Oxysarcodexia, Townsend, 1917

Oxysarcodexia View in CoL clade

Nephochaetopteryx , Oxysarcodexia and Ravinia are included in the Oxysarcodexia clade. These genera showed only one topology with Nephochaetopteryx as the sister taxon of ( Oxysarcodexia + Ravinia ), which received aBS and is supported by moderate JK values ( Fig. 2A View Figure 2 ). This clade is supported by three homoplasies and the following autapomorphy: juxta smooth proximally and wrinkled distally ( Figs 10C, D View Figure 10 , 14G, H View Figure 14 , 18A, D, G View Figure 18 , 29H View Figure 29 ).

Species of Nephochaetopteryx are here included for the first time in a phylogenetic study. The phylogenetic affinity between this genus and Tricharaea , and also the position of these two genera within the ‘lower’ Sarcophaginae , was suggested by Lopes (1983) on the basis of these genera sharing first-instar larval character states such as a vestigial labrum [= mandible in Lopes (1983)] and the dorsal bridge [= clypeal arch in Lopes (1983)] situated posterior to the parastomal bar [= paraclypeal phragma in Lopes (1983)]. Interestingly, in the same study, Lopes also considered the clade composed of Oxysarcodexia and Ravinia as sister group of Nephochaetopteryx due to these genera also sharing the first-instar larval character states mentioned above. Later, in his phylogenetic study of the Sarcophaginae males with proclinate orbital setae, Lopes (1990) placed Nephochaetopteryx as sister to Rettenmeyerina due to these two genera sharing the distiphallus articulated with the basiphallus. However, here we found that only Rettenmeyerina possesses a fully developed hinge between basi- and distiphallus ( Fig. 28D View Figure 28 ), while Nephochaetopteryx generally has a desclerotized strip or a superficial hinge and only dorsally ( Fig. 29H View Figure 29 ). Nephochaetopteryx was placed together with Bahamiola , Sarcofahrtiopsis , Rettenmeyerina and Tricharaea in the tribe Sarothromyiini by Lopes (1969a), due to all males of these genera having proclinate fronto-orbital setae. Males with proclinate fronto-orbital setae are largely confined to genera within the ‘lower’ Sarcophaginae , with few exceptions like in Duckemyia , two species of Lepidodexia , species of Panava , one species of Tripanurga and a few species of Helicobia . The sister-group relationship between Oxysarcodexia and Ravinia was highlighted already by Roback (1954), who pointed out similarities in phallic structures such as the lack of a juxta (i.e. the lack of juxtal hinge) and the presence of the acrophallic levers [= dorsal rods in Roback (1954)]. This was later followed by Downes (1955), who added larval and female traits in support of this relationship. Using Buenaventura & Pape’s (2015) broader definition of the juxta, all genera of Sarcophaginae possess this structure. The hypothesis of a sister-group relationship between Oxysarcodexia and Ravinia was corroborated by Pape (1994) and Giroux et al. (2010) based on morphological data. One molecular-based phylogenetic analysis found strong support for this relationship ( Stamper et al., 2012), while two others ( Kutty et al., 2010; Piwczyński et al., 2014) did not, although the last two analyses showed low branch supports. In our analysis, the clade ( Oxysarcodexia + Ravinia ) is supported by the homoplasious character state of a ctenidium of flattened spines (also found in Mecynocorpus and most Paramacronychiinae ). This clade is also supported by the first-instar larval character state of festoon-like oral ridges ( Downes, 1955; Lopes, 1983; Leite & Lopes, 1987; Lopes & Leite, 1987; Pape, 1996).

