Fig 1.
Bivariate plot derived from first two axes from scores of linear discriminant analyses performed for adult males (N = 124) of Xenopholis scalaris—Atlantic forest; Xenopholis scalaris—Amazon; Xenopholis undulatus, and Xenopholis werdingorum.
Fig 2.
Bivariate plot derived from first two axes from scores of linear discriminant analyses performed for adult females (N = 159) of Xenopholis scalaris—Atlantic forest; Xenopholis scalaris—Amazon; Xenopholis undulatus and Xenopholis werdingorum.
Fig 3.
Bivariate plot derived from first two axes from scores of linear discriminant analyses performed for adult males (N = 108) from subpopulations of Xenopholis scalaris—Atlantic forest, North Amazon and South Amazon.
Fig 4.
Bivariate plot derived from first two axes from scores of linear discriminant analyses performed for adult females (N = 113) from subpopulations of Xenopholis scalaris—Atlantic forest, North Amazon and South Amazon.
Table 1.
Analysis of 95% confidence intervals: Group 1 (Xenopholis scalaris—Atlantic forest); Group 2 (Xenopholis scalaris—AM, South of the Amazon river and West of Rio Negro); Group 3 (Xenopholis undulatus), Group 4 (Xenopholis werdingorum) and Group 5 (Xenopholis scalaris—AM, Northern Amazon river and East Rio Negro).
Fig 5.
Hemipenial morphology variability in asulcate (upper) and sulcate (lower) sides of organs of Xenopholis scalaris: X. scalaris from municipality of Magé, state of Rio de Janeiro, Brazil (A—IVB 3552); from municipality of Jaqueira, state of Pernambuco, Brazil (B—URCA 6210); from municipality of Canavieiras, state of Bahia, Brazil (C—CZGB 1089); from locality of Campamento San Jacinto, district of Trompeteros, region of Loreto, province of Loreto, Peru (D—CORBIDI 1512); from municipality of Paranaita, state of Mato Grosso, Brazil (E—ZUEC 3443,); from locality of Campamento Bajo algodon, district of Putumayo, region of Loreto, province of Putumayo, Peru (F—CORBIDI 17429); and from locality Sierra del Divisor, district of Yaquerana, Loreto region, province Requena, Peru (G—CORBIDI 2447).
Fig 6.
Population frequency of the hemipenes features through distribution of Xenopholis scalaris, considering its disjunct set of populations at Amazonia and Atlantic forest.
Graphs referring to the hemipenian variability of X. scalaris. For the population of the Atlantic Forest, 71.43% presented capitulum smaller than hemipenial body (blue) and 28.57% capitulum as long as the hemipenial body (orange) (100% of Amazonian hemipenis have capitulum equivalent to hemipenial body). Digital elevation model (DEM—GTOPO30) source: U.S. Geological Survey’s EROS Data Center in Sioux Falls, South Dakota. U.S. Geological Survey’s Center for Earth Resources Observation and Science (EROS) (open source).
Fig 7.
Predictions of species distribution models for: (a) Current climate and (b) Last Glacial Maximum for Xenopholis scalaris. (c) Current climate and (d) Last Glacial Maximum for X. undulatus. Digital elevation model source: Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010). Earth Resources Observation and Science (EROS) Center (open source). DOI: 10.5066/F7J38R2N.
Fig 8.
Predictions of species distribution for Xenopholis werdingorum using ensembling of small models.
(a) Current climate. Areas with high suitability are distributed in the Pantanal basin and also beyond the known range of this species in the lowlands of Caatinga, Cerrado and Chaco. (b) Last Glacial Maximum (LGM). The model for the LGM does not differ considerably, but suitability values are generally smaller for the past conditions. Digital elevation model source: Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010). Earth Resources Observation and Science (EROS) Center (open source). DOI: 10.5066/F7J38R2N.
Table 2.
Niche overlap (Schoener’s D metric) results for each pair of species and for the for the disjunct Xenopholis scalaris populations from Amazonia and Atlantic forest.
Fig 9.
Color variability of the Xenopholis scalaris in life.
A—tributary between Madeira and Purus Rivers, state of Amazonas, Brazil; B—D municipality of Juara, state of Mato Grosso, Brazil; E—municipality of Una, state of Bahia, Brazil; F—Itapuã do Oeste, state of Rondônia; G—Murici, state of Alagoas; H—Assis Brasil, state of Acre. Photos by V. Carvalho (A); T. Rodrigues (B–D); M. A. Freitas (E); D. Meneghelli (F); M. A. Freitas (G–H).
Table 3.
Selected variables synthesizing the meristic and morphometric variation of Xenopholis scalaris.
Fig 10.
Asulcate (A) and sulcate (B) side of the hemipenis of Xenopholis scalaris from municipality of Almadina, state of Bahia, Brazil (CZGB 13474).
Fig 11.
Dorsal (A), ventral (B), and lateral (C) views of the skull of Xenopholis scalaris (MNRJ 17070) from Cabo de Santo Agostinho, state of Pernambuco.
Abbreviations are as follow: Cb = compound bone; So = supraoccipital; Pro = prootic; P = parietal; F = frontal; Mx = maxilla; Na = nasal; Pm = premaxilla; Pf = prefrontal; Po = postorbital; Ect = ectopterygoid; St = supratemporal; Q = quadrate; Pt = pterygoid; Exo = exoccipital; V = vomer; Sm = septomaxilla; Pal = palatine; Pbs = parabasisphenoid; Bo = basioccipital; Ca = columella auris; and D = dentary.
