Lungfish
Evolution

About 420 million years ago, during the Devonian, the last common ancestor of both lungfish and the tetrapods split into two separate evolutionary lineages, with the ancestor of the extant coelacanths diverging a little earlier from a sarcopterygian progenitor. Youngolepis and Diabolepis, dating to 419–417 million years ago, during Early Devonian (Lochkovian), are the currently oldest known lungfish, and show that the lungfishes had adapted to a diet including hard-shelled prey (durophagy) very early in their evolution. The earliest lungfish were marine. Almost all post- Carboniferous lungfish inhabit or inhabited freshwater environments. There were likely at least two transitions amongst lungfish from marine to freshwater habitats. The last common ancestor of all living lungfish likely lived sometime between the Late Carboniferous and the Jurassic. Lungfish remained present in the northern Laurasian landmasses into the Cretaceous period.
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