Genus ICRIOSPATHODUS Krahl et al., 1983

Type species and holotype. Neospathodus collinsoni Solien, 1979 .

Type stratum and locality. Unit D, Taynes Formation, near Salt Lake City, Utah, USA .

Remarks. Originally, the basis for establishing this genus was the characteristic ridge-like denticulation of the P 1 element of Ic. collinsoni . Orchard (2005) reconstructed the multi-element apparatus of Ic. collinsoni, showing a smaller degree of denticulation of the P 2, M and S elements in comparison to Novispathodus . Because their S elements (especially the S 1) are significantly different from those of the subfamily Novispathodinae, he regarded their subfamily assignment as uncertain. Pending future multi-element reconstructions of the herein included taxa, we tentatively retain Icriospathodus within the Novispathodinae . Te affinity of Ic. collinsoni, Ic. crassatus and Ic. zaksi was recognized in several studies (Koike, 1992; Orchard, 2007; Maekawa & Igo in Shigeta et al., 2014; Maekawa in Maekawa et al., 2018), and we follow these authors.