Kelletia
Kelletia is a genus of large sea snails, whelks, a marine gastropod molluscs in the family Austrosiphonidae, the true whelks. Distribution. One extant species "Kelletia lischkei" occurs in the Sea of Japan off the coasts of Japan and South Korea, and another "K. kelletii" is found of along the coasts of California, United States and in the Baja California, Mexico. Fossil species are documented in Japan, California, and Ecuador. Evolution. A molecular phylogeny of Buccinidae based on the mitochondrial 16S rRNA gene suggested that "Kelletia" is a closely related to "Penion", a true whelk genus with extant species distributed  in waters off of New Zealand and Australia. Results of a further molecular phylogenetic studies using mitochondrial genomic and nuclear ribosomal DNA sequence data re-affirmed this relationship, and also demonstrated that "Kelletia" and "Antarctoneptunea" found in the southern Pacific and Southern oceans are sister clades. The common ancestor of the three genera most likely evolved in the southern Pacific Ocean, and a lineage leading to "Kelletia" dispersed over millions of years up the western coast of the Americas into the northern Pacific Ocean. Radulae and opercula morphology is similar between "Penion" and "Kelletia".