Kirkbyidae gen. et sp. indet.

Fig. 4J

Material examined

USA • 1 complete carapace; Guadalupe Mountains, West Texas, ‘ McKittrick Canyon’ Member, Bell Canyon Formation, MKCS1 section, sample 4 (GM5); Capitanian, Middle Permian; MNHN.F. F63374 .

Remarks

This specimen shows a clear oval kirkbyan pit in the middle part of the valve. The right valve has PB and AB with a different radius of curvature, whereas they are quite equivalent in Kirkbyidae . Herein, the PB has a very small radius of curvature and AB a large one. The ornamentation is coarse.

Occurrence

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