Browsing by Author "Cole, Charles J."
Now showing 1 - 20 of 35
Results Per Page
Sort Options
Item Amphibians and reptiles of the Madrean Archipelago of Arizona and New Mexico. (American Museum novitates, no. 3810)(American Museum of Natural History., 2014-07-30) Bezy, Robert L.; Cole, Charles J.The Madrean Archipelago in southern Arizona and southwestern New Mexico consists of 22 mountain ranges south of the Mogollon Rim. Herpetofaunal lists for these ranges and a segment of the rim were constructed based on museum specimens from Madrean evergreen woodland, petran montane conifer forest, and interior chaparral. Few or no species have been recorded from these communities in the Sierrita, Little Dragoon, and Big Hatchet mountains, emphasizing the need for additional sampling in the archipelago. A total of 83 species are found in the remaining 20 ranges, with lizards (28) and snakes (35) predominating. No two mountain ranges had the same herpetofauna. Species richness varies from 15 to 44 (mean 28.1). Phenetic analyses of herpetofaunal similarity among the ranges identify three groups: a northern group with eight ranges from the Rincon Mountains to the Pinaleño Mountains to the Sierra Ancha; a southwestern group consisting of the Baboquivari, Santa Rita, Pajarito, and Patagonia mountains; and a southeastern group with seven ranges from the Huachuca and Whetstone mountains to the Animas Mountains; the Mogollon Rim segment is placed as the first "branch" of the phenogram. The analyses place the Patagonia Mountains in the SW group and the Huachuca Mountains in the SE group, although the two are connected by woodland. The Madrean line separating the northern group from the two southern groups approximates the southern limit of interior chaparral. The ranges of the southwestern group are in contact with semitropical Sonoran desert scrub at low elevations, whereas Chihuahuan desert scrub and semidesert grassland surround the southeastern ranges. With few exceptions, published studies of phylogeography within species suggest that divergence among montane populations in the archipelago does not predate the Pleistocene. Phylogeographic analyses using nuclear and mitochondrial gene sequences and including all ranges of the Madrean Archipelago inhabited by a species are needed to determine the extent to which shared historic biogeographic events may underlie the groups of mountain ranges identified on the basis of herpetofaunal similarities in this study.Item Apparent triploidy in the unisexual brahminy blind snake, Ramphotyphlops braminus. American Museum novitates ; no. 2868(New York, N.Y. : American Museum of Natural History, 1987) Wynn, Addison H., 1955-; Cole, Charles J.; Gardner, Alfred L."Specimens of Ramphotyphlops braminus (all females) from hawaii, the Seychelles, and south Florida, were karyotyped and compared to other typhlopid species. thechromosome number of R. braminus is 42, compared to 2n = 32 for the diploid species Rhinotyphlops schlegelii and Typhlops simoni, and 2n = 34 for Typhlops jamaicensis and T. richardi. The higher number of chromosomes found in R. braminus is best explained by interpreting the karyotype to be triploid, and the chromosomes can easily be grouped into triplets. With the triploid interpretation, few Robertsonian changes are necessary to explain differences between the haploid karyotypes of R. braminus and T. jamaicensis, with which it is directly compared. Furthermore, the electrophoretic pattern of one dimeric protein, heterozygous in all five individuals from the Seychelles, is best interpreted as having a 1:4:4 pattern, consistent with an interpretation that R. braminus is triploid. Chromosomal heteromorphisms found in all individuals from the three populations are consistent with evidence that R, braminus is parthenogenetic, regardless of the interpretation of ploidy level"--P. []1.Item The blue and green whiptail lizards (Squamata, Teiidae, Cnemidophorus) of the Peninsula de Paraguana, Venezuela : systematics, ecology, descriptions of two new taxa, and relationships to whiptails of the Guianas. American Museum novitates ; no. 3207(New York, N.Y. : American Museum of Natural History, 1997) Markezich, Allan L.; Cole, Charles J.; Dessauer, Herbert C.Item Chromosome evolution in selected treefrogs, including casque-headed species (Pternohyla, Triprion, Hyla, and Smilisca). American Museum novitates ; no. 2541(New York, N.Y. : American Museum of Natural History, 1974) Cole, Charles J."The chromosome complements of five species