A New Species of Marsupial Frog (Anura: Hylidae: Gastrotheca) from the Amazonian Slopes of the Cordillera Oriental in Peru

A new species of marsupial frog, Gastrotheca, with prominent cranial crests is described from humid montane forest on the eastern slopes of the Andes in Departamento de Pasco, Peru. The frog has an exceedingly robust cranium that most closely resembles that of G. cornuta; however, the cranial crests of G. cornuta are less well developed, and less obvious externally, than those of the new taxon. Within the genus Gastrotheca, one of the most variable parts of the skull is the squamosal, which has a variety of articular arrangements with the maxilla, the pterygoid, and in some taxa, the frontoparietal. In contrast to the modifications of dermal cranial elements, the postcranial skeleton seems to be relatively conserved in Gastrotheca.

Describimos una nueva especie de Gastrotheca de los bosques montanos de la vertiente oriental de los Andes en el Departamento de Pasco, Perú. La nueva especie se caracteriza por sus prominentes crestas craneales y por poseer un cráneo extremadamente robusto, similar al de G. cornuta; sin embargo, las crestas craneales de G. cornuta son menos evidentes extrenamente. En el género Gastrotheca, el hueso escamosal es una de las partes más variables del cráneo, teniendo una variedad de arreglos articulares con el maxilar superior, pterigoideo y, en algunos taxa, con el frontoparietal. En contraste con las modificaciones presentes en los elementos dermales del cráneo, el esqueleto postcraneal parece ser relativamente homogéneo en Gastrotheca.

Figure 1

Gastrotheca carinaceps.

Heinz Plenge photographed this individual, for which there is no voucher, in the Parque Nacional Yanachaga, Peru; the original photo appeared in a publication of the Instituto Nacional de Recursos Naturales (2000). Note the distinctive coloration of the ends of the fingers.

Figure 2

Palmar view of right hand (A) and plantar view of right foot (B) of holotype of Gastrotheca carinaceps (MHNSM 19901, female).

Figure 3

Skull of Gastrotheca carinaceps (MTD 45942, female) in dorsal (A), ventral (B), and lateral (C) aspects.

Abbreviations: fen ovalis = fenestra ovalis, fpar = frontoparietal, max = maxilla, nas = nasal, neopal = neopalatine, pars fac = pars facialis, pmax = premaxilla, proc = process, prsph = parasphenoid, pter = pterygoid, qj = quadratojugal, sept nas = septum nasi, sphen = sphenethmoid, sq = squamosal, st = stapes, ven = ventral, vom = vomer, zyg = zygomatic.

Figure 4

Vertebral column and pelvis of Gastrotheca carinaceps (MTD 45942, female) depicted in dorsal aspect.

The outline was traced from a radiograph. Structural details that could not be seen in the radiograph are approximated with dashed lines. Presacral vertebrae are numbered I–VIII.

Figure 5

Pectoral girdle of Gastrotheca carinaceps (MTD 45942, female) depicted in ventral aspect.

The outlines of the bones taken from a radiograph. Structural details that could not be seen in the radiograph are approximated with dashed lines, and presumed areas of cartilage are shown in gray.

Figure 6

Dorsal views of skeletal elements of hand (A) and tarsus (B) of Gastrotheca carinaceps (MTD 45942, female).

Fingers are numbered II–V, and metatarsals I–V. The outlines of the bones were traced from a radiograph. Abbreviations: C = carpal, fib = fibulare, ph = prehallux, r = radiale, T = tarsal, tib = tibiale, u = ulnare, Y = Element Y.

Contributor Notes

(WED, LT) NATURAL HISTORY MUSEUM AND BIODIVERSITY RESEARCH CENTER, DEPARTMENT OF ECOLOGY AND EVOLUTIONARY BIOLOGY, UNIVERSITY OF KANSAS, LAWRENCE, KANSAS 66045-7561;

Received: 03 Nov 2005

Accepted: 08 Aug 2006