Windowpane flounder is one of five types of flatfish that have been appearing on dinner tables along the North American Atlantic coast since humans moved into that territory about 12,000 years ago. The other flatfish are summer (Paralichthys dentatus), winter (Pleuronectes americanus), witch (Glyptocephalus cynoglossus), and yellowtail (Pleuronectes ferrugineus) flounders. The windowpane flounder, so named because its thin skin is almost transparent, is also called sand dab and papermouth. If a windowpane flounder is held up to the light, the bones are clearly visible. Windowpane flounder are taken commercially by otter trawl, and 75 percent of landings now come from the Gulf of Maine and Georges Bank.