Fig. 3From: ‘Arm brains’ (axial nerves) of Jurassic coleoids and the evolution of coleoid neuroanatomyAcanthoteuthis sp., KI306, Etches collection, Kimmeridgian, Kimmeridge Bay (United Kingdom). Photo by Terry Keenan. a photo of specimen, with magnified detail to show the striation of the axial nerves. b Sketch of the specimenBack to article page