Wednesday, December 27, 2023

[Herpetology • 2023] Rhinella kukaMisjudged for Long: A New toad of the Rhinella veraguensis species group (Anura: Bufonidae) from the Yungas Forests of Bolivia

Rhinella kuka 
Köhler, Vences, Padial, Plewnia & Lötters, 2023

We re-evaluate the taxonomic status of specimens of Rhinella collected from rainforests on the eastern Andean slopes and foothills of central Bolivia. The respective populations have been allocated to different nominal taxa, namely Rhinella fissipes and R. leptoscelis, in the past. By detailed morphological comparisons, including the type specimens of crucial taxa, as well as a phylogenetic analysis based on the mitochondrial 16S rRNA gene, we here demonstrate that the focal populations represent a divergent lineage within the Rhinella veraguensis species group, being apparently closely related to R. rumbolli from northern Argentina, but only distantly related to R. leptoscelis, with which they share several morphological character states. Also, the specimens of the focal lineage differ by a unique combination of morphological character states from all known nominal species currently assigned to the R. veraguensis group. Consequently, we describe this lineage as a new species. We discuss the history of its changing taxonomic allocations and demonstrate that former conclusions were barely justified and wrong. We also provide a description of the osteology of this species using computer tomography (micro-CT). Furthermore, we discuss the status of the nominal taxon Bufo pleuropterus Schmidt, 1857, currently considered to represent a junior synonym of Rhinella margaritifera (Laurenti, 1768), and provide arguments for the specific distinctness of these two taxa. Consequently, we regard Rhinella pleuroptera (Schmidt, 1857) a valid species. Based on its external morphology, which is rather similar to that of R. inca, we speculate that R. pleuroptera is possibly related to species in the R. veraguensis group, although this remains in need of further research. 

Key words. Amphibia, Bufo pleuropterus, computer tomography (micro-CT), molecular genetics, morphology, osteology, Peru, taxonomy, systematics

Rhinella kuka sp. n.
Dorsolateral views (left column) and ventral views (right column) of paratypes in life:
 (A, B) female ZFMK 72670; (C, D) female ZFMK 80036; and (E, F) male ZFMK 80035.

Rhinella kuka sp. n. 
Definition: A large-sized species in the Rhinella veraguensis species group, based on morphological similarities and phylogenetic relationships. The new species is characterized by (1) large size, SVL 62.8 mm in adult male (n = 1), SVL 66.0–72.1 mm in adult females (n = 5); (2) eight presacral vertebrae, presacrals I and II (atlas and axis) fused; skull hyperossified; (3) snout short, acuminate in dorsal view, rounded in lateral profile; (4) canthal, preorbital, supraorbital, and postorbital crests distinct and continuous; pretympanic crest present; supratympanic crest distinct, short; occipital crests prominent, elevated; (5) tympanic membrane and tympanic annulus distinct; tympanum slightly higher than wide, its diameter slightly more than ...

Etymology: The specific epithet kuka is the Quechuan word for the coca plant (Erythroxylum coca). It refers to the fact that the known distribution of the new species is largely equivalent to the major range of coca plantations in the Bolivian Yungas. The name is treated as a noun in apposition.

Jörn Köhler, Miguel Vences, José M. Padial, Amadeus Plewnia and Stefan Lötters. 2023. Misjudged for Long: A New toad of the Rhinella veraguensis species group (Anura: Bufonidae) from the Yungas Forests of Bolivia. SALAMANDRA. 59(4): 307–326.