Fig 12.
Three-dimensional cutaway views along the transverse axis of Xenopholis scalaris (MNRJ 17070), from the anterior edge of the skull.
Abbreviations are as follow: pt. Pm = transverse process of premaxilla; pa. Pm = ascendant process of premaxilla; pc. Sm = conchal process of septomaxilla; lf = lacrimal foramen of prefrontal; Po = postorbital; P = parietal; sos = frontal supraorbital shelf; ip = interolfactory pillar of frontal; of = optic foramen; p. of = parietal process of optic foramen; sub = subolfactory process of frontal; of c. = optic foramen canal of parabasisphenoid; Cb = compound bone; Q = quadrate; Pp = parietal pillar.
Fig 13.
Three-dimensional cutaway views along the longitudinal axis of Xenopholis scalaris (MNRJ 17070), from the dorsal edge of the skull.
Abbreviations are as follow: avsc = anterior vertical semicircular canal; pvsc = posterior vertical semicircular canal; cVc = crest of the Vidian foramina; hsc = horizontal semicircular process; cv = cavum vestibuli; mp = mesomedial process of prefrontal; smp = septomaxilar process of frontal; voc = vomeronasal organ capsule; lp = lacrimal process of prefrontal; lf = lacrimal foramen of prefrontal; of = optic foramen; P = parietal; Bo = basioccipital; oc = occipital condyle.
Fig 14.
Three-dimensional cutaway views along the longitudinal axis of Xenopholis scalaris (MNRJ 17070), from the ventral edge of the skull.
Abbreviations are as follow: cp = choanal process of palatine; pp = palatine process of maxilla; mp = maxillary process of palatine; onc = optic nerve canal; pr = parasphenoid rostrum; voc = vomeronasal organ capsule; pvp = posteroventral process of frontal; apVc = anterior opening of Vidian canal; So = supraoccipital; Exo = exoccipital; cv = cavum vestibuli; Pp = parietal pillar; P = parietal; F = frontal; Na = nasal.
Fig 15.
Known distribution of the genus Xenopholis.
Xenopholis undulatus is mostly distributed in riparian forests of the Cerrado and Caatinga highlands, whereas X. scalaris is mostly distributed in lowland tropical forests. Xenopholis werdingorum is distributed mostly within the Pantanal wetlands and in the Chiquitanos forests. Digital elevation model source: Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010). Earth Resources Observation and Science (EROS) Center (open source). DOI: 10.5066/F7J38R2N.
Fig 16.
Color variability of Xenopholis undulatus in life.
A—Palmas, state of Tocantins, Brazil; B—Lajeado, state of Tocantins, Brazil; C—Lindóia, state of São Paulo, Brazil; D—Salto da Divisa, state of Minas Gerais, Brazil. Photos by O. Marques (A); M. R. Duarte (B, C); M. A. Freitas (D).
Table 4.
Selected variables synthesizing the meristic and morphometric variation of Xenopholis undulatus.
Fig 17.
Asulcate (A) and sulcate (B) sides of the hemipenis of Xenopholis undulatus from state of Minas Gerais, Brazil (FUNED 2180).
Fig 18.
Dorsal (A), ventral (B), and lateral (C) views of the skull of Xenopholis undulatus (UMMZ 108820) from Lajeado, state of Tocantins.
Abbreviations are as follow: Cb = compound bone; So = supraoccipital; Pro = prootic; P = parietal; F = frontal; Mx = maxilla; Na = nasal; Pm = premaxilla; Pf = prefrontal; Po = postorbital; Ect = ectopterygoid; St = supratemporal; Q = quadrate; Pt = pterygoid; Exo = exoccipital; V = vomer; Sm = septomaxilla; Pbs = parabasisphenoid; Bo = basioccipital; Ca = columella auris; and D = dentary.
Fig 19.
Color variability of the Xenopholis werdingorum in life.
A–B Serra de São Vicente, state of Mato Grosso, Brazil; C—Pirizal, Nossa Senhora do Livramento, state of Mato Grosso, Brazil; D—Poconé, state of Mato Grosso, Brazil. Photos by A. Andrade-Jr. (A–B); C. Strussman (C) and O. Marques (D).
Table 5.
Selected variables synthesizing the meristic and morphometric variation of Xenopholis werdingorum.
Fig 20.
Asulcate (A) and sulcate (B) side of the hemipenis of Xenopholis werdingorum from Corumbá state of Mato Grosso do Sul, Brazil (UFMT-R 1193).
Fig 21.
Dorsal (A), ventral (B), and lateral (C) views of the skull of Xenopholis werdingorum (UFMT-R 12051) from Santo Antônio do Leverger, state of Mato Grosso.
Abbreviations are as follow: Cb = compound bone; So = supraoccipital; Pro = prootic; P = parietal; F = frontal; Mx = maxilla; Na = nasal; Pm = premaxilla; Pf = prefrontal; Po = postorbital; Ect = ectopterygoid; St = supratemporal; Q = quadrate; Pt = pterygoid; Exo = exoccipital; V = vomer; Sm = septomaxilla; Pal = palatine; Pbs = parabasisphenoid; Bo = basioccipital; Ca = columella auris; and D = dentary.
Table 6.
Comparison of the cranial morphology in the three species of the genus Xenopholis.