Pygodus serra ( Hadding, 1913 )

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 : 250

publication ID	https://doi.org/ 10.3853/j.0067-1975.63.2011.1586
persistent identifier	https://treatment.plazi.org/id/03CCEB77-FFFF-635D-FFBE-FE299038FAFB
treatment provided by	Felipe
scientific name	Pygodus serra ( Hadding, 1913 )
status

Treatment

Pygodus serra ( Hadding, 1913)

Fig. 25A–R View Figure 25

Arabellites serra Hadding, 1913, p. 13 , pl. 1, figs 12, 13.

Pygodus aff. anserinus Lamont & Lindström. –Viira, 1967: fig. 4.6.

Haddingodus serra (Hadding) .–Viira, 1967: fig. 4.7.

Pygodus serrus (Hadding) .– Bergström, 1971: 149, pl. 2, figs 22, 23; Bergström et al., 1974: pl. 1, fig. 18; Nicoll, 1980: fig. 3H–L; An, 1981: pl. 4, figs 1–3; Ni, 1981: pl. 1, figs 28–29; An & Ding, 1982: pl. 5, figs 4, 13, 14, 16, 19, 22; Chen et al., 1983: pl. 1, figs 11, 12; Zeng et al., 1983: pl. 12, figs 3, 5; Chen & Zhang, 1984b: 130–131, pl. 2, figs 16–17; Wang & Luo, 1984: 279, pl. 11, fig. 18; An et al., 1985: pl. 17, figs 2–6; An, 1987: 177, pl. 24, fig. 25, pl. 26, figs 1–8, 13, 15, pl. 29, figs 2–3; Ding, 1987: pl. 5, figs 6–7; Chen & Zhang, 1989: 223, pl. 5, figs 1–2; An & Zheng, 1990: pl. 13, figs 11–14, 17–21; Zhong, 1990: 152, pl. 16, figs 10–11, 13–15, pl. 20, partim only, figs 14, 16, 18 (not fig. 17 = P. anserinus ); Gao, 1991: 136, pl. 10, fig. 5; Ding et al., in Wang, 1993: 198, pl. 30, figs 10, 13, 15–18, 20–22, 24, pl. 35, 24, 26; Wang et al., 1996: pl. 1, fig. 14; Wang & Zhou, 1998: pl. 3, figs 1–2; Lehnert et al., 1999: pl. 2, fig. 12; Zhao et al., 2000: 220–221, partim only, pl. 30, figs 7–10, 18; Wang, 2001: 357, pl. 2, figs 4, 11, 16, 19; Wang & Qi, 2001: pl. 2, fig. 24; Xiong et al., 2006: pl. 1, figs 15–16, 18.

Pygodus serra (Hadding) .– Harris et al., 1979: pl. 2, fig. 18; Zeng et al., 1983: pl. 12, figs 3, 5; Ni & Li, 1987: 435, pl. 59, fig. 25; Bergström, 1990: pl. 1, figs 23–24; Pohler & Orchard, 1990: pl. 1, fig. 18; McCracken, 1991: p. 51, pl. 2, figs 4, 6 7, 9, 11, 12, 14–18, 20–23, 28–30; Dzik, 1994: 103–105, pl. 17, figs 9–12, text-fig. 26; Wang et al., 1996: pl. 1, fig. 14; Wang & Zhou, 1998: pl. 3, figs 1–2; Zhang, 1998a: 96, pl. 2, figs 3–5, 8–14, text-figs 2C1, C3, 4B (doubtful pl. 2, figs 1, 2, 6, 7, text-fig. 2C2 = P. xinjiangensis ) (cum syn.); Lehnert et al., 1999: pl. 2, fig. 12; Ottone et al., 1999: 242, pl. 6, figs 2–3; Percival et al., 1999: fig. 8.18; Stouge & Bagnoli, 1999: 154, text-fig. 5; Pickett & Percival, 2001: fig. 4C; Wang, 2001: p. 357, pl. 2, figs 4, 11, 16, 19 (cum syn.); Wang & Qi, 2001: pl. 2, fig. 24; Norford et al., 2002: pl. 3, figs 7–10; Bergström, 2007: fig. 4; Percival & Zhen, 2007: pl. 1, figs 1–3, 19.

Pygodus protoanserinus Zhang, 1998a: 96 , text-fig. 2D, pl. 3, figs 9–18 (cum syn.); Zhang, 1998b: 86–87, pl. 16, figs 6–8 (cum syn.); Zhen et al., 2004b: 158, fig. 9B–J (cum syn.); Percival & Zhen, 2007: pl. 1, figs 17–18.

Pygodus serrus-anserinus transition.–Zhao et al., 2000: 221, partim, only pl. 30, fig. 5.

Pygodus anserinus Lamont & Lindström, 1957: 68 , partim, only fig. 1d; Armstrong, 1997: 777–778, partim only pl. 4, fig. 4.

Pygodus cf. anserinus Lamont & Lindström. –Dong & Wang, 2006: pl. 7, fig. 17.

? Pygodus serra (Hadding) .–Zhen et al., 2004b: 158, fig. K–L = Pygodus xinjiangensis .

? Pygodus xinjiangensis Wang & Qi, 2001: 144 , pl. 2, figs 18, 20.

Material. 839 specimens plus 1518 specimens of undifferentiated Pb and S elements of both P. anserinus and P. serra (see Tables 1–2).

Remarks. Zhang (1998a) proposed Pygodus protoanserinus to accommodate intermediate forms between P. serra and P. anserinus , and defined it as having three rows of denticles on the Pa element with the middle row situated more towards the outer lateral row rather than in a mid position or towards the inner row as in P. serra . However, based on examination of topotypes of P. serra, Bergström (2007) considered P. protoanserinus to be a junior synonym of P. serra , and indicated that Zhang’s definition of P. serra also include forms ascribed to Pygodus xinjiangensis by Wang and Qi (2001). The latter has a Pa element bearing a narrower platform with outer and inner margins parallelling each other distally and with the middle row of the denticles located more closely to the inner lateral margin (Wang & Qi, 2001, pl. 2, fig. 18) rather than closer to the outer margin as in P. serra .

The abundant material of Pygodus species (both P. serra and P. anserinus ) from the Dawangou section shows a distally expanding triangular outline of the platform, and the Pa element of P. serra exhibits the middle row of denticles varying from nearly centrally-positioned ( Fig. 25E View Figure 25 ) to closer to the outer lateral margin ( Fig. 25D View Figure 25 ). Zhang (1998a) also illustrated some specimens of P. serra bearing a narrow platform with parallel distal margins and a centrally positioned middle row of denticles from the Hällekis section of Sweden (Zhang, 1998a, text-fig. 2C2, pl. 2, fig. 7). Similar forms were also reported from the Guniutan Formation of South China ( An, 1987, pl. 26, figs 1, 2, 5). These intermediate forms between typical P. serra and those referred to as P. xinjiangensis by Wang and Qi (2001) made it difficult to distinguish between these species on the characters originally employed. Moreover, forms referable to P. xinjiangensis occurred in association with P. serra ( An, 1987; Zhang, 1998a, fig. 2). Therefore, we follow Bergström’s (2007) opinion that P. xinjiangensis is a possible junior synonym of P. serra pending further study. Forms typical of P. xinjiangensis have not been recognized in the Dawangou material.

Kingdom	Animalia
Phylum	Chordata
Class	Conodonta
Order	Conodontophorida
Family	Pygodontidae
Genus	Pygodus