>> >578-552 mya no gills, lungs present, legs present
>> >378 mya gills present, lungs present, lobe fins
>> >368 mya no gills, lungs present, 7 digit hind legs
>> >362 mya gills present, lungs present, 8 digit hind legs
>> >
>> >giving rise to amphibious Tetrapods... gills present, lungs present, 5
>> >digits or less today
>
> Glenn,
> I had assumed your 558-552 mya date was a typo. I thought you meant
> 358-352mya. Do you realize this is base Cambrian! I mean why did these
> things 'turn' intoamphibians? There wasnt anything much to live on on
> land? Anyway a 200myr gap
>between forms isnt really a transition at all! The amphibian form had been
> known200 myr BEFORE the transition!!!
AAAAAGH!!! Geofrey is absolutely correct. I did mean 358-352. I need to
learn to read what I write. Even the second time, it didn't register. To
will clear up the confusion here is a corrected list.
And I apologize to Paul for this confusion. This is my fault and my
stupidity.
Here is the correction
378 MYR ago- Pandericthys--These are lobe-finned fish. Their brain case is so
much like that of the earliest tetrapod, they were originally classified as
tetrapods until a complete skeleton was found. Then is was proven that they
were really still fish. (Ahlbert and Milner, 1994, p. 508). This fish also
had lungs and nostrils (Schultz and Trueb, 1991, p.87) These things really
looked like tetrapods until you see the fins. The teeth had infolding enamel
which is identical to that of the earliest tetrapods. Unlike all fish but like
the tetrapods, the Panderichthys have lost the dorsal and anal fins, leaving 4
fins in the place where legs would be in the Tetrapods.(Ahlberg and Milner, p.
508. This contradicts Gish's claim that there is no fossil which shows loss of
fins. (Gish, 1978, p. 78-79)
368 MYR-Ichthyostega-- much like Acanthostega but has 7 digits on his
hindlimb. He has lungs. His legs were only good for being in water. They could
not support his weight. (Coates and Clack, 1990, p. 67)
362 MYR- Acanthostega- has four legs, lungs but still has gills. (Coates and
Clack , 1991, p. 234) He has 8 digits on his front leg. His legs could not
support his weight either. (Coats and Clack, 1990, p. 66-67). He has fishlike
lower arm bones (Coates and Clack 1990, p. 67)
358-352 MYR A fossil found in Pennsylvania which is the second oldest
amphibian, has only lungs and no gills and is fully capable of walking on
land. (Washington Post, 117:(239): A2, Mnday Aug. 1, 1994)
Thank you Geoffrey
glenn
Foundation,Fall and Flood
http://members.gnn.com/GRMorton/dmd.htm