carboniferous fossil gap

[DariusAmurdarja]

We have fossils of tetrapods from the late devonian and from the middle carboniferous. But there are almost no fossils from the early carboniferous. It´s a big mystery. Whats your opinion about that? The variscan orogeny was at her peak during that time. We know that there were excellent fossilization conditions in the mid carboniferous though. We also have alot of fossils from the early carboniferous, such as insects, lycopodiaceae and several other clades.

Anther striking event during the late devonian was the formation of large forests. Those forests were completly new for earth. Before that, plants had only small roots. Those trees (Archaeopteris) had massive roots and opened the upper surface. They created the first real soil. Erosion could swep much more nurtitions into the rivers and the sea. I believe that played a big role in the mass extinction at the end of the devonian and also in the following romer´s gap during the early carboniferous.

 

[Cohazard]

....and you decided to post this in a forum designated for the discussion of polypterus?

 

[bigchief]

ohhhh darius is messing up all over the place.

 

[DariusAmurdarja]

Cladistia can be traced back to that specific time. It is a very important time frame for the development of polypteridae.

 

[Cohazard]

Cladistia can be traced back to that specific time. It is a very important time frame for the development of polypteridae.

But your post clearly isn't focused on the development of polypteridae, which makes the thread off-topic for this forum.

 

[wantokeeptrout]

from my understanding the devonian ended with a mass extinction related to global warming. If it was global warming then the drying water bodies would have resulted in less habitat for early tetrapods. these dried water bodies would have a large number of amphibian and fish fossils originally aka late devonian but once the water level became too low during the early carboniferous in warm seasons the conditions may have been good for air breathing arthropods and hibernating lungfish and amphibians but not year round active water dwellers. Given the suddenness of the environmental crisis few of the primitive tetrapods would have adapted to seasonal dryness that may have occured. the fastest solution would have been for tetrapods and fish to change habitat. the habitat they would have moved to likely would have been larger lakes. considering trees would have only been around for since the late devonian there may be lots of sediments in swampy habitats but larger lakes would not be inundated with the sediment that good fossilization conditions require.

P.S next time put this in the general discussion area

 

[DariusAmurdarja]

The thing is, we have alot of plant fossils from that time. It is obvious, that there was a lack of oxygen. The fossils we have indicate, that the oceans collapsed. A massive algae bloom could be the reason for that lack of oxygen. I already mentioned the impact off the first forests and the resulting nutrition overflow.

 

[wantokeeptrout]

there is evidence for an increase in temperature. The temperature increase doesn't mean desert conditions, the humidity could have remained high and created humid rainforests that had a wet season much like the modern amazon. but given how primitive tetrapods were at the time combined with originally low oxygen levels the lack of year round standing liquid water in a warming world would have driven primitive amphibians to lakes. however the seasonally flooded areas would have been perfect for preserving life in that area such as plants and arthropods.

 

[Theseabean]

This is interesting, but one question. How does this discussion of the fossilization gap relate to the discussion of polypterids. I realize that this was a crucial point for their development, but how does this topic in any way answer questions about the keeping of Polypterus in aquaria or their wild counterparts. I realize this is about the evolution of Polypterids, but what does this help. They're here now.

 

[DariusAmurdarja]

One of the few Tetrapods that we know from that time supports your ideas. Do you know Crassigyrinus? It has a streamlined body and very weak limbs. I think it was unable to even move on land. It was completly aquatic. That means it was bound on large rivers and lakes which did not dry out.