Aenigmatistes Shelford, 1908

Ament, Danilo César, 2017, Phylogeny of Phorinae sensu latu (Diptera: Phoridae) inferred from a morphological analysis with comprehensive taxon sampling and an uncommon method of character coding, Zoological Journal of the Linnean Society 181 (1), pp. 151-188 : 157-162

Schmitz + Aenigmatistes Shelford , part of the Bothroprosopa -group and part of Phora species ( Fig. S1 ).

3. Vein C length/wing length ( Fig. S2 , optimization; Fig. 5 , states discrimination).

Original interval: 0.18–1.0 (scaled to states 0–9). C.I. = 12; R.I. = 34.

The relative length of the costal vein is used in Phoridae taxonomy in distinct contexts from species descriptions to inferences of relationships. However, the only use of this information as a character of a comprehensive phylogenetic analysis was character 2 of table 8 of Brown (1992) ‘ Costa exceptionally long ’, which was recovered as a synapomorphy of Ceratusa Borgmeier + Cyphometopis Borgmeier. This character is coded here with nine additive states given its broad and continuous variation.

A shortening of vein C was optimized at the base of Jealia Brown + Euphorida, while even greater reductions in this vein length are optimized independently for small groups within Euphorida ( Fig. S2 ).

4. Foremetatarsus width/length ( Fig. S2 , optimization; Fig. 6 , states discrimination).

Original interval: 0.10–0.58 (scaled to states 0–9). C.I. = 11; R.I. = 19.

Foremetatarsus dimensions were used here for the first time in a phylogenetic analysis of the family. This character was optimized with a plastic evolution in the tree but being informative in less inclusive levels. A relatively short foremetatarsus was recovered as synapomorphic for Chonocephalus Wandolleck + Termitoxeniinae and Euryphora Schmitz + Aenigmatias Meinert.

5. Scutellum length/width ( Fig. S3 , optimization; Fig. 7 , states discrimination).

Original interval: 0.22–0.77 (scaled to states 0–9). C.I. = 12; R.I. = 27.

Scutellum dimensions are possibly related to character 34 of Brown et al. (2015) ‘ Posterior scutellar setae: (0) close together, (1) broadly separated ’, which was considered by these authors as correlated with body size. Scutellum length/width ratio was chosen among these three measures as it can be measured independently from other characteristics such as the number and arrangement of scutellum setae.

A relatively narrow scutellum was optimized in most groups of Phoridae with two major groups presenting a wider scutellum, the Metopininae and the Thaumatoxena -group ( Fig. S3 ).

6. Distance R 1 –costal apex/C length ( Fig. S3 , optimization; Fig. 8 , states discrimination).

Original interval: 0.22–0.59 (scaled to states 0–9). C.I. = 19; R.I. = 29.

Besides the relative costal length (character 3), the radial system varies also regarding the R 1 relative length. Apparently, there is no correlation of long Costa to R 1 relative length, as there are taxa with long Costa with relatively short R 1 –costal apex distance (e.g. Dohrniphora Dahl ) and with relatively long R 1 –costal apex distance (e.g., Bothroprosopa Schmitz ). However, most taxa with short costa have R 1 –costal apex distance shortened possibly due to dependence between these conditions. This possible dependence was considered to apply this character only to taxa with costal measuring 0.37 or more of the wing length. A short R 1 –costal apex distance was recovered as homologous in most taxa of the Thaumatoxena -group, with a reversion optimized at the base of the Hypocera -subgroup.

OTHER CHARACTERS

7. Frontal furrow: (0) absent, (1) present ( Fig. 9 ). C.I. = 16; R.I. = 68.

Brown (1992) referred to this character as an example of possible atavism in the evolution of the family, recognizing this furrow in phorids as a possible re-expression of the furrow of other Diptera families. According to Brown, the furrow in Phora and Coniceromyia Borgmeier would be independent synapomorphies of both of these genera. The present analysis corroborated these independent origins optimizing two other presences of this furrow within Metopininae .

Some genera as Archiphora have a vestigial frontal furrow restricted to a concavity at the venter of the frons, a condition which was coded here as furrow absent.

