Dianthidium platyurum Cockerell, 1923:90, ♂♀. Holotype ♂, San Francisquito Bay, Lower California, May 10, 1921 (Mus. Calif. Acad. Sci., No. 950, leg. F.P. Van Duzee). - Brindis, 2019Brindis, A.F. 2019. . Dissertation , , 1-143. La Paz, Baja California Sur. (distribution); Nava-Bolaños & Osorio-Olvera, 2022Nava-Bolaños, A. & L. Osorio-Olvera 2022. Estado del arte del conocimiento de biodiversidad de los polinizadores de México. Revista Mexicana de Biodiversidad 93:1-77. (distribution). - As Dianthidium platyurum platyurum: - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209. (distribution).
Dianthidium parvum baculifrons Cockerell, 1925:365, ♀. Holotype ♀, Soboba Springs, Riverside Co., California, June 5, 1917 (Mus. Calif. Acad. Sci., No. 1746, leg. E.P. Van Duzee). - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209.:1995 ( listed as synonym of Dianthidium platyurum platyurum Cockerell, 1923).
Dianthidium ulkei riparii Schwarz, 1928:400 - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209.:1995 ( listed as synonym of Dianthidium platyurum platyurum Cockerell, 1923).