Araripescolia magnifica Nel, Escuillie & Garrouste

Nel, André, Escuillie, François & Garrouste, Romain, 2013, A new scoliid wasp in the Early Cretaceous Crato Formation in Brazil (Hymenoptera: Scoliidae), Zootaxa 3717 (3), pp. 395-400 : 396-398

Araripescolia magnifica Nel, Escuillie & Garrouste , sp. nov.

( Figs 1–3 )

Material. Holotype specimen WDC-CCFB-7 (a complete body with four wings and two legs), Wyoming Dinosaur Center-Crato, Wyoming, USA.

Etymology. Named after the wonderful state of preservation of the wings of this fossil.

Age and outcrop. Chapada do Araripe, northeastern Brazil; Upper Aptian, Nova Olinda member of the Crato formation.

Diagnosis. As for the genus.

Description. Head length 4.2 mm, 4.1 mm wide, mesosoma 7.4 mm long, 7.1 mm wide, metasoma 12.9 mm long, 5.8 mm wide; fore wing 16.1 mm long, 5.8 mm wide; hind wing 10.9 mm long, 4.5 mm wide; head mediumsized and suboval; eyes large but poorly preserved; details of head structures not clear; antennae long, curved, with separation between distal segments indistinct; scape enlarged; pedicel small; mesosoma large; pronotum short medially; scutellum inversely trapezoidal; metanotum short; propodeum broad; wings hyaline, presence of longitudinally wrinkled structures of apical parts of fore and hind wings; fore wing with pterostigma narrow, widened apicad, slightly sclerotised; costal vein confluent before pterostigma; radial vein uninterrupted; basal section of Rs as long as that of M; no vestigial 1 r-rs; distal section of Rs sigmoidal, 2.7 mm long; crossvein r-rs short, straight; veins 3 r-m and 2 m-cu present; veins 1 m-cu and 2 m-cu ending in cell 1+2 Rs; anterior side of cell 1+2 Rs 0.5 mm long; cell 2 R1 1.5 times as long as pterostigma, three times as long as wide, with apex not contiguous with wing margin; cell 3 Rs closed, nearly as long as wide; cu-a aligned with basal section of M, slightly shorter than basal section of M; cell 2 Cu nearly parallel-sided, with sides arcuate; hind wing with Rs short beyond 1 r-m; 1 r-m long and curved; cell 1 Rs closed, longer than wide; cu-a postfurcal, long sigmoidal and oblique to A; metasoma long (longer than head and thorax combined), somewhat constricted between 1st and 2nd segments; sting not clearly visible.

Discussion. Araripescolia gen. nov. has a fore wing venation very similar to that of an Archaeoscoliinae (very similar to that of the Mesozoic genera Archaeoscolia Rasnitsyn, 1993 or Cretoscolia Rasnitsyn, 1993) (Rasnitsyn 1993), in the following points: fore wing cell 2 R1 long; cell 3 Rs closed; crossvein r-rs short, straight; crossveins 3 rm and 2 m-cu present; hind wing Rs and M very long before r-m.

Cretoscolia brasiliensis is the unique described Archaeoscoliinae from Araripe, it is much smaller than Araripescolia , and it has not the longitudinally wrinkled structure of the apical parts of the fore wings, clearly visible in Araripescolia (Osten 2007) .

Rasnitsyn (1993) considered the Archaeoscoliinae as a paraphyletic group in respect to the other Scoliidae . Argaman (1996) considered that the Archaeoscoliinae are not Scoliidae but ‘Anthoboscidae’ (= Tiphiidae : Anthoboscinae ) for the presence of notauli. This structure is not preserved in Araripescolia . Later authors did not follow Argaman’s opinion (Rasnitsyn & Martínez-Delclòs 1999, Zhang et al. 2002). After Pilgrim et al. (2008), the Tiphiidae is a polyphyletic group with the Anthoboscinae clearly not closely related to the Scoliidae , while the Scoliidae would belong to a clade that comprises the Formicidae and Apoidea. Notauli are present in these two last groups, suggesting that their absence in modern Scoliidae is an apomorphy. The plesiomorphic presence of notauli in the Archaeoscoliinae is therefore not a sufficient argument to exclude them from the scoliid lineage. It remains that a phylogenetic analysis of the Scoliidae that integrates these fossils is necessary to clarify the situation.

