Article: Affinity of the Cambrian alga Tubomorphophyton and its significance for the Epiphytaceae
Robert Riding and Larisa Voronova
The problem of the true nature of the alga Epiphyton Bornemann and its allies centres upon the difficulty of recognizing features of affinity in these morphologically simple fossils. They have been compared with algae in a number of different groups, including, especially, florideophycidean rhodophytes. However, the general dimensions and shape of the Cambrian epiphytacean Tubomorphophyton Korde in specimens from Siberia suggest that it could be a bangialean rhodophyte, but details of its morphology and style of calcification are more consistent with its being a filamentous ensheathed cyanophyte. Its tubiform morphology is obscured in some specimens, probably due to the thickness of the calcified sheath material and to diagenetic alteration. This suggests that other epiphytaceans with apparently solid skeletons could be cyanophytes. Alternatively, the Epiphytaceae may be a heterogeneous group of algae superficially similar in gross morphology. These possibilities require reassessment of the nature and diversity of early Phanerozoic algal communities.