Skeptic Friends Network

Username:
Password:
Save Password
Forgot your Password?
Home | Forums | Active Topics | Active Polls | Register | FAQ | Contact Us  
  Connect: Chat | SFN Messenger | Buddy List | Members
Personalize: Profile | My Page | Forum Bookmarks  
 All Forums
 Community Forums
 General Discussion
 Shark facts from the Discovery Channel
 New Topic  Topic Locked
 Printer Friendly Bookmark this Topic BookMark Topic
Author Previous Topic Topic Next Topic  

furshur
SFN Regular

USA
1536 Posts

Posted - 08/03/2006 :  04:58:05  Show Profile Send furshur a Private Message
My daughter and I have been watching shark week on the Discovery Channel together. I have a phobia about sharks and she wants to swim with them so it makes for some entertaining dialog.
The point is that there are many different shows and they all seem to disagree with each other. In one night I discovered that:

The mako is the fastest shark with a top speed of 31 mph

A Great white however can swim at 40 mph

The shark that has killed the most people is the Tiger and the Great White and the Bull shark.

Great Whites kill the most people in Australia

Tiger sharks kill the most people in Australia.

I thought these shows were suppose to be at least somewhat scientific - silly me, it is just like the news in the United States - entertainment trumps facts.


If I knew then what I know now then I would know more now than I know.

Edited by - furshur on 08/03/2006 04:58:44

filthy
SFN Die Hard

USA
14408 Posts

Posted - 08/03/2006 :  05:30:40   [Permalink]  Show Profile Send filthy a Private Message
The plain fact is: they simply don't know so one guess is as good as another as far as fastest, most dangerous, and so forth is concerned.

The so-called requiem sharks (great white, tiger, bull, pelagic white tip, and so forth) are all dangerous under the right circumstances. During the sea turtle nesting season, for example, tiger sharks can be especally aggressive, as can the great whites during seal/sea lion breeding season when their natural prey is congregated in a small area.

During WW-II, the pelagic white tip was known to have finished off many ship-wrecked sailors and downed fliers.

So, to all surfers, SCUBAdooers, and naked beach apes I say unto you: count your blessin's and love them sharks. It could be one hell of a lot worse!






"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)

"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres


"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude

Brother Boot Knife of Warm Humanitarianism,

and Crypto-Communist!

Edited by - filthy on 08/03/2006 05:32:36
Go to Top of Page

Chippewa
SFN Regular

USA
1496 Posts

Posted - 08/03/2006 :  12:59:07   [Permalink]  Show Profile  Visit Chippewa's Homepage Send Chippewa a Private Message
That's one Gnarley Beast! (Even his eyeball has armor plating.)

While on this subject (or off it,) I've wondered about the stories of WWII downed airmen in the Pacific being either pushed away from sharks and/or toward land by friendly dolphins. I haven't found anything on it but have occasionally heard this tale from time to time.

Diversity, independence, innovation and imagination are progressive concepts ultimately alien to the conservative mind.

"TAX AND SPEND" IS GOOD! (TAX: Wealthy corporations who won't go poor even after taxes. SPEND: On public works programs, education, the environment, improvements.)
Go to Top of Page

filthy
SFN Die Hard

USA
14408 Posts

Posted - 08/03/2006 :  13:32:01   [Permalink]  Show Profile Send filthy a Private Message
quote:
Originally posted by Chippewa

That's one Gnarley Beast! (Even his eyeball has armor plating.)

While on this subject (or off it,) I've wondered about the stories of WWII downed airmen in the Pacific being either pushed away from sharks and/or toward land by friendly dolphins. I haven't found anything on it but have occasionally heard this tale from time to time.


I think it's another legend of the sea. I've never seen nor heard of any confirmed incident of rescue by dolphins. They have been known, however, attack sharks in defense of another pod member or calf.

The beast, gnarly to the absolute extreme, is dunkleosteous, the terror of the Devonian seas. It is considered to have had the most powerful jaws ever, and could chop up any shark that ever lived, including C. Megalodon.





"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)

"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres


"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude

Brother Boot Knife of Warm Humanitarianism,

and Crypto-Communist!

