Rhinella inopina Vaz-Silva, Valdujo & Pombal, 2012, sp. nov.

Abstract

<i>Rhinella inopina</i> sp. nov. <p>(Figs. 1–2)</p> <p> <i>Rhinella</i> cf. <i>pombali</i> - Valdujo <i>et al</i>. 2009: 905.</p> <p> <b>Holotype.</b> Brazil, State of Goiás, São Domingos municipality (13º23'S; 46º20'W), MNRJ 75231, adult male, S. P. Andrade and E. P. Vitor col., on 2 August 2010.</p> <p> <b>Paratypes.</b> Brazil, State of Goiás, São Domingos municipality (13º23'S; 46º20'W), MNRJ 53069, juvenile, F. F. Gontijo col., 28 January 2007; MNRJ 63752, adult female, R. M. F. Rodrigues col., 29 July 2009; MNRJ 67272, juvenile, S. P. Andrade and E. P. Vitor col., 0 9 May 2010; MNRJ 67273, juvenile, S. P. Andrade and E. P. Vitor col., 10 May 2010; MNRJ 75232, juvenile, S. P. Andrade and E. P. Vitor col., 20 July 2010; MNRJ 75234 and MNRJ 75236, adult males, MNRJ 75235, adult female, MNRJ 75233, juvenile, S. P. Andrade and E. P. Vitor col., 25 July 2010.</p> <p> <b>Diagnosis.</b> A member of <i>Rhinella crucifer</i> species group based on the combination of morphological characters proposed by Duellman and Schulte (1992) and Baldissera <i>et al.</i> (2004) such as: presence of a row of glandular keratinized tubercles at the corners of mouth; absence of the pre-ocular ridge in the smaller specimens, but always present and strongly elevated in the larger ones; a row of glandular keratinized tubercles following the lateral edges of the body, with the first tubercle united or not to the parotoid gland; parotoid gland elliptical in dorsal view, triangular in lateral view and elongate; tympanum visible, covered by a tegumentary fold on posterior region; snout rounded to mucronate in dorsal view; and, dorsal integument varying from extremely granular to smooth. <i>Rhinella inopina</i> sp. nov. is characterized by the following combination of features: 1) largest size for the group (SVL 102.6 mm in males and 136.1 mm in females); 2) head wider than long (Fig. 2 A); 3) snout rounded to mucronate in dorsal view (Fig. 2 A); 4) snout rounded and elongated in lateral view (Fig. 2 B); 5) parotoid glands overhanging the lateral edges of body dorsally (Fig. 3); 6) in life and preservative yellow spots on flanks from posterior surface on parotoid gland to inguinal region, posterior surface of thighs and near the cloacae; 7) vertebral line absent or very thin (Fig. 3); 8) a conspicuous fringe on the ventral surface of the tarsus; 9) parotoid gland elongated (Fig. 3); 10) oblique arrangement of the parotoid gland in relation the midline of the body (Fig. 1).</p> <p> <b> Comparisons with other species of the <i>Rhinella crucifer</i> species group.</b> The new species is distinguished from <i>Rhinella ornata</i> and <i>Rhinella abei</i> by the presence of yellow marks on flanks (in some specimens), around the cloacae and on the posterior surface of thighs (vs. absence), parotoid glands overhanging the lateral edges of body dorsally (vs. not overhanging), elongate parotoid gland in lateral view (vs. rounded), and presence of a fringe on the ventral surface of tarsus (vs. a row of small tubercles); from <i>Rhinella henseli</i> by the parotoid glands overhanging the lateral edges of body dorsally (vs. not overhanging), and presence of a fringe on the ventral surface of tarsus (vs. a row of small tubercles); from <i>Rhinella pombali</i> by elongated snout in lateral view (vs. short snout), and elongate parotoid gland in lateral view (vs. rounded); from <i>Rhinella crucifer</i> by the presence of yellow marks on flanks, around the cloacae and on the posterior surface of thighs (vs. only around the cloaca and thighs), and elongate parotoid gland in lateral view (vs. rounded). <i>Rhinella inopina</i> sp. nov. differs from the all other species of <i>R. crucifer</i> group by having an oblique arrangement of the parotoid gland in relation to midline of the body (ANP/POP: <i>R. inopina</i> = 0.72; <i>R. ornata</i> = 0.68; <i>R. abei</i> = 0.67; <i>R. henseli</i> = 0.59; <i>R. pombali</i> = 0.66; <i>R. crucifer</i> = 0.67).</p> <p> <b>Description of holotype.