Molecular phylogenetic analysis of Punctoidea (Gastropoda, Stylommatophora)

Abstract

A phylogenetic analysis using a combination of mitochondrial (COI, 16S) and nuclear markers (ITS2, 28S) indicated that Punctoidea, as previously interpreted, is polyphyletic. It comprises two main groups, containing northern hemisphere (Laurasian) and predominantly southern hemisphere (Gondwanan) taxa respectively, treated here as separate superfamilies. Within Punctoidea sensu stricto, Punctidae, Cystopeltidae and Endodontidae form separate monophyletic clades, but Charopidae, as currently interpreted, is paraphyletic. Most of the charopid taxa that we sequenced, including Charopa coma (Gray, 1843) and other Charopinae, grouped in a clade with Punctidae but some charopid taxa from Australia and South America grouped with Cystopeltidae. Cystopeltidae previously contained a single Australia-endemic genus, Cystopelta Tate, 1881, but our analysis suggests that it is considerably more diverse taxonomically and has a much wider distribution. For taxonomic stability, we suggest that Charopidae be retained as a family-level group for now, pending further study of the systematic relationships of its constituent taxa. A new superfamily, Discoidea, is erected here for two Northern Hemisphere families, Discidae and Oreohelicidae, which were previously assigned to Punctoidea. The North American species Radiodomus abietum, previously in Charopidae, is also here assigned to Discoidea. The phylogenetic relationships of Helicodiscidae, previously assigned to Punctoidea, were not fully resolved in our analysis, but the family is apparently closely related to Arionoidea Gray, 1840 and infraorder Limacoidei.

Discordance of genetic diversification between deep‐ and shallow‐water species of Kobeltocochlea Lindholm, 1909 (Caenogastropoda: Truncatelloidea: Benedictiidae) endemic to Lake Baikal with the description of a new species, review of the genus, and notes on its origin

“…Notably, the paraphyly observed within Benedictiidae is not unusual for gastropods belonging to different taxa. For instance, paraphyly is known in Mitridae Swainson, 1831 and Ptychatractidae (Neogastropoda; Fedosov et al, 2015), land snails Trochulus Chemnitz, 1786 (Pulmonata: Hygromiidae; Kruckenhauser et al, 2014), and Punctoidea Morse, 1924 (Salvador et al, 2020) as well as within freshwater North American Pyrgulopsis Call & Pilsbry, 1886 (Caenogastropoda: Hydrobiidae; Hershler et al, 2016). Some explanations of paraphyly include an insufficient number of samples for analysis, inadequate phylogenetic information, imperfect taxonomy, incomplete lineage sorting, and introgression via hybridization (Funk & Omland, 2003).…”

Molecular phylogenetics and premating isolation in the punctoid land snails of Belau (Republic of Palau, Oceania)

“…Solem (1976, 1983) summarized the morphology and taxonomy of the described Belau punctoids, but there are no published molecular data for any Belau species. Although the first‐ever sequences of Pacific punctoids are beginning to be incorporated into large‐scale phylogenies (Salvador et al., 2020), no DNA sequence data existed for Belau punctoids prior to the present study, as is also the case for punctoids from most Pacific archipelagos. Solem (1976) attempted to resolve the relationships of the Pacific endodontid genera using early cladistic methods on internal morphological (e.g., genitalia) and conchological (shell) traits (Figure 2).…”

Geographic distribution modeling and taxonomy of Stephadiscus lyratus (Cothouny in Gould, 1846) (Charopidae) reveal potential distributional areas of the species along the Patagonian Forests

“…Hylton Scott, understanding the value of anatomical information, was the only researcher to provide anatomical descriptions of some South American charopids such as Stephacharopa testalba, Stephadiscus lyratus, S. mirabilis, Zilchogyra leptotera (Mabille, 1886). Recently, a study on Punctoidea phylogeny provided molecular information on some charopid species ( Salvador et al, 2020 ). Stephadiscus lyratus , as all the species of the genus, has similar ornamentation in the shell protoconch and the teleoconch, without a marked limit between them.…”

“…Charopidae is a family of Punctoidea land gastropods with an extensive distribution that includes South America, South Africa, Australia, New Zealand, and Oceania ( Salvador et al, 2020 ). Southern Argentina and Chile are particularly rich in endemic species of Charopidae ( Miquel & Cádiz Lorca, 2008 ).…”