Pelomedusa schweinfurthi, Petzold & Vargas-Ramírez & Kehlmaier & Vamberger & Branch & Preez & Hofmeyr & Meyer & Schleicher & Široký & Fritz, 2014

Petzold, Alice, Vargas-Ramírez, Mario, Kehlmaier, Christian, Vamberger, Melita, Branch, William R., Preez, Louis Du, Hofmeyr, Margaretha D., Meyer, Leon, Schleicher, Alfred, Široký, Pavel & Fritz, Uwe, 2014, A revision of African helmeted terrapins (Testudines: Pelomedusidae: Pelomedusa), with descriptions of six new species, Zootaxa 3795 (5), pp. 523-548 : 539-540

Pelomedusa schweinfurthi sp. nov.

Diagnosis: Small to medium-sized, dark-coloured helmeted terrapins with a known maximum straight carapacial length of 15.7 cm. Pectoral scutes rectangular with wide midseam contact or triangular with narrow midseam contact. Temporal head scales large, mostly undivided. Two small barbels under chin. In adults, carapace and plastron rather dark; soft parts ventrally lighter than dorsally. Pelomedusa schweinfurthi differs from all other Pelomedusa species by the presence of thymine (T) instead of cytosine (C) at position 279, by the presence of guanine (G) instead of adenine (A) or a gap at position 297, and by the presence of adenine (A) instead of guanine (G) at position 305 of the 360-bp-long reference alignment of the 12S rRNA gene (Supporting Information).

Holotype: Senckenberg-Museum , Frankfurt am Main ( SMF 56161, female, Liria, Central Equatoria, South Sudan, N4°38.66 E32°4.83; leg. C. Scherpner, 3 March 1955; Fig. 4 bottom).

Description of the holotype: Straight carapacial length 12.3 cm, plastral length 10.5 cm. Pectoral scutes rectangular with wide midseam contact. Temporal scale divided on left side, undivided on right side of head. Two small barbels under chin. Carapace and plastron dark brown. Dorsal side of soft parts and entire forelegs dark grey, ventral side of hind legs light grey. Tail short.

Paratypes: Senckenberg-Museum, Frankfurt am Main ( SMF 56160, 65162 , males, same data as holotype); Museum für Naturkunde, Berlin ( ZMB 15697, juvenile, Djur River W Wau, Western Bahr el Ghazal, South Sudan) .

Derivatio nominis: We dedicate this species to Georg August Schweinfurth (29 December 1836 – 19 September 1925) who was the last of the great explorers of Africa. Schweinfurth collected the oldest of the paratypes (ZMB 15697) during his famous third Africa expedition (1868–1871) “inside the heart of Africa” ( Schweinfurth 1874) in present-day South Sudan.

Distribution: Central African Republic ( Vargas-Ramírez et al. 2010) and South Sudan (this study).

Remarks: Pelomedusa schweinfurthi corresponds to mtDNA lineage IV of Vargas-Ramírez et al. (2010), which was previously only recorded from the Central African Republic. Our new 12S sequences of the type specimens provide evidence for the occurrence in South Sudan. The temporal scale is divided on the left side of the head in the holotype, but undivided on the right side, as it is in all paratypes. The largest specimen (SMF 56162) has a straight carapacial length of 15.7 cm. Unlike many other Pelomedusa species , P. schweinfurthi is overall quite dark coloured, with a predominantly brown plastron.

Pelomedusa schweinfurthi belongs to the northern species group and is with high support sister to candidate species B from Sudan ( Fig. 1 ).

Figures

FIGURE 1. Maximum Likelihood tree for helmeted terrapins (Pelomedusa spp.) using 1848 bp of mitochondrial DNA (12S, cyt b, ND4+tRNAs), rooted with Pelusios sinuatus. Terminal clades collapsed to cartoons. The topology of the Bayesian 50% majority rule consensus tree was identical. Numbers along branches indicate bootstrap support and clade support under BI (posterior probabilities) greater than 50 or 0.95, respectively. Asterisks represent maximum support under both methods. Colours and symbol correspond to the map (Fig. 2). On the right, proposed species names indicated; in brackets, mtDNA lineages. For clade membership of individual samples, see Table S1. The questionable sample MTD T 5484 from Swellendam District (Western Cape), South Africa, is highlighted in red (see text). The shown terrapins are Pelomedusa neumanni (top; Kakamega, Kenya) and P. galeata (bottom; Port Elizabeth, South Africa—photos: H. Prokop and W.R. Branch).

FIGURE 4. Dorsal and ventral aspects of the holotype of Pelomedusa neumanni sp. nov. (NMP6V 74974, adult male, Kakamega, Kenya; top) and of Pelomedusa schweinfurthi sp. nov. (SMF 56161, female, Liria, Central Equatoria, South Sudan; bottom). Scale bars, 3 cm. Photos: P. Široký and E. Morawa.