De Laet (2015) claimed that minimization of ad hoc hypotheses of homoplasy does not lead to a preference for trivial optimizations when analysing unaligned sequence data, as claimed by Wheeler (2012; ...see also Kluge and Grant, 2006). In addition, De Laet asserted that Kluge and Grant's (2006) parsimony rationale is internally inconsistent in terms of Baker's (2003) theoretical framework. We argue that De Laet used extraneous presuppositions to critique Wheeler's position and, as such, his criticism should be considered cautiously in terms of its scope. Finally, we demonstrate that considering Kluge and Grant's parsimony rationale as inconsistent rests on De Laet's misunderstanding of the ideographic character concept and the consequences of relating it to Baker's rationale.
A new species of
is described from the lowlands of southwestern Colombia. The new species exhibits a yellowish coloration in life, a character that it shares with other three species in the genus-
,
..., and
. The new species differs from all other congeners in having two chrome orange spots (=glandlike protrusions) on sacral region, smooth ventral skin, basal webbing between the toes, and distal papillae at tips of disc covers on fingers II-IV and toes II-IV. Further, the new species differs from all congeners by an uncorrected
of > 5.56% of the 16S rRNA gene fragment examined. In addition to the new species described herein, we demonstrated that the possession of a yellowish coloration in life optimizes unambiguously as a synapomorphy of a clade within
, which may be recognized as the
species group. We also discussed the phylogenetic significance of two morphological characters previously considered of systematic value in
, the occurrence of oval palmar tubercles (undivided) and longitudinal folds (of the vocal sacs) on the throat. On this basis, we demonstrated that these characters appear to be symplesiomorphies rather than synapomorphies of
. Regarding pointed disc covers (ungual flap) present in some species of
, we show that this character conflates various characters, involving variation in pad shape, dorsal outline of the disc (ungual flap), and dependence between discs of different digits. Finally, considering that phenotypic data are a valuable source of evidence in testing phylogenetic hypotheses of terraranan frogs, we encourage future research to incorporate phenotypic evidence into phylogenetic studies involved in the genus
.
We describe a new species of Pristimantis from one of the most isolated regions of Colombia, at elevations of 700–800 m in the Tame River basin at the eastern slope of the Cordillera Oriental in ...Colombia (Department of Arauca). This locality has been in the grasp of guerrilla groups and right-wing paramilitaries, and as a consequence, this region has been historically inaccessible or risky for researchers. The new species is a diurnal forest dweller, similar to Pristimantis savagei and P. vilarsi. It is distinguished from its congeners by having finely shagreened dorsum skin, areolate ventral skin, moderate tympanic membrane size (length = 37.2–58.8% of eye length), long hind limbs (tibia length = 53.6–63.6% of snout–vent length), and an advertisement call composed of a short single note, while lacking ridges on scapula, tubercles on upper eyelid and heel, and basal webbing in toes. In addition to the new species described herein, we demonstrate that subarticular tubercles display more variation than what is commonly described in taxonomic studies of terraranan frogs.
Abstract
Ancestral character-state reconstruction is a powerful method in phylogenetics that can be applied to elucidate the evolutionary history of secondary sexual characters. Here, we surveyed the ...variation and reconstructed the ancestral states of secondary sexual characters (i.e. sexual dichromatism, vocal slits and nuptial pads) for the most species-rich genus of anurans (Pristimantis) using maximum parsimony, maximum-likelihood and Bayesian methods. This study demonstrates that at least five independent transformation series account for the occurrence of sexual dichromatism in Pristimantis: dorsum, throat, venter, groin and posterior surface of thighs. The ancestral reconstructions suggest that the most recent common ancestor of Pristimantis lacks sexual dichromatism on these five body areas. Likewise, the occurrence of vocal slits and the absence of nuptial pads were inferred as ancestral conditions. Morphological synapomorphies were identified for Yunganastes and two infrageneric units within Pristimantis (the Pristimantis devillei and Pristimantis unistrigatus species groups). Our results demonstrate that the evolutionary history of the secondary sexual characters in Pristimantis followed a rather complex pattern of multiple independent gains and losses for which this genus is a promising model to investigate the evolution of secondary sexual characters in the context of the complex interactions between natural and sexual selection.
