We all know about the size of dinosaurs, of course, but how about a rodent the size of a bull, a sea scorpion bigger than a man, a frog as large as a beach ball, a penguin the size of a small adult human, a 1,000-pound ground-sloth-like marsupial, and a shark that may have grown longer than 50 feet and weighed up to 30 times more than the largest modern great white?
All these titans existed, although not in the same place or period.
Illustration of Titanoboa cerrejonensis by Jason Bourque/ Released by Nature
The biggest snake that ever lived (that we know about) was a massive anaconda-like beast that slithered through steamy tropical rainforests about 60 million years ago feasting on primitive crocodiles, National Geographic News reported today.
"Fossils discovered in northeastern Colombia's Cerrejon coal mine indicate the reptile was at least 42 feet (13 meters) long and weighed 2,500 pounds (1,135 kilograms)," contributor John Roach reported.
The snake would have kil*ed its prey by slow suffocation -- wrapping around it and squeezing, just like a modern python or boa. Only this snake was twice the size of today's largest constrictors.
Humans would stand no chance against one of these giant snakes, said Hans-Dieter Sues, paleontologist and associate director for research and collections at the National Museum of Natural History of the Smithsonian Institution in Washington, D.C. "Given the sheer size, the sheer cross section of that snake, it would be probably like one of those devices they use to crush old cars in a junkyard."
2. Bull-Size Rodent Discovered -- Biggest Yet
The giant skull of a one-ton prehistoric rat -- shown here next to a modern-day rat -- was revealed on January 16, 2008.
"Measuring 53 centimeters (21 inches) long, the skull was found in Uruguay by an amateur fossil hunter among fallen cliff rocks in the San José region. Analysis of the bizarre find by paleontologists suggests it belonged to a bull-size species, which has since been named Josephoartigasia monesi," National Geographic News reported.
The megarodent lived in lowland rain forests between two and four million years ago, perhaps using its massive teeth to fend off saber-toothed cats and giant, flightless, meat-eating birds, researchers said
The newfound species was reported in a study led by Andrés Rinderknecht of the National Museum of Natural History and Anthropology in Montevideo, Uruguay.
The previous holder of the title world's largest rodent was a "buffalo-size" fossil creature from Venezuela, revealed by scientists in 2003.
3. Giant "Frog From Hell" Fossil Found in Madagascar
Scientists working in Madagascar found what may be the largest frog that ever lived, National Geographic News reported a year ago.
The bad-tempered Beelzebufo, or "devil frog" was a "rather intimidating animal the size of a beach ball, 16 inches (41 centimeters) high and weighing about 10 pounds (4.5 kilograms)."
Paleontologist David Krause of Stony Brook University in New York and his colleagues began unearthing the the 70-million-year-old frog as a specimen in bits and pieces more than a decade earlier. "Over the years a 75-piece puzzle emerged that was only recently put together by fossil-frog expert Susan Evans of University College London," National Geographic's story said.
Evans, lead author of a paper detailing the find, said that, like its closest modern-day relatives -- a group of big-mouthed frogs in South America called ceratophyrines -- the devil frog also probably had a very aggressive temperament."These ceratophyrines are really aggressive, ambush predators. They are round with big mouths, and they will sit there and grab onto anything that walks past."
"They're sometimes called Pac-Man frogs," she added, "and even the little ones will go for you. It's a frog with attitude, even today. And at two or three times the size of the largest living ceratophyrines, Beelzebufo would have had quite a lot more attitude."
The animal sported a protective shield and powerful jaws that may have enabled it to kil* hatchling dinosaurs, National Geographic News reported.
4. Giant Penguins Once Roamed Peru Desert, Fossils Show
Penguins about the size of humans roamed South America some 35 million years ago, and they didn't need ice to survive, National Geographic News reported in June 2007.
The study by North Carolina State University paleontologist Julia Clarke and her colleagues unveiled two new species of giant penguins from fossils unearthed in Peru's Atacama Desert, pushing the date of penguin migration to equatorial regions back more than 30 million years, to one of the warmest periods of the last 65 million years.
The artist's illustration above shows the approximate sizes of two recently discovered Peruvian giant penguin species.
"The fearsome five-foot (1.5-meter) Icadyptes salasi (right) lived about 36 million years ago, while Perudyptes devriesi (left) lived about 42 million years ago. The two extinct animals are shown to scale with Peru's only living penguin species, Spheniscus humbolti (center)," our story said.
5. Giant Sea Scorpion Discovered; Was Bigger Than a Man
Scientists said this 18-inch (46-centimeter) fossil claw (bottom) belonged to the world's largest known bug: an 8.2-foot (2.5-meter), 390-million-year-old sea scorpion called Jaekelopterus rhenaniae, National Geographic News reported in November 2007.
"The size of a large crocodile, the 390-million-year-old sea scorpion was the top predator of its day, slicing up fish and cannibalizing its own kind in coastal swamp waters, fossil experts say," our report said.
Jaekelopterus rhenaniae measured some 8.2 feet (2.5 meters) long, scientists estimate, based on the length of its 18-inch (46-centimeter), spiked claw.
"The find shows that arthropods -- animals such as insects, spiders, and crabs, which have hard external skeletons, jointed limbs, and segmented bodies -- once grew much larger than previously thought," said paleobiologist Simon Braddy of the University of Bristol in the United Kingdom. "We have known for some time that the fossil record yields monster millipedes, supersized scorpions, colossal cockroaches, and jumbo dragonflies," he added. "But we never realized, until now, just how big some of these ancient creepy-crawlies were."
The fossilized claw of the sea scorpion was uncovered in a quarry near Prüm in Germany.
6. Ancient Giant Shark Had Strongest Bite Ever, Model Says
Prehistoric megalodon -- literally "megatooth" -- sharks had the most powerful bite of any creature that has ever lived, National Geographic News reported in August 2008
"Its bite was strong enough to crush an automobile and far exceeded that of the great white shark and even Tyrannosaurus rex."
Known mostly from the large teeth it left behind, Carcharodon megalodon first appeared in Earth's seas about 16 million years ago (in the Neogene period) and dined on giant prehistoric turtles and whales, we reported.
"Megalodon's kil*ing strategy was to bite the tails and flippers off large whales, effectively taking out their propulsion systems," said study leader Stephen Wroe of the University of New South Wales in Australia.
The prehistoric shark may have grown to lengths of over 50 feet (16 meters) and weighed up to 30 times more than the largest great white.
"A great white is about the size of the clasper, or penis, of a male megalodon," said Peter Klimley a shark expert at the University of California at Davis, who was not involved with the current research.
7. Giant Prehistoric "Kangaroos"
Hunting on the Australian island Tasmania exterminated several prehistoric animals, including the kangaroo-like beasts, marsupial "hippopotamuses," and leopard-like cats, National Geographic News reported in August last year.
The 1,000-pound (500-kilogram) prehistoric ground-sloth-like marsupial depicted here -- Palorchestes azael -- was among a handful of Tasmanian megafauna species driven to extinction by human activity more than 40,000 years ago, our story said.
The study challenged previous research suggesting an ice age kil*ed off the giant creatures before humans arrived on the island.
Other species included in the research were "three kangaroos that would have been in the 220-pound (100-kilogram) size range," said team member Tim Flannery of Australia's Macquarie University.
"There was a marsupial leopard, which was probably 100 to 220 pounds [50 to 100 kilograms] in weight," he said.