Tesserodoniella, Vaz-De-Mello & Halffter, 2006

Vaz-De-Mello, Fernando Z. & Halffter, Gonzalo, 2006, A new dung beetle genus with two new species from Chile (Coleoptera: Scarabaeidae: Scarabaeinae), Zootaxa 1193 (1), pp. 59-68 : 66-67

Biogeography of Tesserodoniella

The discovery of Tesserodoniella in South America and its hypothesized close relationship with the Australian genera Tesserodon and Aptenocanthon leads to a series of interesting biogeographical considerations:

1. As pointed out before, the other two canthonine species occurring in Chile belong to predominantly Neotropical genera. Scybalophagus has four species distributed in the Patagonian biogeographical subregion (as defined by Morrone 2001, 2006). A fifth species, occurring in Chile, occurs in what Morrone (2006) called the South American Transition Zone. Megathopa (with two species) is occurs from Regions IV to IX in Chile, from Córdoba to Chubut in Argentina, and in Uruguay. Neither Scybalophagus or Megathopa are closely related to or sympatric with Tesserodoniella .

2. The presence of Tesserodoniella in the Santiago and Maule biogeographic provinces supports Morrone’s (2001, 2006) proposals on the composition and biogeographic affinities of those areas. Morrone (2001, 2006) divided South America into two regions (Neotropical and Andean) with a transition zone that roughly corresponds with the Andes. The Andean Region is included in the Austral kingdom, originating from Western Gondwana, which also includes the Antarctic, Cape (or Afrotemperate), Neoguinean, Temperate Australian, and Neozealandic regions. The Andean Region was divided by Morrone into subregions and provinces. Santiago Province is included in the Central Chilean subregion, and Maule Province in the Subantarctic subregion. However, both provinces are strongly related, as Maule is the southern limit of many distributional areas. Interestingly, the Santiago Province contains the highest number of endemic species in the southern part of South America ( Morrone et al. 1997).

3. Of the closely related Australian genera, Tesserodon is widely distributed in northern and western Australia, with two species in New Guinea; while Aptenocanthon is distributed in eastern and northern Australia ( Matthews 1974, Storey 1984, Paulian 1985, Storey 1991, Storey & Monteith 2000). The biogeographical affinities between southern South America, Australia, and New Zealand, known as the southern Gondwana distributional pattern ( Sanmartín & Ronquist 2004), have been illustrated by many plant and insect examples ( Crisci et al. 1991, Sequeira & Farrell 2001, Sanmartín & Ronquist 2004).