Craugastor mexicanus
Creators: name: Jameson, Tom J. M.
name: Streicher, Jeffrey W.
name: Manuelli, Luigi
name: Head, Jason J.
name: Smith, Eric N.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Amphibia
Anura
Craugastoridae
Craugastor
Craugastor mexicanus

description: <i>Craugastormexicanus</i> (Brocchi 1877) <i>Leiuperus mexicanus</i> Brocchi 1877:184. Holotype unsexed (MNHNP 6218) from ‘‘ Mexico ’’ (<i>¼</i> Cerro San Felipe, Oaxaca, Mexico [Smith and Taylor 1950]). [Examined]. <i>Paludicola mexicana</i> (Brocchi): Boulenger 1882:237; Neiden 1923:513. <i>Pleurodema mexicana</i> (Brocchi): Parker 1927:475. <i>Microbatrachylus oaxacae</i> Taylor 1940:505. Holotype male (FMNH 100001) from ‘‘Cerro San Flipe, near Oaxaca, Oaxaca, Mexico.’’ [Examined]. <i>Microbatrachylus lineatissimus</i> Taylor 1941:87. Holotype male (FMNH 1000036) from ‘‘Cerro San Flipe, near Oaxaca, Oaxaca, Mexico.’’ [Examined]. <i>Microbatrachylus fuscatus</i> Davis and Dixon 1957:146. Holotype female (TCWC 12171) from ‘‘ 20 miles east of Tulancingo, Hidalgo, Mexico.’’ [Not examined; neartopotypic specimen from Hidalgo examined (UTA A-66138)]. <i>Eleutherodactylus oaxacae</i> (Taylor): Lynch 1965:3. <i>Eleutherodactylus lineatissimus</i> (Taylor): Lynch 1965:3. <i>Eleutherodactylus mexicanus</i> (Brocchi): Gorham 1966:86. <i>Craugastor mexicanus</i> (Brocchi): Crawford and Smith 2005:536. <b>Diagnosis.</b> —Based on 26 specimens. Aspecies of <i>Craugastor</i> distinguished by the following combination of characters: (1) large adult size (maximum SVL <i>¼</i> 40.5 mm); (2) full ossification of the skeleton in adults; (3) presence of posterolateral projection of frontoparietal (Fig. 26B); (4) presence of vomerine odontophores (in larger individuals); (5) presence or absence of raised tubercles on eyelids, &lt;4 smooth to round and only slightly protruding tubercles; (6) supratympanic fold developed; (7) face flank, labium barred with or without distinctive canthal stripe; (8) one (or two fused) postrital tubercles; (9) gular region peppered with melanocytes; (10) dorsal surface extremely variable, ranging from dark or light stripes, dark hourglass, dark or pale dorsal stripe of different widths, being unicolored dark or pale brown, to bird-dropping coloration (black peppered grayish dorsum with a dirty white medial streak and bright-white heels), all color morphologies have variable presence of interocular band and suprascapular or rump blotching or stripping; in most snout colored as rest of body but sometimes pale; (11) variable middorsal ridge; (12) dorsal skin smooth or tubercular and may have hourglass and/or vertebral and/or paravertebral ridges; (13) body flank unicolored pale, slightly darker anteriorly, or spotted posteriorly and or anteriorly, supratympanic dark coloration sometimes reaching posterior axillary area; smooth to shagreened; (14) inguinal gland present and axillary gland sometimes present in adults; (15) when leg adpressed to body, heel reaches snout tip or beyond; (16) outer tarsal ridge with 0–5 rounded tubercles; smooth or with thick but only slightly raised fringe; (17) finger and toe tips round and expanded (rarely slightly spatulate or barely expanded and somewhat pointed); (18) inner metatarsal tubercle larger than outer metatarsal tubercle. <b>Comparisons.</b> — <i>Craugastor mexicanus</i> can be differentiated from <i>C. candelariensis, C. cueyatl, C. hobartsmithi,</i> and <i>C. portilloensis</i> by the equal sizes of the inner and outer metatarsal tubercles (unequal sizes in <i>C. mexicanus</i>). It can be differentiated from <i>C. bitonium</i> and <i>C. pygmaeus</i> by the absence of a posterolateral projection of the frontoparietal (present in C. <i>mexicanus</i>). It can be differentiated from <i>C. polaclavus</i> and <i>C. rubinus</i> by the absence of vomerine odontophores (present in <i>C. mexicanus</i>). It can be differentiated from <i>C. montanus</i> by the condition of supratympanic folds in adults; developed in <i>C. mexicanus</i> versus moderate to poorly developed in <i>C. montanus</i>. It can be differentiated from <i>C. omiltemanus</i> by ventral skin texture in life; smooth to granular in <i>C. mexicanus</i> versus areolate in <i>C. omiltemanus</i>. <i>Craugastor mexicanus</i> is most similar to <i>C. saltator</i>. We were unable to identify any reliable morphological characters to differentiate <i>C. mexicanus</i> and <i>C. saltator;</i> however, they have nonoverlapping geographic distributions, with <i>C. saltator</i> only occurring in western Guerrero (Fig. 6). <b>Description.