As well as major contributions to stratigraphy and geological mapping, G. N. Frederiks is particularly remembered for his contributions to the paleontology of the late Paleozoic era (Carboniferous and Permian periods), notably Brachiopoda, Ammonoidea, and Bryozoa.
Marine fossils (bivalves and ammonites) may be found within some of the limestone beds.
The name Neocephalopoda was first published (in Lehmann & Hillmer, 1980) as an Infraclass, which (in a reversal of the usual Linnean hierarchy) included the Subclasses Bactritoidea, Ammonoidea, and Coleoidea.