[FulcrumPilot]

Andrewsarchus:




Andrewsarchus

A rhino-sized, wolf-like carnivore, Andrewsarchus is actually a relative of our familiar hoofed animals and a distant relative of the early whale, Basilosaurus. Its fossils are usually found around water, and as single specimens, so it seems that these animals might have been solitary scavengers along riverbanks and tide lines.

PRONUNCIATION: AND-ROOZ-ARK-US
LIVED: 60 – 32 million years ago
SIZE: 6 feet tall and 16 feet long, with a skull around 33 inches long
FACT: Weighed more than a car, and stretched the length of two
MEANING: Andrews' beast (after paleontologist Roy Chapman Andrews, the role model for Indiana Jones)
CLOSEST LIVING RELATIVE: Whales and hoofed animals
RANGE: Eastern Asia

[budster101]

409 or so Million Years Old. They aren't exactly sure though... could be older.
How old is the oldest shark alive? ...

A rare fossil sheds light on the poorly understood relationship between early sharks and bony fishes
Susan Turner, Randall F. Miller
click for full image and caption


The evolution of jaws was a crucial step in vertebrate history, but it took place so long ago that fossils from this period consist mostly of teeth and a bewildering variety of skin scales. Now an almost complete shark fossil gives paleontologists the opportunity to investigate the poorly understood transition between sharks and modern fishes and to interpret isolated fossils from a new perspective. The remarkably intact 409 million year-old example preserves the braincase, jaws, teeth and pectoral fins in the correct anatomical position. Based on this finding, the authors revise the geography of early shark evolution and question the accepted picture of shark evolution as it relates to other major fish groups.

Source: Sorry, no full article. (Not a subscriber)

Facts about Sharks:

1. Great White Sharks grow about 10 inches per year. Great Whites can grow to mature lengths of 12 to 14 feet.

2. New teeth are constantly being formed in rows in a shark's jaw. Shark's teeth are normally replaced every eight days.

3. Some species of sharks can shed as many as 30,000 teeth in their lifetime.

4. Whale Sharks have approximately 300 rows of teeth, with hundreds of tiny teeth in each row.

5. Dried shark skin (shagreen) was used in the past as sandpaper. In Germany and Japan, shark skin was used on sword handles for a non-slip grip.

6. In 1937, shark liver oil was discovered to be rich in vitamin A. Sharks were hunted for the vitamin until 1950, when a synthesizing method was developed for vitamin A.

7. The average life span of a shark is 25 years, but some sharks can live to be 100.

8. The dogfish sharks are named for their tendency to attack their prey as a pack of wild dogs would.

9. Great White Sharks can go as long as three months without eating.

10. Not all sharks have to be in continuous motion to breathe.

11. Bull Sharks can tolerate a wide range of salinity and are often found in freshwater rivers and lakes in Africa and South America.

12. More people are killed each year by dogs, pigs and deer than by sharks.

13. The Pygmy Shark has a maximum length of 11 inches.

14. Sharks have no bones. A shark's skeleton is made up of cartilage.

15. There are more than 340 known species of sharks.

16. Sharks first appeared in the fossil record over 400 million years ago.

17. A significant physical trait that separates a modern shark from an ancient shark is the protrusile jaw, which gives the modern shark more biting force.

18. Sharks can generate about six and a half tons per square inch of biting force.

19. A shark's skin is embedded with dermal denticles, which resemble teeth.

20. The Shortfin Mako shark is probably the fastest fish in the ocean, clocked at about 60 mph.


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"The Great White Shark"

WHAT DO GREAT WHITES EAT?The GW's diet consists mostly of fish (lingcod, salmon, and tuna), squid, other sharks, cetaceans (dolphins and whales), and pinnipeds (seals and sea lions). They also show a preference for carcasses, especially large whales.

ABOUT HOW LONG DOES THE AVERAGE GW LIVE?No one has accurate answers to this question. Since the GW population is so migratory and also so isolated from one fish to the next, it is impossible to pick an animal and follow it. However, scientists studying GW's off the Farallon Islands (currently one of the hotbeds in the world for GW research) have identified by dorsal markings several individual animals and one, Stumpy, so named because she is missing the top portion of her caudal fin, has been observed returning to feed for 18 years. Is she an old shark? A young shark? No one can say for sure.

HOW BIG DO THEY GROW?The GW's maximum size is unknown, mostly because if today we see a 25-footer, we'll say 25. If tomorrow we see a 30-footer, it'll jump to 30 feet. To stick with my latest numbers, the average GW is between 12-16 feet in length. Some of the monsters at the Farallons are 18 feet but this is the exception, rather than the rule. (why bigger at the Farallons? The GW population hasn't been fished out like in other GW hotspots, Australia and South Africa).

WHERE ARE MOST GW'S FOUND?My first inclination is to say 'water' and I would only be half-joking. GW's have been found in the coastal waters of every continent except Antarctica. Most GW excursions happen in Australia and South Africa, due to the denser populations found there.

HOW FAST CAN THEY SWIM?Estimates of 15 miles an hour in burst mode are common. the best thing I've ever seen in talking about a shark design for speed is this, again from McCosker and Ellis' book. The design of the GW and other fast swimming sharks imparts "...characteristics that are well-described by resorting to automotive terminology: the tail imparts low-speed torque, and its high stall speed shape makes acceleration difficult, but once the shark is under way its forward movement is almost effortless." Cool, huh?

HOW MANY PEOPLE ARE KILLED EACH YEAR BY GW ATTACKS?There are about 100 shark attacks each year, 30 of which are fatal. Of these 30, the GW can be reasonably assumed to be responsible for perhaps half to a third. Just 10 to 15 people each year out of MILLIONS swimming on the beach.