of hylid frogs are described and illustrated. One of the species, Smilisca baudini, is a 'generalized' hylid and is used for comparative purposes. The other four species, Pternohyla fodiens, Triprion petasatus, Hyla septentrionalis, and Hyla brunnea, are among those having cephalic adaptations that are referred to as the casque-headed hylids. Three of these (P. fodiens, T. petasatus, and H. septentrionalis) have karyotypes that are indistinguishable from that of the generalized S. baudini: This includes a diploid number of 24 bi-armed chromosomes (12 pairs), of which six are relatively large and six relatively small. The karyotype of the other casque-headed species is vastly different, however: Hyla brunnea has a diploid number of 34 chromosomes, of which 20 are uni-armed. Following a review of the chromosome variation known to occur within the Hylidae, it is inferred that the karyotype of H. brunnea was derived from an ancestral karyotype similar to that of H. septentrionalis by means of at least five whole-arm chromosomal aberrations"--P. 3.Item Chromosomes of Bipes, Mesobaena, and other amphisbaenians (Reptilia), with comments on their evolution. American Museum novitates ; no. 2869(New York, N.Y. : American Museum of Natural History, 1987) Cole, Charles J.; Gans, Carl, 1923-"Karyotypes of three amphisbaenians (Bipes tridactylus, the monotypic Mesobaena, and Amphisbaena gonavensis) are presented for the first time. The karyotypes of all three species of Bipes are compared, using new material for each species, and all published karyotypes for representatives of the Amphisbaenia (approximately 20% of the Recent species, worldwide) are reviewed. Diploid chromosome numbers vary from 25 to 50, and centric fission of macrochromosomes appears to have been a major type of karyotypic evolution in these animals. Bipes tridactylus is the only amphisbaenian known to have recognizable sex chromosomes, with a ZZ([male]):ZW([female]) system (female heterogamety)"--P. [1].Item Comparative meristic variability in whiptail lizards (Teiidae, Aspidoscelis) : samples of parthenogenetic A. tesselata versus samples of sexually reproducing A. sexlineata, A. marmorata, and A. gularis septemvittata. (American Museum novitates, no. 3744)(American Museum of Natural History., 2012-05-23) Taylor, Harry Leonard.; Cole, Charles J.; Manning, Glenn J.; Cordes, James E.; Walker, James M. (James Martin)Is it correct, as is often assumed, that the clonal form of inheritance in parthenogenetic lizards results in less variability than occurs with genetic recombination in their sexually reproducing (gonochoristic) relatives? We tested this hypothesis by comparing morphological variability in samples of parthenogenetic Aspidoscelis tesselata and several gonochoristic species of whiptail lizards. To control for environmental factors that might differentially affect embryonic development of morphological characters, we compared samples obtained from the same or geographically adjacent localities. In addition, we compared apparently "uniclonal" and multiclonal samples from each of two color-pattern classes (C and E) of A. tesselata. For univariate meristic characters, parthenogenetic A. tesselata matched the variability of a sympatric gonochoristic species in 11 of 20 comparisons, had lower variability in six comparisons, and was more variable in three. For multivariate characters derived from principal components analyses (PCA), the relative meristic variability of samples of A. tesselata could not be predicted by its reproductive mode, color-pattern class, apparent "uniclonal" or multiclonal state, or geographic location. In addition, we compared A. tesselata, A. sexlineata, A. marmorata, and A. gularis septemvittata in a single PCA, with the latter two species representing the two ancestral taxa from which A. tesselata was derived through hybridization. Once again, relative variability of A. tesselata was not always predictable based on its reproductive mode. It had greater variability than A. sexlineata, equivalent variability with A. gularis septemvittata, and less variability than A. marmorata.Item Congruent patterns of genetic and morphological variation in the parthenogenetic lizard Aspidoscelis tesselata (Squamata, Teiidae) and the origins of color pattern classes and genotypic clones in eastern New Mexico. American Museum novitates ; no. 3424(New York, NY : American Museum of Natural History, 2003) Taylor, Harry Leonard.; Cole, Charles J.; Dessauer, Herbert C.; Parker, E. D., Jr.Item Hybrid origin of a unisexual species of whiptail lizard, Cnemidophorus neomexicanus, in western North America : new evidence and a review. American Museum novitates ; ; no. 2905.