Abstract
Brachycephaloidea (composed of 1183 species) is the most diverse superfamily of amphibians. In recent years, molecular techniques utilizing genetic markers have significantly improved our ...understanding of the phylogeny of this superfamily. However, with the expansion of molecular techniques, phenotypic characters have received increasingly less attention. In an effort to highlight the contributions that phenotypic characters can make to understanding the phylogeny of Brachycephaloidea, we studied novel characters from pelvic and thigh musculature and digital discs on fingers. On this basis, we provide new phenotypic synapomorphies to recognize three clades previously recognized solely on the basis of DNA. The first two synapomorphies, related to the origins of the m. iliacus externus and m. tensor fasciae latae, diagnose Ceuthomantis and Phrynopus, respectively. The third synapomorphy, related to the relative size of the disc on finger I, diagnoses the Pristimantis conspicillatus species group, which is the largest species group within the species-rich genus Pristimantis. We conclude that phenotypic data are a valuable source of evidence in testing phylogenetic hypotheses of Brachycephaloidea and emphasize the need to reassess all phenotypic characters previously used in brachycephaloid taxonomy to delimit them objectively as transformation series and include them in total evidence analyses.
The Andean Cordilleras of Colombia, especially the Cordillera Occidental, are among the areas with the highest diversity of Pristimantis frogs in the world. Within the Cordillera Occidental, the ...Serranía de los Paraguas is famous for its high diversity of sympatric species of Pristimantis frogs. In this study, we investigated acoustic frequency segregation in five sympatric and syntopic species of the genus Pristimantis inhabiting this Serranía. It is important to point out that three of the five species' calls are described for the first time: Pristimantis brevifrons, P. ptochus, and P. silverstonei. Our results showed that acoustic frequency segregation occurs among these five Pristimantis species. Another notable result was the inverse relationship between dominant frequency and male body size, which was corroborated in all species except in P. alius. Finally, we suggested that for improving our knowledge on species coexistence in Pristimantis, future research should also focus on species history and character evolution, given that the evolutionary history is also fundamental for explaining species coexistence.
The Serranía de los Paraguas is a mountainous region situated in the central part of the Cordillera Occidental of Colombia. It rises some 2500 m above the wet forest and supports a high concentration ...of species richness and endemism for plants and terrestrial vertebrates (amphibians, birds, and mammals). In the case of amphibians, 61 named species occurring in The Serranía de los Paraguas are recognized in the literature, which are mostly the works of J.D. Lynch and P. Ruíz-Carranza in the 1990s. During a 9-d survey in the wet season (19–27 July 2019) on the Reserva Natural Comunitaria Cerro El Inglés (one of the hills of the Serranía de los Paraguas) on the frontier between Chocó and Valle del Cauca departments, we discovered two new species of the genus Pristimantis. Both species share a divided palmar tubercle as well as a distinctive color pattern on the groin, of which both are distinctive within Pristimantis. The first new species is distinguished by its small size and having a distinctive carmine red color pattern on groin, uniform lateral fringes on fingers (no crenulated), palmar tubercle deeply bifid (or divided), advertisement call composed of a short single note distinctly pulsed, and absence of nuptial pads as well as hyperdistal tubercles, inner tarsal tubercle and fold, and partial fusion of Toe IV and V. The second new species is distinguished by having dermal ridges on scapular region, conical tubercle on upper eyelid and heel, palmar tubercle divided, differentiated tympanic membrane, males with vocal slits, orange spots on groin, advertisement call composed of distinctly pulsed 6–8 notes, and absence of dorsolateral folds as well as cranial crest, hyperdistal tubercles, and toe webbing. Considering these new species, the number of amphibians inhabiting the Serranía de los Paraguas has increased to 63 species. It is important to point out that within this outstanding species richness of amphibians, there are 10 endemic species and 17 threatened species according to the International Union for Conservation of Nature Red List (7 Critically Endangered, 5 Endangered, and 5 Vulnerable). Likewise, it is noteworthy that 29 terraranan species can be found in the Reserva Natural Comunitaria Cerro El Inglés. Thus, based on the species richness, endemism, diversity at higher taxonomic levels, and the number of threatened species, it seems reasonable to say that the Serranía de los Paraguas is a priority site for conservation of amphibians in Colombia.
