Ceratobairdia pratti Forel sp. nov.

urn:lsid:zoobank.org:act: 97132C11-D593-4D25-AFA4-05B453873EA4

Figs 5G, 11C–G

Diagnosis

A species of Ceratobairdia with a nodular dorsal blade at LV displaying 6 very small triangular nodules?, AB and PB prolonged by short horizontal spines, posterior end reduced.

Etymology

Named after the geologist Wallace Pratt who donated a part of the McKittrick Canyon which became part of the Guadalupe Mountains National Park, Guadalupe Mountains, West Texas, USA.

Material examined

Holotype USA • complete carapace (Fig. 11C); Guadalupe Mountains, West Texas, Williams Ranch Member, Cutoff Formation, Quarry section, sample GM1; Roadian, Middle Permian; MNHN.F. F63456.

Paratype USA • 1 left valve, (Fig. 11D); Guadalupe Mountains, West Texas, Williams Ranch Member, Cutoff Formation, Quarry section, sample GM1; Roadian, Middle Permian; MNHN.F. F63457 .

Additional material

USA • 1 left valve; Guadalupe Mountains, West Texas, Williams Ranch Member, Cutoff Formation, Quarry section, sample GM1; Roadian, Middle Permian; MNHN.F. F63458 • 1 left valve; same locality as for preceding; Roadian, Middle Permian; MNHN.F. F63459 • 1 left valve; same locality as for preceding; Roadian, Middle Permian; MNHN.F. F63460 • 43 left valves; Guadalupe Mountains, West Texas, Williams Ranch Member, Cutoff Formation, Quarry section, samples GM1, GM2; Roadian, Middle Permian; MNHN.F. F63499 .

Dimensions

L= 981–1317 µm; H =607–846 µm (Fig. 5G, only complete left valves measured, not considering spines).

Description

Sub-rectangular in lateral outline with Hmax around mid-L and Lmax around mid-H; dorsal margin uniformly convex with ADB straight and short; strong overlap of LV on RV along entire dorsal margin, much narrower along venter; PB steep, short and concave; dorsal margin transformed into nodular blade with 6 small triangular nodules; AB large with maximum of curvature around upper ⅓ rd and AVB plump, very convex; ventral margin straightly to slightly concave around mid-L; PB reduced, relatively large with maximum of curvature around mid-H; AB and PB slightly compressed laterally, prolonged by thick, short horizontal spines; surface smooth.

Occurrence

Samples GM1, GM2, Quarry section, Williams Ranch Member, Cutoff Formation, Guadalupe Mountains, West Texas, USA, Roadian, Middle Permian (this work).

Remarks

Ceratobairdia pratti sp. nov. is unique among species of Ceratobairdia known to date by the disposition of nodules along a nodular blade at LV and by the spines terminating AB and PB.