what is the fate of notochord in vertebrates
Notochord Notochords are thought to be advantageous (both in an evolutionary and developmental context) because they provide(d) rigid structure for muscle attachment, but were still flexible. In some chordates, it persists throughout life as the main structural support of the body, while in most vertebrates it becomes the nucleus pulposus of the intervertebral disc.[1] The notochord plays a key role in signaling and coordinating development. Embryos of vertebrates still form transient notochord structures today during the gastrulation phase of development. The notochord is found ventral to the neural tube.
Pangolin Pangolins were formerly[when?] classified with various other orders, for example Xenarthra, which includes the ordinary anteaters, sloths, and the similar-looking armadillos. Newer genetic evidence, however, indicates their closest living relatives are the Carnivora with which they form the clade Ferae.[47][48] Some palaeontologists, placing Ernanodonta in a separate suborder of Cimolesta near Pholidota,[49] have classified the pangolins in the order Cimolesta, together with several extinct groups indicated (â€ ) below, though this idea has fallen out of favor since cimolestids have been determined to have not been placental mammals.[50] A 2015 study has supported close affinities between pangolins and the extinct group Creodonta, as well as many former Cimolestans (Cimolestes itself was recovered as a far more basal mammal).[51]