</b> An adult male (Fig. 1 A–B, Fig. 2 A–D) with body robust; head wider than long; head width 37% of SVL; snout rounded in dorsal and lateral views; <i>canthus rostralis</i> well defined by canthal crest, almost straight; loreal region slightly concave; nostrils lateral, protuberant, slightly directed backwards, near to the snout tip; inter-nostril distance smaller than the eye-to-nostril distance (IND / END = 0.90); eye diameter and upper eyelid width larger than the tympanum diameter (ED/TD = 1.23; UEW/TD = 1.07); eye-to-nostril distance smaller than eye diameter (END /ED = 0.78), upper eyelid width (END /UEW = 0.89), and tympanum diameter (END /TD = 0.96); eye diameter larger than the upper eyelid width (ED/UEW = 1.14) and tympanum diameter (ED/TD = 1.23); upper eyelid width 51% of interorbital distance; preorbital and supraorbital crests developed; parietal crest absent; postorbital crest weakly developed; tympanum large, vertically elliptical, with a distinct annulus; horizontal diameter of tympanum 90% of the vertical diameter; parotoid glands, in dorsal view, medium size, elliptical (on right side more elongated), in lateral view triangular connected with the postorbital crest; paratoid gland length larger than the postorbital crest length; small V-shaped incision on maxilar symphysis; vocal sac not visible externally; vocal slits, sideways to the tongue; choane oval, small, lateral, widely separated; tongue large, two times long as wide, free and not notched behind. Forearms robust, arms slender; hand with long and slender fingers, not webbed, in crescent order of size, II IV<I<III; lateral fringes poorly developed, formed by a line of spinulose tubercles, absence on inner surface of finger I; finger tips slightly expanded; palmar tubercle large, nearly ovoid, smooth; thenar tubercle approximately one third of the palmar tubercle, ovoid, smooth; subarticular tubercles developed, protruding, single, except by divided distal tubercle on the III finger; numerous supernumerary tubercles varied in size, distinct, rounded, irregularly distributed on the ventral surfaces of hand and fingers; keratinous small spicules on the upper surfaces of the finger I and part of finger II. Legs moderately robust; thigh length slightly smaller than tibia length (THL/TBL = 0.95); sum of tibia and thigh lengths 84% of SVL; tarsus-foot length larger than the tibia and thigh lengths, 58% of SVL; outer metatarsal tubercle small, rounded; inner metatarsal tubercle small, elliptical, with the external border free; foot medium-size, with robust toes; toes in increasing order of size, I<II<III V<IV; webbing moderately developed, plantar formula I2-2II1-3 - III2 +-4- IV4-2 +V; small rounded bulbs toe tips, smooth, posteriorly delimited on ventral surfaces by a groove; subarticular tubercles small, conical, unique; supranumerary tubercles distinct, rounded or conical, unequal in size, irregularly distributed on the ventral surfaces of foot and toes. Skin on dorsum, flanks, and limbs with many irregularly distributed round warts; ventral surfaces finely granulose; warts of dorsum, limbs and granules on throat with many keratinized tips.</p> <p> <b>Color of holotype in preservative.</b> General color of body grayish light olive; a tiny vertebral light gray line; a light gray bar on tarsus; some light olive small elongated blotches and spots on the thighs; keratinized spicules on brown warts, tympanum light brown; iris silver. Under surfaces cream olive, throat slightly darker than belly; tubercles on hand palms and sole of feet brown.</p> <p> <b>Measurements of holotype (in mm).</b> Snout-vent length 92.5; head length 26.3; head width 34.3; inter-narial distance 5.5.; eye to nostril distance 6.1; eye diameter 7.8; upper eyelid width 6.8; interorbital distance 13.2; eye border to upper maxilla distance 3.2; canthal ridge length 7.8; supratympanic ridge length 5.6; eye to tympanum distance 2.2; tympanum diameter 6.3; tympanum height 7.0; inter-parotoid distance 24.2; forearm length 22.0; upper arm length 28.7; inner carpal tubercle length 4.2; inner carpal tubercle width 2.5; hand length 11.3; armpitgroin distance 33.3; thigh length 38.0; tibia length 40.0; tarsal length 21.1.</p> <p> <b>Variation.</b> The variations in measurements are summarized in Table 1. <i>Rhinella inopina</i> has typical color polymorphism found in the species of the <i>Rhinella crucifer</i> group (e.g. Baldissera <i>et al.