Abstract
Convergent evolution has been shown to be a prominent feature of anuran evolutionary history. Studying the morphological pathways involved in the evolution of a convergent character allows ...us to test whether deterministic or contingent forces drive the evolution of characters. Here, we have assessed the morphological pathways associated with arboreal habits in species of six families of anurans (Hylidae, Eleutherodactylidae, Strabomantidae, Centrolenidae, Bufonidae and Hemiphractidae) through a comparative analysis of 19 phenotypic characters related to climbing ability. All species showed differences in the assessed characters, exhibiting variations in the distribution of their states and different ranges in all limb lengths. These variations implied a wide distribution across the morphospace as defined by a non-metric multidimensional scaling analysis (NMDS), with Rhinella paraguas (Bufonidae) being the most distinctive species, presenting unique characters such as the absence of intercalary elements, adhesive pads, subarticular tubercles and interphalangealis muscles of the hands. Our findings demonstrate that the morphological mechanisms involved in climbing ability of the ten species are different, suggesting distinct morphological pathways. Consequently, we advocate that historical contingency has an essential role in the evolution of arboreal habits among the species studied.
We describe two new species of Pristimantis from southwestern Colombia. The first new species inhabits the humid Pacific slopes of the Cordillera Occidental, Valle del Cauca; it is most similar to ...three allopatric Ecuadorian species—P. eugeniae (Lynch and Duellman 1997), P. nyctophylax (Lynch 1976), and P. subsigillatus (Boulenger 1902). It is distinguished, however, by having subarticular tubercles beneath the joint between distal phalanges, basal webbing on outer edge of toe IV, papilla at the tip of snout, and uniform cream-brown coloration on the anterior surfaces of thighs and in the groin. The second new species inhabits the high mountains of the Cordillera Central, Cauca, and it is most similar to P. boulengeri (Lynch 1981) and two Peruvian species—P. deyiLehr et al. 2013 and P. schultei (Duellman 1990). However, it differs by having subarticular tubercles beneath the joint between distal phalanges, dorsal skin with low warts, papilla at the tip of snout, and by lacking tympanic membranes, dentigerous processes of the vomer, and vocal slits.
The island of Hispaniola (Dominican Republic and Haiti) is home to four endemic species of treefrogs: Hypsiboas heilprini, Osteopilus dominicensis, O. pulchrilineatus and O. vastus. These species ...occur sympatrically over large areas below 1,850 m elevation and are commonly encountered together. We redescribe the external larval morphology of O. dominicensis, O. vastus, and Hybsiboas heilprini, and describe the tadpole of O. pulchrilineatus for the first time based on laboratory-reared specimens representing stages from earlyâlate metamorphosis. Some tadpoles were raised to adults in order to confirm species identity. We document intraspecific variation in labial tooth-rows formulas, report ontogenetic changes in coloration, compare tadpoles of related species, and provide an identification key to the hylid tadpoles of Hispaniola. Hispaniolan hylid tadpoles inhabit fast-running streams or pools. Whereas the lotic larvae of O. vastus and H. heilprini exhibit characteristics commonly associated with flowing water (robust body with strong tail musculature, small to medium fins, relatively enlarged oral disc, increased number of labial tooth rows, and complete marginal papillae), the lentic tadpoles of O. dominicensis and O. pulchrilineatus are characterized by morphological adaptations to ponds (medium-sized body and tail musculature, high fins, small oral disc, fewer number of labial tooth rows and incomplete marginal papillae). Consequently, the tadpole of O. vastus is more similar to that of H. heilprini than it is to its congeners.
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