Jaekelopterus rhenaniae a.k.a Giant Sea Scorpion: Believe it or not. Bigger Than A Man...
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A fearsome fossil claw discovered in Germany belonged to the biggest bug ever known.
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.
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.
"This is an amazing discovery," Braddy said.
"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 newfound fossil creature is estimated to be at least one and a half feet (46 centimeters) longer than any previously known prehistoric sea scorpion, a group called eurypterids.
Braddy and co-author Markus Poschmann of the Mainz Museum in Germany report the find in the latest issue of the journal Biology Letters.
Poschmann uncovered the fossilized claw in a quarry near Prüm in Germany.
Rock layers encasing it suggest the creature lived in a brackish coastal swamp or river delta, the researchers said.
Smaller sea scorpions are known to have crawled ashore to mate or shed their outer skins. But "there's no way this monster bug would have been able to do that, because it was just too big," Braddy said.
"Its legs were relatively flimsy compared to the size of its body," he added. Without water buoying the big beast up, its legs would have collapsed under the weight of its body, Braddy said.
The arthropod was top of the food chain, he said."They were cannibals but they also would eat some of the early armored fish that were around at the time."
Some researchers think that some primitive jawless fish evolved protective bony shields because of predatory pressure from sea scorpions, he added.
Though J. rhenaniae has been known for many years, no one realized the species grew so huge, according to paleontologist Paul Selden of the University of Kansas.
"It would pretty much have eaten anything smaller than itself," Selden said.
The animal's claws were armed with long sharp teeth that "would have grasped even a slippery fish."
Held at the ready on two long, folding arms, those claws would have been used to ambush prey, Selden said.
"I think they were designed for shooting out when close to prey, like the arms of a praying mantis," he added.
Eurypterids, the relatives of modern-day land scorpions and spiders, likely reached such massive sizes due to lack of competition from fish and other vertebrates—animals with backbones—study author Braddy said.
Credits fr. NationaL Geographic. . .
Wed Jul 03, 2013 9:01 pm
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