Go to Top of Page

pleco
SFN Addict

USA
2996 Posts

Posted - 08/03/2006 :  13:51:47   [Permalink]  Show Profile  Visit pleco's Homepage Send pleco a Private Message
The Dirty Jobs episode for Shark Week was very good. I love that show.

by Filthy
The neo-con methane machine will soon be running at full fart.
Go to Top of Page

HalfMooner
Dingaling

Philippines
15831 Posts

Posted - 08/03/2006 :  14:30:08   [Permalink]  Show Profile Send HalfMooner a Private Message
In the late 60's, I worked for a time in a steel fabricating plant, Bethlehem Steel's Point Richmond plant. The jaws of that "dunkleosteous" fellow remind me of a monstrous steel sheering press that I worked on, and with which I once came close to losing my hands.

That guy looks like a specialist feeder, perhaps one that dines mainly on armored critters that can fight back. I assume from his own armor that dunkleosteous was not as fast as some fish such as Megalodon, so it may have fed on creatures which were slower still. I'm thinking of those free-swimming, long-cone-shelled, tentacled mollusks, the whatchamcallits. Do you know, or have, any theories about what dunkleosteous ate, Filthy?


Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive.
Go to Top of Page

Chippewa
SFN Regular

USA
1496 Posts

Posted - 08/03/2006 :  16:24:59   [Permalink]  Show Profile  Visit Chippewa's Homepage Send Chippewa a Private Message
I knew Filthy would know the proper name: Dunkleosteous! I was googling "Dunkleothis" and "Dunkleothat" and getting nowhere. Thanks!
quote:
Originally posted by HalfMooner

In the late 60's, I worked for a time in a steel fabricating plant, Bethlehem Steel's Point Richmond plant. The jaws of that "dunkleosteous" fellow remind me of a monstrous steel sheering press that I worked on, and with which I once came close to losing my hands.

I have a friend who ran a print shop which had a massive paper cutting machine. The machine was designed so that it would not operate unless two buttons far apart were pushed simultaneously, then the big chopper blade would descend and slice a ream of paper. Good idea, probably saved some hands.

Diversity, independence, innovation and imagination are progressive concepts ultimately alien to the conservative mind.

"TAX AND SPEND" IS GOOD! (TAX: Wealthy corporations who won't go poor even after taxes. SPEND: On public works programs, education, the environment, improvements.)
Go to Top of Page

HalfMooner
Dingaling

Philippines
15831 Posts

Posted - 08/03/2006 :  16:39:20   [Permalink]  Show Profile Send HalfMooner a Private Message
quote:
Originally posted by Chippewa

I have a friend who ran a print shop which had a massive paper cutting machine. The machine was designed so that it would not operate unless two buttons far apart were pushed simultaneously, then the big chopper blade would descend and slice a ream of paper. Good idea, probably saved some hands.


The machine I was operating also had the same sort of safety device, two buttons that had to be pressed at the same time. I was required to repeatedly feed the press thick sheets of steel, hours at a time. The problem came when the brake on the press failed, and its cyclic momentum kept it crunching away as I was reaching in to pull out the last sheet of steel. Lucky for me, I snatched back my hands at the last moment. Shaken, I then stepped aside and yelled for the maintenance mechanic to fix the damned thing.

I'm just guessing, but I'll bet dunkleosteous didn't have any safety device, or brake, in its design.


Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive.
Go to Top of Page

filthy
SFN Die Hard

USA
14408 Posts

Posted - 08/04/2006 :  04:59:31   [Permalink]  Show Profile Send filthy a Private Message
My own hypothesis is that our Dunk was an ambush predator; one that would take on anything that came within range. It is often pictured as free-swimming, but I think that the sheer mass of the skull and shoulder plating argues against that. It would require too much energy to haul all that around on a regular basis.

It was certainly a predator of Devonian sharks, which were relatively small -- megalodon didn't show up until much later; the Cretatious, if memory serves. It is interesting to note that sharks never reached much size until the placoderms such as Dunk died out.

The fossil record tells us that dunkleosteous was also a cannibal.

What a marvelous animal! Those drop-shear jaws were entirely of bone, ever growing and kept trim and sharp by constant grinding and rubbing against each other.

Chip, the name you might be looking for is, “Dinicthys, (sp?)” the “terrible fish.” There were many species of these, all placoderms similar to Dunk, but not so large. “Dunkleosteous” (pronounced: dunk-lee-osteous) means, “Dunkle's armored fish.”

When it comes to pure, predatory savagery, T. rex was no where near the league Dunk played in. I'd happily trade everything I own including my soul if such exists, for a year's rental on a time machine.






