Monophthalmus

Monophthalmus is a genus name that has appeared in zoological literature to designate certain small invertebrate organisms. The term derives from Greek roots meaning “one eye,” a reference used by early describers to describe perceived eye structures or arrangement in the organisms grouped under this name. In the 19th and early 20th centuries, various authors erected species into Monophthalmus, often within crustacean or other invertebrate groups. As taxonomic methods advanced, many of these species were moved to other genera, and the status of Monophthalmus became uncertain.

In contemporary classifications, Monophthalmus is largely treated as historical or of limited and disputed validity. Some authorities regard the name as a defunct junior synonym of other genera, while others retain it only in narrowly defined or historical contexts. Because taxonomic opinions differ, the exact placement of species formerly assigned to Monophthalmus varies among sources.

The history of Monophthalmus illustrates common issues in taxonomy, including changes in classification as new morphological and molecular data become available, and the tendency for older genus names to be relegated to synonymy or obsolescence. Today, Monophthalmus is primarily of interest to historians of science and to specialists reviewing legacy literature rather than as a live, widely recognized genus with clearly defined modern species.