Nine genera of small calcareous fossils, generally attributed to the algae, are in samples from the Upper Devonian Fairholme Group exposed at the southeastern margin of the Ancient Wall reef complex at Mount Haultain, near Jasper, Alberta. In order of decreasing abundance these are Renalcis, Sphaerocodium, Girvanella, Keega, Solenopora, Parachaetetes, Vermiporella, Epiphyton, and Litanaia. Except locally, these organisms are of minor quantitative importance. They produced little identifiable loose sediment and their principal rock-forming roles appear to have been as frame-binders and secondary frame-builders associated with the stromatoporoid reef facies marking the edge of the carbonate platform.

The 3 most abundant genera at Mount Haultain exemplify some of the problems of taxonomy and affinity which are common among Paleozoic fossils usually referred to the calcareous algae. Renalcis, Sphaerocodium, and Girvanella generally are considered to be blue-green algae. Renalcis and Sphaerocodium differ in both size and form from extant blue-green algae. The branching series of chambers forming the test of Renalcis are more characteristic of the Foraminiferida. Its simple wall structure and irregular form suggest an affinity with the Parathuramminacea. The systematic position of Sphaerocodium is uncertain. Girvanella is a microscopic tubiform fossil reported to range from the Cambrian to the Cretaceous. Its resemblance to the calcified sheaths of several species of extant filamentou blue-green algae suggests that it may be possible to remove it from its conventional position in the artificial group Porostromata, to define its relations to blue-green algal structure and taxonomy more precisely, and to extend its geologic range to the Holocene.

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