Palaeosabella Clarke, 1921 is an elongated cylindrical boring with a swollen distal end formed in carbonate substrates. It is similar to Trypanites except for the clavate expansion at its termination. Palaeosabella has a complicated ichnotaxonomic history. It was considered nomen dubium by Teichert (1945), resurrected by Plewes (1996), Bromley (2004) and Wilson (2007), and erroneously considered a junior synonym of the later established Clionoides Fenton and Fenton, 1932 by Furlong and McRoberts (2014). We are here considering
Palaeosabella a valid ichnotaxon because it does not branch like Clionoides.
2.66. Clavate-shaped borings
Palaeosabella is a clavate boring with length-to-width ratio of < 10:1, and although morphologically different from Trypanites, the two ichnogenera have often been confused.
Remark: Unbranched, cylindro-clavate borings.