CO2 is contradicted as a significant driver for warming in many periods. One of the best examples is the devonian-carboniferus: The terrestial flora evolved, Co2 dramaticly dropped yet temperature is not affected by this for 50 mio years. The ordovician is even more extreme, 6000 ppm can not stop the glaciation in any way. The faint sun paradox could not compensate this.
Dr. Siversson leaves dangling the question of 'what is an ichthyosaur?' That was answered here: pterosaurheresies.wordpress.com/2011/08/27/the-origin-and-evolution-of-ichthyosaurs/ and is fine-tuned here with the addition of many more taxa: www.reptileevolution.com/reptile-tree.htm
Dr. Siversson appears to have no idea where ichthyosaurs came from. Answer: Wumengosaurus, a type of pachypleurosaur. He also suggests that no other reptile evolved a fish-like appearance. That ignores odontocetes, mysticetes, manatees, penguins, Cartorhynchus and mosasaurs, more or less. The first three did so after going through an arboreal tree shrew phase, which is quite an accomplishment.
Great presentation - I especially enjoyed the last segment that had to do with our current approach to climate change, this is news-worthy stuff.
CO2 is contradicted as a significant driver for warming in many periods. One of the best examples is the devonian-carboniferus: The terrestial flora evolved, Co2 dramaticly dropped yet temperature is not affected by this for 50 mio years. The ordovician is even more extreme, 6000 ppm can not stop the glaciation in any way. The faint sun paradox could not compensate this.
Hopefully we have stopped that ice age cycle now with our release of CO2 but hopefully we don't overdo it.
Dr. Siversson leaves dangling the question of 'what is an ichthyosaur?' That was answered here: pterosaurheresies.wordpress.com/2011/08/27/the-origin-and-evolution-of-ichthyosaurs/ and is fine-tuned here with the addition of many more taxa: www.reptileevolution.com/reptile-tree.htm
Dr. Siversson appears to have no idea where ichthyosaurs came from. Answer: Wumengosaurus, a type of pachypleurosaur. He also suggests that no other reptile evolved a fish-like appearance. That ignores odontocetes, mysticetes, manatees, penguins, Cartorhynchus and mosasaurs, more or less. The first three did so after going through an arboreal tree shrew phase, which is quite an accomplishment.
That's playing it a bit fast and loose with "reptile and fish-like, isn't it?
Wumengosaurus lived after early ichthyosauroformes like the Omphalmosaurs.
@@themousegaming2191 That's OK. Fossil strata are pinpricks on the Earth. Very rare. Amphioxus = Branchiostoma is still out there.