, jaguarundi, tigers, bobcats, mountain lions, ocelots and cheetahs Members of this group are the ultimate carnivores A distinguishing feature is their four toes ending in retractable claws Top class hunters, with acute sense of smell, hearing and excellent balance Felidae: Cats

Two groups separates the Felidae into the big cats (genus Panthera) and the small cats (genus Felids) The ability to purr distinguishes these two groups Unable to run for long distances they are excellent sprinters Felidae: Cats contd.

Includes the sea lions, walruses and seals First appeared during Oligocene to Miocene Made the move from land to water Four feet are transformed into paddles with webbing between toes Large size, with thick blubber The Pennipeds

Ottaridae • Represented by eared seals and sea lions • Males larger then females • Able to dive and remain submerged for extended periods of time • Fur has even black color • Dentition specialized for eating fish Seal

Odobenidae • Represented by walrus • A strong carnivore with little to no hair and no external ears • Diet consists out of mollusks taken from sea bottom with lips and tusks • Sociable and with groups of 1000 and more also polygamous http://www.nature.ca/notebooks/english/walrus.htm

Of all the aquatic carnivores this group is most abundant Known to be monogamous as well as polygamous Hind limbs specialized for swimming cannot be used on land Mottled fur that is spotted or banded Phocidae

Newly discovered carnivores • This order is very progressive, and even today new members are being discovered • The cat-fox is a potentially new carnivore • Discovered in Indonesia (Borneo) • “The mammal is slightly larger then a cat, with red fur, a long tail and hind legs longer then the front legs” (http://en.wikipedia.org/wiki/Cat-fox) http://www.herkimer.edu/communityed/cogar/yacovella/pages/Fox_jpg.htm

Colbert E.H., Morales (M) (1991) Evolution of the Vertebrates, 4th Ed. New York Wiley-Liss (Chapter 25) www.mun.ca/biology/scarr/5405_Colbert_&Morales_1991.htm www.shsu.edu/~bio_mlt/Carnivor.html www.paleocene-mammals.de/predators.htm http://en.wikipedia.org/wiki/Carnivora http://en.wikipedia.org/wiki/Creodonta http://en.wikipedia.org/wiki/Cat-fox http://www.sinc.sunysb.edu/paleo.amnh.org/...c1.html References:

http://www.kidcyber.com.au/topics/seals.htm http://www.nature.ca/notebooks/english/walrus.htm http://www.herkimer.edu/communityed/cogar/yacovella/pages/Fox_jpg.htm References:

Placental Carnivores: Past and Present