(New York, N.Y. : American Museum of Natural History, 1988) Cole, Charles J.; Dessauer, Herbert C.; Barrowclough, George F.Item Hybridization among western whiptail lizards (Cnemidophorus tigris) in southwestern New Mexico : population genetics, morphology, and ecology in three contact zones. Bulletin of the AMNH ; no. 246([New York] : American Museum of Natural History, 2000) Dessauer, Herbert C.; Cole, Charles J.; Townsend, Carol R.Cnemidophorus tigris punctilinealis of the Sonoran Desert and C. t. marmoratus of the Chihuahuan Desert contact each other and interbreed in the Animas Valley of southwestern New Mexico. More than 600 specimens have been examined from the contact region, and data on biochemical genetics (mitochondrial DNA haplotypes, protein electrophoresis of nuclear gene products), chromosomes, external morphology (coloration, size, scalation), reproduction, and fitness have been compared for three hybrid zones. Habitats in the contact region were mapped and photographed, and they are discussed in the context of vegetational changes during Pleistocene to Recent times, which affected the geographic distribution of these animals. Data from mitochondrial DNA, allele frequencies at four protein loci (of 36 analyzed), and body coloration demonstrate that the areas of contact have steep, concordant, and coincident step-clines in which most gene exchange occurs in hybrid zones that are 3.2-7.8 km wide. Analyses of allele frequencies, genotype frequencies, and fixation indices (including Hardy-Weinberg equilibrium, linkage equilibrium, and cytonuclear equilibrium) indicate a population structure determined primarily by random mating and an absence of selection against hybrids. Estimates of gene flow indicate that the clines resulted from neutral secondary contact initiated with the newest reconnection of the Sonoran and Chihuahuan deserts within the present interglacial episode, from 1000 to 5000 years ago. This timeframe is consistent with paleoecological data from packrat middens. Analyses of karyotypes, morphology, reproduction, and physiology also fail to detect differences in fitness among lizards with various genotypes. Although it is possible that there are fitness differences that are too small to be detected by the sample sizes we employed, the data indicate that reproductive success, fitness, and the dynamics of populations within the hybrid zones presently are no different from those in nonhybrid populations. Earlier data, which suggested that one of the step-clines was moving, are not supported. The clines are located in fragile semiarid habitats that are subject to desertification. Consequently, we present considerable data and dated photographs of habitats, precise locations of sampling sites, and local allele frequencies, so that future investigators can monitor changes in position, width, or dynamics of these hybrid zones. In addition, the population genetics data are discussed in the context of the following: (1) absence of rare, apparently novel alleles forming in the hybrid zones; (2) genetic comparisons with additional subspecies of C. tigris (C. t. aethiops and C. t. septentrionalis); and (3) interspecific hybridization between C. tigris and other whiptail lizards of either bisexual or unisexual (parthenogenetic, clonal) species. Cnemidophorus tigris is one of the ancestors of some of the parthenogens, which are of hybrid origin, and our interest in their evolutionary history fuels our efforts to improve understanding of hybridization among whiptail lizards.Item Hybridization between parthenogenetic lizards (Aspidoscelis neomexicana) and gonochoristic lizards (Aspidoscelis sexlineata viridis) in New Mexico : ecological, morphological, cytological, and molecular context. American Museum novitates ; no. 3492(New York, NY : American Museum of Natural History, 2005) Manning, Glenn J.; Cole, Charles J.; Dessauer, Herbert C.; Walker, James M. (James Martin)Whiptail lizard guilds consisting of different combinations of parthenogenetic Aspidoscelis exsanguis, Aspidoscelis neomexicana, and Aspidoscelis tesselata pattern classes C and D and gonochoristic Aspidoscelis sexlineata viridis inhabit numerous sites in the immediate vicinity of Conchas Lake, San Miguel County, New Mexico. Based on morphological identification by other workers of specimens collected in 