Wikipedia
Endeiolepis
Endeiolepis is an extinct jawless fish that lived during the Late Devonian period, similar to that of living lampreys for its gill pouches, but Endeiolepis had an unusually large number of gill pouches. Also, Endeiolepis was described as being quite similar to Euphanerops, the main difference being a long series of elongated scales forming a ventrolateral protuberance on each side of Endeiolepis’ body. Endeiolepis had a strongly heterocercal tail.