Aleksandr Mironenko (2015)
Перейти к источникуRemnants of a color pattern on the shells of Middle Jurassic (Callovian) and Upper Jurassic (Volgian) ammonites from Central Russia are described. In Callovian Funiferites and Quenstedtoceras, the color pattern is represented by dark stripes on a light background. This pattern is very similar to the coloration of Triassic ammonoids from Nevada. In Quenstedtoceras, the stripes coincide with “temporary apertures” - areas of growth interruption. The color pattern of Callovian Brightia and Sublunulocerasis represented by frequent, thin longitudinal stripes. Their frequency and location coincides with the ridges on the wrinkle layer of these ammonites. The color pattern of Upper Volgian Craspedites and Kachpurites is represented by frequent and relatively wide dark stripes on a light shell surface. In all cases, the color pattern is unstable and may fade on exposure to sunlight.