Anellotubulates, “ring-tubers,” are tubular structures of microscopic size, creamy white to brownish in color, and composed of a phosphatic material. Their outline may be trumpet shaped to bell shaped, vermiform, or in the form of a parallel-sided or irregularly swollen tube. The outer walls may be roughened or may show annular lines; the inner wall is typically smooth. The size of these structures is in the range of 200–1000 μm (Fig. 1).
- McLachlan, I. R., 1973. Problematic microfossils from the Lower Karroo Beds in South Africa, Palaeontol. Africana, 15, 1–21.Google Scholar
- Picket, J., and Scheibnerova, V., 1974. The inorganic origin of “anellotubulates,” Micropaleontology, 20, 97–102.Google Scholar
- Richardson, G., Gregory, D., and Pollard, J., 1973. Anellotubulates are manufactured “microfossils,” Nature, 246, 347–348.Google Scholar
- Wetzel, O., 1967. Rätselhafte Mikrofossilien des Oberlias (ε); Neue Fünde von “Anellotubulaten” O. We. 1957, Neues Jahrb. Geol. Paläontol., Abh., 128, 341–352.Google Scholar