</i> 2004). In life, color pattern varies from uniform yellowish-cream to brown, with sparse dark spots adjacent to vertebral line, which may be absent. Females have more numerous yellowish flank blotches than males. Males usually have uniform color pattern, whereas juveniles tend to be blotchy. Discontinuous dark stripes on the internal surface of thighs more frequent in juveniles (Fig. 3). Color in preservative is similar to color in life, except the yellow color is replaced with cream.</p> <p> <b>Etymology.</b> Inopinus, an adjective, is a Latin word, meaning unexpected. The name is appropriate because is the most inland species of the <i>Rhinella crucifer</i> species group. The other species known of the <i>Rhinella crucifer</i> species group are found in Atlantic Forest Biome, except for <i>R. pombali</i> which is distributed in the domains of the Central Brazilian Plateau, in the transition from the Atlantic Rain Forest to the Cerrado (Baldissera <i>et al</i>. 2004).</p> <p> <b>Natural History.</b> Adult males were found calling during a rainy night, after 0h00, in November 2008. It was one of the first heavy rains of the rainy season. The toads were found in the water very close to the margins of a temporary pond next to São Desidério river, in a valley between two calcareous rock outcrops, a location known as Pedra do Santo, municipality of São Desidério, State of Bahia. One amplected couple was found during the same night and another female was found four days before during a drier night in the same location. Other species calling from the same pond were <i>Hypsiboas crepitans</i> (Wied-Neuwied 1824), <i>Dendropsophus nanus</i> (Boulenger 1889), <i>Leptodactylus mystaceus</i> (Spix 1824), and <i>Leptodactylus</i> cf. <i>chaquensis</i> Cei 1950. At Sítio d´Abadia juvenile specimens were captured close to Corrente river in pitfall traps in deciduous forest dominated by <i>Acacia farnesiana</i> (L.) Willd., a tree species typical of Caatinga biome. At São Domingos adult specimens were collected in areas of gallery forest of the São Domingos and Galheiros rivers, and Dry Forest with calcareous rock outcrop (Fig. 4). During the dry season specimens were found inside caves.</p> <p> <b>Geographic Distribution.</b> <i>Rhinella inopina</i> has been found in São Domingos municipality (type locality) and Sítio d´Abadia municipality, in Goiás State, Combinado municipality and Aurora do Tocantins municipality, in Tocantins State and São Desidério municipality, in Bahia State (Fig. 5).</p> <p> <b>Remarks.</b> The Cerrado Biome covers about 2 million km2, representing 22% of Brazil, and small areas in eastern Bolivia and northwestern Paraguay. It extends from the southern borders of the Amazonian forest to areas in the southern States of São Paulo and Paraná. The distribution of the Cerrado is coincident with the plateau of central Brazil (Oliveira-Filho & Ratter 2002). <i>Rhinella inopina</i> occurs in the Cerrado biome, having the most inland distribution within the <i>R. crucifer</i> group, and it is apparently restricted to the disjunct Seasonal Tropical Dry Forests enclaves in western Cerrado.</p> <p> The <i>Rhinella crucifer</i> species group is widely distributed in Atlantic Forest. Only <i>R. pombali</i>, <i>R. crucifer,</i> and <i>R. inopina</i> are known to occur in the transition zones or within the Cerrado biome (Baldissera <i>et al</i>. 2004; Thomé <i>et al</i>. 2010). <i>Rhinella inopina</i> is allopatric to all other species in the group, and its distribution is associated with forest vegetation types in eastern Cerrado, such as seasonal tropical dry forest, semidecidual forest and gallery forest in karstic relief and limestone areas, all in the transition between Cerrado and Caatinga biomes. So far, we have detected five populations of this species that depend upon the conservation of forest vegetation in eastern Cerrado to persist.</p>Published as part of <i>Vaz-Silva, Wilian, Valdujo, Paula Hanna & Pombal, José P., 2012, New species of the Rhinella crucifer group (Anura, Bufonidae) from the Brazilian Cerrado, pp. 57-65 in Zootaxa 3265</i> on pages 58-63, DOI: <a href="http://zenodo.org/record/212911">10.5281/zenodo.212911</a&gt