Some Anthoboscinae (e.g. Tiphiodes Brèthes, 1913) have a fore wing venation very similar to those of Araripescolia and Cretoscolia (Genise 1984). Araripescolia can be attributed to the Scoliidae because of the presence of the typical longitudinally wrinkled structures of the apical parts of the fore and hind wings, absent in the Tiphiidae (Day et al. 1981, Argaman 1996). These structures are also absent in the archaeoscoliine genera Cretoscolia and Archaeoscolia (Rasnitsyn 1993, Rasnitsyn & Martínez-Delclòs 1999, Zhang 2004, Osten 2007), and badly known in the two other archaeoscoliine genera, viz. the Mesozoic Protoscolia Zhang et al., 2002 and the Cenozoic Floriscolia Rasnitsyn, 1993 (Rasnitsyn 1993, Zhang et al. 2002). Araripescolia strongly differs from Cenozoic Floriscolia Rasnitsyn, 1993 in the fore wing with apex of cell 2 R1 not contiguous with wing margin, cell 3 Rs nearly as long as high, and hind wing with cu-a well distal of M-Cu fork (Rasnitsyn 1993). Araripescolia differs from Protoscolia Zhang et al., 2002 in the absence of a vestige of 1 r-rs, and the apex of radial cell nearly aligned to 3 r-m (Zhang et al. 2002).

Thus Araripescolia can be accurately attributed to the Scoliidae , but, if it strongly differs from the Archaeoscoliinae, its exact relationships with this group remain uncertain.

Araripescolia shares with the Scoliinae (sensu Rasnitsyn 1993, including the Campsomerinae and Colpinae sensu Argaman 1996) the following characters: the costal vein is confluent before the pterostigma, while it is interrupted in the Proscoliinae and in Archaeoscoliinae (Rasnitsyn, pers. comm.); the radial vein is uninterrupted in the Scoliinae, while it is very narrow at the pterostigmal base in Proscoliinae and almost interrupted in some Archaeoscoliinae (Day et al. 1981, Rasnitsyn & Martínez-Delclòs 1999). The character ‘interruptions of costal and radial veins’ is the general ‘rule’ in the clade that comprises the Scoliidae , Formicidae and Apoidea. Thus the absence of interruption would rather be an apomorphic character, supporting a position of Araripescolia in the Scoliinae sensu Rasnitsyn (1993) and a possible basal position for the Proscoliinae.

Araripescolia differs from the Campsomerinae Betrem, 1972 (sensu Argaman 1996) (a group reduced to the two genera Carbonelis Betrem, 1972 and Dasyscolia Bradley, 1951 ), in the presence of a fore wing cell 1+2 Rs with a anterior side long and the presence of a closed cell 3 Rs. Araripescolia differs from the modern Scoliinae (sensu Argaman, 1996) in the presence of two veins ending in cell 1+2 Rs and therefore it would rather fall near the Colpinae Argaman, 1996. Some Colpinae have long closed cells 2 R1 and 3 Rs as in Araripescolia but they generally differ from Araripescolia in their cell 1+2 Rs with anterior side much shorter (or reduced to a point) (Betrem 1972, Argaman 1996). Unfortunately the body structures of Araripescolia are not enough well preserved to be compared to those of the modern Scoliidae .

The hind wing cell 1 Rs closed of Araripescolia is quite a rare character in Apocrita and can be considered as an autapomorphy of this taxon (Rasnitsyn, pers. comm.)

Most modern scoliid species are external parasitoids of soil-inhabiting scarab beetle larvae. The Scarabaeidae are well known in the Early Cretaceous, and dung beetles are recorded from the Crato formation (Wolf- Schwenninger & Schawaller 2007) suggesting a similar biology for these Cretaceous Scoliidae . Modern scoliid adults are frequently floricolous and could participate to pollination, but it is delicate to infer such behaviours for the Early Cretaceous.

Figures

FIGURE 1. Araripescolia magnifica gen. et sp. nov., holotype specimen WDC-CCFB- 7, photograph of habitus. Scale bar = 10 mm.

FIGURE 2. Araripescolia magnifica gen. et sp. nov., holotype specimen WDC-CCFB- 7, photograph of fore wing apex. Scale bar = 1 mm.

FIGURE 3. Araripescolia magnifica gen. et sp. nov., holotype specimen WDC-CCFB- 7, photograph of hind wing. Scale bar = 1 mm.