. Early Devonian fishes from Utah : Arthrodira. Fishes, Fossil; Paleontology -- Devonian; Paleontology -- Utah. Fig. 97. Aethaspis major, anterior laterals (X 2/3). PF 560; B, right side, inner face, PF 561. A, left side, outer face. the case in Actinolepinae. In PF 1638 (fig. 96), doubtfully referred to A. utahensis, the posterior dorso-lateral agrees in general shape and proportions with that of A. major. The anterior lateral plate is known only in A. major (figs. 97; 110, D), where it has quite distinctive features. The center of ossification is placed anteriorly and low, and in front of it
. Early Devonian fishes from Utah : Arthrodira. Fishes, Fossil; Paleontology -- Devonian; Paleontology -- Utah. Fig. 97. Aethaspis major, anterior laterals (X 2/3). PF 560; B, right side, inner face, PF 561. A, left side, outer face. the case in Actinolepinae. In PF 1638 (fig. 96), doubtfully referred to A. utahensis, the posterior dorso-lateral agrees in general shape and proportions with that of A. major. The anterior lateral plate is known only in A. major (figs. 97; 110, D), where it has quite distinctive features. The center of ossification is placed anteriorly and low, and in front of it the plate is bent sharply mediad to form a clearly demarked and finely tuberculated inner wing (fig. 110, D, iw). The dorsal part of the plate is unreduced and on the inner side shows wide areas for overlap of the anterior and posterior dorso-laterals (fig. 110, D, s. ADL, s. PDL). Behind the posterior dorso-lateral overlap there is probably a very small overlap area for the posterior lateral (fig. 110, D, s. PL), although this is not clear on the one specimen showing the inner side (PF 561). Lateral and ventral to the posterior lateral overlap area, the posterior edge of the anterior lateral is concave; in its dorso-median part it is thick- ened, indicating the probable position of the pectoral fenestra and fin; in its ventro-lateral part it is thinner where presumably it came in contact with the anterior ventro-lateral. The ventral edge of the plate is somewhat shortened, a feature that is indicative of a reduced attachment for the spinal. The plate is relatively higher than in Simblaspis (fig. 110, C) and Bryantolepis (fig. 110, E). It differs from Anarthraspis (fig. 110, F), in which the dorsal part of the plate is greatly shortened antero-posteriorly, resulting in a relatively short, high anterior lateral. I. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illus
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Keywords: ., bookcentury1900, bookcollectionbiodiver, booksubjectfishesfossil
