. Advances in herpetology and evolutionary biology : essays in honor of Ernest E. Williams. Williams, Ernest E. (Ernest Edward); Herpetology; Evolution. Figure 6. Anterior end of the dorsal armor, PC 13 fonward, with selected precaudal scale rows numbered on: A. Crocodylus johnstoni, MCZ 35006. B. C. niloticus, USNM 195783. C. C. niloticus, MCZ 12552. D. C. niloticus, USNM 63592. three to six scutes in PC 26. PC 25 appears lost or perhaps coalesced with PC 26. PC 24 has zero to four minor elements. Crocodylus niloticus In Crocodylus niloticus (Fig. 6B-D) the continuous and contiguous precaudal
. Advances in herpetology and evolutionary biology : essays in honor of Ernest E. Williams. Williams, Ernest E. (Ernest Edward); Herpetology; Evolution. Figure 6. Anterior end of the dorsal armor, PC 13 fonward, with selected precaudal scale rows numbered on: A. Crocodylus johnstoni, MCZ 35006. B. C. niloticus, USNM 195783. C. C. niloticus, MCZ 12552. D. C. niloticus, USNM 63592. three to six scutes in PC 26. PC 25 appears lost or perhaps coalesced with PC 26. PC 24 has zero to four minor elements. Crocodylus niloticus In Crocodylus niloticus (Fig. 6B-D) the continuous and contiguous precaudal armor is moderately regular, particularly in the sacral and lumbar regions and along the midline. There are 16 or 17 continuous rows of precaudal armor, with four to nine, usually six, scutes per trans- verse row at midbody. The median scute pair of the anteriormost thoracic row is often enlarged. Laterally, detached ele- ments may form up to two additional keeled rows. In some individuals, especially from Madagascar, a row of two scutes intervenes between the thoracic and cervical armor. We interpret this as PC 19 on the basis of it being closer to the cervical than the thoracic armor, but this identification is not certain. PC 20+21 has two scutes, and PC 22+23 has four. These two transverse compounds tend to be closely adjacent, forming an ovate cervical shield. The compound nature of these rows is demonstrated by occasional variants exhibiting one or the other row in an uncompound state (Fig. 6B, D). The nape has three to six scutes in PC 26, and zero to four small elements in PC 24. PC 25 is absent, or perhaps fused with PC 26. Crocodylus palustris In Crocodylus palustris (Fig. 7D), the continuous and contiguous precaudal armor is fairly regular. At the anterior end of the thoracic armor, small scales some- times occur between transverse rows and between the scutes within a transverse row, leading to a loss of contiguity. There are four to eight contiguous scutes per tran
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Keywords: ., bookauthorharvarduniver, bookcentury1900, booksubjectherpetology
