Supplements for: Review and revision of the Olivoidea (Neogastropoda) from the Paleocene and Eocene of the U.S. Gulf Coastal Plain

Numerous species of “oliviform” gastropods have been recognized in the
Paleogene of the U.S. Gulf Coastal Plain, many of which have previously
been allied to the “Bullia group” in the family Nassariidae, and placed in
a variety of poorly-defined genera. We review these species, revise their
generic and familial placement, and present a phylogenetic analysis. Of 19
species considered valid, all are assigned to Olivoidea, six to Olividae
-- one to Oliva, five to Agaronia -- and the rest to Ancillariidae. The
highly variable species Ancillaria altile Conrad, 1832 is referred in the
genus Ancillopsis and appears to have evolved anagenetically over an
interval of more than 15 million years. Ancillaria tenera Conrad, 1834a
and Ancillaria scamba Conrad, 1832 are placed in the new genus Palmoliva.
Monoptygma Lea, 1833 is demonstrated to belong to Ancillariidae, and to
contain only a single species. Some specimens assigned to Lisbonia expansa
Palmer, 1937 are split into adults assigned to Ancillopsis altilis and
juveniles (together with several other species) in Anbullina elliptica
(Whitfield, 1865). Coastal Plain ancillariids may have evolved from one or
more species of the Cretaceous-Paleocene genus Eoancilla. We agree with
previous authors who have suggested that the late Eocene species Oliva
mississippiensis Conrad, 1848 is the earliest known representative of this
genus and the subfamily Oliviinae, perhaps derived from a species of
Agaronia. The oldest Agaronia is Lower Eocene (Ypresian).