Remarks on the genus Laophontodes T. Scott, 1894 (Copepoda, Harpacticoida, Ancorabolidae, Laophontodinae), including the (re-)description of four species

Phylogeny of the taxon Paralaophontodes Lang (Copepoda, Harpacticoida, Laophontodinae), including species descriptions, chorological remarks, and a key to species

“…The above presented discussion confirms that the taxon Laophontodes is actually quite a heterogeneous collection of species (George and Gheerardyn 2015) that urgently needs to be re-examined. In addition to previous revisionary work (Lang 1965, Conroy-Dalton 2004, Gheerardyn and Lee 2012, the reassignment of the "armatus-group" into Paralaophontodes is another important step towards an elucidation of the systematics of Laophontodes and even Laophontodinae.…”

“…Yet, each of these taxa present numerous autapomorphies (cf. George 1998, Conroy-Dalton and Huys 2000, Conroy-Dalton 2001, 2003a, George 2006a, b, c, Gheerardyn and George 2010, Gheerardyn and Lee 2012, George and Müller 2013, George and Gheerardyn 2015 absent from Paralaophontodes, so it is likely they are not closely related. It must be supposed that the reduction (in a phylogenetic, not an ontogenetic, sense) of a 3-segmented to a 2-segmented P1 exopod has convergently occurred more than once.…”

“…Such an assumption seems to be justified when considering the differences between the original descriptions of e.g. Laophontodes bicornis A. Scott, 1896 or L. whitsoni T. Scott, 1902 with recent re-descriptions: In their original descriptions both species lack all of the above mentioned features, but all were observed on re-examination (George and Gheerardyn 2015).…”

New species of Eurycletodes Sars, 1909 and Odiliacletodes Soyer, 1964 from the deep Gulf of California (Copepoda, Harpacticoida, Argestidae)

“…Argestidae are common inhabitants of muddy substrates, are one of the dominant groups of meiobenthic deep-sea harpacticoids (Menzel and George 2009), and some of its genera, e.g., Mesocletodes and Eurycletodes Sars, 1909, are the most abundant in deep-sea samples, accounting for more than 25% of total abundance of Argestidae (Menzel 2011a). Due to their high abundance and high species richness, this family might play an important ecological role in the benthic realm and is a good subject for phylogenetic, biogeographical, and chorological investigations on deep-sea harpacticoids and meiofauna due to its worldwide distribution (Menzel and George 2009, George 2011). For example, George (2004) hypothesized on how deep-sea argestids may have colonized shallow habitats, and Gómez (2018) reported on some new species of Mesocletodes from the Gulf of California, whose closest relatives have been found in the Angola Basin (Central Atlantic), and are probably present also in the Clarion-Clipperton Fracture Zone (Pacific Ocean) (pers.…”

“…Additionally, from Menzel et al (2011), Menzel and George (2012), and Gómez (2018) it is evident that the same species or closely related species are present in distant localities across vast areas of the world ocean, seemingly “ignoring” geographical barriers. Nevertheless, despite its importance, only few studies are available on the diversity of Argestidae and few of them have tackled the monophyly of the entire family and its constituent genera (e.g., Huys and Conroy-Dalton 1997, George 2004, 2008, 2011, Menzel and George 2009, Corgosinho and Martínez Arbizu 2010, Menzel 2011a, Menzel et al 2011). …”