Gorbyoceras undefined-A

Gorbyoceras sp. A Fig. 12N Material examined ESTONIA • 1 spec.; Kohila quarry; Kõrgessaare Formation, Vormsi Regional Stage; TUG 42-417. Description The specimen is a ca 75 mm long fragment of a curved body chamber with external sculpture partly preserved. The original diameter was larger than 35 mm. The fragment is annulated with ca 4–5 regularly spaced annulations per distance equal to the corresponding conch diameter. The annulations are relatively shallow. Additionally, the conch is ornamented with numerous fine longitudinal lirae and subordinate transverse growth lines, producing a reticulate pattern. The longitudinal and transverse lirae are ca 1 mm distant. Remarks The ornamentation of this fragment is similar to other species of Gorbyoceras. Its curved, relatively large body chamber (conch diameter> 35 mm) is similar to G. textumaraneum, from which it differs by its fine reticulate ornamentation. The fragmentary preservation of this specimen does not permit a species level determination.