Emys olivacea Schweigger, 1812

Fritz, Uwe, Petzold, Alice, Kehlmaier, Christian, Kindler, Carolin, Campbell, Patrick, Hofmeyr, Margaretha D. & Branch, William R., 2014, Disentangling the Pelomedusa complex using type specimens and historical DNA (Testudines: Pelomedusidae), Zootaxa 3795 (5), pp. 501-522 : 510

Emys olivacea Schweigger, 1812

Schweigger (1812: p. 307) described a carapace from the Adanson Collection of the Paris Museum as the new species Emys olivacea . According to the original description, the specimen originates “in sabulosis Nigritiae” [in the sands of Senegal] and is still present in the collection of the Muséum National d’Histoire naturelle, Paris (MNHN 7971). This specimen was not available to us.

Starting with Loveridge (1941), many authors used the name Pelomedusa subrufa olivacea for helmeted terrapins from the more northern parts of the species’ range, which usually have the pectoral scutes of the plastron separated, even though this character cannot be determined in the holotype, which consists only of a carapace. Moreover, Gasperetti et al. (1993) disputed the reliability of this trait, and since then most authors have treated P. subrufa as monotypic (see above and the review in Boycott & Bourquin 2008).

In our phylogenetic analyses ( Fig. 1 ), the concatenated 12S and cyt b sequences ( Wong et al. 2010; this study) of a Senegalese Pelomedusa (ZFMK 17076) are assigned with high support to lineage III of Vargas-Ramírez et al. (2010). The placement of this topotypic terrapin suggests that Emys olivacea has to be identified with lineage III, which is otherwise known to occur in Benin, Burkina Faso, Niger, and Nigeria ( Vargas-Ramírez et al. 2010; Wong et al. 2010). The pectoral scutes of ZFMK 17076 are triangular, but the tips just meet in the midline of the plastron. A comparison of 21 helmeted terrapins from Niger, Nigeria, and Senegal from the collections of the natural history museums in Bonn, Frankfurt am Main, London, Port Elizabeth, and Vienna shows that specimens with pectoral scutes in narrow contact, as well as specimens with completely separated pectorals, both occur in lineage III.

If terrapins of lineage III should be regarded as taxonomically distinct in the future, Emys olivacea Schweigger, 1812 would be the oldest available name.

Figures

FIGURE 1. Maximum Likelihood tree for Pelomedusa, based on 1848 bp of mitochondrial DNA (12S, cyt b, ND4+tRNAs), rooted with Pelusios sinuatus. The tree topology completely matches the one inferred by Bayesian analyses. Numbers along nodes indicate bootstrap support and Bayesian posterior probabilities greater than 50 or 0.95, respectively (not shown for some terminal clades with short branches). Sample codes are voucher numbers; see Table S1 for explanation. Name-bearing types (red) and paralectotypes or topotypic samples (blue) highlighted. On the right, mitochondrial lineages of Vargas-Ramírez et al. (2010) indicated. No topotypic material of Pelomedusa galeata orangensis Hewitt, 1935 could be sequenced. However, the lost holotype is thought to come from the vicinity of Kimberley (South Africa) and all South African samples belong to lineage IX, so it can be concluded that Pelomedusa galeata orangensis represents the same lineage. Inset: Helmeted terrapin from the Addo Elephant National Park, South Africa. Photo: M. Gregorič.