Salterella

Salterella
S. pulchella
Scientific classification
Kingdom:	Animalia (?)
Phylum:	Agmata
Genus:	†Salterella Billings

Salterella is an enigmatic Cambrian–Ordovician genus with a calcareous shell that appears to be septate, but is rather filled with stratified laminar deposits. Its shell contains grains of sediment, which are obtained selectively (with a preference for denser grains) by a manner also observed in foramanifera.

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Wikipedia