GBIF Taxonomic Backbone & Wikipedia Registry Profile
Diagnosis. A small species of Chiasmocleis distinguished from all other members in the genus by the following combination of characters: (1) small size, SVL 17.2 – 18.3 mm in females, body ovoid; (2) snout round in dorsal and lateral views; (3) canthus rostralis indistinct, rounded in cross-section; loreal region posterior to nostril slightly concave; (4) skin on dorsal surfaces slightly shagreen (smooth in alcohol), with tiny tubercles and scattered miniature light dermal spines dorsolaterally; outer margin of tarsus and toe V with scattered minisized light spines; (5) fingers I and IV reduced, finger IV shorter than finger II; fingers basally webbed, slightly fringed, lacking discs; finger tips depressed, pointed asymmetrically; (6) toe I reduced; toes free, distinctly fringed, toes II – V having flat asymmetrically pointed discs, disc not grooved; (7) subarticular tubercles absent; inner metatarsal tubercle small, ovoid; (8) large unpigmented eggs; (9) in life, dorsal surfaces dark brown with minute white spots irregularly scattered on flanks and hind limbs; a whitish stripe extending from tip of snout along the canthal region reaching the posterior end of upper eyelid margin; fore limbs reddish brown; (10) in life, ventral surfaces brown with irregularly scattered white flecks, belly becoming translucent in posterior part; (11) iris dark brown in life. Comparisons. Chiasmocleis magnova can be distinguished from other species of Chiasmocleis by its distinctly reduced fingers I and IV. Additionally, in comparison to the Amazonian species of Chiasmocleis, the new species differs from C. anatipes by free toes, and by colouration (C. anatatipes has a white belly and ventral surfaces of legs with brown-black marks, fully webbed feet) (Walker & Duellman 1974, Rodríguez & Duellman 1994); from C. bassleri by fringes on toes and by colouration (C. bassleri has black inguinal spots, white belly with large black spots, pale dorsal surfaces of arms, lacks fringes on toes) (Dunn 1949, Rodríguez & Duellman 1994); from C. hudsoni by absence of grooved terminal discs and by colouration (C. hudsoni has white ventral surfaces with brown stippling on gular region and a brown reticulum on the limbs, and black plantar surfaces) (Parker 1940); from C. jimi by smaller size, tips of fingers III an IV not swollen, and by colouration (C. jimi has a cream heavily greyish spotted venter and lacks a light canthal stripe) (Caramaschi & Cruz 2001); from C. shudikarensis by smaller size, free toes and by colouration (C. shudikarensis has a light middorsal line, black inguinal spots, light median line on the throat, and cream ventral side with black spotting or mottling) (Dunn 1949); and from C. ventrimaculata by smaller size, free toes and by colouration (C. ventrimaculata has yellowish white ventral surfaces with large brown spots) (Andersson 1945). FIGURE 1. Adult female holotype of Chiasmocleis magnova sp. nov. (MHNSM 19993) in life. Photograph by J. Moravec. FIGURE 2. Ventral view of adult female holotype of Chiasmocleis magnova sp. nov. (MHNSM 19993) in life. Photograph by J. Moravec. Other species of Chiasmocleis from non-Amazonian regions are distinguished from C. magnova as follows: C. capixaba Cruz, Caramaschi and Izecksohn, C. cordeiroi Caramaschi and Pimenta, C. crucis Caramaschi and Pimenta, and C. leucosticta (Boulenger) all exhibit well-developed webbing on feet (Cruz et al. 1997, Caramaschi & Pimenta 2003). C. centralis Bokermann is larger (SVL 24.4 mm in female), has broader lateral fringes on toes. C. albopunctata (Boettger) is larger (SVL 28.2 – 38.0 mm in females) and, together with C. mehelyi Caramaschi and Cruz has less reduced fingers, broader white canthal stripes and numerous small spines on dorsum (Caramaschi & Cruz 1997). C. schubarti Bokermann is larger (SVL 20.4 – 34.5 mm in females), exhibits light longitudinal lines at posterior surfaces of thighs and a cream coloured venter marbled with dark brown blotches. C. atlantica Cruz, Caramaschi and Izecksohn is larger (SVL 30.0 – 31.8 mm in females) and has a cream coloured venter with dark marbling. C. carvalhoi Cruz, Caramaschi and Izecksohn has less reduced fingers, smooth dorsal skin and a whitish venter (Cruz et al. 1997). C. alagoanus Cruz, Caramaschi and Freire is larger (SVL 25.5 – 27.8 mm in females), has a more stubby body shape, a truncate snout in dorsal view, and a light longitudinal line at posterior side of thighs (Cruz et al. 1999). C. gnoma Canedo, Dixo and Pombal has less reduced fingers, weaker fringes on toes, posterior surface of thighs with cream longitudinal line, and belly boldly marbled in brown and pale cream (Canedo et al. 2004). C. panamensis Dunn, Trapido and Evans has less reduced fingers, a white venter with brown flecks and a light brown dorsum with irregular dark brown stripe (Dunn et al. 1948). The new species is somehow similar to an unnamed microhylid frog mentioned by Duellman & Mendelson (1995) as " Microhylidae incerta sedis " by sharing similar size, reduction of fingers I and IV and toe I, brown dorsum with minute cream spots, light canthal stripe, and grey venter with white flecks. However, C. magnova clearly differs from this taxon by the absence of an external tympanum, less reduced fingers and toes and a dark brown iris in life. The tympanum of C. magnova (diameter 0.8 mm) is embedded under the skin and covered by muscles posterodorsally. Similar tympanum condition was found also in C. bassleri (tympanum completely hidden under muscles) and C. ventrimaculata (tympanum hidden posteriorly).
