. Annals of the New York Academy of Sciences. Science. Fig. 3.—Skull patterns of Trimerorhachis and Diplopterus A, Permo-Carboniferous stegocephalian, Trimerorhachis mediits (order Temnospondyli), after Broom. B, Devonian osteolepid rhipidistian Diplopterus, after Jaekel (lettering somewhat altered). Abbreviations as in Fig. 2, p. 330 ; also : It, intertemporal; , hyomandibular (colu- mella auris) ; ? sy, ? symplectic (? extra columella). In B the interfrontal foramen is identified by authors as the pineal opening. The brain M-as probably located far forward. (a modified centrum). Again the
. Annals of the New York Academy of Sciences. Science. Fig. 3.—Skull patterns of Trimerorhachis and Diplopterus A, Permo-Carboniferous stegocephalian, Trimerorhachis mediits (order Temnospondyli), after Broom. B, Devonian osteolepid rhipidistian Diplopterus, after Jaekel (lettering somewhat altered). Abbreviations as in Fig. 2, p. 330 ; also : It, intertemporal; , hyomandibular (colu- mella auris) ; ? sy, ? symplectic (? extra columella). In B the interfrontal foramen is identified by authors as the pineal opening. The brain M-as probably located far forward. (a modified centrum). Again the elements of the chondrocranium, so far as they are known in Stegocephali (Trimerorhachis, Eryops), seem to correspond in general plan with the conditions in the existing Polypterus. It is conceivable that the Stegocephali may have branched off from the stem of the Ehipidistia before the skull-roof became fully ossified, but the existence of such an extensive series of correspondences offers strong evidence of community of origin. It seems reasonable, therefore, to conclude that the primitive stegocephalian skull has been derived from the rhipidistian skull through the following advances:. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original New York Academy of Sciences. New York, New York Academy of Sciences
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectscience, bookyear1877
