Megafauna

From Wikipedia, the free encyclopedia

The term megafauna (Ancient Greek megas "large" + New Latin fauna "animal") has two distinct meanings in the biological sciences. The less commonly found meaning is of any animal which can be seen with the unaided eye, in contrast to microfauna. The more commonly found meaning, discussed in this article, is of "giant", "very large" or "large" animals — although there is no standard definition of a minimum size.

In practice the most common usage encountered in academic and popular writing describes land animals roughly larger than a human which are not (solely) domesticated. The term is especially associated with the Pleistocene megafauna — the giant and very large land animals considered archetypical of the last ice age such as mammoths.^[1] It is also commonly used for the largest wild land animals surviving today, especially elephants, giraffes, hippopotamuses, rhinoceroses, moose, condors, etc.

Other common uses are for giant aquatic species, especially whales, any larger wild or domesticated land animals such as larger antelope and cattle, and dinosaurs and other extinct giant reptilians.

Some technical definitions of size however go down to as small as 40–45 kg (90 lbs)^[2]^[3] and thus encompass a great many animals commonly regarded as not especially large, such as goats and (larger) domestic dogs.

The term is also sometimes applied to animals (usually extinct) of great size relative to a more common or surviving type of the animal, for example the 1m (3 ft) dragonflies of the Carboniferous age.

[edit] Ecological strategy of megafauna

Megafauna — in the sense of the largest mammals and birds — are generally K-strategists, with great longevity, slow population growth rates, low death rates, and few or no natural predators capable of killing adults. These characteristics, although not exclusive to such megafauna, make them highly vulnerable to human over-exploitation.

[edit] Megafauna mass extinctions

The two most well-known mass extinctions of megafauna are the Cretaceous–Tertiary extinction event in which the dinosaurs and most other giant reptilians were wiped out, and the Pleistocene-Holocene extinction event at the end of the last ice age in which the giant ice age animals such as mammoths were wiped out.

[edit] Existant Megafauna examples

rhino

The Largest flightless bird height of over 2.7 m (9 ft) and weighing over 156 kg (345 lb).[28] Eggs laid by the Ostrich can weigh 1.4 kg (3 lb) and are the largest eggs in the world today

crocodiles largest reptiles

For the purposes of this list, The definitions of megafauna are as follows:

Land Mammals 500 lbs+ and largest mammal

Marine Mammals ???

Birds 100 lbs+

Reptiles 100 lbs+

Freshwater Fish 250 lbs+

Ocean Fish 1000 lbs+

Other ???

[edit] African megafauna

Mammals

African Buffalo (Syncerus caffer)
African Bush Elephant (Loxodonta africana)
African Forest Elephant (Loxodonta cyclotis)
Black Rhinoceros (Diceros bicornis)
Giraffe (Giraffa camelopardalis)
Hippopotamus (Hippopotamus amphibius)
Lion (Panthera leo)
White Rhinoceros (Ceratotherium simum)
Western Gorilla (Gorilla gorilla)

Birds

Ostrich (Sturthio camelus)

Reptiles

Nile Crocodile (Crocodylus niloticus)

Freshwater Fish

Nile Perch (Lates niloticus)

[edit] Gallery

Jaekelopterus (sea scorpion).	Dunkleosteus was a gigantic, 3.5 meter (11 ft) long prehistoric fish.	Dimetrodon and Eryops- Early Permian, North America.	Liopleurodon ferox (right) harassing Leedsichthys problematicus.
Several macronarian Sauropods, from left to right Camarasaurus, Brachiosaurus, Giraffatitan, and Euhelopus.	Life restoration of a Tyrannosaurus rex.	Certain birds like Argentavis had 8 meter wingspans.	Megalodon with the great white shark and a human for scale.
Titanis walleri, the only known North American terror bird.	Pleistocene of South America showing Megatherium and two Glyptodon.	American Lion became extinct about 10,000 years ago.	Elephants are considered the largest living land animals on Earth.