8. Supra-antennal setae: (0) absent, (1) present ( Fig. 10 ). C.I. = 10; R.I. = 73.

Phorids may have zero, one pair, or two pairs of supra-antennals. As all taxa with two pairs of supra-antennals have these setae reclinated, I considered these conditions possibly related and coded the present character with only the distinction between supra-antennals absent/present. The information on supra-antennals inclination is dealt in character 9.

Brown (1992) coded presence of supra-antennals in character 2 of table 4 assigning the state of supra-antennals present to all Euphorida. Brown et al. (2015) considered this information only for hypocerines in character 76 ‘ Supra-antennal setae of hypocerines: (0) present, (1) absent ’, though scoring taxa external to them as ‘0’. However, the variability of the presence of these setae within Phoridae was not completely recovered by the Bauplan approach of Brown (1992) and by Brown et al. (2015), as the absence of supra-antennals in taxa such as Aenigmatias and Termitophyllomyia Schmitz was not accounted in their coding.

Supra-antennals were coded here for the entire family being optimized as a possible synapomorphy at the base of Metopininae + Phorinae , with nine reversions occurring within these subfamilies, in some cases corroborating large groups such as the reversion close to the base of the Hypocera -subgroup.

9. Supra-antennal setae inclination: (0) reclinate, (1) proclinate ( Fig. 11 ). C.I. = 100; R.I. = 100.

Supra-antennal setae reclinate has been recognized as one of the clearest characters diagnosing the Metopinini (monophylum 4 in Brown, 1992). The present character coded this information similarly to character 68 of Brown et al. (2015), except that here the character was applied only to taxa with the condition ‘Supra-antennals present’ (character 7). Supra-antennals reclinate was corroborated as a synapomorphy of Metopinini being recovered at the base of Megaselia Rondani + Allochaeta Borgmeier.

10. Frontal ventral row of setae: (0) absent, (1) only interfrontals present, (2) all four setae present ( Fig. 12 ). C.I. = 18; R.I. = 68.

Phoridae ventral row of setae generally comprises a pair of interfrontals (VIF) and a pair of fronto-orbitals (VFO). The pair of VIFs was coded in character 64 of Brown et al. (2015) ‘ Modern frontal setation of phorids (ventral interfrontal setae present): (0) present, (1) absent ’, which was recovered by these authors as a synapomorphy of Euphorida. However, genera that do not have ventral interfrontal setae such as Chonocephalus , Cyphocephalus Borgmeier , Thaumatoxena Breddin & Börner , Misotermes and others were coded as having them. The pair of ventral fronto-orbitals was coded in Brown’s (1992) analysis of ‘Hypocerinae’ as character 6 of table 5 ‘ Lower fronto-orbital seta absent ’. Both of these characters were united here in one with three conditions, which was analysed for the entire family and treated as additive.

The complete ventral row was recovered as a synapomorphy of Phorinae + Metopininae . Nine reversions to an incomplete ventral row corroborate small groupings.

11. Inclination of frontal ventral row of setae: (0) approximately in the same horizontal line, (1) angulated, with interfrontals shifted ventrally, (2) very angulated ( Fig. 13 ). C.I. = 12; R.I. = 74.

This character was applied only to taxa with all four setae of the frontal ventral row (character 10, state 2), and treated as additive ( Fig. 13 ). Non-angulated or slightly angulated rows are optimized at the base of large groups while very angulated row was optimized as a synapomorphy of groups of medium inclusiveness, such as the grouping of Spiniphora Malloch species and of Phora + New amber genus P.

12. Frontal dorsal row of setae: (0) absent, (1) only interfrontals present, (2) all four setae present ( Fig. 14 ). C.I. = 18; R.I. = 35.

Phoridae dorsal row of setae generally comprises a pair of interfrontals and a pair of fronto-orbitals. The three observed conditions of presence/absence of these pairs were treated here as an additive character ( Fig. 14 ). A complete frontal dorsal row of setae was optimized present in the most basal nodes of Phoridae , with independent losses occurring at the base of Chonocephalus + Termitoxeniinae , Dohrnigma Disney & Ellwood + Misotermes + Aenigmatistes and of some other taxa.

13. Inclination of frontal dorsal row of setae: (0) approximately in the same horizontal line, (1) interfrontals more dorsal than fronto-orbitals ( Fig. 15 ). C.I. = 16; R.I. = 44.

