Beginning about 1900 a handful of workers began to study the North American rotifer fauna. These included S.A. Forbes, H.S. Jennings, and D.S. Kellicott. Besides his taxonomic work, Jennings was the first rotifer researcher who used life table experiments (Jennings 1928 a,b). A bit later H.K. Harring and F.J. Myers, two major American rotiferologists, began some important contributions. Harring published "Synopsis of the Rotatoria" in which he listed and cross-referenced all rotifer species known at that time (Harring 1913). Myers initiated his contributions to the field when he published a series of papers on the rotifers of Mount Desert Island (Maine) and other localities. However, the most significant contribution of these workers was their series of volumes called "Rotifers of Wisconsin" (Harring and Myers 1922, 1924, 1926, 1928, and Myers 1930), a contribution that covered may more rotifers than that of a single state.

In the 1930šs and 1940s two very important workers began to make significant contributions to the understanding of the North American fauna and the ecology of rotifers in general. And while each went on to make even more important contributions in limnology, they were first known for their work with the "Rotatoria." In 1939 Robert Pennak began his studies of the interstitial rotifers in inland lakes. Eventually he published an important textbook on the freshwater invertebrates in 1953. This book, now in its third edition, is exceeding useful to students of freshwaters (Pennak, 1989). W.T. Edmondsonšs early work was on taxonomy and the ecology of sessile rotifers. Later he made important contributions to the trophic ecology of planktonic rotifers and to population dynamics. He also edited and important reference work on freshwater biology (Edmondson, 1959) which included his own chapters on rotifers and methods and equipment. Of course, he is probably most well know for his classic work on eutrophication, especially of Lake Washington (Washington, USA).

Currently, there are numerous workers in North American, including both professional biologists and amateurs. Many of these workers are exploring ecological themes, but a growing number are interested in topics of cell and molecular biology. Unfortunately, very few of our current North American workers have received much training in rotifer taxonomy.