</b> —In previous literature, described as largebodied, long-legged with row of small tubercles on outer edge of the tarsus (Taylor 1941); variable palmar tubercle arrangements (palmar tubercle divided, single, or evaginated; Lynch 1965); inner metatarsal tubercle larger than outer metatarsal tubercle; lack of tarsal tubercles (Lynch 2000). Holotype (MNHNP 6318) is large (~ 40 mm SVL); owing to poor preservation, columella of holotype partially ruptured the tympana on both sides (Fig. 1B); finger lengths III&gt; IV&gt; II&gt; I; toe length IV&gt; V <i>¼</i> III&gt; II&gt; I. <b>Distribution.</b> —This species is widespread throughout eastern Mexico in high-elevation habitats (1554–2700 m) of Oaxaca, Puebla, Hidalgo, and Veracruz (Fig. 6). These habitats span the Sierra Madre Oriental and Sierra Madre del Sur. Canseco Márquez and Gutiérrez Mayén (2010) report that <i>C. mexicanus</i> occurs in the forests adjacent to the Tehuacán-Cuicatlán Valley in Puebla and Oaxaca. It is likely this species occurs in Guerrero; however, most specimens resembling <i>C. mexicanus</i> we examined from Guerrero are referrable to <i>C. saltator</i>. Downloaded From: https://bioone.org/journals/Herpetological-Monographs on 04 May 2022 <b>Phylogenetics.</b> —The concatenated data set placed <i>C. mexicanus</i> as the sister taxon to a clade of <i>C. omiltemanus þ C. saltator</i> with high support in the BAYES analysis (0.98) but moderate support in the ML analysis (75; Fig. 3). This appears to be a relationship supported exclusively by the mtDNA data set because separate analysis of the nDNA markers did not confidently infer a sister taxon of <i>C. mexicanus</i> (Figs. 4 and 5). Although BAYES analyses strongly supported the monophyly of <i>C. mexicanus</i> (&gt; 0.90), the ML analyses recovered variable support ranging from 79 (concatenated analysis) to 54 (nDNA-only analysis). In terms of genetic distances (Table 4), <i>C. mexicanus</i> was most similar to <i>C. omiltemanus</i> (4.9%), followed by similarity to <i>C. saltator</i> (5.1%). <b>Intraspecific variation.</b> —We examined over 220 specimens of <i>C. mexicanus</i> for this revision (Appendix I), and briefly provide some patterns of intraspecific variation that we observed. Many populations have substantial colorpattern polymorphism (Fig. 27), similar to what is observed in the <i>C. rhodopis</i> series (Lynch 1966; Streicher et al. 2014). In some northern populations (Hidalgo and Puebla), the canthal mask is broken into a black spot posterior to the tympanum (often with a thin yet distinctive white margin). Specimens throughout Oaxaca varied in whether they had a single or divided palmar tubercle (as reported by Lynch 1965, see his Fig. 2); in six specimens we examined there was asymmetry with a single palmar tubercle on one hand and divided on the other. Patterns of dorsal ridging and coloration often coincide, with observations of the following morphs: (1) straight raised ridges that are tubercular and darker in coloration than the rest of the dorsum; (2) straight raised dorsal ridges that are tubercular but of the same color as the rest of the dorsum; (3) straight lines of color that are dark but with no tubercular raised ridges; (4) ridges that are not straight but form an hourglass shape and are tubercular; (5) ridges that are not straight but form an hourglass shape and are not tubercular; (6) scattered tubercles on the dorsum, which are sometimes dark and sometimes same color as the background; (7) pale or dark unicolored dorsum; (8) a unicolored dorsum with a pale median stripe that can be ridged or smooth; (9) a wide dark band on the dorsum, which usually co-occurs with a pale upper labium; and, (10) white hills of coloration and a peppered grayish dorsum sometimes with a diffused lighter cream color, a pattern that may mimic bird droppings (appearing superficially as a smear of uric acid and digestive waste). Downloaded From: https://bioone.org/journals/Herpetological-Monographs on 04 May 2022 <b>Remarks.