Novispathodus brevissimus ( Orchard, 1995 )

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 : 32-36

Novispathodus brevissimus ( Orchard, 1995)

Figs. 19A, B, D, F ; 21A–J, L, M ; 22B, C, E, F ?

(See figure on next page.)

1981 Neospathodus triangularis Bender ; Koike, pl. 1, fig. 6.

*1995 Neospathodus brevissimus n. sp., Orchard, pp. 117, pl. 3, figs. 14–15, 20–22.

2011 Neospathodus brevissimus Orchard ; Ji et al., p. 219, fig. 3, nr. 7.

2014 Novispathodus triangularis (Bender) ; Maekawa and Igo in Shigeta et al., p. 241–243, figs. 172.1–9, 172.13–27, 173.1–3, 173.6–12, 173.16–21, 173.28–44, 174.1–174.24. 2015 Triassospathodus brevissimus (Orchard) ; Yan et al., p. 240, fig. 3.4.

2016 Novispathodus triangularis (Bender) ; Komatsu et al., p. 69, fig. 5.8.

2018 Novispathodus brevissimus (Orchard) ; Maekawa in Maekawa et al., p. 34, figs. 19.4, 19.5, 19.7.

2019 Neospathodus curtatus Orchard ; Chen et al., fig. 6 nr. 13, 14.

2019 Neospathodus brevissimus Orchard ; Chen et al., fig. 6 nr. 15.

2019a Triassospathodus brevissimimus [sic.] (Orchard); Wu et al., fig. 4, nr. 36.

2019 Novispathodus brevissimus (Orchard) ; Liu et al., p. 14, pl. 4, figs. 15, 18

Number of specimens.> 50.

Original diagnosis. “Species characterized by small, short, and high segminate elements with a length:height ratio of 1:1, about 8–12 largely fused, generally upright denticles atop a deep blade, and a large basal cavity with a subcircular basal outline that occupies most of the lower side” ( Orchard, 1995).

Remarks. Characteristic of this species is the posterior lateral margin which is slightly to strongly curved. Subcircular to subtriangular outline of the large basal cavity in the lower view. Te denticles are fused and compressed with an erect to radial outline (bouquet-like). Te carina is relatively high. In lateral view, the upper edge is usually straight to slightly arched. Cusp is usually undistinguishable from other denticles.

Te here illustrated adult specimens are a bit larger with more denticles than the holotype ( Orchard, 1995; pp. 117, Pl. 3, fig. 22), but the denticulation and the convex posterior edge of the process is very distinct in this species. Terefore, the holotype ( Orchard 1995) might represent a younger, juvenile morphotype of this taxon. Novispathodus eotriangularis (Zhao & Orchard in Zhao et al., 2007) has a more triangle-shaped basal cavity and the anterior half of the carina is gradually declining in height, whereas Novispathodus brevissimus shows a more abrupt decline at the posterior end. Compared to Novispathodus clinatus ( Orchard 1995) , this species shows more numerous, short and upright denticles. Novispathodus brevissimus shares most similarities with Novispathodus curtatus ( Orchard, 1995) , but the latter has a relatively smaller basal cavity, is longer and bears larger and more reclined denticles. Some specimens (e.g. Fig. 19F ) bear the postero-lateral pinching that is usually considered diagnostic of Nv. triangularis (Bender) , as revised by Orchard (1995). Chen et al. (2015) illustrated very similar specimens from a higher horizon (their figs. 7.9, 7.10). Contrary to ‘true’ Nv. triangularis , our specimens have more rounded denticles tips and the pinching is less conspicuous, suggesting they can still be retained within Nv. brevissimus sensu lato.

Occurrence. Oman, Jabal Safra, lower Spathian ( Orchard, 1995); Japan, Taho Limestone, occurs with Nv. pingdingshanensis, Tahogawa Member ( Koike, 1981; Maekawa et al., 2018); Nanpanjiang basin, South China and North Vietnam, together with Tirolites sp. nov. and Icriospathodus collinsoni ( Komatsu et al., 2016; Liu et al., 2019; Shigeta et al., 2014; Yan et al., 2015).

Figures

Fig. 19 Novispathodinae from Qiakong,Laren 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 Novispathodus cf.brevissimus (Orchard); LIL515C,PIMUZ 39199. B, F Novispathodus brevissimus (Orchard); B LIL515B, PIMUZ 39200; F BAN1, PIMUZ 39201. C Triassospathodus homeri (Bender); LIL515D,PIMUZ 39317. D, H Novispathodus?brevissimus (Orchard); D LIL515D,PIMUZ 39202; H LIL514A, PIMUZ 39203. E Triassospathodus cf.homeri (Bender); LIL515C, PIMUZ 39318. G, K, O–Q Novispathodus n. sp. A; G LIL504,PIMUZ 39251; K LIL504,PIMUZ 39252; O LIL505, PIMUZ 39253; P LIL505, PIMUZ 39254;Q LIL505,PIMUZ 39255. I, L, M, Triassospathodus symmetricus (Orchard); I QIA141, PIMUZ 39336; L LIL512, PIMUZ 39337; M LIL514A, PIMUZ 39338. J Novispathodus ex gr.pingdingshanensis (Zhao & Orchard); QIA138, PIMUZ 39237. N Triassospathodus cf. symmetricus; LIL514B, PIMUZ 39339.R Novispathodus praebrevissimus n.sp; LIL505, PIMUZ 39289

Fig. 21 Novispathodinae 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–J, L, M, Novispathodus brevissimus (Orchard); A LIL515A, PIMUZ 39184; B LIL513A,PIMUZ 39185; C BAN2,PIMUZ 39186; D SHA312, PIMUZ 39187; E SHA313, PIMUZ 39188; F LIL515A, PIMUZ 39189; G LIL509, PIMUZ 39190;H LIL509, PIMUZ 39191; I LIL514B, PIMUZ 39192;J LIL509, PIMUZ 39193;L QIA141, PIMUZ 39195; M QIA144, PIMUZ 39197.K, Novispathodus clinatus (Orchard and Sweet in Orchard); BAN5, PIMUZ 39207

Fig. 22 Novispathodinae from Laren 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, D Icriospathodus cf. crassatus? (Orchard); A BAN1, PIMUZ 39168; D LIL513A,PIMUZ 39169.B, E Novispathodus brevissimus (Orchard); B LIL513B,PIMUZ 39194; E LIL514A,PIMUZ SQL55056. C, F Novispathodus cf, brevissimus (Orchard); C LIL513A, PIMUZ 39196; F, LIL514A, PIMUZ 39198

Fig. 20 (See legend on previous page.)