Skip to comments.
Mass Extinctions: 'Giant' Fossils Are Revolutionizing Current Thinking
ScienceDaily ^
| February 11, 2010
| Adapted from materials provided by CNRS
Posted on 02/15/2010 11:29:02 AM PST by SunkenCiv
click here to read article
Navigation: use the links below to view more comments.
first 1-20, 21-27 next last
1
posted on
02/15/2010 11:29:04 AM PST
by
SunkenCiv
To: 75thOVI; aimhigh; Alice in Wonderland; AndrewC; aragorn; aristotleman; Avoiding_Sulla; BBell; ...
2
posted on
02/15/2010 11:30:04 AM PST
by
SunkenCiv
(Happy New Year! Freedom is Priceless.)
To: StayAt HomeMother; Ernest_at_the_Beach; 1ofmanyfree; 21twelve; 24Karet; 2ndDivisionVet; 31R1O; ...
3
posted on
02/15/2010 11:30:25 AM PST
by
SunkenCiv
(Happy New Year! Freedom is Priceless.)
To: SunkenCiv
my favorite pet theory about the predominance of gigantism in fossils is that the earth had much higher barometric pressure in the distant past. Higher pressure allows cells to grow larger since they can be oxygenated better.
So aminals had the same DNA, same number of cells, just each cell was larger.
This changed after earth’s pressure was reduced by meteor strike and/or global flood calamity.
To: BereanBrain
What would account for the giant anal orifices permeating the Obama administration? lol
5
posted on
02/15/2010 11:38:23 AM PST
by
verity
(Obama Lies)
To: BereanBrain
While the story was interesting, I confess that I was more interested by the little box at the bottom, offering a choice of citation formats.... My kids are to the point now where they’re writing papers that require references, and the article offered a couple of alternatives (APA and MLS). Pretty nifty little gadget!
6
posted on
02/15/2010 11:39:03 AM PST
by
r9etb
To: SunkenCiv
7
posted on
02/15/2010 11:39:24 AM PST
by
Hegemony Cricket
(The emperor has no pedigree.)
To: BereanBrain
The problem with that theory is that the largest living organisms that have ever been discovered are still alive today; Blue whales.
So apparently, higher barometric pressure is not necessary for large size.
To: SunkenCiv
Huh. They all died at one time. Interesting. Like- there could have been a great big flood....
9
posted on
02/15/2010 11:45:30 AM PST
by
Nachum
(The complete Obama list at www.nachumlist.com)
To: SunkenCiv
A lot of the unknowns can be explained with two phenomena. The first is the unequal distribution of fossils. That is, fossilization is very rare, and only takes place in very limited conditions around the world. If these places become uninhabited, it seems like lots of species have disappeared. But in truth, it just means a gap until they next occupy a place where fossilization occurs.
The other phenomena is the flip side of this, called “the Lazarus effect”, where most of a species is killed off, leaving only a few small colonies behind, taking them a great length of time to repopulate regions in which they used to live.
Between the two, it is not surprising to imagine strange extinction and recovery events. We live in a very volatile world.
To: BereanBrain; Fred Nerks
11
posted on
02/15/2010 11:54:20 AM PST
by
SunkenCiv
(Happy New Year! Freedom is Priceless.)
To: Hegemony Cricket
Huge midgets. $9.99 a pound under the name "Jumbo Shrimp" ...
12
posted on
02/15/2010 12:24:24 PM PST
by
TexGuy
(If it has the slimmest of chances of being considered sarcasm ... IT IS!)
To: SunkenCiv
Ammonite fossil.
13
posted on
02/15/2010 12:24:28 PM PST
by
Fred Nerks
(fair dinkum!)
To: EnderWiggins; BereanBrain
The theory isn’t completely dead, It could still apply to critters without a decent circulatory system and set of lungs/gills.
Dragonflies with 3 foot wingspans come to mind.
(Side question, how much atmosphere did the Chicxulub impact blast into space?)
14
posted on
02/15/2010 12:25:04 PM PST
by
null and void
(We are now in day 389 of our national holiday from reality. - 0bama really isn't one of US.)
To: null and void
"The theory isnt completely dead, It could still apply to critters without a decent circulatory system and set of lungs/gills.
Dragonflies with 3 foot wingspans come to mind.
A 30 inch wingspan is not the key measure. The body of the Meganeura "dragonfly" was only 18 inches long. There are walking sticks that are 13 inches long that are living today. So... yeah they were big, but not uniquely so.
The real problem though is that gigantism doesn't actually associate with specific time frames. Different organisms or types of organisms express gigantism at different times. They don't provide a pattern of generally larger to smaller over time, or as the result of a certain event where suddenly organisms generally became smaller.
Certainly, the fossil record tends to preserve larger organisms preferentially over smaller... and we also tend to emphasize in our media the extremes over the ordinary. Giant dragonflies and cockroaches of the Carboniferous get our attention... but the simple truth is that most dragonflies and cockroaches of the Carboniferous were little bitty guys, just like today.
As to your aside... it is not clear to me that the K-T event would have blasted any atmosphere into space. I certainly cannot find any references or models that would indicate it did. (Side question, how much atmosphere did the Chicxulub impact blast into space?)
To: Fred Nerks
That’s a lot of escargot. ;’)
16
posted on
02/15/2010 12:58:35 PM PST
by
SunkenCiv
(Happy New Year! Freedom is Priceless.)
To: Fred Nerks
Was that found in Australia?
To: Hegemony Cricket
“The world’s smallest large-screen television”.
18
posted on
02/15/2010 1:09:31 PM PST
by
wbill
To: SunkenCiv
We have these and Large-sized gastropods (up to 7 cm) (some bigger) in our backyard here in central Texas. (elevation about 990 ft.)
19
posted on
02/15/2010 1:15:29 PM PST
by
wolfcreek
(http://www.youtube.com/watch?v=Lsd7DGqVSIc)
To: Ernest_at_the_Beach
AMMONITE FOSSILS. LINKsorry, I saved the image but not the source, and the above website that features the same ammonite doesn't say. Here's a nice one:
20
posted on
02/15/2010 1:25:02 PM PST
by
Fred Nerks
(fair dinkum!)
Navigation: use the links below to view more comments.
first 1-20, 21-27 next last
Disclaimer:
Opinions posted on Free Republic are those of the individual
posters and do not necessarily represent the opinion of Free Republic or its
management. All materials posted herein are protected by copyright law and the
exemption for fair use of copyrighted works.
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson