While that is close to true for coelacanths, other famous «living fossils,» which have the slowest molecular evolutionary rate among vertebrates, the Lingula genome has been evolving rapidly, despite the lack of changes in appearance. (sciencedaily.com)
While one analysis pointed to a tricellular ancestry, another analysis — which allowed evolutionary rates of the traits to vary across a phylogeny — found more uncertainty at the base, with a tricellular ancestor only slightly more likely than a bicellular ancestor. (sciencedaily.com)