</b> —The skull of <i>C. mexicanus</i> is similar to that of <i>C. omiltemanus</i> and <i>C. saltator,</i> with more anteriorly placed anterior suture of the frontoparietal and prootic than in other species. We noticed that the ‘‘ <i>M. lineatissimus</i> ’’ morphotype (raised and parallel ridges on the dorsum) occurs widely throughout the range of <i>C. mexicanus</i>. Interestingly, the examined paratype of ‘‘ <i>M. lineatissimus</i> ’’ has a unique skull shape for <i>C. mexicanus</i>. The shape is similar to that of <i>C. hobartsmithi, C. montanus,</i> and <i>C. pygmaeus,</i> with a more posteriorly placed anterior suture of the frontoparietal and prootic than in other species, coupled with a narrower back of the skull than in any other species (Fig. 27A). This unique condition likely explains the specimen as an outlier in several of our statistical analyses (Figs. 9, 11, and 12). However, we were unable to CT-scan other individuals with the ‘‘ <i>M. lineatissimus</i> ’’ morphotype (or the holotype of <i>M. lineatissmus</i>), so future investigation is necessary to determine whether the examined paratype (FMNH 104548) is an aberrant individual of <i>C. mexicanus</i> or represents a valid taxon. Lynch (1965) reports that ‘‘ <i>E. oaxacae</i> ’’ has parotoid glands. However, we saw no evidence of these glands in the two type specimens that we examined (FMNH 100001 and FMNH 126638), nor are we aware of any species of <i>Craugastor</i> that possess parotoid glands (<i>¼</i> large poison glands on the nuchal region). <i>Craugastor mexicanus</i> likely co-occurs with <i>C. omiltemanus</i> at high-elevation localities of central Oaxaca (Figs. 6 and 8). At intermediate elevation localities in Veracruz and Oaxaca, it may overlap with <i>C. pygmaeus</i> (Fig. 7). Male <i>C. mexicanus</i> have significantly larger tympana than do female <i>C. mexicanus</i> (Fig. 13).
description: Published as part of <i>Jameson, Tom J. M., Streicher, Jeffrey W., Manuelli, Luigi, Head, Jason J. &amp; Smith, Eric N., 2022, Miniaturization in Direct-Developing Frogs from Mexico with the Description of Six New Species, pp. 1-48 in Herpetological Monographs 36 (1)</i> on pages 27-29, DOI: 10.1655/0733-1347-36.1.1, http://zenodo.org/record/6518587
description: {"references": ["Brocchi, P. 1877. Sur quelques batraciens raniformes et bufoniformes de l'Amerique Centrale. Bulletin de La Societe Philomathique de Paris 1: 175 - 179. [In French.]", "Smith, H. M., and E. H. Taylor. 1950. Type localities of Mexican reptiles and amphibians. The University of Kansas Science Bulletin 33: 313 - 339.", "Boulenger, G. A. 1882. Catalogue of the Batrachia, Salientia and Ecaudata in the Collection of the British Museum. Natural History Museum Publications, UK.", "Neiden, F. 1923. Anura. I. Subordo Aglossa und Phaneroglossa, Sectio 1. Arcifera. Das Tierreich 46: 32 - 584. [In German.]", "Parker, H. W. 1927. A revision of the frogs of the genera Pseudopaludicola, Physalaemus, and Pleurodema. Journal of Natural History 20: 450 - 478.", "Taylor, E. H. 1940. Herpetological miscellany No. I. University of Kansas Science Bulletin 26: 489 - 571.", "Taylor, E. H. 1941. Some Mexican frogs. Proceedings of the Biological Society of Washington 54: 87 - 94.", "Davis, W. B., and J. R. Dixon. 1957. Notes on Mexican amphibians, with description of a new Microbatrachylus. Herpetologica 13: 145 - 147.", "Lynch, J. D. 1965. A Review of the Eleutherodactylid Frog Genus Microbatrachylus (Leptodactylidae). Chicago Academy of Science, USA.", "Crawford, A. J., and E. N. Smith. 2005. Cenozoic biogeography and evolution in direct-developing frogs of Central America (Leptodactylidae: Eleutherodactylus) as inferred from a phylogenetic analysis of nuclear and mitochondrial genes. Molecular Phylogenetics and Evolution 35: 536 - 555.", "Lynch, J. D. 2000. The relationships of an ensemble of Guatemalan and Mexican frogs (Eleutherodactylus: Leptodactylidae: Amphibia). Revista de La Academia Colombiana de Ciencias Exactas, Fisicas y Naturales 24: 129 - 156.", "Canseco Marquez, L., and M. G. Gutierrez Mayen. 2010. Anfibios y Reptiles del Valle Tehuacan-Cuicatlan. Comision Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO), Mexico.", "Lynch, J. D. 1966. Multiple morphotypy and parallel polymorphism in some neotropical frogs. Systematic Biology 15: 18 - 23.", "Streicher, J. W., U. O. Garcia-Vazquez, P. Ponce-Campos, O. Flores-Villela, J. A. Campbell, and E. N. Smith. 2014. Evolutionary relationships amongst polymorphic direct-developing frogs in the Craugastor rhodopis Species Group (Anura: Craugastoridae). Systematics and Biodiversity 12: 1 - 22."]}