1978, A. neomexicana was the species most recently added to the list of whiptail lizards known to occur at Conchas Lake, about 190 km east of its main distribution area in the Rio Grande Valley. We sampled guilds consisting of A. neomexicana and its congeners at Conchas Lake from 2000 through 2003. In 2002 we also collected specimens of what appeared to be another tokogenetic array of A. neomexicana east of the Rio Grande Valley in syntopy with A. tesselata E and A. sexlineata viridis at Fort Sumner, De Baca County, New Mexico. Comparison of karyotypes revealed that individuals of A. tesselata and those assigned by their discoverers to A. neomexicana from Conchas Lake and Fort Sumner have identical diploid karyotypes (2n = 46) that include diagnostic haploid complements of chromosomes derived from independent hybridizations between species in the tigris and sexlineata species groups. Consequently, we used electrophoretic data for 23 gene loci, of which the sMDH, sMDHP, sIDH, ESTD, PEPA, PEPB, ADA, MPI, GPI, and PGM2 loci were definitive, to further validate the hypothesis that the disjunct groups of putative A. neomexicana in eastern New Mexico had been correctly identified. The specimens analyzed electrophoretically also indicated that the Conchas Lake clone of A. neomexicana is identical to the most widely distributed clone of the species in the Rio Grande Valley of New Mexico and that the Fort Sumner clone possessed a distinctive allele. We describe the habitat for A. neomexicana at Conchas Lake at three sites north of the Canadian River and two sites south of the river. Two of the sites north of the Canadian River were studied as examples of guilds that did not include A. sexlineata viridis. The latter species was observed with A. neomexicana, A. tesselata, and A. exsanguis at one site north of the Canadian River and two sites south of the river. At Fort Sumner, we studied A. neomexicana at two sites where it was syntopic with A. tesselata E and A. sexlineata viridis. We identified 15 lizards from three sites at Conchas Lake as hybrids of A. neomexicana 3 A. sexlineata viridis. Most of these hybrids were found in either patchy or weedy chronically disturbed habitats in which the parental forms were forced into unusually close syntopic relationships. Hybrids between these parental forms were collected in each year from 2000-2003 and represented a minimum of four and a maximum of five generations. Although hybrids of A. neomexicana x A. sexlineata viridis were characterized by distinctive color patterns, all were rather similar to maternal parent A. neomexicana, but with modifications resulting from the genetic contribution of its paternal parent A. sexlineata viridis. All specimens identified as hybrids by color pattern also possessed meristic characters that distinguished them from both parental forms. Univariate and multivariate analyses of scutellation also revealed evidence of the genetic effects of the parental species on the hybrids. One live hybrid male of A. neomexicana x A. sexlineata viridis was collected at Conchas Lake. The hybrid (American Museum of Natural History R-151739) was a triploid (3n = 69) including the complete diploid complement of A. neomexicana (= A. tigris marmorata x A. inornata) plus a second haploid complement of sexlineata group chromosomes. Karyotypically, in all details this triploid appeared to be an F1 hybrid of A. neomexicana x A. sexlineata viridis. This confirmed hybrid possessed a similar array of color pattern and scutellation characters observed in the other individuals of presumptive A. neomexicana x A. sexlineata viridis from Conchas Lake. Of the 23 allozyme loci analyzed, 9 showed no allelic variation among the individuals of the parental taxa and the hybrid examined; however, 12 loci were particularly informative for identifying the hybrid and its parental species. For most of these loci, the suspected hybrid (based on morphology and triploid karyotype) had electrophoretic banding patterns consistent with a triploid bearing a combination of alleles that included the two found in diploid A. neomexicana plus a third allele from the local A. sexlineata viridis. This is consistent with a cloned A. neomexicana ovum having been fertilized by a haploid A. sexlineata viridis spermatozoan. We present the first evidence of perennial hybridization in Aspidoscelis between a parthenogen and a species other than a progenitor. However, we found no evidence that occasional hybridization between A. neomexicana and A. sexlineata