Heterobranchia, the heterobranchs, is a taxonomic clade of snails and slugs, which includes marine, aquatic and terrestrial gastropod mollusks.
A protoconch is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called "nucleus". The protoconch may sometimes consist of several whorls, but when this is the case, the whorls show no growth lines.
Columbariidae, known as pagoda shells, are a family of large deepwater sea snails, marine gastropod mollusks in the superfamily Turbinelloidea. Some 60 extant species have been described.
Architectonicidae, common name the staircase shells or sundials, are a family of sea snails, marine gastropod mollusks in the informal group "Lower Heterobranchia" of the clade Heterobranchia.
Architectonica is a genus of sea snails in the family Architectonicidae.
Adelphotectonica reevei is a species of sea snail, a marine gastropod mollusk in the family Architectonicidae, known as the staircase shells or sundials.
Gyriscus asteleformis is a species of sea snail, a marine gastropod mollusk in the family Architectonicidae, known as the staircase shells or sundials.
Architectonicoidea is a superfamily of sea snails, marine gastropod mollusks in the informal group Lower Heterobranchia.
Architectonica perspectiva, whose common name is the clear or perspective sundial shell, is a species of sea snail, a marine gastropod mollusk in the family Architectonicidae, which are known as the staircase shells or sundials.
Purpuraturris tanyspira is a species of sea snail, a marine gastropod mollusk in the family Turridae, the turrids.
Ptychatractus youngi is a species of sea snail, a marine gastropod mollusk in the family Ptychatractidae.
Psilaxis is a genus of sea snails, marine gastropod mollusks in the family Architectonicidae, the staircase shells or sundials.
Discotectonica is a genus of sea snails, marine gastropod mollusks in the family Architectonicidae, the staircase shells or sundials.
Discohelix is a genus of extinct sea snails, marine gastropod mollusks in the family Discohelicidae.
Solatisonax is a genus of sea snails, marine gastropod mollusks in the family Architectonicidae, the staircase shells or sundials.
Solatisonax cabrali is a species of deep-water sea snail, a marine gastropod mollusk in the family Architectonicidae, the staircase shells or sundials.
Pseudotorinia is a genus of sea snails, marine gastropod mollusks in the family Architectonicidae, the staircase shells or sundials.
Pseudotorinia phorcysi is a species of sea snail, a marine gastropod mollusk in the family Architectonicidae, the staircase shells or sundials.
Architectonica gualtierii is a species of sea snail, a marine gastropod mollusk in the family Architectonicidae, which are known as the staircase shells or sundials.
Spirolaxis is a genus of sea snails, marine gastropod mollusks in the family Architectonicidae, the staircase shells or sundials.
