Discretella pseudodieneri, Leu & Bucher & Vennemann & Bagherpour & Ji & Brosse & Goudemand, 2022

Leu, Marc, Bucher, Hugo, Vennemann, Torsten, Bagherpour, Borhan, Ji, Cheng, Brosse, Morgane & Goudemand, Nicolas, 2022, A Unitary Association-based conodont biozonation of the Smithian-Spathian boundary (Early Triassic) and associated biotic crisis from South China, Swiss Journal of Palaeontology (19) 141 (1), pp. 1-61 : 45-46

Discretella pseudodieneri n. sp.

Figs. 15F, H, K, M, P ; 16G–I, K, L, N, O

2013 Neospathodus dieneri Sweet ; Yan et al., p. 516, fig. 6S (only).

2014 Neospathodus dieneri Sweet ; Maekawa & Igo in Shigeta et al., p. 224, fig. 162, nr. 40–42, 46–54 (only).

2014 Discretella sp. indet. A; Maekawa & Igo in Shigeta et al., p. 202–207, fig. 151.13–151.15 (only).

2015 Discretella sp. ; Chen et al., p. 112, fig. 8.12.

2018 Neospathodus dieneri Sweet ; Maekawa in Maekawa et al., p. 26, fig. 15.32–15.34 (only).

2021 Neospathodus cf. dieneri discreta ; Sun et al., fig. 5.10.

2021 Discretella sp. A ; Sun et al., fig. 6.15.

Etymology: Named after its superficial resemblance to Ns. dieneri .

Holotype: specimen illustrated in Fig. 16O .

Paratype: specimen illustrated in Fig. 16H .

Type locality: Shanggang road cut, Luolou formation, Guangxi Province, China.

Type level: Luolou Formation, within the early-to-middle Smithian limestones ( Owenites beds).

Number of specimens:>30

Diagnosis. Segminate P 1 element, laterally flattened. Few, discrete, large denticles. Terminal cusp. Flat to slightly posteriorly upturned basal margin. Asymmetrical basal cavity.

Description. Tese P 1 elements have markedly discrete denticles and a relatively large cusp, sometimes slightly larger than the other denticles that is situated terminally. In early ontogenetic stages (for adult forms, see Leu et al., submitted), the elements bear 3 erect to slightly and gradually reclined denticles. Te basal margin is straight to slightly upturned posteriorly. In aboral view, the basal cavity is sub-rounded to lanceolate and asymmetrical.

Remarks. Te P 1 element of this species shows some superficial similarities with that of Neospathodus dieneri , but differs in being laterally flattened and having much less denticles (usually 3, vs. 5 to 10 in Ns. dieneri ). Moreover, N. dieneri ranges up to the early Smithian only, whereas D. pseudodieneri occurs in the middle Smithian Owenites beds. Included here are also specimens where the cusp is less discrete, more robust and broader at the base ( Figs. 15M , 16L ).

Occurrence. Tahogawa Member, Olenekian Nv. ex gr. waageni Zone , Japan ( Maekawa et al., 2018). Jiarong, Discretella discreta Zone, Smithian age Nanpanjiang basin, southern Guizhou, South China ( Chen et al., 2015).

Figures

Fig. 15 Neogondolellinae and Mullerinae from Qiakong, Laren and Shanggang. Magnification is ×80.The scale bar is 400 μm. All elements are considered to be P1 elements if not specifically identified otherwise. A, D Neospathodus bevelledi n. sp.; A SHA333,PIMUZ 39176; D, SHA332, PIMUZ 39177. B, J Discretella aff. discreta (MÜller); B SHA304, PIMUZ 39104; J SHA334,PIMUZ 39105. C, L Discretella discreta (MÜller); C SHA334, PIMUZ 39107; L SHA332, PIMUZ 39108. E Guangxidella bransoni (MÜller); SHA304, PIMUZ 39139.F, H, K, M, P Discretella pseudodieneri n. sp.; F QIA124, PIMUZ 39120; H QIA124,PIMUZ SQL54990; K QIA121, PIMUZ 39121; M QIA120, PIMUZ 39122; P LAR232, PIMUZ 39123. G Discretella cf. discreta (MÜller); QIA120, PIMUZ 39109.I sp. indet.; QIA120, PIMUZ 39294. N Discretella? n. sp. B; LAR232, PIMUZ 39112.O Discretella? n. sp. C; SHA342,PIMUZ 39114

Fig. 16 Neogondolellinae, Novispathodinae and Mullerinae from Shanggang and Youping cascade. Magnification is ×80.The scale bar is 400 μm. All elements are considered to be P1 elements if not specifically identified otherwise. A, F, M Discretella? n. sp. C; A YC16,PIMUZ 39115; F YC16, PIMUZ 39116; M SHA342C, PIMUZ 39117. B Discretella? n. sp. B;YC16, PIMUZ 39113. C Discretella aff.discreta (MÜller);YC22,PIMUZ 39106. D, S Discretella discreta (MÜller); D YC16, PIMUZ 39110; S SHA304C, PIMUZ 39111. E Novispathodus ex gr. abruptus (Orchard);YC41, PIMUZ 39225. G–I, K, L, N, O Discretella pseudodieneri n. sp.; G YC16, PIMUZ 39124; H YC25, PIMUZ 39125; I SHA304C,PIMUZ 39126; K YC22, PIMUZ 39127,L YC25, PIMUZ 39128; N SHA304C,PIMUZ 39129; O SHA343C,PIMUZ SQL54979. J Guangxidella bransoni (MÜller);YC16, PIMUZ 39140. P–R Neospathodus bevelledi n. sp.; P SHA 304C,PIMUZ 39178; Q SHA333C, PIMUZ 39179; R YC12, PIMUZ 39180