viridis has had a significant negative effect on either of these species at Conchas Lake.Item Hybridization between the endangered unisexual gray-checkered whiptail lizard (Aspidoscelis dixoni) and the bisexual western whiptail lizard (Aspidoscelis tigris) in southwestern New Mexico ; American Museum novitates, no. 3555(New York, NY : American Museum of Natural History, 2007) Cole, Charles J.; Painter, Charles W. (Charles Wilson), 1949-; Dessauer, Herbert C.; Taylor, Harry Leonard.Hybridization between the unisexual Aspidoscelis dixoni and the bisexual Aspidoscelis tigris punctilinealis in southwestern New Mexico is documented by observations and analyses of external morphology (coloration, size, scalation), chromosomes (karyotypes), nuclear gene products (allozymes), and mitochondrial DNA. The locality (Hidalgo County, Antelope Pass of the Peloncillo Mountains, centered at 10.5 km west of Animas), consisting of only a few square kilometers, is the only place where this particular unisexual clone of A. dixoni exists. Because of its extreme rarity in recent years, A. dixoni has been listed as an endangered species in New Mexico, and the status of its populations has received intense study. Today, the cause(s) of endangerment remains unknown, although we hypothesize that interspecific competition may be the problem. Aspidoscelis dixoni is a diploid unisexual species that normally reproduces by parthenogenetic cloning, as demonstrated here with genetic data from laboratory-reared lizards. However, fertilization of its eggs in Antelope Pass is possible if mating occurs with a male of the syntopic bisexual species A. tigris punctilinealis. The resulting hybrids closely resemble their maternal parent morphologically, but they are triploid and the females observed to date have been sterile. Aspidoscelis t. punctilinealis is a recent invader of southwestern New Mexico. It is the dominant species of whiptail lizard today in the low-elevation, semiarid habitat of creosote desertscrub in Antelope Pass. The present rarity of A. dixoni in Antelope Pass, in contrast to its abundance a few decades ago, may result from negative interactions with this dominant species, including asymmetrical destabilizing hybridization. Only a few other populations of A. dixoni are known to exist, each in a limited area in southwestern Texas, so there is a hiatus of nearly 500 km between the small and restricted populations in New Mexico and Texas. Comparative genetic data presented here indicate that although these populations are similar, the population in New Mexico represents a unique clone. It has three alleles at 3 nuclear gene loci (among 31 examined) that distinguish it from the Texan populations, and it lacks a microchromosome that occurs in Texan populations. In addition, in this paper we present new comparative genetic data confirming that the origin of A. dixoni itself was from a hybrid between an A. tigris marmorata [female] x A. gularis septemvittata [male], consistent with earlier studies.Item Hybridization between whiptail lizards in Texas : Aspidoscelis laredoensis and A. gularis, with notes on reproduction of a hybrid. (American Museum novitates, no. 3947)(American Museum of Natural History., 2020-03-06) Cole, Charles J.; Dessauer, Herbert C.; Paulissen, Mark A.; Walker, James M. (James Martin)Karyotypes and allozyme data for 32 genetic loci overwhelmingly support the conclusion that Aspidoscelis laredoensis is a diploid all-female species that had a hybrid origin between A. gularis x A. sexlineatus. Comparisons of allozymes in individuals representing three mother-to-daughter generations raised in the laboratory suggest that they reproduce by parthenogenetic cloning. In addition to two previously described morphotypes (pattern classes A and B) that occur in southern Texas, we report the existence of three all-female clonal lineages based on allozymes. Individuals of at least one of these lineages occasionally hybridize in nature with males of A. gularis, producing viable and healthy triploid offspring that can grow to adulthood, one of which herself produced an offspring in the laboratory and could have represented a new, clonal triploid species. The possibility exists that cloned offspring of triploid hybrids are present in South Texas and/or northern Mexico, awaiting discovery. These would represent a new species that would appear to be very similar to A. laredoensis.Item Karyotype of a South American teiid lizard, Cnemidophorus lacertoides. American Museum novitates ; no. 2671(New York, N.Y. : American Museum of Natural History, 1979) Cole, Charles J.; McCoy, C. J. (Clarence J.); Achaval, Federico."Two males typical of Cnemidophorus lacertoides from Abra de Perdomo, Uruguay, had a diploid number of 50 chromosomes, including 26 macrochromosomes (all telocentric or essentially so, excepting one pair of submetacentrics) and 24 microchromosomes. A dotlike satellite occurred on the end of the largest chromosome opposite the centromere (telocentric). A variant form of C. lacertoides occurring in an isolated population at Cabo Polonio, Uruguay, is reported also. This form has the dorsal color pattern reduced, but its karyotype and scutellation are similar to those of the typically patterned form. Among all other teiids whose chromosomes have been investigated, the karyotype of Cnemidophorus lacertoides is most similar to that of some Ameiva and Kentropyx striatus. The full significance of these observations to South American teiid systematics cannot be assessed, however, until additional comparative investigations are completed"--P. [1].Item Karyotypes and evolution of the spinosus group of lizards in the genus Sceloporus. American Museum novitates ; no. 2431(New York, N.Y. : American Museum of Natural History, 1970) Cole, Charles J."Karyotypes of all the species in the spinosus group of lizards of the genus Sceloporus were analyzed by means of the colchicine, hypotonic citrate, air-dried technique, employing both bone marrow and testicular tissues. The following cytogenetic phenomena were found within this species group: interspecific and intraspecific variation in chromosome number and morphology; polymorphism in local populations; cytologically recognizable sex chromosomes; and natural chromosomal aberrations. There are four general karyotypes in the species group, though some exhibit relatively minor variations. Diploid chromosome numbers range from a high of 40 (with nearly all chromosomes telocentric) to a low of 22 (with all or nearly all chromosomes metacentric or submetacentric). The cytogenetic data, together with ecological, behavioral, and biogeographic data, indicate that speciation within the group has produced several phylads. Karyotypic evolution primarily involved chromosomal centric fusion (whole-arm translocation). The proposed phylogeny of the group is strongly compatible with the evidence that desert-dwelling species were derived from ancestors occurring in tropical to subtropical forests"--P. 41-42.Item Karyotypes and systematics of the lizards in the variabilis, jalapae, and scalaris species groups of the genus Sceloporus. American Museum novitates ; no. 2653(New York, N.Y. : American Museum of Natural History, 1978) Cole, Charles J."Karyotypes of 11 species of Sceloporus are described and illustrated. Lizards included are all species of the variabilis group as recognized by Smith (1939), all species of the jalapae and scalaris groups as recognized by Thomas and Dixon (1976), and Sceloporus siniferus of the siniferus group (for comparisons). The lizards examined include four of the seven species placed in the genus Lysoptychus by Larsen and Tanner (1975), karyotypes of the other three species of which I described earlier. Data from karyotypes and other morphological characteristics suggest the following: (1) Lysoptychus is a junior synonym of Sceloporus; (2) the variabilis group is distinctive; (3) S. teapensis is not specifically distinct from S. variabilis; (4) the variabilis group includes S. variabilis, S. chrysostictus, S. couchii, S. cozumelae, and S. parvus; (5) the species in the jalapae group (S. jalapae, S. ochoterenae) are very similar to each other; and (6) the scalaris group (S. scalaris, S. aeneus, S. goldmani) is distinctive"--P. [1].Item Karyotypes of coralsnakes (Reptilia: Elapidae) from the western hemisphere, with comments on intraspecific variation and centric fission of chromosomes (American Museum novitates, no. 3972)(American Museum of Natural History., 2021-07-19) Cole, Charles J.Karyotypes are described for Micruroides euryxanthus from Arizona and Micrurus tener from Texas. These are compared with karyotypes of other elapids from around the world, which exhibit significant interspecific variation. The largest macrochromosome of M. euryxanthus, which is metacentric, is shared by only two other species of coralsnakes from the New World. This may be a shared ancestral chromosome homologous to the largest macrochromosome that occurs in most other snakes, including some of the