Lithochrysa concinnula (Cockerell, 1909)

Makarkin, Vladimir N., Antell, Gwen S. & Archibald, S. Bruce, 2022, A revision of Chrysopidae (Neuroptera) from the late Eocene Florissant Formation Colorado, with description of new species, Zootaxa 5133 (3), pp. 301-345 : 328

Lithochrysa concinnula (Cockerell, 1909)

Fig. 20

Palaeochrysa concinnula Cockerell, 1909b: 218 , 219, Fig. 5 ; Cockerell 1914: 717; Carpenter 1935: 262; Schlüter 1984: 4; Martins-Neto & Vulcano 1989: 189, 190; Séméria & Nel 1990: 30; Meyer 2003: 208; Nel et al. 2005: 67; Makarkin & Archibald 2013: 143; Archibald & Makarkin 2015: 361; Archibald & Makarkin 2017: 399, 400.

Lithochrysa concinnula: Carpenter 1935: 266 , Fig. 5 ; Martins-Neto & Vulcano 1989: 190.

Paleochrysa [sic] concinnula: Rodeck 1938: 290 ; Adams 1967: 231; Schlüter 1982: 261.

Type material. Holotype UCM 4220, deposited in UCM, collected by S.A. Rohwer; at least a forewing and a part of a hind wing according to the original description, covered with Canada balsam.

Type locality and horizon. USA: Colorado: Teller County: Florissant (Station 14, NW SE NW Section 11, Township 13S, Range 71W); Eocene, late Priabonian; Florissant Formation .

Diagnosis. May be distinguished from other species of the genus by the hind wing RP1 located proximad first crossvein ra-rp [other species: distad].

Description (emended from Cockerell 1909b). Forewing ca. 12 mm. RA space with probably eight or nine crossveins (“nine cells”). Crossvein 2m-cu relatively short, located proximal one-third of im, only slightly proximad level of 1r-m. Inner gradate series probably in smooth line (“cells between [RP and inner gradate series] “successively shorter from the fourth on, but without any abrupt change of size, as in Tribochrysa ”). Six branches of RP forked.

Hind wing. MA basally oblique, then fused with RP from long distance. RP1 originating proximad first crossvein ra-rp.

Remarks. Practically nothing is now discernable in the specimen as it was covered by Canada balsam, which has lost clarity with age ( Fig. 20A ), and so all we know of the species is from the short original description and drawings of fragments of the fore- and hind wing venation reproduced here ( Fig. 20B, C ). The original description provides few potentially informative character states (see above), and at least one is diagnostic (see above). Although its generic affinity may be disputed due to the condition of the fossil, the main diagnostic character state of Lithochrysa distinguishing it from similar genera Palaeochrysa and Tribochrysa (i.e., the smooth arrangement of the inner gradate series) appears to be present.

Figures

FIGURE 5. Archaeochrysa sp., specimen NHM.I.26921 (counterpart). NHMUK PI I.26921 image © The Trustees of the Natural History Museum. Scale bar = 3 mm.

FIGURE 20. Lithochrysa concinnula (Cockerell, 1909), holotype UCM 4220. A, specimen in current condition, obscured by Canada balsam; B, forewing venation; C, hind wing venation (redrawn from Cockerell 1909b: Fig. 5). Scale bar = 3 mm (B, C not to scale, no scale on original).