“…They mostly occur individually, but are rarely preserved in situ within the body chambers (e.g., Lehmann, 1967Lehmann, , 1971Lehmann, , 1979Mutvei, 1992, 1993;Tanabe and Landman, 2002;Kruta et al, 2010Kruta et al, , 2011Landman et al, 2010;Tanabe et al, 2012Tanabe et al, , 2013Klug and Jerjen, 2012). Especially when preserved in calcareous and phosphate concretions, they generally retain their original three-dimensional morphology, although their primarily organic composition is replaced by phosphate minerals during diagenesis (Kanie, 1982;Tanabe and Fukuda, 1983;Tanabe et al, 2012;Gupta et al, 2008).…”