The SealGrebe is a family of grebes, including one of the largest grebe on earth, ranging in size from grebe-size to walrus-sized ones. Almost all species of sealgrebes are flightless. There are about 4,348 species of SealGrebes. Many species live in marshes, swamps, and shorelines, with some that can adapt to cities, towns, urban areas, and suburbs. Some species of sealgrebes can tolerate very well with human activities. They are found in almost all parts of North America. They resemble a cross between a grebe and a long-extinct hesperornid-grouped birds of the mesozoic, but with no teeth.