Date of this Version
Huchet J-B. 2021. Two new species of Nothochodaeus Nikolajev, 2005 from Palawan Island, Philippines (Coleoptera: Scarabaeoidea: Ochodaeidae). Insecta Mundi 0893: 1–12.
Nothochodaeus minotaurus Huchet, new species, and N. huxleyi Huchet, new species (Coleoptera: Scarabaeoidea: Ochodaeidae), from Palawan Island, Philippines, are described and illustrated.
Following my study of the Ochodaeidae of the Philippine archipelago (Huchet 2014a, 2014b, 2017, 2018, 2019), I describe here two new species of the genus Nothochodaeus Nikolajev, respectively N. minotaurus Huchet, new species, and N. huxleyi Huchet, new species, bringing to four species, all endemic, the representatives of this genus in the archipelago. Both species described here are illustrated and compared with their closest relatives. These new species originate from the island of Palawan. This discovery is interesting in several respects since it is the first mention of the family Ochodaeidae on this island. Morphologically, these new species present no obvious affinities with the other relatives inhabiting the archipelago. In all likelihood, the morphological originality of these taxa is due to the fact that the biogeographical history of Palawan and surrounding smaller islands is very distinct from that of the other islands of the Philippines. Palaeogeographical reconstructions have evidenced that, unlike the other islands of the archipelago, Palawan was contiguous with Borneo when sea level dropped repeatedly during the Pleistocene (Heaney 1985; Robles et al. 2015). Accordingly, due to its geological and biogeographical history, Palawan has been considered to be a portion of the Sunda Shelf and present more biotic affinities with Borneo than with all the other islands of the archipelago (Everett 1889; Dickerson 1928; Heaney 1985, 1986; Esselstyn et al. 2004). Heaney (1985) argued that the high endemicity demonstrated by the mammal fauna of Palawan Island implies a long separation from their conspecifics in Borneo. According to Robles et al. (2015), a land bridge existed between Borneo and Palawan during the Middle Pleistocene, perhaps ca. 440 Ka or earlier at ca. 630 Ka.