Malacology[a] is the branch of invertebrate zoology that deals with the study of the Mollusca (molluscs or mollusks), the second-largest phylum of animals in terms of described species[1] after the arthropods.
Organisms with shells were classified under "Testacea", reflecting a limited understanding of their broader biological characteristics.
[3] In 1795, French naturalist Georges Cuvier introduced a new classification system for invertebrates based on anatomical observations.
This approach laid the groundwork for the transition from conchology to malacology, as it highlighted the importance of internal anatomy over external shell features.
Scientists began studying not only the external shells of mollusks but also their internal anatomy, physiological functions, and ecological roles.
The term "malacology" was officially introduced in 1825 by French zoologist and anatomist Henri-Marie Ducrotay de Blainville.