Saturday, March 16, 2019

[Herpetology • 2019] Lynchius megacephalus • A Bizarre New Species of Lynchius (Anura, Strabomantidae) from the Andes of Ecuador and First Report of Lynchius parkeri in Ecuador

Lynchius megacephalus 
Sánchez-Nivicela, Urgiles, Navarrete, Yánez-Muñoz & Ron, 2019

We describe a new species of Lynchius from the eastern montane forest of southern Ecuador. We also report the occurrence of L. parkeri in Ecuador, on paramos of Yacuri National Park, near the border with Peru. We used morphological and genetic evidence for the description of the new species and the new report of L. parkeri. Phylogenetic analyses were carried out using both maximum likelihood and Bayesian inference on DNA sequences for mitochondrial and nuclear genes. The phylogeny shows that L. simmonsi is sister to a clade composed of the remaining species of Lynchius and that the new species is sister to L. flavomaculatus. The new species has a prominent and heavily ossified head with noticeably spiculate cranial exostosis that easily distinguishes it from all its congeners. The dorsal region and limbs present several reduced subconical and rounded tubercles and pronounced dermal ridges on the dorsum. We also describe the osteology of the new species based on x-rays of the holotype. Only six species of Lynchius, two known to occur in Ecuador (L. flavomaculatus and L. simmonsi). The description of Lynchius megacephalus sp. nov. and new record of L. parkeri double the number of known Lynchius in Ecuador and suggest that the diversity of Ecuadorian and Peruvian Lynchius is still underestimated.

Keywords: Systematics, osteology, morphology, co-ossified skull, natural history, Morona Santiago, new record, Amphibia

Holotype of Lynchius megacephalus sp. n., female MZUA.AN.0633 (SLV 41.8 mm) in life.

Lynchius megacephalus sp. nov.

Etymology. The name megacephalus is derived from the Greek mega meaning big and cephala meaning head. The name refers to the wide and robust head of this new species. The epithet is used as a noun in apposition.

Distribution and Natural history. Lynchius megacephalus is only known from one specimen collected at the type locality in the Tinajillas-Río Gualaceño Ecological Conservation Area, Morona Santiago province, 2770 m of elevation. The holotype was collected during the night (approximately 22h00) on the forest floor, between leaflitter in the middle of a heavy rainy week. The ecosystem is Eastern Montane Forest (according to Ron et al. 2018 natural regions). The forest at the type locality is characterized by small streams and leaflitter> 10 cm thick ( Urgilés & Nieves 2014). The dense canopy can exceed 20 m height. The vegetation includes species of the genus Oreopanax, Weinmannia, Cinchona, Chusquea, and Baccharis (Baez et al. 2013). The new species was recorded in sympatry with Pristimantis versicolor, P. andinognomus, P. atratus, P. cryophilius, P. gualacenio, P. proserpens, P. spinosus, and an undescribed Lynchius species similar to L. flavomaculatus.

Juan C. Sánchez-Nivicela, Veronica L. Urgiles, María José Navarrete, Mario H. Yánez-Muñoz and Santiago R. Ron. 2019. A Bizarre New Species of Lynchius (Amphibia, Anura, Strabomantidae) from the Andes of Ecuador and First Report of Lynchius parkeri in Ecuador. Zootaxa. 4567(1); 1–24. DOI: 10.11646/zootaxa.4567.1.1 

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