Denticupachydomella bellcanyonensis Tarnac & Forel & Nestell & Nestell & Crasquin 2021, sp. nov.

Denticupachydomella bellcanyonensis Forel sp. nov.

urn:lsid:zoobank.org:act: 89B99A6B-AD6C-43DD-BAAD-D85F291FCBD3

Fig 5H, 11P–Q

Diagnosis

A species of Denticupachydomella with a row of nodules uniform in size along DB of LV and a surface ornamented by nodules.

Etymology

After the Bell Canyon Formation (Middle Permian, West Texas) that yielded this new species.

Material examined

Holotype USA • complete carapace, (Fig. 11P); Guadalupe Mountains, West Texas, ‘ McKittrick Canyon’ Member, Bell Canyon Formation, MKCS1 section, sample 4 (GM5); Capitanian, Middle Permian; MNHN.F. F63469.

Paratype USA • 1 left valve, (Fig. 11Q); Guadalupe Mountains, West Texas, ‘ McKittrick Canyon’ Member, Bell Canyon Formation, MKCS1 section, sample 2 (GM6); Capitanian, Middle Permian; MNHN.F. F63470.

Additional material

USA • 1 complete carapace, 13 valves; Guadalupe Mountains, West Texas, ‘ McKittrick Canyon’ Member, Bell Canyon Formation, MKCS1 section, samples 4 (GM5) and 2 (GM6); Capitanian, Middle Permian; MNHN.F. F63500.

Dimensions

L= 387–756 µm; H =247–433 µm (Fig. 5H).

Description

Small carapace sub-rectangular, H/L=0.57–0.69; DB straight on both valves; row of nodules long DB of LV; AB with quite large radius of curvature with maximum located below mid-H; VB almost straight at both valves; PB with large radius of curvature for genus with maximum of curvature located in lower part of H; presence of spine in posteroventral part of carapace; overlap of LV on RV all around carapace; presence of nodules on surface of both valves.

Occurrence

Samples 4 (GM5) and 2 (GM6), MKCS1 section, ‘McKittrick Canyon’ Member, Bell Canyon Formation, Guadalupe Mountains, West Texas, USA, Capitanian, Middle Permian (this work).

Remarks

Denticupachydomella bellcanyonensis sp. nov. is very similar to the type species Denticupachydomella spinosa Yuan in Yuan et al., 2009 from the Changhsingian of South China (Yuan et al. 2009) but is larger and lacks the two horny spines at the anterior and posterior cardinal angles. Denticupachydomella bellcanyonensis sp. nov. differs from Denticupachydomella multinodosa (Forel in Crasquin et al. 2010) from the Changhsingian (Late Permian) of Sichuan, south-west China (Crasquin et al. 2010) by the presence of a postero-ventral spine and by the organisation of nodules along dorsal and ventral margins at both valves. Herein, the dorso-central shoulder at RV is absent and the surface is covered by nodules. The species from the Late Capitanian of the Penglaitan section (Guadalupuan–Lopingian GSSP) in Guangxi, South China (Zazzali 2016: fig. 13o–p, unpublished material) differs from Denticupachydomella bellcanyonensis sp. nov. by a more elongate carapace and a PB with smaller radius of curvature. The species from the Penglaitan section is also new and has to be described.