During course of evolution, which of the following has evolved earliest? (a) Ichthyosaurus (b) Seaweeds (c) Jawless fishes (d) Dryopithecus
Option C. jawless fishes has evolved earliest.The oldest jawless fish with bone is known from 470 million years ago (Arandaspis). It is similar to the oldest complete fossil of Sacabamaspis from the Late Ordovician. The earliest Ordovician fish seem to be relatives (and perhaps ancestral to) the later group of heterostracans.
