# Hylodidae
**Hylodidae** (Günther, 1858) is a family of stream-dwelling frogs, the Giant Neotropical Torrent Frogs, endemic to the Atlantic Forest region of South America, ranging from northwestern Brazil to southern Brazil and northern Argentina.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) The family contains 48 recognized species in four genera: *Crossodactylus*, *[Hylodes](https://www.edgepedia.org/hylodes)*, *Megaelosia*, and *Phantasmarana*.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae)
| Key fact | Detail |
|---|---|
| Scientific name | Hylodidae Günther, 1858; earlier names include Hylodinae, Elosiidae, Elosiinae, and Elosiini[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) |
| Species count | 48 species in four genera[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) |
| Genera | *Crossodactylus* (13 species), *Hylodes* (26), *Megaelosia* (1), *Phantasmarana* (8)[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) |
| Distribution | Northwestern Brazil to southern Brazil and northern Argentina[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) |
| Common name | Giant Neotropical Torrent Frogs (de Sá, Condez, Lyra, Haddad, and Malagoli, 2022)[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) |
| Phylogenetic position | Sister taxon of Alsodidae; together with Batrachylidae and Cycloramphidae forms the clade Neoaustrarana[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) |
| Habitat | Streams and stream margins of the Brazilian Atlantic Forest; eggs and tadpoles restricted to streams in studied species[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC4498819/) • [3](https://onlinelibrary.wiley.com/doi/full/10.1111/btp.70208) |
## Composition and classification
The family-group name has a long synonymy. Günther established Hylodinae in 1858 with *Hylodes* Fitzinger, 1826 as type genus; Miranda-Ribeiro later proposed Elosiidae (1923) with *Elosia* Tschudi, 1838 as type genus, and the group was frequently referred to as Elosiinae in earlier literature before Savage (1973) restored Hylodinae.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae)
**Modern delimitation.** Frost, Grant, Faivovich, Bain, Haas, Haddad, de Sá, Channing, Wilkinson, Donnellan, Raxworthy, Campbell, Blotto, Moler, Drewes, Nussbaum, Lynch, Green, and Wheeler, in their 2006 amphibian tree of life (Bulletin of the [American Museum of Natural History](https://www.edgepedia.org/american-museum-of-natural-history) 297), treated the group as the subfamily Hylodinae of a broadly defined Cycloramphidae, alongside *Crossodactylus*, *Hylodes*, and *Megaelosia*.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) • [4](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Cycloramphidae) In the same year, Grant, Frost, Caldwell, Gagliardo, Haddad, Kok, Means, Noonan, Schargel, and Wheeler (Bulletin 299) showed that Hylodinae is the sister taxon of Dendrobatidae and recognized Hylodidae as a distinct family, distantly related to Cycloramphidae.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae)
**Shifting relationships.** Molecular work has since moved the family away from the poison-dart frogs. Pyron and Wiens, in a 2011 large-scale phylogeny of Amphibia based on 2,871 species, resolved Hylodidae as the sister taxon of Alsodidae and far from Dendrobatoidea; Grant, Rada, Anganoy-Criollo, Batista, Dias, Jeckel, Machado, and Rueda-Almonacid (2017) corroborated the sister-group relationship with Alsodidae.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) Streicher, Miller, Guerrero, Correa-Quezada, Ortiz, Crawford, Pie, and Wiens (2018) placed Hylodidae and Alsodidae together with Batrachylidae and Cycloramphidae in a monophyletic group they named Neoaustrarana.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) • [4](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Cycloramphidae)
## Generic relationships
A 2022 revision of the family by de Sá, Condez, Lyra, Haddad, and Malagoli, based on molecular and morphological evidence, produced the generic topology *Crossodactylus* + (*Phantasmarana* + (*Hylodes* + *Megaelosia*)), with *Phantasmarana* described as a new genus in 2021 by Vittorazzi, Augusto-Alves, Neves-da-Silva, Carvalho-e-Silva, Recco-Pimentel, Toledo, Lourenço, and Bruschi.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) Earlier morphological analysis by Nuin and Val (2005) had recovered *Megaelosia* + (*Crossodactylus* + *Hylodes*) with all three genera monophyletic.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) Later sampling complicated this picture: a phylogeny recovered the clade (Cycloramphidae (Hylodidae + Alsodidae)) and showed that the only sampled species of *Megaelosia*, *M. goeldi*, is embedded within *Hylodes*, suggesting that *Hylodes* may be paraphyletic.[5](https://teses.usp.br/teses/disponiveis/41/41133/tde-09082017-095226/publico/Rachel_Montesinos_SIMPL.pdf)
