Page 48 - Present Day Wildlife_Float

The true crocodile is a large amphibious reptile, found in the genera Crocodylus, Mecistops and
Osteolaemus, in the family Crocodylidae, which is a member of the order Crocodilia. This order also
contains other families that contain large semiaquatic reptiles such as, the gharial, false gharial, alli-
gators and caimans. These other families like, Alligatoridae and Gavialidae are often referred to as
crocodilian or informally as crocodiles. There is however, only 18 recognised species of true croco-
diles. The true crocodile is found in the tropics
in Africa, across Asia, the Americas, Australia
and neighbouring islands. There are two distinct
groups of the true crocodile, the freshwater and
saltwater crocodiles. The largest of the species
is the saltwater crocodile that measures around
3 to 4 meters, while the smallest, the dwarf
crocodile, measuring about 1.9 metres.

With a lineage stretching back 200 million
years it’s not surprising that crocodiles are well
developed and ideally suited for their aquatic
and predatory lifestyle. Their body has smooth
sides with a smooth underside and the top skin
is covered in armoured scales and large smooth
osteoderms, bony-like protrusions that help pro-
tect it from large predators. They are strong
swimmers and when submerged can block off
Family Crocodylidae their mouth and nostrils to keep water out. Their
Genus Crocodylus bodies are trim and streamlined allowing them to slide swiftly and si-
American crocodile lently through the water with the minimum of disturbance. They have
Hall's New Guinea crocodile webbed feet but keep their legs tucked in while swimming to prevent
Orinoco crocodile any drag, using their webbed feet only to initiate swimming or ma-
Freshwater crocodile noeuvre swiftly to the sides. It’s the crocodiles strong muscular tail
Philippine crocodile that is its source of power. Its smooth undulating or sinusoidal move-
Morelet's crocodile
Nile crocodile ment drives it through the water at incredible speed and for short
New Guinea crocodile bursts on land at speeds faster than a human can run. The crocodile
Mugger crocodile also uses the power of its tail to propel itself upwards and out of the
Cuban crocodile water snatching prey drinking at the water’s edge .
Saltwater crocodile
Siamese crocodile Like most multi-species spread across the globe, crocodiles habi-
West African crocodile tats vary. They do not like the cold, so their habitats are often in the
Borneo crocodile warm and tropical regions of the world and being semiaquatic, close to
Subfamily: Osteolaeminae freshwater rivers, lakes, wetlands and sometimes, brackish water or
Genus Osteolaemus
Osborn's dwarf crocodile saltwater. Apart from the saltwater crocodile, they are not territorial
Dwarf crocodile and will happily mix and congregate together. The saltwater crocodile,
Genus Mecistops however, is very territorial and will not tolerate another male near it or
West African slender-snouted on its territory. Not only is it the largest but it’s also the most aggres-
crocodile sive and dangerous crocodile of the species. While most crocodiles do
Central African slender-snouted not see humans as food, and if unprovoked will usually avoid contact
crocodile with man, the saltwater crocodile given the chance will attack and eat a
human.

Crocodiles are carnivorous, feeding mostly on vertebrates such as fish, reptiles, birds and
mammals. All, are semiaquatic, snatching most of their land based prey browsing at the water’s edge.
The dwarf crocodile, however, is more terrestrial. It spends its nights hunting on land catching any-
thing that fits into its powerful jaws. Crocodiles are not fussy eaters and will eat almost anything they
can catch; the only limit to the size of the prey is the size of the crocodile itself. Larger animals will
tackle large prey, while smaller animals hunt smaller prey. Its wide and diverse diet is possible be-
cause it’s a Polyphyodont. Catching a large hard shelled turtle, for instance, and losing a few teeth
trying to access its fleshy parts is only a temporary problem. Its lost teeth will be replaced. Its esti-
mated that each tooth in a crocodiles jaw is replaced 50 times during its lifetime. (For further info
See: Alligator)