Williams, David M., Pat A. Sims, and Paul Chambers. 2025. “Two New Cretaceous Species of Sphynctolethus and a New Name for ‘Sphynctolethus pacificus’ (Bacillariophyta: Hemiaulaceae)”. Phytotaxa 730 (1). Auckland, New Zealand:75-81. https://doi.org/10.11646/phytotaxa.730.1.5.