Jaymoytius: A vegetarian Silurian lamprey?

Abstract

Jamoytius kerwoodi was a primitive, eel-like jawless fish that lived in the Early Silurian period (444–433 myr) and lived over a stagnant bottom environment, at the transition from a marine-influenced, probably brackish-water, deep-water basin to a shallower water, less saline and probably freshwater basin. Jamoytius lacked teeth and was most likely a free-living herbivore grazing on floating plants, as were possibly many of its euphanaropid relatives. The palaeoenvironment in which it lived compares well with that of living lampreys, especially as their ectoparasitic mode of life may have evolved from ancestral grazers.