From editor or global species database
Nomenclature Cossmann considered that Thiarella Sacco, 1890 was preoccupied by Thiarella Swainson, 1840 and established Crenisutura as a substitute name. Tiarella was used (p. 130-131) by Swainson as an alternative original spelling and has been selected as the valid spelling by First Reviser choice by Herrmannsen, 1849, Indicis generum malacozoorum primordia, 2: 573, 576; however the spelling Thiarella is/has been in prevailing usage. [details]