. Advances in herpetology and evolutionary biology : essays in honor of Ernest E. Williams. Williams, Ernest E. (Ernest Edward); Herpetology; Evolution. Fossil Lizard Distribution • Estes 391. Figure 13. Suggested area of origin (stippled) and later dispersals (arrows) of varanids. X = position of Lan- thanotus. Varanid dispersal from Asia into North America and Europe was in the Early Cenozoic. Map data as in Figure 3. Dates at end of arrows indicate earliest pre-Pleistocene fossils of the group in that area. See text for further explanation. America (Fig. 13), but the paucity of the Cretaceo
. Advances in herpetology and evolutionary biology : essays in honor of Ernest E. Williams. Williams, Ernest E. (Ernest Edward); Herpetology; Evolution. Fossil Lizard Distribution • Estes 391. Figure 13. Suggested area of origin (stippled) and later dispersals (arrows) of varanids. X = position of Lan- thanotus. Varanid dispersal from Asia into North America and Europe was in the Early Cenozoic. Map data as in Figure 3. Dates at end of arrows indicate earliest pre-Pleistocene fossils of the group in that area. See text for further explanation. America (Fig. 13), but the paucity of the Cretaceous record in Europe and Paleo- gene in Asia makes a clear-cut decision difficult to make. Owen's Hypothesis and the Position OF Southeast Asia The continental reconstructions of Owen (1976, 1981, 1982) are of interest here since they provide a much more extensive and intimate connection be- tween eastern Laurasia and Gondwana during the Mesozoic, in contrast to the reconstructions commonly used ( Smith and Bryden, 1977) in which a large Eastern Tethys seaway separates these two regions widely. In Figure 14, I have used Owen's reconstruction for the Early Cretaceous as a base map. In brief, Owen's view is that this eastern Tethys is a geometric artifact produced by assum- ing an Earth of constant dimensions. He suggested that the Early Mesozoic earth was about 20% smaller in diameter than at present, and that it has expanded ex- ponentially throughout Phanerozoic time. The assumption of an equal amount of subduction for each area of oceanic crust production by sea floor spreading is unwarranted in this view. Owen has given additional support for his hypothe- sis in later papers (1981, 1982), and the reviews by Sunderman and Brosche (1978) and Scrutton (1978) are also of in- terest in this regard. Beyond distortions that may be the result of an expanding Earth, the choice of a map base may fur- ther distort this region. A case in point is the Lambert equal-area projection
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