"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)

"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres


"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude

Brother Boot Knife of Warm Humanitarianism,

and Crypto-Communist!

Go to Top of Page

Chippewa
SFN Regular

USA
1496 Posts

Posted - 08/04/2006 :  10:25:16   [Permalink]  Show Profile  Visit Chippewa's Homepage Send Chippewa a Private Message
quote:
Originally posted by filthy

My own hypothesis is that our Dunk was an ambush predator; one that would take on anything that came within range. It is often pictured as free-swimming, but I think that the sheer mass of the skull and shoulder plating argues against that...Chip, the name you might be looking for is, “Dinicthys, (sp?)” the “terrible fish.” There were many species of these, all placoderms similar to Dunk, but not so large. “Dunkleosteous” (pronounced: dunk-lee-osteous) means, “Dunkle's armored fish.”
When it comes to pure, predatory savagery, T. rex was no where near the league Dunk played in. I'd happily trade everything I own including my soul if such exists, for a year's rental on a time machine.

Yes, Dinicthys. Dunk's slightly smaller brother. Very cool. Also found this:

Dinicthys intermedius Newberry. Restoration.
http://geology.cwru.edu/~huwig/catalog/slides/675.%20.35.jpg

Maybe these creatures also used their boney heads to disable large prey by ramming them and then chopping them up. Then again, some artists imagine dunkleosteous with fins so maybe he swam a short way or lunged out like a modern eel.
http://artattack.to/display.php?art=1000018499

Dinichthys fossils:

Dinichthys, an arthrodire. The top of the cranium anterior end up.
http://geology.cwru.edu/~huwig/catalog/slides/675.%20.16.jpg

Dinichthys, an arthrodire. Underside of the head showing pineal pit.
http://geology.cwru.edu/~huwig/catalog/slides/675.%20.17.jpg

Dinicthys clarki. Full set of jaw parts in proper position. From Big Creek, Cleveland.
http://geology.cwru.edu/~huwig/catalog/slides/675.%20.18.jpg

Dinicthys intermedius Newberry. Mandibles.
http://geology.cwru.edu/~huwig/catalog/slides/675.%20.19.jpg

These were found using "Dinichthys" in Windows "Edit" "Find this page" on the following massive list:
geology.cwru.edu/~huwig/catalog/catalog.html

Dunkleosteous fossil uncovered in 2005:
http://palaeoblog.blogspot.com/2005/05/cmnh-uncovers-new-dunkleosteous.html

Diversity, independence, innovation and imagination are progressive concepts ultimately alien to the conservative mind.

"TAX AND SPEND" IS GOOD! (TAX: Wealthy corporations who won't go poor even after taxes. SPEND: On public works programs, education, the environment, improvements.)
Go to Top of Page

Dave W.
Info Junkie

USA
26009 Posts

Posted - 08/05/2006 :  19:32:42   [Permalink]  Show Profile  Visit Dave W.'s Homepage Send Dave W. a Private Message
Chippewa, that's nearly a post for "Weird evolution? God went off his meds?" It's due for a resurrection, anyway.

filthy, here is the National Museum of Natural History's take on Dunk:



Photo taken during the June 10th SFN East coast get-together. I could have sworn I took one of the Dunk skull they had there, too, but if I did it's not there with all the rest of the photos, now. I also took the following photo with you in mind, filthy:



If you can't see the teeny-tiny text, it's a matamata skeleton.

- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too.
Go to Top of Page

filthy
SFN Die Hard

USA
14408 Posts

Posted - 08/06/2006 :  02:56:29   [Permalink]  Show Profile Send filthy a Private Message
Thanks, guys!

Dunk was an elasmobranch and I think that it was probably built much on the lines of a shark. An eel's build simply wouldn't generate the sheer power required for this animal to, again, move that extraordinary head in an attack mode. As far as I know, there is no evidence for rayed fins. I think Dave's picture is probably close to accurate.

Love the matamata. It is one of the largest and most grotesque of the side-necked turtles. I seem to recall writing an essay on it somewhere. If it wasn't here, I'll do another. It is certainly worth a close look.

Haven't got time at the monent to go through the links, but I'll get back to them shortly, Chip. Again, thanks!




"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)

"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres


"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude

Brother Boot Knife of Warm Humanitarianism,

and Crypto-Communist!

