We propose Takahashiceras as a replacement name for the pre-occupied Upper Cretaceous ammonite genus Takahashia Matsumoto 1984.
The Cretaceous ammonite genus Takahashia Matsumoto (1984, p. 33) with its originally designated type species T. eureka was erected as a tetragonitid, but was recently transferred by Shigeta, Hoffmann, and Izukura (2010) to the Lytoceratidae. Takahashia Matsumoto, 1984, is preoccupied by Takahashia Cockerell (1896, p. 385) an insect (Homoptera, Coccidae). To remove this primary homonym Cooper (2012, p. 185) proposed Takahashiella as a replacement name, with Takahashiella eureka (Matsumoto, 1984) as its type species (described and figured by Wright, 1996, p. 8). However, Takahashiella itself is preoccupied by Takahashiella Borkhsenius, 1964, p. 164, which again is an insect. To remove this second junior homonym we propose Takahashiceras as a replacement name with T. eureka (Matsumoto, 1984) as type species.
