Karyotypes of the five monotypic species groups of lizards in the genus Sceloporus. American Museum novitates ; no. 2450

Abstract

"The karyotypes of the five species of Sceloporus that comprise monotypic species groups are described on the basis of examination of chromosomes in approximately 340 cells from 28 lizards (19 males, 9 females), and the following broad conclusions are reached: (1) S. chrysostictus (2n = 34) has karyotypes (including an X-Y sex chromosome system) virtually identical to those of species in the variabilis group and unlike those of other species in the genus, which indicates that its affinities lie with that group. (2) S. graciosus (2n = 30) has a karyotype distinctly different from that of all other species analyzed in the genus, which is compatible with its comprising a monotypic group. (3) S. maculosus (2n = 33 in males; 2n = 34 in females) has distinctive karyotypes (including an X[subscript]1X[subscript]2Y(male):X[subscript]1X[subscript]1X[subscript]2X[subscript]2(female) sex chromosome system) that are different from those of all other species analyzed in the genus, which is consistent with its comprising a monotypic group. (4) S. merriami (2n = 46) has the highest chromosome number shown in the genus and also has distinctive karyotypes (including an X-Y sex chromosome system) that are different from those of all other species analyzed in the genus. (5) S. utiformis (2n = 34) has karyotypes (also including an X-Y sex chromosome system) virtually identical to those of species in the siniferus group, which, together with features of external morphology, indicates that its affinities lie with that group"--P. 14-15.