With a leg span of up to 3.7m (12 ft), the Japanese spider crab is one of the world's largest Arthropods.
Posted on 04/22/2005 12:50:39 PM PDT by demlosers
Spectacular specimen: This bug's a big one - 8 feet long - and New Mexico scientists nabbed some of its fossils
Think mosquitoes and millipedes are nasty?
Then don't look too deeply into New Mexico's past.
Today, you can squish the tiny bugs, but 300 million years ago, 8-foot-long millipedes were in control of the landscape, and humans weren't even a gleam in evolution's eye.
New Mexico is now a world record holder of such "exquisitely grotesque creatures," as one worker at the New Mexico Museum of Natural History and Science calls them. Evidence of the largest arthropleura - its technical name - ever found was recovered by the museum on Friday.
"In today's world, you couldn't have a bug this big," said Spencer Lucas, paleontology curator at the museum. "This is basically the Tyrannosaurus of the Pennsylvanian period, millions of years before dinosaurs evolved. If you took a time machine back, you'd definitely want to check your sleeping bag for these suckers before getting in."
The Pennsylvanian time period lasted from 325 to 280 million years ago.
The museum has not found the bug itself. What it did find in a remote canyon near Española were the fossilized tracks of such a creature - which looks like a 3-by-8 speed bump with flat wings holding hundreds of nasty, ribbed, horseshoe-shaped feet.
"This is a very spectacular thing," said Adrian Hunt, director of the museum, who went out in the field with the team to recover it. "Think of it as a much bigger cross between a millipede and a centipede. It probably lived in swampy forest debris. Something like this has never been found before in the Western United States."
Evidence of the creatures has also been found in Nova Scotia and Scotland, but Jorg Schneider, an international expert on them and a paleontologist from the Freiberg Mining Academy in Germany, said New Mexico's find is evidence of the biggest arthropleura ever.
The second-largest creature was probably a few inches smaller than the one found in New Mexico. The New Mexico track is 39.3 centimeters wide, compared with the second-largest track, in Scotland, which is 36 centimeters wide, Schneider said.
Schnieder came to New Mexico for a two-week visit to look at the track and other New Mexico rocks from the same time period, he said.
"One question we have is, could such a large beast live on plant material only?" Schneider said. "In millipedes from the modern era, we know that scolopender (a type of millipede) is a predator. Possibly these big extinct versions also ate other animals. This was the top of the food chain - with no natural enemy - for about 40 to 50 million years during the Pennsylvanian."
The creatures might have been vegetarians, but their large size suggests they might have eaten early reptiles that later evolved into dinosaurs and mammals, Schneider said.
One favorite snack could have been the pelycosaur, a relative of the dimetrodon, a small, sail-backed lizard common in that age, Lucas said.
"We're still really not sure what they ate," Lucas said. "This guy was probably out patrolling the forest floor eating smaller bugs - which were still pretty big by today's standards - and maybe eating small vertebrates. New Mexico was near the equator then, and the land was much warmer and wetter."
Arthropleura died out at the end of the Pennsylvanian, probably because the amount of oxygen in the air was reduced from 30 percent during that time period to closer to the 21 percent we have today, Lucas said.
"They just couldn't survive at that size in modern air," Lucas said. "Their lungs weren't as evolved as ours. For an insect to get that big, you'd need to have a lot more oxygen in the air. These guys were an evolutionary dead end."
Millipedes and centipedes aren't directly related to arthropleura, he added, but might be from a related branch of the now-extinct creature's family tree, Lucas added.
"Breathing, food, locomotion are all problematic for a bug that big," Lucas said. "When the world changed, they just couldn't adapt."
Need a jumbo can of Raid for that thing!!
But not in ways that plants of today normally release it. More plants would only get you a few tenths of a percentage of oxygen, as the consume the last remnants of carbon dioxide. Currently, the limiting factor on plants is carbon dioxide and water available to them. Oxygen would clearly have left the system, but not because of the lack of quantity of plants.
Meteor strikes? Bleedoff into space? Bacteria that feed off of oxidized metals becoming rarer? These might do it. "Fewer plants" would only make sense if there was a lot of unconverted CO2 in the air today.
"Quantity of plants" is not an adequate explanation. Either the plants that were good at stripping oxygen from oxides died out (and there was no force for newer plants to regain that ability as diminishing return effects were themselves diminished), or the cause was a different mechanism.
I don't see anything there that does that.
I'm guessing that whatever reduced an entire planet to rubble and formed the asteroid belt also removed nearly all the atmosphere from the nearest planet - Mars, and most of the atmosphere form the next nearer planet - Earth.
The other planets were were far enough away that they missed the full impact.
Mercury is close enough to the Sun that its' atmosphere has long since been boiled away...
With a leg span of up to 3.7m (12 ft), the Japanese spider crab is one of the world's largest Arthropods.
Nah, I'm "The Crazed Unknown Hermit" 'cause
I just lurk.... but everybody seems to know him.
I don't see anything there that does that.
Well, there is this little tidbit:
Hydroplate. Walt Brown's model proposes that the Flood waters came from a layer of water about ten miles underground, which was released by a catastrophic rupture of the earth's crust, shot above the atmosphere, and fell as rain.
- How was the water contained? Rock, at least the rock which makes up the earth's crust, doesn't float. The water would have been forced to the surface long before Noah's time, or Adam's time for that matter.
- Even a mile deep, the earth is boiling hot, and thus the reservoir of water would be superheated. Further heat would be added by the energy of the water falling from above the atmosphere. As with the vapor canopy model, Noah would have been poached.
- Where is the evidence? The escaping waters would have eroded the sides of the fissures, producing poorly sorted basaltic erosional deposits. These would be concentrated mainly near the fissures, but some would be shot thousands of miles along with the water. (Noah would have had to worry about falling rocks along with the rain.) Such deposits would be quite noticeable but have never been seen.
It seems Dr. Brown's model defies physics in that "Noah would have been poached" by the excessive heat generated. Of course, I guess you didn't actually read this far down, did you?
I read that and found it far from convincing. Have you read Dr. Brown?
Initially the earth's atmosphere had less than 1% oxygen. But activity by blue-green algae species billions of years ago gradually increased these levels. For them it was just a waste product of a respiration process that relied on releasing hydrogen from water. By 1.3 billion years ago, levels had risen to 1%. Around 500 million years ago, oxygen levels had reached 10%. This was sufficient to switch on the all-important ozone layer, which protects the earth's surface from blazing destructive UV radiation.
From then on, other life forms could evolve.
O2 may have reached 35% in the late Carboniferous age, when life was mainly plant-based. The present level of 21% was settled around 5 million years ago. As a result, oxygen is the most prevalent element in the Earth's crust (53%); rock is basically silicon dioxide, with additions
A lot of it appears to be bound up in the vast hydrocarbon deposits, such as coal, that came from the period of high oxygen (the Carboniferous).
This Word document seems to indicate that some of that extra oxygen now comprises the ozone layer: http://trc.ucdavis.edu/ATM_ECI149/Notes/ChI-04-2.doc
Not convincing? You don't seem to have even a high school grasp of physics.
I see Dr. Suess was drawing for ads back then.
Either that, or your ride's broke down.
There are cultures that once worshipped beetles...
Yeah Yeah Yeah
Repeat: Have you read Dr. Brown?
Now I make it a point to never watch my DVDs in my media room in the basement without being armed......
Maybe that would explain why my dates never come back.
Starship Troopers, one of the best all time SciFi movies in my opinion!
350 billion years ago, people just squished those bugs same as now. Folks had much bigger feet in those days.
Gasp! Is that a Tengler?
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