Spathicuspus, Orchard 2005

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 : 49

Genus SPATHICUSPUS Orchard 2005

Type species. Neospathodus spathi Sweet, 1970, pp. 257– 258 , pl. 1, fig. 5.

Type stratum and locality. Mittiwali Member , Mianwali Formation, Narmia, Pakistan .

Remarks. Based on his reconstruction of the multi-element apparatus of ‘Neospathodus’ spathi Orchard (2005) considered these taxa deserved assignment not only to a new genus, but also to a new subfamily.

Spathicuspus n. sp. A

Fig. 13M, P

2005 Neospathodus spathi Sweet ; Gaetani et al., p. 288, pl. 1, fig. 2

2015 Spathicuspus spathi (Sweet) ; Chen et al., p. 112, fig. 8.16–8.17.

2015 Spathicuspus spathi (Sweet) ; Lehrmann et al., p. 123, fig. 5.28.

2016 Spathicuspus spathi (Sweet) ; Liang et al., p. 385, fig. 4.10.

Number of specimens:>10

Description. Short segminate P1 element with large, terminal, reclined or recurved cusp. Only two anterior denticles. Basal cavity is drop-shaped.

Remarks. Very similar to Spathicuspus ? n. sp. B (see below), but much shorter and with a larger basal cavity. Similar elements have been illustrated from other Chinese sections by Chen et al. (2015) and Liang et al. (2016) and hence this species may be useful as an index fossil for intrabasinal correlations.

Occurrence. South China: Luolou Formation, Spathian, Nanpanjiang basin, Mingtang section, ( Liang et al., 2016) Upper Guandao section, ( Lehrmann et al., 2015), Triassospathodus homeri zone, Jiarong ( Chen et al., 2015).

Spathicuspus ? n. sp. B

Fig. 13J–L, O (N, R juvenile forms?)

2005 Spathicuspus sp. A ; Orchard, p.77, fig. 2, Nr. A.

2016 Spathicuspus spathi (Sweet) ; Liang et al., p. 385, fig. 4.9.

2019 Spathicuspus spathi (Sweet) ; Chen et al., fig. 7, nr. 6–8.

2021 Spathicuspus spathi (Sweet) ; Chen et al., fig. 7.8 (only).

Number of specimens:>30

Description. Slender segminate P 1 element with a terminal, reclined or recurved cusp that is usually broader than adjacent denticles, a shallow, posteriorly rounded basal cavity and three to seven anterior denticles.

Remarks. Despite their overall resemblance with Spathicuspus spathi these elements are either too long and bear too many denticles or their cusp is not broad and blunt enough to be assigned to that species. Some of them may not belong to Spathicuspus at all. Similar and apparently coeval elements were illustrated by Liang et al. (2016) and Chen et al. (2019) from other sections in China and Oman. Te element illustrated by Orchard (2005) has similar aspect ratio and denticulation as for instance the specimen we illustrated in Fig. 13O , but it is also much younger and may be only superficially similar.

Occurrence. South China: Luolou Formation, Spathian, Mingtang section, Nanpanjiang basin ( Liang et al., 2016), Upper Guandao section ( Orchard, 2005). Oman: Wadi Bani Khalid section, Spathian UAZ 7 ( Chen et al., 2019).

F13

Spathicuspus ? n. sp. C

Fig. 13Q

2016 Spathicuspus spathi (Sweet) ; Liang et al., p. 385, fig. 4.11.

2021 Spathicuspus spathi (Sweet) ; Chen et al., fig. 7.5 (only).

Number of specimens:>5

Description. Small P1 element with a rounded basal cavity, a large, reclined and broad cusp, a small posterior denticle and a couple of declining denticles to the anterior.

Remarks. Although the relationship of this species to Spathicuspus spathi and Spathicuspus n. sp. A is unclear, its shape is intermediate. It differs in the presence of a posterior denticle.

Occurrence. South China: Luolou Formation, Spathian, Mingtang section, Nanpanjiang basin ( Liang et al., 2016).

Figures

Fig. 13 Gladigondolellinae, Neogondolellinae and Cornudininae from Qiakong, Laren, Shanggang and Lilong. Magnification is ×80.The scale bar is 400 μm. All elements are considered to be P1 elements if not specifically identified otherwise.A Borinella buurensis (Dagis), LAR212, PIMUZ 39103. B, C, G Gladigondolella laii (morphotype A); B LAR231C, PIMUZ 39132; C BAN2, PIMUZ 39133;G LAR227C, PIMUZ 39134. D, sp.indet.(P2 element?), SHA319, PIMUZ 39293.E, F, H, I Gladigondolella laii (morphotype B); E LIL510,PIMUZ 39135; F LIL512, PIMUZ 39136; H QIA140, PIMUZ 39137;I LIL510,PIMUZ 39138. J–L, O, Spathicuspus spathi (Sweet); J QIA141, PIMUZ 39300; K QIA144, PIMUZ 39301; L BAN1, PIMUZ 39302; O SHA322,PIMUZ 39303. M, P Spathicuspus n. sp. A; M QIA144, PIMUZ 39297; P, QIA143, PIMUZ 39298. N, R Spathicuspus spathi (juvenile) (Sweet); N, LIL515D, PIMUZ 39304; R QIA143,PIMUZ 39305. Q Spathicuspus n. sp.B; LAR226C, PIMUZ 39299