Ammonites of the family Lytoceratidae from the Middle Jurassic Inferior Oolite Formation,
Aalenian to lowermost Bathonian, of Dorset are rarely described, perhaps because the
macroconchs are often very large and difficult to collect intact and the microconchs
are very small and easily overlooked. Detailed stratigraphical collecting over several
years has shown them to be a minor part of the ammonite fauna but more common at certain
horizons. Four genera, Lytoceras, Megalytoceras Nannolytoceras and Pleurolytoceras
have been shown to have different strat-igraphical ranges and abundances in the Aalenian
and Bajocian but they have not been found in the Lower Bathonian of Dorset. The taxonomic
basis of several of the well-known species is poorly described in the litera-ture
and is remedied here. (c) 2023 The Geologists' Association. Published by Elsevier
Ltd. All rights reserved.