Urdyella unicorna, 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 : 50

Urdyella unicorna n. sp.

Fig. 26A–W , AE?

1970 Neospathodus peculiaris Sweet ?; Hasenmüller, p. 62, pl. 2, fig. 10

2005 Aduncodina unicosta Ding ; Zhao, pl. 6, nr. 9–10.

Etymology: Named after the unicorn, a mythical creature with a single horn on its forehead, for the huge cusp of theP 1 element of this species.

Holotype: specimen illustrated in Fig. 26A .

Paratypes: specimens illustrated in Fig. 26K, Q, W .

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

Type level: Luolou Formation, upper Owenites to lower Anasibirites beds, middle Smithian to early late Smithian, Olenekian, Early Triassic.

Number of specimens.> 40.

Diagnosis. P 1: Short coniform-to-segminiscaphate element with a very long, needle-like, recurved cusp, sometimes one (or two in large specimens) tiny, anterior denticle, and a broadly excavated basal cavity.

Description. P 1: Te cusp is about 3–4 times longer than the basal cavity is broad, is usually slightly recurved, sometimes only reclined, and it makes an angle of about 40°–60° with the baseline of the lower margin in lateral view. Many specimens are coniform and may bear a tiny anterior process, some (usually larger) specimens have a very short anterior process bearing up to two anterior denticles and may be better described as segminiscaphate. Te deep basal cavity is oval to drop-shaped in aboral view. In lateral view, the base of the cusp occupies the anterior half of the basal cup.

Remarks. Specimens of this species were found by Zhao et al., (2007, without illustrations; but two specimens are illustrated in Zhao’s Ph.D thesis, 2005) in coeval strata of the Chaohu section, Anhui Province but reported as Aduncodina unicosta , a possibly related form that in all our collections from China is otherwise restricted strictly to the Spathian interval.

Occurrence. India: Mud, Mikin Formation, maximal horizon 1 ( Goudemand, 2011); Western USA, Parachirognathus-Furnishius zone, Taynes Formations, Utah (Hasenmüller, 1970). South China: Chaohu section, Anhui Province ( Zhao, 2005; Zhao et al., 2007); Pingtang Syncline, uppermost Daye Formation and Luolou Formation, Smithian (this paper). Upper Smithian, Khunamuh Formation, Guryul Ravine, Northern Indian Margin (Leu et al. in prep.), Oman (Leu et al. submitted).

Figures

Fig. 26 Cornudininae 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–W Urdyella unicorna n. gen. n. sp.; A LAR225, PIMUZ 39345; B LAR225, PIMUZ 39346;C LAR229, PIMUZ 39347; D LAR227, PIMUZ 39348;E LAR229,PIMUZ 39349; F LAR229,PIMUZ 39350; G LAR225,PIMUZ 39351; H LAR229,PIMUZ 39352; I QIA123, PIMUZ 39353; J LAR227,PIMUZ 39354; K QIA123, PIMUZ 39355; L QIA123, PIMUZ 39356; M LAR227,PIMUZ 39357; N LAR225, PIMUZ 39358; O QIA120, PIMUZ 39359; P LAR225, PIMUZ 39360; Q QIA121, PIMUZ 39361; R LAR232, PIMUZ 39362; S LAR232, PIMUZ 39363; T QIA124,PIMUZ 39364; U LAR232, PIMUZ 39365; V QIA123, PIMUZ 39366; W SHA341, PIMUZ 39367.X-AA Urdyella tridenta n. gen. n. sp.; X LAR227, PIMUZ 39341; Y LAR227, PIMUZ 39342; Z LAR227, PIMUZ 39343; AA LAR227, PIMUZ 39344.AB, AC Discretella? n. sp. D; AB QIA124, PIMUZ 39118; AC QIA123, PIMUZ 39119. AD Neostrachanognathus n. sp. A; LAR232, PIMUZ 39183. AE Urdyella n. sp. A; LAR232, PIMUZ 39340