The phylogenetic position of Dinogeophilus and a new evolutionary framework for the smallest epimorphic centipedes (Chilopoda: Epimorpha)

Abstract

The centipedes of the clade Epimorpha change slightly during post-embryonic growth but there is huge variation between species in the maximum body size. New specimens of the rarely collected Neotropical genus Dinogeophilus provide further evidence that this genus comprises the smallest species of the Epimorpha, with a recorded maximum length of 5.5 mm. Up to now Dinogeophilus has been invariantly classified in Geophilidae but different sources of evidence (examination by SEM, cladistic evaluation of morphology, similarity and phylogenetic analysis of molecular data) agree on a very different phylogenetic hypothesis: Dinogeophilus is actually a derived lineage of Schendylidae, only distantly related to Geophilidae, and possibly belong to a mainly Neotropical subgroup of schendylids. A comparison of Dinogeophilus with the most closely related taxa suggests that body miniaturization was accompanied by possibly paedomorphic traits, including lower number of some multiple elements (antennal sensilla, processes on the mouth-parts, coxal organs) and shorter setae. Possibly associated with miniaturization are also a few novel features of Dinogeophilus, among which the unique subterminal denticles of the forcipules, suggesting a possible change in the feeding behaviour.

The first geophilid centipedes from Malesia: a new genus with two new species from Sumatra (Chilopoda, Geophilidae)

“…Actually, we cannot rule out the possibility that most similarities between the two species comprise convergent adaptive characters or shared ancestral conditions. As a matter of fact, body miniaturization evolved independently in different lineages of geophilids (Bonato et al 2015), as happened with the elongation of the head and the forcipules. On the other hand, second maxillae with unusually elongate claws are common in other genera of Geophilidae that are mainly distributed in tropical regions (Table 2), and they evolved independently at least in one species of Geophilus , Geophilus oweni Bollman, 1887 (Crabill 1954).…”

First record of the endemic Neotropical genusHyphydrophilus(Chilopoda: Geophilomorpha, Geophilidae) from Argentina, with description ofH. minelliisp. nov., a new centipede with small tentorial process, inhabiting the Yungas

“…Hyphydrophilus is one of the geophilid genera including miniature species, and H. projectus is only 10 mm long. Extreme body miniaturization evolved repeatedly in the history of the Epimorpha (Lewis 2002;Foddai et al 2003;Pereira 2013b;Bonato et al 2015). A detailed account of the epimorphic centipedes, for which the maximum body length measured in adults is 11 mm or less, can be found in Bonato et al (2015).…”

“…Extreme body miniaturization evolved repeatedly in the history of the Epimorpha (Lewis 2002;Foddai et al 2003;Pereira 2013b;Bonato et al 2015). A detailed account of the epimorphic centipedes, for which the maximum body length measured in adults is 11 mm or less, can be found in Bonato et al (2015). Several other species with reduced body size are known to occur for diverse families of the Geophilomorpha (see Crabill 1960;Pereira et al 1994Pereira et al , 1995Pereira et al , 2000Foddai & Minelli 1999;Minelli et al 2000;Foddai et al 2003;Minelli 2003;Uliana et al 2007;Pereira 2009Pereira , 2011Pereira , 2012Pereira , 2013aPereira , 2013bPereira , 2013cPereira , 2014aPereira , 2014bMoretto et al 2015).…”