This character was applied only to taxa with all four setae of the frontal dorsal row (character 12, state 2). The state of interfrontals more dorsal than fronto-orbitals was recovered as homologous in Diplonevra Lioy + Dohrniphora and possibly as a synapomorphy of Hirotophora + Chaetocnemistoptera + Neopleurophora .

14. Additional frontal setulae: (0) absent, (1) present ( Fig. S4 , optimization). C.I. = 100; R.I. = 100.

This character was used by Mostovski (1999) in the investigation of the relationships among Sciadocerinae , Prioriphorinae and Euphorida. In the present analysis, only Sciadocera and Archiphora do not have these setulae, and their presence was recovered as homologous in all taxa that have this condition. However, this character may have a more complicated optimization given that these setulae are recognized as absent in some ‘prioriphorine’ genera not included here, such as Prioriphora McAlpine & Martin and Maksika Mostovski ( Mostovski, 1999) .

15. Length of additional frontal setulae: (0) short, (1) long ( Fig. S4 , optimization). C.I. = 50; R.I. = 83.

This character was applied only to taxa with additional frontal setulae (character 13, state 1). The condition of long additional frontal setulae was optimized as a synapomorphy of a clade comprising part of the Phora species.

16. Size of ocellar triangle: (0) relatively small, (1) well-developed ( Fig. S4 , optimization). C.I. = 100; R.I. = 100.

This corresponds to character 10 of table 5 of Brown (1992) ‘ Vertex with raised lip ’. Ocellar triangle well-developed was recovered here as a synapomorphy of Peromitra Enderlein + Stichillus Enderlein.

17. Frontal surface: (0) approximately plane, (1) with a transversal fold ( Fig. S4 , optimization). C.I. = 100; R.I. = 100.

Figures

Figure 1. Transition costs and their resultant homologies (represented as dashed forms) of two hierarchical coding schemes: an additive multistate character (left) and a multistate character with another type of step-matrix (right).

Figure 2. Strict consensus of the three most parsimonious trees obtained. Bremer support values are indicated under each node. Extinct taxa in brown.

Figure 3. Examples of different conditions of character 1 (frontal height/width).

Figure 4. Examples of different conditions of character 2 (hind femur height/length).

Figure 5. Examples of different conditions of character 3 (vein C length/wing length).

Figure 6. Examples of different conditions of character 4 (foremetatarsus width/length).

Figure 7. Examples of different conditions of character 5 (scutellum length/width).

Figure 8. Examples of different conditions of character 6 (distance R1–costal apex/C length).

Figure 9. Character 7 (frontal furrow). (A–D), examples of its states; (E), optimization in the strict consensus (colours representing states: green 0; blue 1; pink missing, inapplicable, or ambiguous data).

Figure 10. Character 8 (supra-antennal setae). (A–E), examples of its states; (F), optimization in the strict consensus (colours representing states: green 0; blue 1; pink missing, inapplicable, or ambiguous data).

Figure 11. Character 9 (supra-antennal setae inclination). (A–C), examples of its states; (D), optimization in the strict consensus (colours representing states: green 0; blue 1; pink missing, inapplicable, or ambiguous data).

Figure 12. Character 10 (frontal ventral row of setae). (A–D) Examples of its states; (E) transition costs and inferred hierarchical homology hypotheses; (F) optimization in the strict consensus (colours representing states: green, 0; blue, 1; black, 2; pink, missing, inapplicable or ambiguous data).

Figure 13. Character 11 (inclination of frontal ventral row of setae). (A–E) Examples of its states; (F) transition costs and inferred hierarchical homology hypotheses; (G) optimization in the strict consensus (colours representing states: green, 0; blue, 1; black, 2; pink, missing, inapplicable or ambiguous data).

Figure 14. Character 12 (frontal dorsal row of setae). (A–E) Examples of its states; (F) transition costs and inferred hierarchical homology hypotheses; (G) optimization in the strict consensus (colours representing states: green, 0; blue, 1; black, 2; pink, missing, inapplicable or ambiguous data).

Figure 15. Character 13 (inclination of frontal dorsal row of setae). (A–E) Examples of its states; (F) optimization in the strict consensus (colours representing states: green, 0; blue, 1; pink, missing, inapplicable or ambiguous data).