About glossary terms

This glossary presents specialized terms that diatomists use to describe structures, particularly those of the diatom cell wall. Many definitions include illustrations. A good starting point for learning about the diatom cell wall is the term frustule.

Terms can present several challenges. They may be specific to a particular taxonomic group, such as partecta, found only in Mastogloia, and carinoportulae, found only in Orthoseira. Occasionally, the same term may be applied to very different structures. For example, the annulus of Thalassiosira is much different from the annulus of Geissleria. In other cases, some terms describe structures that are physically similar, but are not homologous (derived from a common ancestor). For example, the stigma of Gomphonema has a different origin than the stigma of Luticola. This is an example of convergent evolution. In this glossary, we attempt to clarify terms so that they may be used for learning about diatoms.

Contact us if you have suggestions for additions or improvements.