Crocodiles as we know them appeared on earth around 150 million years ago, the time when dinosaurs still roamed our planet. They have similar structural and behavioral characteristics as that of a T – Rex. Their brain sizes are proportional. Speaking of their toughness, the prehistoric crocodiles also known as Sarcosuchus were almost 11 to 12 meters or 36 – 39 feet from head to tail and their diet mainly comprised of other dinosaurs that came to drink water by the rivers and lakes. These fantastic tiny brained creatures even survived the great extinction that the dinosaurs couldn’t and over the time they have evolved into their present forms.
Where are Crocodiles found at present?
Currently their major habitats are the entire Indian subcontinent, South – East Asia, Northern Australia, Central Africa, Southern North America and Northern South America.
Species of Crocodiles
There are mainly 14 species of crocodiles namely American Crocodile, Slender – Snouted Crocodile, Orinoco Crocodile, Fresh Water Crocodile, Morelet’s Crocodile, Philippine Crocodile, Nile Crocodile, Mugger Crocodile, New Guinea Crocodile, Salt Water Crocodile, Cuban Crocodile, Siamese Crocodile, Desert Crocodile and Dwarf Crocodile. The teeth, snout, brain and other physiological characteristics of the present day crocodiles are similar to those of their ancestors but only diminished in size.
The diet of the present day crocodiles comprises of all mammals and reptiles that step into their paths except elephants and hippos and giant snakes. One startling characteristic feature of the crocodiles is the way they reproduce. The reproduction consists of the usual mating which takes place in water and is followed by the laying of eggs. And this is where the startling feature comes in.
The embryos lack sex chromosomes, which means sex is not determined genetically. In fact it is determined by temperature where at 30 °C (86 °F) or less, most hatchlings are females and at 31 °C (88 °F), offspring are of both sexes. A temperature of 32 to 33 °C (90 to 91 °F) gives mostly males whereas above 33 °C (91 °F) in some species continues to give males but in other species resulting in females, and also called as high-temperature females.
How does Global Warming Affect Crocodiles?
The temperature also determines their survival. By laying eggs in different locations with different temperature, a constant sex ratio is maintained. And this is where global warming comes in. Global warming affects marine life a lot. Due to gradual increase in temperatures across the globe, the lower end of the temperature spectrum will be missing within a span of few years. Which means female crocodiles will no longer be born and one day the many species of the crocodiles will be extinct due to acute imbalance in sex ratio. This will be the end of one of the toughest creatures on our planet which has held its ground for more than 150 million years.
So if you still want see this magnificent beast surprisingly taking down its prey in the Savannah grassland of Africa or the fresh water lakes of India, you got to do your bit.
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By Fauna
May 26, 2014
Updated:
Published: May 26th, 2014
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