Chitinozoan - Classification

Classification

Alfred Eisenack's original description of the Chitinozoans placed them in three families, spanning seven genera, based on morphological grounds. Further genera were identified, at first on an annual basis, as time progressed. Since its publication in 1931, Eisenack's original classification has been much honed by these additional discoveries, as well as advances in microscopy. The advent of the scanning electron microscope in the 1970s allowed the improved detection of surface ornamentation which is hugely important in identification - as can be appreciated by a comparison of the images on this page. Even the light microscope image here is of far greater quality than could have been achieved earlier in the century, using poorly preserved specimens and less advanced microscopes. The original three families proposed by Eisenack represented the best classification possible with available data, based largely on the presence or absence of chains of organisms and the chamber's shape. The orders were subsequently revised to conform better to Linnean taxonomy, placing related organisms more closely together. This was made possible as scientific advances permitted the identification of distinctive traits in organisms across Eisenack's groups. Features of the base and neck, the presence of spines, and perforations or connections are now considered the most useful diagnostic features.