Cephalopods Present and Past Symposium

[monty]

cool and congratulations!

What's the evidence for hypoxia and hypercapnia other than the large scope? I forget how much I've mentioned Ward's recent book "Out of Thin Air" about oxygen levels driving evolution, but I really found it fascinating, so I'm curious to learn more about how it applies to cephs. Ward suggested hypothetically, for example, that the funnel and jet propulsion arose in cephs not initially as locomotion, but because there was a sudden drop in oxygen, so they needed a way to pump a whole lot more water past their gills for efficient oxygen extraction for an active lifestyle, and that that indirectly was used for locomotion and then the shell chambers developed to add neutral buoyancy. I forget if I mentioned this, but the recent nautilus embryology paper showed that the origin of the funnel was not where one might expect, like the foot of a gastropod or the arms of a ceph, but rather from the collar region. I seem to remember that it migrates around during development in ways that seem consistent with this hypothesis (although far from conclusive) too.

 

[Architeuthoceras]

Try this paper: Paleophysiology and end-Permian mass extinction Andrew H. Knoll, Richard K. Bambach, Jonathan L. Payne, Sara Pruss, Woodward W. Fischer (pdf ~1m)

Also some of these.

Basically, geochemical analysis and lack of carbonate skeletons in Early Triassic rocks.

Or the Permian cephalopods were burning to many fossil fuels.