Hippochrenes amplus: an elegant gastropod

One of the more unusual looking but memorable middle Eocene gastropods (snails) is Hippochrenes amplus (Solander, in Brander, 1776). It is unusual because of its large and very wide “wing.” This genus belongs to superfamily Stromboidea and, depending on which researcher's classification system you choose to use, the genus belongs to either family Rostellariidae, the latter of which includes also the genus Tibia (see previous post), or belongs to family Hippochrenidae. 

The first picture shown here is a published sketch, made by Solander (in Brander, 1766), of a complete specimen of Hippochrenes amplus from England. 

The original name of this gastropod was Strombus amplus Solander. Solander (1733–1782) was a pupil of C. Linnaeus, the Swedish naturalist and originator of the Linnaean (1758) system of nomenclature of lifeforms. Solander's paper describing Strombus amplus might be the first time Linnaean nomenclature (i.e., a binomial name) was used to name a fossil. 

Solander's species was was later transferred to the genus Hippochrenes Montfort, 1810 (v. 2). This genus name is derived from the early 17th century, via Latin and from Greek, and refers to "hippocrene," literally "a fountain of the horse" (from hippos [horse] + krene [fountain]). The latter refers to a "fountain' on Mount Helicon,  sacred to the Muses. According to legend, the fountain was produced by a stroke of Pegasus' hoof (www.lexico.com). 

This next picture is of a specimen of H. amplus that I collected from an upper middle Eocene bed in southeastern England. It is 152 mm in height, but its fragile "wing" (along the right side of the shell) is mostly missing.

The next two pictures are also of an actual specimen (height 125 mm, incomplete) of Hippochrenes amplus collected by my colleagues from the same, above-mentioned fossil bed containing shallow-marine gastropods and bivalves in southeastern England, but, unfortunately, the specimen is not complete. Nevertheless, you can see at least half of its "wing," as well as  the whorls (revolutions) of the shell, except the anterior end of the shell.

Hippochrenes amplus is best known from upper middle Eocene (Bartonian Stage) strata in southeastern England. Specimens are known also from Eocene strata elsewhere in Western Europe.