New species of flea-toad, genus Brachycephalus (Anura: Brachycephalidae) from the Atlantic Forest of Espírito Santo, Brazil

Abstract

We describe a new species of dull-colored flea-toad, genus Brachycephalus, from the Atlantic Forest of Caparaó mountains in southeastern Brazil. The new species is characterized by its diminutive size, “leptodactyliform” body, brownish color with an inverted V-shaped dark mark on dorsum, skin smooth, hyperossification and dorsal shield absent, linea masculinea absent, Fingers I and IV vestigial, Toe I externally absent, Toe II reduced but functional, Toes III and IV with pointed tips, Toe V vestigial, and ventral color uniformly brown. It is a leaf litter dweller, known only from type locality in the humid forests on the eastern slopes of Parque Nacional do Caparaó mountains, a protected area in the states of Espírito Santo and Minas Gerais, southeastern Brazil. It is the third flea-toad occurring in the state of Espírito Santo recovered as sister to all other Brachycephalus distributed from the state of São Paulo northward in the Atlantic Forest.

Relationships of mineralized dermal layer of mountain endemic miniature frogs with climate

“…Thus, we argue that expansion of heterogeneous MDL to these more exposed regions of the skin would possibly be a strategy that allows water loss reduction. Interestingly, the other montane group of Brachycephalus, B. ephippium, has other structures on the dorsum and sides of the body that have been tentatively associated with protection against desiccation, that is, dermal ossification and osteoderms, respectively (Ruibal & Shoemaker, 1984;Clemente-Carvalho et al, 2009;but Silva et al, 2021;Campos et al, 2010;Clemente-Carvalho et al, 2009Condez et al, 2014Condez et al, , 2020Condez et al, 2021;Folly et al, 2020;Guimarães et al, 2017;Nunes et al, 2021;Pombal Jr. & Izecksohn, 2011). We argue that this speculation opens an avenue for future studies on whether these structures have a function analogous to the dorsal and lateral MDL expansions of certain species of Brachycephalus in protecting against desiccation.…”

“…Interestingly, the other montane group of Brachycephalus , B. ephippium , has other structures on the dorsum and sides of the body that have been tentatively associated with protection against desiccation, that is, dermal ossification and osteoderms, respectively (Ruibal & Shoemaker, 1984; Clemente‐Carvalho et al., 2009; but see Vickaryous & Sire, 2009 and Condez et al., 2020 for other possible functions). All 14 described species of this group present dermal ossification, whereas three also present osteoderms ( B. crispus Condez, Clemente‐Carvalho et al., 2014, B. margaritatus Pombal Jr. & Izecksohn, 2011, B. nodoterga Miranda‐Ribeiro, 1920) (Almeida‐Silva et al., 2021; Campos et al., 2010; Clemente‐Carvalho et al., 2009, 2012, 2016; Condez et al., 2014, 2020; Condez et al., 2021; Folly et al., 2020; Guimarães et al., 2017; Nunes et al., 2021; Pombal Jr. & Izecksohn, 2011). We argue that this speculation opens an avenue for future studies on whether these structures have a function analogous to the dorsal and lateral MDL expansions of certain species of Brachycephalus in protecting against desiccation.…”

“…Restriction to colder and wet environments of mountain tops isolated by hotter environments at lower altitude, has been hypothesized as the reason why montane groups have diverged into so many species (Bornschein, Firkowski et al., 2016; Firkowski et al., 2016; Pie, Faircloth, et al., 2018). Brachycephalus pernix and B. ephippium groups include 19 and 14 species, respectively, whereas the B. didactylus group includes only five species (Almeida‐Silva et al., 2021; Bornschein, Pie et al., 2019; Condez et al., 2021; Nunes et al., 2021).…”