Published November 22, 2022 | Version v1
Taxonomic treatment Open

Spathicuspus Orchard 2005

  • 1. Paleontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland

Description

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).

Notes

Published as part of 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, pp. 1-61 in Swiss Journal of Palaeontology (19) (19) 141 (1) on page 49, DOI: 10.1186/s13358-022-00259-x, http://zenodo.org/record/12000082

Files

Files (789 Bytes)

Name Size Download all
md5:3035667efb9f68ab7b43bddc330f4ccc
789 Bytes Download

System files (31.3 kB)

Name Size Download all
md5:e40979185b8b240a6851feb024785897
31.3 kB Download

Linked records

Additional details

Biodiversity

References

  • Orchard, M. J. (2005). Multielement conodont apparatuses of Triassic Gondolelloidea. Special Papers in Palaeontology, 73 (73), 73 - 101.
  • Sweet, W. C. (1970). Uppermost Permian and Lower Triassic conodonts of
  • Chen, Y., Jiang, H., Lai, X., Yan, C., Richoz, S., Liu, X., & Wang, L. (2015). Early Triassic conodonts of Jiarong, Nanpanjiang Basin, southern Guizhou Province, South China. Journal of Asian Earth Sciences, 105, 104 - 121. https: // doi. org / 10.1016 / j. jseaes. 2015.03. 014
  • Liang, L., Tong, J., Song, H., Song, T., Tian, L., Song, H., & Qiu, H. (2016). Lower- Middle Triassic conodont biostratigraphy of the Mingtang section, Nanpanjiang Basin, South China. Palaeogeography, Palaeoclimatology, Palaeoecology, 459, 381 - 393. https: // doi. org / 10.1016 / j. palaeo. 2016.07. 027
  • Lehrmann, D. J., Stepchinski, L., Altiner, D., Orchard, M. J., Montgomery, P., Enos, P., Ellwood, B. B., Bowring, S. A., Ramezani, J., Wang, H., Wei, J., Yu, M., Griffiths, J. D., Minzoni, M., Schaal, E. K., Li, X., Meyer, K. M., & Payne, J. (2015). An integrated biostratigraphy (conodonts and foraminifers) and chronostratigraphy (paleomagnetic reversals, magnetic susceptibility, elemental chemistry, carbon isotopes and geochronology) for the Permian-Upper Triassic strata of Guandao section, Nanpanjiang Basin, south China. Journal of Asian Earth Sciences, 108, 117 - 135. https: // doi. org / 10.1016 / j. jseaes. 2015.04. 030
  • Chen, Y., Richoz, S., Krystyn, L., & Zhang, Z. (2019). Quantitative stratigraphic correlation of Tethyan conodonts across the Smithian-Spathian (Early Triassic) extinction event. Earth-Science Reviews. https: // doi. org / 10. 1016 / j. earscirev. 2019.03. 004