Protopanderodus Lindström, 1971

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 : 236

Protopanderodus Lindström, 1971

Type species. Acontiodus rectus Lindström, 1955a .

Remarks. McCracken (1989) and Mellgren & Eriksson (2006) presented a comprehensive study of this genus, particularly reconstruction of the species apparatuses, and the latter revision was based on a large, well-preserved, collection of several species of Protopanderodus from the Swedish Middle Ordovician. Three species, P. cooperi , P. graeai and P. calceatus , dominate many of the Dawangou samples. Our study of the Tarim material supports, in general, the apparatus reconstruction and notation system proposed by Mellgren & Eriksson (2006), namely, the antero-posteriorly compressed M elements with a non-costate anterior face and costate or carinate posterior face, the short-based and costate P elements, and generally long-based and costate S elements that form a symmetry transition series. However, as Zhen et al. (2009a) suggested, material that Mellgren & Eriksson (2006) described as Protopanderodus robustus ( Hadding, 1913) should in fact be referred to P. cooperi . Our current study also indicates that Protopanderodus parvibasis Löfgren, 1978 may be a junior synonym of P. graeai (see further discussion under remarks of the relevant species).