Australian elapids. The karyotype of M. tener from Texas has a ZZ:ZW1W2 sex chromosome system, which differs from individuals of this species reported previously from Louisiana. Over the relatively young 35-million-year global history of the Elapidae, karyotypes appear to have varied more than those of most other snakes throughout a 140-million-year history.Item Karyotypes of six species of colubrid snakes from the Western Hemisphere, and the 140-million-year-old ancestral karyotype of Serpentes. (American Museum novitates, no. 3926)(American Museum of Natural History., 2019-04-29) Cole, Charles J.; Hardy, Laurence M.Karyotypes are described for six species of snakes from the Western Hemisphere, and comparisons are made with all species of snakes from around the world that have been karyotyped with modern methods. Although there is significant karyotypic variation in snakes, there is one basic karyotype that is shared by members of all families of snakes, representing widely divergent lineages, extending from today back through the evolutionary history of the Serpentes. Long-term survival of the ancestral snake karyotype may be a result of canalization, similar to some ancient chromosomes of turtles.Item Karyotypes of the five monotypic species groups of lizards in the genus Sceloporus. American Museum novitates ; no. 2450(New York, N.Y. : American Museum of Natural History, 1971) Cole, Charles J."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.Item Karyotypes of the North American parthenogenetic whiptail lizard Aspidoscelis velox, and return of Aspidoscelis innotatus to the synonymy of A. velox (Reptilia, Squamata, Teiidae). (American Museum novitates, no. 3936)(American Museum of Natural History., 2019-08-30) Cole, Charles J.; Cordes, James E.; Walker, James M. (James Martin)Aspidoscelis velox is a triploid parthenogenetic species with clonal inheritance. We studied karyotypes of population samples representing diverse localities from much of its range. All specimens were triploids, but six different karyotypes were found with small differences among them, apparently resulting from chromosomal mutations that occurred after the origin of the species. As in other parthenogens, karyotypes and allozymes reveal variant clones in A. velox, but we do not recommend naming any of these genetic lineages as separate species. Specimens from the vicinity of Kanab, Kane County, Utah, have been treated by other herpetologists as a separate but morphologically similar species, Aspidoscelis innotatus, based on the assumption that they represented a diploid species. That assumption, made without any genetic evidence of ploidy, was recently based on evidence of histoincompatibility among certain population samples, but that could have been caused by factors other than ploidy (e.g., mutations at histocompatibility loci). We have examined specimens from Kane County, Utah, and all individuals were triploids similar to other population samples of A. velox from Arizona and New Mexico.Item Kentropyx borckiana (Squamata, Teiidae) : a unisexual lizard of hybrid origin in the Guiana region, South America. American Museum novitates ; no. 3145(New York, N.Y. : American Museum of Natural History, 1995) Cole, Charles J.; Dessauer, Herbert C.; Townsend, Carol R.; Arnold, Margaret G."More than 100 females and yet no males of Kentropyx borckiana are known from northern South America and Barbados. Features of external morphology, karyotypes, and biochemical genetics (electrophoresis of proteins encoded by 45 presumptive gene loci) reveal that individuals of K. borckiana from Guyana represent a unisexual clone that originated from one or more parthenogenetic F1 hybrids between Kentropyx calcarata X Kentropyx striata, the other two species of this genus known previously from the Guiana Region. Comparisons include data for Kentropyx altamazonica also, including the first specimens known from Venezuela (Amazonas Territory). Although K. altamazonica and K. calcarata are morphologically similar, genetically they are quite distinct. Origin of the unisexual Kentropyx borckiana involved hybridization between both morphologically and ecologically distinct ancestral species, unlike several other unisexual lizards of Neotropica. For example, clones of the parthenogenetic Gymnophthalmus underwoodi, Cnemidophorus cryptus, and Cnemidophorus pseudolemniscatus originated in the Guiana Region from hybrids between morphologically and ecologically similar, yet genetically distinct, ancestral species"--P. 2.