Spathicuspus, Orchard 2005
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publication ID |
https://doi.org/ 10.1186/s13358-022-00259-x |
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DOI |
https://doi.org/10.5281/zenodo.13127771 |
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persistent identifier |
https://treatment.plazi.org/id/038B1D1D-6459-FF81-FF1B-EFDBD5A6F887 |
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treatment provided by |
Felipe |
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scientific name |
Spathicuspus |
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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 View Fig
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 View Fig (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 View Fig , 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 View Fig
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).
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