Tannuolina Explained

Tannuolina is a genus of tommotiid, belonging to the brachiopod stem lineage.

Its phosphatic shells exhibit a complex series of open pores/chambers/channels in outer shell layer.^{[1] [2]} It is conventionally interpreted as an essentially bivalved organism, similar to Micrina, though some use the unequal ratio of stellate to mitrate sclerites to argue for a halkieriid-like anatomy.^[3]

More recently a tube-like construction inspired by Eccentrotheca has been proposed.^[4]

Species

• T. fonini Esakova in Esakova & Zhegallo, 1996
• T. maroccana Skovsted & Clausen in Skovsted, Clausen, Álvaro & Ponlevé, 2014^[4]
• T. multifora Fonin & Smirnova, 1967
• T. pavlovi Kouchinsky et al., 2010^[1]
• T. zhangwentangi Qian & Bengtson, 1989

Notes and References

1. Kouchinsky, A., Bengtson, S. & Murdock, D. J. E. A new tannuolinid problematic from the lower Cambrian of the Sukharikha River in northern Siberia. Acta Pal. Pol. 55, 321–331 (2010).
2. Skovsted, C. B. Small shelly fauna from the upper Lower Cambrian Bastion and Ella Island Formations, north-east Greenland. J. Paleontol. 80, 1087–1112 (2006).
3. Li, G.-X. & Xiao, S.-H. Tannuolina and Micrina (Tannuolinidae) from the Lower Cambrian of Eastern Yunnan, South China, and Their Scleritome Reconstruction. J. Paleontol. 78(5), 900–913 (2004).
4. Skovsted, C. B., S. Clausen, J. J. Álvaro, and D. Ponlevé. 2014: Tommotiids from the early Cambrian (Series 2, Stage 3) of Morocco and the evolution of the tannuolinid scleritome and setigerous shell structures in stem group brachiopods. Palaeontology 57:171–192.