Fossil evidence of transition from water to land

dogjones

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dogjones
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http://news.bbc.co.uk/2/hi/science/nature/4879672.stm
snip

The 383 million-year-old specimens are described as crocodile-like animals with fins instead of limbs that probably lived in shallow water.

snip

"We are capturing a very significant transition at a key moment of time. What is significant about the animal is that it is a fossil that blurs the distinction between two forms of life - between an animal that lives in water and an animal that lives on land."

snip

Professor Jennifer Clack, from the University of Cambridge, said that the find could prove to be as much of an "evolutionary icon" as Archaeopteryx - an animal believed to mark the transition from reptiles to birds.
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Yet more evidence for nutters to ignore! Hurrah!
 
Interesting no doubt.

I prefer http://www.msnbc.msn.com/id/12168265/from/RS.2/


Headline
Fossil shows how fish made the leap to land


fine print
It’s an important new contribution to (understanding) a very, very important transition in the history of life,” said Robert Carroll of McGill University in Montreal.
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I'd agree it's an important contribution from the fossil record, actual significance subject to debate. Feel free to have faith in the headline. ;)
 
There is homology as well between living forms of fish and crocodilians, the garfish and the gharial and the false gharial:

Gar:

http://myfwc.com/Fishing/Fishes/gar.html

Gharial ….a crocodilian:

http://www.flmnh.ufl.edu/cnhc/!ggan1.htm

and the False Gharial which can be seen here (scroll down)

http://www.flmnh.ufl.edu/cnhc/csl.html

With the exception of the gharial & false gharial and the slender-snouted crocodiles, most living crocodilians do have flattened snouts/heads. What is fascinating is that this find indicates that the slender snouted and flat snouted forms may've evolved independently rather than starting out as slender snouted and then evolving a flattened snout afterwards.
 
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Or maybe it's a croc taking a cetacean-like regession to live in the water? ;)
 
Doesn't really matter either way I guess. I’m pretty sure that adaptive changes to move from a terrestrial animal to an aquatic one still counts as evolution. But you would have to have evidence that the crocodile was there first for the idea to make any sense.
 
BronzeDog said:
Got any evidence of crocs existing before the fish?
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Next you'll want to discuss the intricacies of geologic age dating -- the age dates the fossil or the fossil dates the age, depending on what one needs. :)

Re cetacean evolution ... does someone think it's cast in stone??? :D
 
I'd only discuss all that if you performed a major abuse of it... so, yeah, I have a feeling I probably would move onto that... Oh, wait, you already did.
 
hammegk said:
Next you'll want to discuss the intricacies of geologic age dating -- the age dates the fossil or the fossil dates the age, depending on what one needs. :)
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Er, no hamme. There are many methods to dating. The only time when a fossil dates a geological strata is when the precise age of the fossil is known, which would have been found by the fossil being found in a different strata of known age. What is the problem here?

ETA: Ooh, beaten to it! That was the link I was trying to find, BronzeDog.
 
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Taffer said:
ETA: Ooh, beaten to it! That was the link I was trying to find, BronzeDog.
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And dated 1976! Wow! ;)

There are many methods to dating. The only time when a fossil dates a geological strata is when the precise age of the fossil is known, which would have been found by the fossil being found in a different strata of known age. What is the problem here?
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Nothing, once we have established one of those 'precise ages' for both the fossil and the strata. ;)

Last I looked palynology offered the best bottom-to-top sequencing method. The various radioactive stuff used to arrive at actual, point ages, has many weaknesses (or did, some time back when I had reason to stay current in such things).

Please note my tongue firmly in my cheek above, but does someone have a good, recent, precis on age dating methodology & accuracy?
 
LOL.

It was (an apparently feeble) attempt to make a joke. Sorry.

Enough of this derail by me. Please examine the fossil and discuss it in a scientifically appropriate manner as pleases you. I'm outtahere. :)
 
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