Thursday, January 12, 2012

Amphibians, Big and Small

Let's talk a bit about amphibians.

The word "amphibian" means "double life". This refers to the life cycle of frogs and other amphibians - they start out as aquatic animals (tadpoles) before growing up into animals that can live on land (frogs). Aside from frogs and toads, salamanders and newts are also amphibians, as well as a few rarer and lesser-known creatures.

Scientists are always discovering new species of animals, and frogs are one of the more common creatures to pop up on "Newly Discovered" lists. A new frog has been found in Papua New Guinea, and it's one of the smallest invertebrates ever found. The frog averages 7 millimeters long (that works out to 0.27 of an inch). For comparison, a dime is 18 millimeters across.

In direct contrast to this tiny frog, the largest amphibian has been known for quite some time - the Chinese giant salamander can reach six feet in length. Sadly, this very interesting - if not conventionally attractive - creature is critically endangered and almost never gets to reach that size anymore. Thanks to pollution, habitat loss, and the fact that some Chinese consider it a delicacy, the giant salamander generally only grows to 4 feet on average. It has a relative, the Japanese giant salamander, that is almost exactly the same in appearance and habits, although it is a little smaller.

In prehistoric times, amphibians got even larger than six feet. The all-time largest amphibian known to man is Prionosuchus, a prehistoric creature that looked more like a crocodile than today's amphibians, and could reach a length of thirty feet. It went extinct a very long time ago - even before the dinosaurs first appeared.

World's smallest frog:
http://www.bbc.co.uk/news/science-environment-16491477

Photo slideshow dedicated to the giant salamander:
http://news.bbc.co.uk/2/hi/science/nature/8500486.stm

The biggest amphibian of all time, the extinct Prionosuchus:
http://en.wikipedia.org/wiki/Prionosuchus

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