Ichthyostea
It is a genus of early quartz animals that lived in the latter part of Devon. It belongs to one of the first four-footed animals to appear in the fossil record. Ictioste had lungs and limbs, which would have helped to move through the shallow waters of the swamps. Undoubtedly, it has amphibian body and habit, but it does not belong to amphibians in the narrow sense. Amphibians in the first narrow sense appeared in the coal mine. Unlike other early quadrupeds and related fish, which were discovered in the late 20th century, icthiostega, with fish-like tails, gills, and amphibians such as skulls and limbs, was regarded as the only intermediate fossil between fish and tetrapods.