Question Description
develop a detailed, illustrated or illuminated overview of what paleontologists have discovered regarding the origin and evolutionary history of the mammalian order Cetacea(whales and dolphins).
-provide a phylogeny that includes an early stem artiodactyl like Diacodexis, Indohyus, Pakicetus, Ambulocetus, Rhodocetus, Durodon, as well as the modern Odontocetes(toothed whales(orcas, dolphins, etc.) and Mysticetes(baleen whales like humpback and blue whales).
-Diagram and discuss the evidence that the double pulley astragalus found in all artiodactyls, Indohyus, and Pakicetus indicates that whales are descended from ancient artiodactyls(even toed ungulates) and therefore belong to the artiodactyl clade of mammals.
-explain the significance of the thick, dense involucrum found in Pakicetus(a synapomorphy found in all whales).
-Discuss the migration of the nasal openings from the end of the snout in most mammals to the position of the blowwhole(top of forehead) in modern whales
-Discuss the fossil evidence for the progressive reduction and eventual loss of hind legs by ancestral whales,
-Finally, discuss the isotopic evidence for the timing of the adaptive shift by ancestral whales from fresh water to marine habitats.
develop a detailed, illustrated or illuminated overview of what paleontologists have discovered regarding the origin and evolutionary history of the mammalian order Cetacea(whales and dolphins).-provide a phylogeny that includes an early stem artiodactyl like Diacodexis, Indohyus, Pakicetus, Ambulocetus, Rhodocetus, Durodon, as well as the modern Odontocetes(toothed whales(orcas, dolphins, etc.) and Mysticetes(baleen whales like humpback and blue whales).-Diagram and discuss the evidence that the double pulley astragalus found in all artiodactyls, Indohyus, and Pakicetus indicates that whales are descended from ancient artiodactyls(even toed ungulates) and therefore belong to the artiodactyl clade of mammals. -explain the significance of the thick, dense involucrum found in Pakicetus(a synapomorphy found in all whales).-Discuss the migration of the nasal openings from the end of the snout in most mammals to the position of the blowwhole(top of forehead) in modern whales-Discuss the fossil evidence for the progressive reduction and eventual loss of hind legs by ancestral whales, -Finally, discuss the isotopic evidence for the timing of the adaptive shift by ancestral whales from fresh water to marine habitats.