Forthefirsttime,themonophylyof Nephochaetopteryx is tested in a modern phylogenetic context, and its monophyly received strong JK support and has three male external autapomorphies: apical part of wing membrane between veins R 2 + 3 and C fumose, mid-tibia without antero-dorsal setae and hind coxa with strong posterior setae. None of these character states were used in the original description of Nephochaetopteryx by Townsend (1934), but later Dodge (1968a) provided a first diagnosis for this genus, where he included the following character states: mid-tibia with neither antero-dorsal nor antero-ventral setae, wing vein R 1 setulose and arista plumose on basal three-fifths. Later, Lopes (1990), in his handmade cladogram, included the second character state of Dodge (1968a) plus the reduction of the female eighth tergite in his ‘list of synapomorphies’ of Nephochaetopteryx . Lastly, Pape (1996) provided a diagnosis including 14 character states, 13 of which were analysed here, and three of which were found to be autapomorphies for this genus. These three character states, in combination with some of Pape’s (1996) other character states, are used here to diagnose Nephochaetopteryx .

The monophyly of Oxysarcodexia was already inferred in non-cladistic studies ( Lopes, 1943, 1983; Roback, 1954), and later confirmed by phylogenetic analyses using both morphological (Giroux et al., 2010) and molecular ( Stamper et al., 2012; Piwczyński et al., 2014) characters. In our analysis, Oxysarcodexia is supported by two autapomorphies: (1) paraphallus antero-proximally with a paraphallic triangular expansion proximal to the vesica (‘pte’ in Fig. 18H View Figure 18 ) and (2) juxta with a proximal convex membranous expansion (‘jce’ in Fig. 18H View Figure 18 ). The first character state was recognized as diagnostic for this genus in previous studies ( Lopes, 1946; Dodge, 1966; Giroux et al., 2010). The second character state was first described by Lopes (1946) in his detailed revision of Oxysarcodexia , where the species descriptions used mostly male terminalia characters, such as the vesica, since this structure has a remarkable morphological diversity in this genus. In a subsequent work, Lopes (1975b) erected the subtribe Oxysarcodexiina , which he defined with a reduced list of diagnostic character states when compared to his earlier work. A selection of eight of Lopes’s (1946, 1975b) character states was listed in a more recent diagnosis for this genus ( Pape, 1996), which, however, did not include the character states found as autapomorphic here. Subsequent authors used these two character states in descriptions of new species ( Soares & Mello-Patiu, 2010) and in morphological comparative studies ( Silva & Mello-Patiu, 2008). Besides the two autapomorphies and some homoplasies found in our analysis, Oxysarcodexia is here diagnosed with three additional external male character states and two first-instar larval character states as suggested by previous studies.

The monophyly of Ravinia was suggested by Roback (1954) and Lopes (1983), and recently both morphology-based (Giroux et al., 2010) and molecular-based ( Stamper et al., 2012; Piwczyński et al., 2014) phylogenetic studies have corroborated this hypothesis. Here, five autapomorphies supported the monophyly of Ravinia : juxta hood-shaped, partially wrinkled and slightly swollen ( Figs 10C, D View Figure 10 , 14G, H View Figure 14 ), hillae distally blunt ( Fig. 10C View Figure 10 ) or pointed ( Fig. 14E View Figure 14 ), vesica narrow and flake-shaped ( Figs 10C, D View Figure 10 , 14G View Figure 14 ), vesical arm-shaped lever straight proximally ( Fig. 35D View Figure 35 ) and distal section of the vesica flattened or reduced ( Fig. 10D View Figure 10 ). Giroux et al. (2010) found the presence of hillae as the only autapomorphy for this genus, but in our definition this structure is also found in an additional 15 genera. However, the hillae in Ravinia are highly specialized in comparison to those found in other genera. Specifically, hillae with a membranous bladder ( Figs 10C, D View Figure 10 , 14G, H View Figure 14 ) and a groove ( Fig. 10B View Figure 10 ), as described by Giroux et al. (2010), are only found in some species of this genus. The importance of the hillae in the definition of Ravinia was already mentioned by Roback (1954), who also inferred the origin of the acrophallic levers [= acrophallic bars in Roback (1954)] in other taxa [acrophallic levers originated in the ancestor of all Sarcophaginae (clade 4 in Fig. 2A View Figure 2 ) according to our analysis] before the emergence of the Ravinia lineage. Five autapomorphies supporting the monophyly of Ravinia are used to diagnose this genus in combination with other male structures and two larval character states.