Fossil fuels age debate (560 million year old vertebrate)

Sydney Morning Herald ^ | October 22, 2003

[dead]

A fossil, believed to be the oldest vertebrate ever found, has been uncovered in South Australia.

The five-centimetre fossil, which looks like an elongated tadpole and is believed to be at least 560 million years old, was unearthed in sandstone by station owner Ross Fargher at a secret location in SA's Flinders Ranges.

The SA Museum today said the fossil was part of a marine animal known as the Ediacara Chordate.

The Ediacara Chordate discovered in South Australia.
Photo: South Australian Museum

A fin on its back, a set of inclined muscle bars and a head were clearly visible, the museum said.

The fossil's age eclipsed that of one previously considered the oldest at 530 million years that was discovered in China several years ago, museum palaeontologist Jim Gehling said.

"The fantastic thing about this specimen is that it's at least 30 million years older than anything else that could be even vaguely related to vertebrates," Dr Gehling said.

"(The Flinders Ranges fossil is) at least 560 million years old, it could be even about five million years older (565 million years old) - it's very hard to tell."

Dr Gehling said vertebrates were recognised as being the oldest and largest animals to exist on earth.

"They (vertebrate fossils) include some very bizarre things but most of them are almost unrecognisable in terms of the kinds of animals we see today," he said.

"A few of them seem to relate to whales and crustaceans and maybe even starfish and jelly fish."

He said vertebrate fossils were particularly interesting because humans were also vertebrates.

"The holy grail of palaeontology is always to work out where we came from," he said.

The fossil was expected to be brought back to Adelaide for further analysis by museum staff.

"While we say it has a backbone, there's no direct evidence of a backbone," Dr Gehling said.

"It's the shape of the thing and it's the fact that it has these inclined sets of muscles and a head end ... which makes it look like a little fishy tadpole type thing, which is evidence that it's something different to all the other fossils around it."

AAP

[CHATTAB]

First of all, I'm not a scientist...
How do scientists know that their age extimation/dating is correct?
How do scientists know that carbon-dating is accurate?

[CHATTAB]

extimation=estimation ooops!

[Blzbba]

Carbon Dating explained Type "Carbon dating explained" on google for more sites. This is simply the first I grabbed for ya.

[dead]

"Fuels" is the verb.

[_Jim]

Somehow, finding abundant amounts of carbon-based compounds subterranean lead to the term "Fossil fuels" - a misnomer. WHAT other compounds, mined or pumped from the earth, are attributed to 'surface' activity on the earth?

[almcbean]

The answer is they don't. Carbon dating is only accurate for "short" periods-thousands of years. The truth about these "millions of years" prognostications is that they make it up.

[dead]

This article has nothing to do with "fossil fuels".

"Fuels" is a verb in the title.

[_Jim]

This article has nothing to do with "fossil fuels".

Do you also feel a need to apogize for some else's misleading headline (why not "Discovery of Fossil contributes to age debate" as opposed to "Fossil fuels age debate")?

[Axenolith]

Items this old aren't dated via Carbon, that's only good to around 60,000 years. Dating older material involves radioisotopes that have longer half lives. There are also some other methods that involve isotope ratios, but I'm not to familiar with them right now.

For an igneous or a metamorphic rock, the clock is "set" when the rock or its components crystallize. This freezes the quantity of isotope in the matrix which then begins to decay. If the half life is 1,000,000 years and the subject rock has 1/4 of the original amount in it the rock would have solidified 2,000,000 years ago (the original amount divided by 2, then again).

There isn't any question about the validity of the isotopes half lives, but uncertainty arises if the rock is reexposed to heat over time (like a later metamorphic event). Also, the isotope needs to be relatively ubiquitous in its overall concentration (i.e. enrichment or scarcity in a locality could introduce errors).

I'll book mark this and see if I can find some links on the subject...

[Axenolith]

Bentonite? (weathered volcanic ash deposits)
evaporite deposits? (salts)
Placer deposits?

[dead]

Do you also feel a need to apogize for some else's misleading headline

No.

No more than I feel the need to apologize for your lack of reading comprehension.

Neither is my fault.

[js1138]

The answer is they don't. Carbon dating is only accurate for "short" periods-thousands of years.

Show me where this fossil was carbon dated. You just made that up.

[Consort]

It doesn't matter how old it is.

[_Jim]

No more than I feel the need to apologize for your lack of reading comprehension.

You mean I can't even make a tertiary remark about 'fossil fuels' in a thread addressing 'fossils?

You're making assumptions here that you would be sorely pressed to support ...

[js1138]

It's a pun. Some folks like puns, others can't stand them.

[_Jim]

Bentonite? (weathered volcanic ash deposits)

Recent work is showing that many more processes are taking place beneath the surface of the earth, processes that we are only now getting a handle on ...

[ASA Vet]

because humans were also vertebrates

SA remark #1 - "Ok, but what are they now?"

SA remark #2 - "There were no humans then."

[Axenolith]

http://id-archserve.ucsb.edu/Anth3/Courseware/Chronology/09_Potassium_Argon_Dating.html

http://www.geo.titech.ac.jp/hiratalab/ina/ms/index.html
(WAY techno-weenie)