Morphological work has supplied family-level characters. Elias-Costa, Montesinos, Grant, and Faivovich (2017) reported vocal sac anatomy identifying synapomorphies of the family, and Elias-Costa, Araujo-Vieira, and Faivovich (2021) discussed the evolution of submandibular musculature on the Jetz and Pyron (2018) tree.[1](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae) Dias, Vera Candioti, Sabbag, Colaço, Silva, Haddad, Carvalho-e-Silva, and Grant (2021) reported on the comparative anatomy, systematics, functional morphology, and evolution of semiterrestrial tadpoles in the group, and Colaço, Bittencourt-Silva, and Silva (2020) discussed eye morphology as a possible synapomorphy (Shared derived trait defining an evolutionary group).[4](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Cycloramphidae)
## Ecology and conservation
Hylodids are obligate stream-dwellers in the mountainous Atlantic coastal forest of southern and southeastern Brazil. In *Hylodes asper*, adult males, females, and juveniles are restricted to streams, while in *H. phyllodes* the adults live on the forest floor away from streams after hatching and return only to breed; in both species eggs and tadpoles are restricted to streams.[3](https://onlinelibrary.wiley.com/doi/full/10.1111/btp.70208) A 2026 study found that host specificity and activity synchronization drive the incidence of frog-biting midges on torrent frogs.[3](https://onlinelibrary.wiley.com/doi/full/10.1111/btp.70208)
**Declines.** The late 1980s saw the first reports of mysterious drops in amphibian numbers across southern and southeastern Brazil, affecting multiple stream-breeding anuran species from the Hylodidae and Cycloramphidae; populations of *Hylodes* and *Crossodactylus* were said to have declined throughout the mountainous parts of the Atlantic coastal forest.[2](https://pmc.ncbi.nlm.nih.gov/articles/PMC4498819/) Several hylodids are threatened: *Hylodes glaber* is assessed as critically endangered, *Hylodes magalhaesi* as vulnerable, and *Crossodactylus dispar* and *Hylodes meridensis* as critically endangered, with the Serra da Mantiqueira and Serra do Mar ranges identified as hotspots for threatened Atlantic Forest amphibians.[6](https://repositorio.usp.br/directbitstream/c376c3b1-a213-4074-b832-f317b358d4d1/3192706.pdf) Species richness of the family, together with Brachycephalidae, Cycloramphidae, Hylidae, and [Microhylidae](https://www.edgepedia.org/microhylidae), is concentrated in southeastern Brazil.[7](https://doi.org/10.1002%2Fece3.1073)
## References
1. [Hylodidae Günther, 1858, Amphibian Species of the World 6.2, American Museum of Natural History](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Hylodidae)
2. [Seasonal Variation in Population Abundance and Chytrid Infection in Stream-Dwelling Frogs of the Brazilian Atlantic Forest, PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC4498819/)
3. [Host Specificity and Activity Synchronization Drive Frog-Biting Midge Incidence on Torrent Frogs (Hylodidae), Biotropica (2026)](https://onlinelibrary.wiley.com/doi/full/10.1111/btp.70208)
4. [Cycloramphidae Bonaparte, 1850, Amphibian Species of the World 6.2](https://amphibiansoftheworld.amnh.org/Amphibia/Anura/Cycloramphidae)
5. [Montesinos, R. (2017). PhD thesis, Universidade de São Paulo](https://teses.usp.br/teses/disponiveis/41/41133/tde-09082017-095226/publico/Rachel_Montesinos_SIMPL.pdf)
6. [Amphibian conservation status in Brazil: spatial patterns, threats, and challenges](https://repositorio.usp.br/directbitstream/c376c3b1-a213-4074-b832-f317b358d4d1/3192706.pdf)
7. [Campos et al. (2014). The efficiency of indicator groups for the conservation of amphibians in the Brazilian Atlantic Forest, Ecology and Evolution](https://doi.org/10.1002%2Fece3.1073)
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*Topic: Encyclopedia › Life and health › Animals › Vertebrates › Reptiles and amphibians › Amphibians › Frogs and toads (Anura) › Tree frogs and neotropical frog lineages › South American ground and stream frog lineages (Leptodactylidae, Hylodidae)*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 11, 2026; Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
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License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license