We describe a new species of Brachycephalus that is morphologically similar to the flea-toads B. didactylus, B. hermogenesi, and B. pulex. The new species occurs from the sea level up to 1000 m and it is widely distributed throughout southern Atlantic Forest. Brachycephalus sulfuratus sp. nov. is distinguished from all of its congeners by the combination of the following characters: (1) small body size (SVL of adults: 7.4-8.5 mm for males and 9.0-10.8 mm for females); (2) "leptodactyliform" body; (3) pectoral girdle arciferal and less robust compared to the Brachycephalus species with "bufoniform" body; (4) procoracoid and epicoracoid fused with coracoid but separated from the clavicle by a large fenestrae; (5) toe I externally absent; toes II, III, IV, and V distinct; phalanges of toes II and V reduced; (6) skin smooth with no dermal ossifications; (7) in life, general background color brown with small dark-brown spots; skin of throat, chest, arms, and forearms with irregular yellow blotches; in ventral view, cloacal region of alive and preserved specimens surrounded by a dark-brown inverted v-shaped mark outlined with white; (8) advertisement call long, composed of a set of 4-7 high-frequency notes (6.2-7.2 kHz) repeated regularly.

We describe a new species of Brachycephalus from municipality of São Francisco do Sul and municipality of Itapoá, in the state of Santa Catarina, Brazil, southern Atlantic Forest. The new species is known from six localities from near sea level up to 250 meters and represents the first record of a "pumpkin-toadlet" occurring in the lowlands. Morphological traits and phylogenetic analysis of a fragment the 16S mtDNA gene place the new species in the Brachycephalus pernix group. The new species is supported by external morphology, osteology, advertisement call, and mtDNA divergence. It is characterized, among other traits by a dorsal body color dark green with a dark brown vertebral stripe, and an orange background; snout-vent length of 9.2-10.8 mm in males and 11.1-12.4 mm in females; and advertisement call short (0.02-0.03 seconds), composed of one high-frequency note (dominant frequency 6.6-7.3 kHz). We observed synchronized alternation in the emission of vocalizations among neighbor males, indicating that males of the new species are able to hear and use vocalizations to interact with each other. We provide descriptions of clutch, eggs, and juvenile and observations on parental care. The new species has not been recorded within any protected area and can be threatened by human-induced habitat loss and modification.

Since the first, and simplest, description of a species of the genus Brachycephalus Fitzinger 1826, by Spix (1824), an increasing number of informative traits has been investigated to facilitate species diagnoses, including those dealing with osteology (Izecksohn 1971), sexual dimorphism in body size (Alves et al. 2006), hyperossification of the skull and skeleton (Haddad et al. 2010) and advertisement call (Garey et al. 2012), plus traits from molecular data (Condez et al. 2016). However, the recent descriptions of nine species of Brachycephalus (see Pie & Ribeiro 2015; Ribeiro et al. 2015; Bornschein et al. 2016) included inadequate diagnoses, which lacked indispensable information for any further comparisons among species. Herein, we intend to address the main flaws of these species descriptions and highlight the urgent need for a rigorous review of the genus Brachycephalus in order to assess the validity of these taxonomic proposals.

The advertisement calls are known for only eight species within the genus Brachycephalus. Herein, we describe the advertisement calls of B. olivaceus and B. quiririensis, both species from southern Atlantic Forest, state of Santa Catarina, Brazil. The advertisement calls of these species are similar, composed by one short and high-frequency note. The parameters range overlap between calls, as exemplified by the dominant frequency of 6.4–7.0 kHz in B. olivaceus and 6.2–6.5 kHz in B. quiririensis. Additionally, we provide a compilation of the available bioacoustic information for this genus.

Primeiro registro da rã-das-corredeiras Hylodes heyeri (Anura, Hylodidae) para o estado de Santa Catarina, sul do Brasil e comparação acústica com a espécie críptica Hylodes perplicatus (Anura, Hylodidae). Realizamos o primeiro registro da rã-das-corredeiras Hylodes heyeri para o estado de Santa Catarina, sul do Brasil, conhecida anteriormente de localidades ao longo da Mata Atlântica somente nos estados de São Paulo e Paraná. Devido à sua semelhança morfológica e por agora poderem ser encontradas em simpatria, nós também efetuamos uma comparação acústica entre os cantos de anúncio de H. heyeri e H. perplicatus. Há uma maior variação na duração do canto de ambas as espécies, do que consta na literatura, provavelmente relacionada à variação na temperatura do ar. Para distinguir as duas espécies, além das diferenças nas frequências dominantes, um parâmetro temporal que pode ser utilizado é o intervalo entre as notas, porém não a duração do canto devido à inluência da temperatura do ar. Essas descobertas reforçam a urgência de mais atividades de campo para o aumento do conhecimento sobre a distribuição geográica de anuros, sua conservação e chamamos a atenção para a importância de análises acústicas detalhadas para distinguir espécies crípticas.