Figure 2

Figure 2 — Internal morphology of the ammonoid conch and specimens showing rare or unusual preservations. A) Juvenile morphology of Cadoceras sp. including the initial chamber and the rest of the embryonic shell, reconstructed by Robert Lemanis. B) Jurassic Neochetoceras sp. with aptychus at the bottom (blue arrow), parts of the siphuncle (red arrow) preserved and within the body chamber, stomach contents consisting mainly of crinoid remains (black arrow; modified from Keupp 2000). C) CT scan of the Carboniferous ammonoid Arnsbergites, reconstructed by René Hoffmann. D) Early Cretaceous specimen of Cleoniceras besairiei with injuries attributed to stomatopod crustaceans (red arrows; modified after Keupp 2012). E) Early Cretaceous specimen of the heteromorph ammonoid Aegocerioceras housed at the Naturalis Museum in Leiden with complex ammonitic suture lines.

Figure 2 — Internal morphology of the ammonoid conch and specimens showing rare or unusual preservations. A) Juvenile morphology of Cadoceras sp. including the initial chamber and the rest of the embryonic shell, reconstructed by Robert Lemanis. B) Jurassic Neochetoceras sp. with aptychus at the bottom (blue arrow), parts of the siphuncle (red arrow) preserved and within the body chamber, stomach contents consisting mainly of crinoid remains (black arrow; modified from Keupp 2000). C) CT scan of the Carboniferous ammonoid Arnsbergites, reconstructed by René Hoffmann. D) Early Cretaceous specimen of Cleoniceras besairiei with injuries attributed to stomatopod crustaceans (red arrows; modified after Keupp 2012). E) Early Cretaceous specimen of the heteromorph ammonoid Aegocerioceras housed at the Naturalis Museum in Leiden with complex ammonitic suture lines.