(Periophthalmus koelreuteri) and in insects (Sphodromantis lineola). In mammals, erect body postures, for example, may address a threat signal to a rival. This suggests that the configuration-algorithm responsible for the distinction between profitable (e.g., prey-like) vs. dangerous (e.g., threat-like) may be implemented by quite different neural networks. Studies in artificial neuronal nets support this presumption (for an example see Ewert 2004). Stereopsis in Toads Previously thought to be characteristic of solely primates and mammals with front-facing eyes, the ability to process depth information from multiple visual points in space has been determined to be possessed by most amphibians, namely, frogs and toads (Nityananda and Read 2017). From an evolutionary point of view, there has been substantial support for the idea that stereo vision has evolved as a natural progression for animals with binocular vision, meaning, a substantial distance between the two eyes (Nityananda and Read 2017). This theory would mean that stereopsis has evolved independently at least four times to account for stereo vision being present in mammals, birds, amphibians, and some invertebrates. For toads in particular, stereopsis would prove massively advantageous, as depth perception would be particularly useful in aiding in catching prey and calculating distance. See also Feature detection (nervous system) Jörg-Peter Ewert Neuroethology References Carew, T.J (2000). Feature analysis in Toads. In Behavioral Neurobiology, Sunderland, MA: Sinauer, 95-119. Ewert, J.-P. (1974). The neural basis of visually guided behavior. Scientific American, 230(3), 34-42. Ewert, J.-P. (1980). Neuroethology: an introduction to the neurophysiological fundamentals of behavior. Springer-Verlag, Berlin/Heidelberg/New York. Ewert J.-P. (2004) Motion perception shapes the visual world of amphibians. In: Prete F.R. (Ed.) Complex Worlds from Simpler Nervous Systems. Cambridge, MA, MIT Press, pp. 117–160 Ewert J.-P., Schwippert W.W. (2006) Modulation of visual perception and action by forebrain structures and their interactions in amphibians. In: Levin E.D. (ed.) Neurotransmitter Interactions and Cognitive Function. Birkhäuser, Basel, pp. 99–136 González A., Smeets W.J., Marín O. (1999). Evidences for shared features in the organization of the basal ganglia in tetrapods: studies in amphibians. Eur. J. Morphol., 37(2-3), 151-154. Kenigfest N.B., Belekhova M.G., Karamyan O.A., Minakova M.N., Rio J.-P., Reperant J. (2002). Neurochemical organization of the turtle protectum: an immunohistochemical study. Comparative analysis. J. Evol. Biochem. Physiol., 38(6), 673-688. Nityananda, V., and J. C. A. Read. 2017. Stereopsis in animals: evolution, function and mechanisms. Journal of Experimental Biology 220:2502–2512. Reiner A., Medina L., Veenman C.L. (1998). Structural and functional evolution of the