Early Devonian fishes from Utah : Arthrodira earlydevonianfis119deni Year: 1953 DENISON: EARLY DEVONIAN FISHES 481 V â liiiwliiiSiiiil ifcs»i?»-. Fig. 93. Aethaspis, posterior dorsals. A, A. major, type 1, PF 558 (X 4/3); B, A. major, type 2, PF 559 (X 4/3); C, A. sp., type 2, juvenile, PF 557 (X 2). with the postsuborbital, rather than overlapping it as in Coccosteus and Dinichthys. The median dorsal of Aethaspis is a short, broad plate (figs. 92; 94, A; 107, E), having the characteristic proportions of the Actinolepinae. It is considerably arched, has a median crest in its posterior h
Early Devonian fishes from Utah : Arthrodira earlydevonianfis119deni Year: 1953 DENISON: EARLY DEVONIAN FISHES 481 V â liiiwliiiSiiiil ifcs»i?»-. Fig. 93. Aethaspis, posterior dorsals. A, A. major, type 1, PF 558 (X 4/3); B, A. major, type 2, PF 559 (X 4/3); C, A. sp., type 2, juvenile, PF 557 (X 2). with the postsuborbital, rather than overlapping it as in Coccosteus and Dinichthys. The median dorsal of Aethaspis is a short, broad plate (figs. 92; 94, A; 107, E), having the characteristic proportions of the Actinolepinae. It is considerably arched, has a median crest in its posterior half, and a nearly central center of ossification. Internally it has a small, median ridge (fig. 92, A) in the central part of the plate, but lacks, as do other Arctolepida, a prominent keel. In shape and proportions it agrees very closely with the median dorsal of Actinolepis (fig. 107, D) and Kujdanowiasjns (fig. 107, I). Anteriorly it has a median convex- ity, and on either side of this there is a small unornamented area re- sembling a sutural overlap (fig. 107, E, x). Similar areas are found in Actinolepis and Simhlaspis (fig. 107, G, x) and perhaps indicate over- lap by the cranial roof. There is a distinct postero-median lobe, but it is less prominent than in Simhlaspis and Bryantolepis (fig. 107, H), Several median dorsals, ranging in estimated length from 36 to 95 mm., are referable to A. 7najor on the evidence of their ornament. The tendency to a ridged ornament is quite pronounced in the anterior and lateral parts of some of the plates. Only one median dorsal is referable
Size: 1670px × 1197px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
