The Camaroidea, erected by Kozlowski (1938, 1949) as a separate order of the Graptolithina, is a rather poorly known group of encrusting graptolites. To date, they have been reported almost exclusively from the upper Tremadoc of Poland (Kozlowski 1938, 1949), the upper Arenig of the Island of Öland, Sweden (Skevington 1963) and the lower Llanvirn of Estonia (Mierzejewski 2000a). Moreover, some problematic organic microfossils from the Ordovician and Silurian of Baltoscandia were recognized as aberrant camaroid graptolites by Mierzejewski (2000b).
The majority of camaroid genera display several unusual features: the characteristic shape of autothecae composed of of broad camara and narrow collum, the usuallly simple apertural apparatus and the presence of peculiar extracamaral tissue filling the space between adjacent camarae. Most of them are also devoid of bithecae, while stolothecae are rather poorly defined.
According to Kozlowski (1949) the camaroid graptolites were more specialized than other sessile graptolites and were presumably descendants of the Tuboidea.
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