Edited by - filthy on 08/06/2006 03:02:58
Go to Top of Page

filthy
SFN Die Hard

USA
14408 Posts

Posted - 08/07/2006 :  10:35:52   [Permalink]  Show Profile Send filthy a Private Message
Re: the Discovery Channel. Some time ago, I ordered their really excellent Walking with Dinosaurs DVD. Along with it, I also ordered Before the Dinosaurs, a program dealing with the Cambrian and Devonian up to the Permian Extinction. In it, it described the habit of early reptiles ingesting stones to aid in digestion -- something still done by crocodilians today. The narrator described these stones as -- are you ready for this? -- gastropods!

I couldn't let this incredible, and really inexcusable boner rest, so I sent Discovery an e-mail to the effect that the only business a gastropod would have in the stomach of anything would be to be digested, not help it, and the term that they were looking for is gastrolith.

There were a few other, minor errors, but beyond that, it was a pretty decent presentation. However, the Discovery Channel is in no way any sort of a scientific body simply due to such minor but glaring errors. I don't think that they do their fact-checking very well and should be carefully referenced. It is, however, pretty much ok for popular viewing -- they don't fuck up too terribly…..





"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)

"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres


"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude

Brother Boot Knife of Warm Humanitarianism,

and Crypto-Communist!

Go to Top of Page

Ricky
SFN Die Hard

USA
4907 Posts

Posted - 08/07/2006 :  11:55:17   [Permalink]  Show Profile  Send Ricky an AOL message Send Ricky a Private Message
You've never seen a snail stone, filthy?

Why continue? Because we must. Because we have the call. Because it is nobler to fight for rationality without winning than to give up in the face of continued defeats. Because whatever true progress humanity makes is through the rationality of the occasional individual and because any one individual we may win for the cause may do more for humanity than a hundred thousand who hug their superstitions to their breast.
- Isaac Asimov
Go to Top of Page

BigPapaSmurf
SFN Die Hard

3192 Posts

Posted - 08/08/2006 :  05:25:56   [Permalink]  Show Profile Send BigPapaSmurf a Private Message
Well if the gastroliths are fossils then they could also be gastropods, no?

"...things I have neither seen nor experienced nor heard tell of from anybody else; things, what is more, that do not in fact exist and could not ever exist at all. So my readers must not believe a word I say." -Lucian on his book True History

"...They accept such things on faith alone, without any evidence. So if a fraudulent and cunning person who knows how to take advantage of a situation comes among them, he can make himself rich in a short time." -Lucian critical of early Christians c.166 AD From his book, De Morte Peregrini
Go to Top of Page

filthy
SFN Die Hard

USA
14408 Posts

Posted - 08/08/2006 :  06:25:19   [Permalink]  Show Profile Send filthy a Private Message
quote:
Originally posted by Ricky

You've never seen a snail stone, filthy?

Heh, indeedy!

quote:
Well if the gastroliths are fossils then they could also be gastropods, no?
Yeh, if you must have it so, but what are the odds?

Just any, old cobble won't serve as a gastrolith. It all depends on the animal's size. For example, I remember an over-excited newspaper story about small to medium-sized alligators near a golf course snapping up golf balls, much to the golfer's dismay (those things ain't cheap, I'm told). They were, of course, not eating the balls but collecting new gastroliths (when the old ones wear to a certain size, they are expelled, so there is a fairly even turnover). The smaller the stomach, the smaller the gastroliths, and thus, gastroliths might range in size from pea gravel in a juvenile crocodilian to some pretty good-sized stones found in association with dinosaur fossils.

Of interest: the sand found in a bird's crop is yet another hint of their reptilian ancestory.




"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)

"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres


"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude

Brother Boot Knife of Warm Humanitarianism,

and Crypto-Communist!

Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Topic Locked
 Printer Friendly Bookmark this Topic BookMark Topic
Jump To:

The mission of the Skeptic Friends Network is to promote skepticism, critical thinking, science and logic as the best methods for evaluating all claims of fact, and we invite active participation by our members to create a skeptical community with a wide variety of viewpoints and expertise.


Home | Skeptic Forums | Skeptic Summary | The Kil Report | Creation/Evolution | Rationally Speaking | Skeptillaneous | About Skepticism | Fan Mail | Claims List | Calendar & Events | Skeptic Links | Book Reviews | Gift Shop | SFN on Facebook | Staff | Contact Us

Skeptic Friends Network
© 2008 Skeptic Friends Network Go To Top Of Page
This page was generated in 0.17 seconds.
Powered by @tomic Studio
Snitz Forums 2000