Apsidognathus, Walliser, 1964

Waid, Christopher B. T. & Cramer, Bradley D., 2017, Telychian (Llandovery, Silurian) conodonts from the LaPorte City Formation of eastern Iowa, USA (East-Central Iowa Basin) and their implications for global Telychian conodont biostratigraphic correlation, Palaeontologia Electronica 42 (6), pp. 1-37 : 9

Genus APSIDOGNATHUS Walliser, 1964

Type species. Apsidognathus tuberculatus Walliser, 1964 .

Diagnosis. Apparatus consists of platform, lenticular, ambalodontan, astrognathodontan, lyriform, compressed, and conical elements. Platform elements are broad, variably ornamented, with several nodose ridges radiating from the center of the element. See Armstrong (1990) and Wang and Aldridge (2010) for thorough diagnosis.

Remarks. The position of the elements within Apsidognathus are unclear. It is likely that the platform element occupied the Pa position and the lenticular and ambalodontan elements occupied Pb/ Pc positions. Wang and Aldridge (2010) suggested that the ornamented elements (platform, lenticular, ambalodontan, lyriform, compressed) may occupy the P and M positions in the apparatus with the S positions filled by conical and astrognathodontan elements.