Cenoelcanus menatensis, Schubnel & Desutter-Grandcolas & Garrouste & Hervet & Nel, 2020

Schubnel, Thomas, Desutter-Grandcolas, Laure, Garrouste, Romain, Hervet, Sophie & Nel, André, 2020, Paleocene of Menat Formation, France, reveals an extraordinary diversity of orthopterans and the last known survivor of a Mesozoic Elcanidae, Acta Palaeontologica Polonica 65 (2), pp. 371-385 : 381-382

Cenoelcanus menatensis sp. nov.

Fig. 8 .

Zoobank LSID: urn:lsid:zoobank.org:act:E1F797A4-4027-472F-A4A8-7622B2EBB123

Etymology: Named after the village of Menat.

Holotype: MNHN.F.A71198 (coll. Philippe Olivier); an incomplete tegmen.

Type locality: Historical quarry of Menat, Menat, Puy-de-Dôme, France.

Type horizon: Middle Paleocene, Menat Basin.

Material.— Holotype only. Diagnosis.—Forewing characters only. Area between R and M+CuA with a series of short crossveins; distal fusion of of CuPaβ, CuPb, and A; base of RP very close to point of separation of M and CuA; M+CuA and RP seem to be aligned; only four branches of RP.

Description.—Distal two-third of a forewing with dark areas along costal part and mid part of tegmen, preserved part 13.0 mm long, 4.2 mm wide in widest part, 3.0 mm in narrowest; posterior margin straight; only distal part of area between C and ScP preserved, 0.7 mm wide, with a series of parallel crossveins; ScP and R not touching, with a series of very short crossveins between them; apex of ScP 8.0 mm distal of that of ScA; area between C and RA 0.3 mm wide, without crossveins; apex of RA 1.3 mm from wing apex; M+CuA not appressed to R, with a series of short crossveins between them, M simple; CuPaα very weak; CuA+CuPaα simple; one row of cells between M and CuA+CuPaα; base of RP as a short oblique veinlet very close to point of separation between M and CuA, 0.15 mm apart; stem of M+CuA aligned with RP; area between RA and RP narrow, 0.4 mm wide, with one row of simple crossveins between them; RP with four posterior branches, with one row of cells between them; one row of cells between CuA+CuPaα and CuPaβ; one row of cells between M+CuA and CuPa, and between CuPa and CuPb; CuPaβ distinctly curved, and parallel to posterior wing margin in distal part; CuPb straight, area between CuPb and first anal vein very narrow; anal area not preserved.

Remarks.— The broad area between ScP and costal margin indicates that this fossil is a tegmen and not a hindwing. The presence of long veins parallel to posterior wing margin, the truncate wing apex, the veins M and CuA separating very far from wing base, and the weak CuPaα are characters present in Caelifera. Cenoelcanus menatensis gen. et sp. nov. has a very particular character, viz. the alignment of RP with stem of M+CuA so that RP seems to be a distal branch of M+CuA. This structure is only present in the pre-Cenozoic superfamily Elcanoidea Handlirsch, 1906 (= Permelcanidae Sharov, 1962 + Elcanidae Handlirsch, 1906 ), and considered as the main synapomorphy of this group by Gorochov and Rasnitsyn (2002: fig. 430). The Permelcanidae would differ from the Elcanidae by the presence of a better defined origin of RP, which is clearly a plesiomorphic state of character ( Sharov 1968). Cenoelcanus gen. nov. better falls in the Elcanidae because the base of RP is reduced to a short oblique veinlet. Gorochov et al. (2006) divided the Elcanidae into Elcaninae and Archelcaninae Gorochov et al. 2006, and characterized the Elcaninae on the basis of the more or less narrowed area between tegminal RA and RP, the fused (with each other) distal parts of CuPaβ, CuPb, and A, and “possibly the rather small spines of the hind tibiae”. As Cenoelcanus gen. nov. has two most important venation characters of the Elcaninae, we consider it belongs to this subfamily. The Archelcaninae would be characterized by the presence of large spines on hind tibia, unknown in our fossil.

Cenoelcanus gen. nov. differs from all the Mesozoic elcanid genera (in which the tegmina are known) by the combination of the two characters: presence of only four branches of RP and a very short vein between M+CuA and RP ( Gorochov 1986; Martins-Neto 1991b; Gorochov et al. 2006; Poinar et al. 2007; Fang et al. 2015, 2018a, b). The very long ScP is a character only present in the Permo- Triassic Meselcana Sharov, 1968 , which could look strange to find in the youngest representative of the Elcanidae . But a reversal is always possible. Burmelcana Peñalver and Grimaldi, 2010 and Hispanelcana Peñalver and Grimaldi, 2010 are based on nymphs in amber, impossible to compare to Cenoelcanus gen. nov. ( Peñalver and Grimaldi 2010; Fang et al. 2015). A structure analogous to the “elcanoid” alignment of M+CuA and RP is present in the extant genus Charilaus Stål, 1875 ( Pamphagodidae Bolívar, 1884 ) but in this genus, M+CuA is making a thick complex vein together with R, from which CuA, M, and RP successively separate. Thus it is certainly not homologous to the structure of the Elcanoidea and Cenoelcanus .

Stratigraphic and geographic range.— Paleocene, Menat Formation, Menat, France.

Figures

Fig. 8. Tegmen of Elcanid orthopteran Cenoelcanus menatensis gen. et sp. nov., holotype, MNHN.F.A71198 from Paleocene of Menat, France. Photograph (A1), reconstruction (A2). Abbreviations: CuA/P, cubitus anterior/posterior; CuPaα, most anterior branch of CuP; M, median vein; RA/P, radius anterior/posterior; ScP, subcostal posterior.