Early teleost otolith morphogenesis observed in the Jurassic of Franconia, Bavaria, southern Germany Author Schwarzhans, Werner https://orcid.org/0000-0003-4842-7989 Zoological Museum, Natural History Museum of Denmark, Universitetsparken 15, 2100 Kobenhavn, Denmark & Ahrensburger Weg 103, 22359 Hamburg, Germany wwschwarz@aol.com Author Keupp, Helmut Freie Universitaet Berlin, Institut fuer Geologische Wissenschaften, Fachrichtung Palaeontologie, Malteser Strasse 74 - 100, Haus D, 12249 Berlin, Germany text Zitteliana 2022 2022-04-12 96 51 67 http://dx.doi.org/10.3897/zitteliana.96.81737 journal article http://dx.doi.org/10.3897/zitteliana.96.81737 2747-8106-96-51 CD8C70BA025345408EFCD430A12F6B35 FCEF2A912BC258BBB022681E86486B06 Animalia Taxon classification Archaeotolithus trigonalis Stolley, 1912 Plate 4, figs 5-7 Archaeotolithus trigonalis 1912 Archaeotolithus trigonalis - Stolley: pl. 7, figs 1-3. Archaeotolithus 2014 archaeotoliths group 2 - Hesse: fig. 29A-E. Archaeotolithus trigonalis 2018 Archaeotolithus trigonalis Stolley, 1912 - Schwarzhans: fig. 8K. Material. 25 specimens from the late Pliensbachian of Buttenheim : 2 specimens Apyrenum subzone (SNSB-BSPG 2022 IV 10 ), 1 specimen "Quellhorizon" (SNSB-BSPG 2022 IV 11 ), 22 specimens Hawkerense subzone (figured specimens SNSB-BSPG 2022 IV 12 , Plate 4 , figs 5-7) . Differential diagnosis. Otoliths with nearly equilateral triangular shape similar to A. bornholmiensis but distinctly less high-bodied than A. doppelsteini . Archaeotolithus trigonalis differs from A. bornholmiensis in being thinner, having a smooth outer face with exposed growth rings (vs with fine radial furrows starting from the middorsal angle), and showing a clear sulcus. It differs from A. doppelsteini not only in the otolith proportions and shape but also in the very short and strongly ventrally extended ostium and the rather straight, inclined cauda. Discussion. Archaeotolithus trigonalis is the most common species of the genus in Buttenheim. It almost always shows some kind of incrustation on the inner face, which often obliterates the sulcus morphology. However, in some instances, such as the figured specimens, it can still be reliably identified. A similar incrustation is also seen on the large paratype of A. doppelsteini , which could have been caused by organic material that was attached to it during the early process of fossilization and mineralization.