You might think that "living fossils" is an oxymoron, but this fascinating list of incredible animals that are living fossils proves otherwise.
You might think that “living fossils” is a bit of an oxymoron, however you’d be mistaken. To be considered one, the living organism in question must more or less maintain the same anatomy and behavior over millions of years while watching the rise and fall of many other still-evolving species. A fascinating look at the world’s most astounding living fossils:
Living Fossils: Nautilus
Somewhere on the cephalopod’s evolutionary journey from snail to octopus sits the Nautilus; which has changed very little in the last 500 million years. At one point, the oceans contained hundreds of different types, but nowadays only six remain, all of which are found along the deep slopes bordering Indo-Pacific coral reefs.
Like the squid and the octopus, the Nautilus has tentacles, but many more of them that lack suckers. It also lacks the complex central nervous system of its advanced family members and has been shown to have a much poorer memory in comparison.
Sumatran Rhino

Source: International Rhino Foundation
Sharing the unenviable title of “world’s most endangered rhino” with its Javan counterpart, it is estimated that there are fewer that 400 Sumatran rhino alive today.
Making its home in the dense highland forests of Malaysia and Indonesia, this smallest of the rhino family is relatively well known because of studies done during a particularly unsuccessful 20-year captive breeding program. While contentious, theories linking the Sumatran rhino to the prehistoric woolly rhinoceros have shown some merit.

Source: Goodfon
Black and Rufous Elephant Shrew

Source: Animals Town
While initially lumped into the same group as shrews because of their superficial resemblance, elephant shrews are not shrews at all. Part of the Sengi family of mammals found up and down East Africa, it is thought that aardvarks, manatees and even elephants may have evolved from a sengi-like critter. Fossil records show Sengi’s presence in Africa going back 30 million years.

Source: Wikimedia
Alligator Snapping Turtle
This terrifying-looking turtle native to the Southeastern United States can grow to a massive 220 pounds and live past 150 years old. Legend has it that specimens have been found with Civil War-era musket balls embedded in their shells. Sitting at the bottom of freshwater lakes and tempting naive fish right into its formidable jaws has proved over 200 million years to be an effective strategy.

Source: Wikimedia
http://www.youtube.com/watch?v=R3VlyFmemyI
Coelacanth, The Living Fosisl Fish

Source: Wikimedia
The Coelacanth is one of the most famous of the living fossils. Captain Hendrick Goosen and Marjorie Courtenay-Latimer discovered the first specimen among a fishing haul in 1938. This came as a massive shock to the scientific community as they were reckoned to have gone extinct 65 million years ago.
In actuality, the Coelacanth has been around and keeping a low profile for almost 400 million years. Two distinct populations have now been observed, one in the West Indian Ocean and the other 6000 miles away in Indonesia.

Source: University of Chicago
http://www.youtube.com/watch?v=NzzxOlFJtzg
Incredible Living Fossils: Horseshoe Crabs
Also known as the King Crab, the Horseshoe Crab is not actually a crab at all, as it’s much more closely related to spiders and mites. Horseshoe Crab-type creatures started showing up around 400 million years ago and around 170 million years later, the species evolved to what we still see today.
http://www.youtube.com/watch?v=0dGluFnnq9I
Chevrotain
34 million years ago the Chevrotain’s home was fairly widespread, but now it’s found only in Southeast Asia and Central-West Africa. Although it looks like a tiny deer (the Asian variety is known informally as the Mouse Deer), its ancestry is not so clear cut.
It does share the usual deer trait of having a many-chambered gut to digest vegetation but differs in that its third stomach is much less developed. It also has four toes like a pig and elongated canine tusks.