Table 201 Classification of Cambrian Calcified Algae and Bacteria Groups Principal Genera and Affinities

Angusticellularia Group CYANOBACTERIA

Angusticellularia

Botomaella Group

Bajanophyton, Bija, Botomaella, Kordephyton Girvanella Group

Batinevia, Cladogirvanella, Girvanella, Razumovskia, Subtifloria Obruchevella Group

Obruchevella

Epiphyton Group ?CYANOBACTERIA

Acanthina, Epiphyton, Gordonophyton, Korilophyton, Sajania,

Tubomorphophyton

Proaulopora Group

Proaulopora

Renalcis Group

Gemma, Renalcis, Tarthinia

Chabakovia MICROPROBLEMATICA

Wetheredella

Amgaella Group ?DASYCLADALEANS

Amgaella, Mejerella, Seletonella

Cambroporella PROBLEMATICA

Edelsteinia

Lenaella

Source: Modified from Riding 1991a.

tonella and Amgaella, which may be dasycladalean green algae (Korde 1950, 1957). Their known distribution is very limited; Seletonella, for example, is known only from its type-locality.

Of the 30 principal genera (table 20.1), 11 can confidently be regarded as cyano-bacteria (Angusticellularia, Botomaella, Girvanella, and Obruchevella groups), a further 10 (Epiphyton, Proaulopora, and Renalcis groups) are possible cyanobacteria, 3 (Chabakovia, Nuia, and Wetheredella) are Microproblematica, 3 (Amgaella group) may be dasycladalean algae, and 3 are Problematica that have been thought to be algae. Members of the Angusticellularia, Botomaella, Girvanella, Epiphyton, and Renalcis groups (figure 20.1) overwhelmingly dominate the flora through much of the Cambrian and make a major contribution to the construction of domes, reefs, and oncoids. These may all represent cyanobacteria, but for important groups such as Epiphyton and Re-nalcis, this interpretation, although likely, has yet to be confirmed from modern analogs. Consequently, collective names have been applied to these calcified microfossils

Figure 20.1 Common Cambrian calcified cyanobacteria and possible cyanobacteria. A, Renalcis, Salaany Gol, western Mongolia, ?Atdabanian; B, Tarthinia (Renalcis Group), Olenek River, Siberia, Tommotian; C, Tubomor-phophyton (Epiphyton Group), Oi-Muraan, Lena River, Siberia, Atdabanian; D, Korilophyton (Epiphyton Group), Fomich River, Anabar,

Figure 20.1 Common Cambrian calcified cyanobacteria and possible cyanobacteria. A, Renalcis, Salaany Gol, western Mongolia, ?Atdabanian; B, Tarthinia (Renalcis Group), Olenek River, Siberia, Tommotian; C, Tubomor-phophyton (Epiphyton Group), Oi-Muraan, Lena River, Siberia, Atdabanian; D, Korilophyton (Epiphyton Group), Fomich River, Anabar,

Siberia, Nemakit-Daldynian; E, Girvanella, Tyuser River, Lena River, Siberia, Atdabanian; F, Subtifloria (Girvanella Group), Salaany Gol, western Mongolia, Tommotian; G, Botomaella, Olenek River, Siberia, Tommotian; H, Angusti-cellularia (=Angulocellularia), Olenek River, Siberia, Tommotian. Magnification for all X70.

in order to distinguish them as a group, even though their collective affinities are not altogether certain. These names include calcibionts (Luchinina 1991,1998) and calci-microbes (=calcified microbial microfossils; James and Gravestock 1990:460).

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