Pygodus Lamont & Lindström, 1957

Zhen, Yong Yi, 2011, Middle to Late Ordovician (Darriwilian-Sandbian) Conodonts from the Dawangou Section, Kalpin Area of the Tarim Basin, Northwestern China, Records of the Australian Museum 63 (3), pp. 203-266 : 247

Pygodus Lamont & Lindström, 1957

Type species. Pygodus anserinus Lamont & Lindström, 1957 .

Remarks. Most Ordovician conodont workers accept that species of Pygodus consisted of a seximembrate or septimembrate apparatus including pygodiform Pa, pastinate Pb, ramiform S (alate Sa, tertiopedate Sb, bipennate Sc and quadriramate Sd), and possibly geniculate M elements (Zhang, 1998a; Rasmussen, 2001; Zhen et al., 2009a, table 2). The M elements of the two Pygodus species ( P. anserinus and P. serra ) occurring in the Dawangou section have not been recovered, although the Pa, Pb and S elements of both species were represented by a large collection ( Tables 1–2). Very rare reports of a geniculate M element occurring in association with other elements of Pygodus have cast doubts on the inclusion of the M element in the Pygodus species apparatus ( Dzik, 1994; Zhen et al., 2009a). Armstrong (1997, 2000) provided an alternative reconstruction for P. anserinus and P. serra , interpreting the P. anserinus species apparatus to include a pygodiform Pa with four rows of denticles and a pygodiform Pb element with three rows of denticles, the latter generally considered by other workers as representing the Pa element of P. serra (Zhang, 1998a) .