About glossary terms

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

Terms 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. In some cases, the same term may be applied to very different structures. For example, the annulus of Thalassiosira is very different from the annulus of Geissleria. In other cases, terms describe structures that are physically similar, but are not homologous (derived from a common ancestor). For example, the stigma of Gomphonema is not the same structure as the stigma of Luticola (we think the two have different origins). The two stigmata provide an example of convergent evolution in different lineages.

In this glossary, we attempt to clarify terms so that they may be used for learning about diatoms.

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