Archive image from page 49 of Devonian fishes of Iowa (1908). Devonian fishes of Iowa . devonianfishesof00east Year: 1908 56 IOWA GEOLOGICAL SURVEY Fig. 3. Fig. 3. Ateleaspis tesselata Tract. Silurian (Downtonian) of Scotland, restored outline showing tail in profile, x k (after Traquair). Diagrammatic by complete skeletons in which the dermal covering consists merely of small shagreen tubercles, sometimes beautifully orna- mented, or of minute hollow spines. Another interesting form of great systematic importance is Ateleaspis (Fig. 3), which is regarded by Dr. Traquair as annectant betwe
Archive image from page 49 of Devonian fishes of Iowa (1908). Devonian fishes of Iowa . devonianfishesof00east Year: 1908 56 IOWA GEOLOGICAL SURVEY Fig. 3. Fig. 3. Ateleaspis tesselata Tract. Silurian (Downtonian) of Scotland, restored outline showing tail in profile, x k (after Traquair). Diagrammatic by complete skeletons in which the dermal covering consists merely of small shagreen tubercles, sometimes beautifully orna- mented, or of minute hollow spines. Another interesting form of great systematic importance is Ateleaspis (Fig. 3), which is regarded by Dr. Traquair as annectant between Heterostraci and the next higher order, Osteostraci. Under the last-named are mcluded such well known forms as Cephalaspis (Fig. 4, page 58), Tremataspis, Thyestes, etc. Only in the case of the most spe- cialized order, Antiarchi, comprising the single family Aster- olepidae, are we unable to trace the lines of descent, owing to non- acquaintance with intermediate forms linking this group with any of the preceding. The suggestion that Asterolepids may have
Size: 836px × 2392px
Photo credit: © Actep Burstov / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: 1900, 1908, archive, book, bookauthor, bookdecade, bookpublisher, booksubject, bookyear, des_moines_iowa_geological_survey, drawing, eastman_charles_rochester_1868_1918, fishes_fossil, historical, history, illustration, image, iowa_geological_survey, page, paleontology, picture, print, reference, vintage