HOW POWERFUL IS THEIR SENSE OF SMELL OR HOW DO THEY SENSE THEIR PREY?It would be easiest to start with the GW's nostrils. Unlike us humans, who require the nostrils to assist in breathing, the GW (who has gills for this!) uses his sniffer for just that....sniffing (or olfaction, as it is scientifically known)! Each nostril is divided by a skin flap that separates the water it is swimming through into an inflowing current and an outflowing current. As the shark moves it's head from side to side, water enters the nostril and passes through an area that contains a large number of tiny sensory organs known as lamellae. These lamellae are shaped like tiny flower petals and are covered with millions of olfactory cells. Since the water travels over so many of these lamellae, it in turn passes over most of the olfactory cells, giving the GW its primary sensitivity to odors in the water. These cells in turn are directly connected to the olfactory bulb in the brain and turn the shark into a "swimming nose".
The second sensory weapon the GW employs against its prey is seen on the shark as hundreds, perhaps thousands of dark holes that cover the top and underside of the snout. These holes are the ampullae of Lorenzini, which makes them sound more like a dish at the Olive Garden if you ask me...but Dr. Lorenzini didn't so that's what they're called. These holes are very small capsules that are filled with jelly excreted by the shark. Each is sensitive to electrical discharges as small as .005 microvolt, this gives the GW the ability to sense the electrical field distributed by a 1,000 MILE-long copper wire hooked to a D-size battery. The pores achieve this astonishing feat by first their great number (the GW, being a large shark, has a great deal more than say a medium-sized blue) and also because, like the nasal lamellae, each pore in turn uses several sensory cells to "pick up" the signal. The sensory cells lies inside alveoli (little sacs) and these alveoli are connected directly to the brain, no muss, no fuss...just a straight signal to Eating Central.
What good does having a built-in electrical field detection have? Quite a bit. Every creature in the water generates a small electrical field from where their skin meets the water. the mucous membranes that coat the mouth and gills of fish also create steady direct current fields and these fields are directly effected by their breathing patterns. Furthermore, if the animal is bleeding, this puts more ions into the water and further increases the signal which the shark can hone in on like a cruise missile in Iraq. In summation, these two sensory packages, the nasal lamellae and the ampullae of Lorenzini, have evolved over millions of years into detection systems for the very things that make prey more attractive - blood, which indicates injured prey and thus easier to catch prey; and movement, generated by an animal in the water. The GW, which is arguably the most efficient super-predator in nature, has evolved as well, using these packages to their fullest extent. Keep in mind that a study showed that the chum and bait used to bring sharks closer to scientists in research vessels could attract sharks from as far away as 5 kilometers. Pretty sensitive...

HOW MUCH FOOD DOES THE AVERAGE GW EAT, AND HOW OFTEN?Again, no way to be sure. Studies at the Farallons show the animals feasting on a large elephant seal and then the animal doesn't eat for days. This feast may consist of one large 800-pound seal, so it is safe to assume (by scientific means but not fact) that the shark eats at least twice a week and when it does eat, it eats A LOT.

Source

[FulcrumPilot]

Originally Posted by budster101

How old is the oldest shark alive? ...

300 mya?

[cjrivera]

[ManOfSteal]

[Rev-O]

Phobosuchus.

Big.
Ass.
Croc.

[Demonhood]

[Kevin]

[RonnieoftheRose]

Here's a prehistoric beast with many who actually follow it!



Respect my beliefs!

[tavilach]

How did this thread deteriorate so quickly? The first two posts were so interesting!

Back to the party .

Indricotherium:

(I don't have a favorite, but this dude is pretty cool)



These ancient members of the rhinoceros family are the largest land mammals in Earth's history. Over twice the height of an elephant and eight times the size of modern rhinos, Indricotherium browsed on the leaves of tall trees. Because an adult was the size of a house, it was invulnerable to attack.

PRONUNCIATION: IN-DRIK-OH-THEER-EE-UM
LIVED: 30 – 25 million years ago
SIZE: 20 to 23 feet tall (15 feet at shoulder)
FACT: Herbivorous, browsing on upper branches of deciduous trees
MEANING: Indrik beast (the Indrik is a mythological animal)
CLOSEST LIVING RELATIVE: Rhinos
RANGE: Asia

[suvsr4terrorists]

Cave Bears. Summary? HUGE bears, herbivores. Yay!

The herbivorous cave bear was essentially a European species. It was named after the places where its remains are commonly found: caves, in the Alps, the Ardennes, the Carpathian and Ural Mountains, and in many other European mountain chains. This is where the animals hibernated year after year, and where they often died. In some Central European caves, such as the Dragon Cave near Mixnitz in Austria, bear bones were slowly amassed to a thick layer representing 30,000 animals at least. Finds from the North Sea and The Netherlands show that Ursus spelaeus finally also ranged into the lowlands of western Europe.

The cave bear and its competitor, the brown bear, had a common ancestor, called Ursus etruscus, that lived nearly 2 million years ago and was already in part herbivorous. The oldest true cave bears appeared some 300,000 years ago. The individual size of the animals gradually increased, although a tendency to diversification sometimes produced relatively small forms. Apart from their usually larger size, cave bears differ from brown bears in the form of their skull, their reduced dentition and the size relations between their limb bones.

In the larger, western part of its range, Ursus spelaeus populations declined after about 40,000 years ago and in the end did not survive the Last Glacial. Competition by the brown bear and hunting by man may both have played a role. In the western Caucasus some held out a few thousand years longer.

[OogaBooga]

Sauroposeidon.

[Randman]

[budster101]

Randman... now I know what the first 4 letters of your nickname stand for... and it isn't your name..

Randy.