Pelomedusa galeata var. disjuncta Vaillant & Grandidier, 1910

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 : 514-515

Pelomedusa galeata var. disjuncta Vaillant & Grandidier, 1910

This taxon was treated by Loveridge (1941: p. 480) as a junior synonym of Pelomedusa subrufa olivacea . It was originally described by Vaillant & Grandidier (1910: pp. 55–56) as a new variety. These authors compared helmeted terrapins from Madagascar and the Cape of Good Hope with specimens of “ Pentonyx gehafie ” from the collection of the Muséum National d’Histoire naturelle, highlighting that the latter differ from Malagasy and South African individuals by separated pectoral scutes. Vaillant & Grandidier (1910: p. 56) assigned the terrapins with the separated pectorals to their new variety Pelomedusa galeata var. disjuncta and mention expressis verbis that specimens of Rüppell’s “ Pentonyx gehafie ” fitting this character are present in the holdings of the Paris Museum. Consequently, it is clear that the description of Pelomedusa galeata var. disjuncta was based on several syntypes. In addition to Rüppell’s specimens, Vaillant & Grandidier (1910: p. 56) mention another terrapin collected by Vicomte Pierre Marie Robert Du Bourg de Bozas (1871–1902) as representing their new variety. Based on this information and locality data from the Paris Museum provided by Fernand Angel, Loveridge (1941: p. 480) restricted the type locality of Pelomedusa galeata var. disjuncta to the “shore of Lake Abaya, Sidamo, Ethiopia ”, where the specimen of Du Bourg de Bozas had been collected. However, this type locality restriction is invalid without lectotype designation (cf. ICZN 1999: Art. 76). The specimen in question is still present in the collection of the Muséum National d’Histoire naturelle (MNHN 1902.346, “Bord du lac Abbay, Sidamo, Ethiopie ”). In addition, there are also two specimens labelled as syntypes 1 of Pentonyx gehafie (MNHN 7870, 9398, “ Abyssinie ”), which bear also syntype status for Pelomedusa galeata var. disjuncta . Consequently, the latter taxon was based on three syntypes and the type locality encompasses distinct localities, the shore of Lake Abaya, Sidamo, Ethiopia, and Abyssinia. Abyssinia can be more exactly identified with the eastern slope of the coastal mountains in present-day Eritrea, where Rüppell (1835: p. 3) discovered his specimens (see also above under Pentonyx gehafie Rüppell, 1835 ).

The syntypes of Pelomedusa galeata var. disjuncta were not available for study. However, since mtDNA sequences could be produced for other type specimens of Pentonyx gehafie (see above), the identity of terrapins from the coastal mountain region of Eritrea could be clarified genetically. Therefore, we designate hereby the topotypic specimen MNHN 7870 from “ Abyssinie ”, being simultaneously a paralectotype of Pentonyx gehafie Rüppell, 1835 , as lectotype of Pelomedusa galeata var. disjuncta Vaillant & Grandidier, 1910 . By this action, we associate the latter name unambiguously with a defined genetic lineage of Pelomedusa . Thus, if the distinct genetic lineage matching the name-bearing types of Pentonyx gehafie and Pelomedusa galeata var. disjuncta should be deemed taxonomically distinct, the latter name would be automatically a subjective junior synonym of Pentonyx gehafie .