Republica Archibald & Cannings, 2021

Archibald, S. Bruce & Cannings, Robert A., 2021, A new genus and species of Euphaeidae (Odonata, Zygoptera) from the early Eocene Okanagan Highlands locality at Republic, Washington, U. S. A., Zootaxa 4966 (3), pp. 392-400 : 395-396

Republica Archibald & Cannings , new genus

Fig. 1

Diagnosis. The following character states of the Republica forewing (preseumed, see below) most easily separate it from those of other Eodichromatini :

1- narrow, 3.9 times longer than maximum width (L/W); nodus to apex length 2.5 maximum width (N/W);

2- arculus near to, just basal to Ax2;

3- many (at least 28) antenodal crossveins preserved in first row, (at least 26) Ax2 to nodus; not aligned with second row;

4- costal space distal to pterostigma maximum three cells wide;

5- both rows of antenodal, postnodal crossveins with numerous branching, some connected by horizontal crossveins;

6- one secondary antenodal crossvein between Ax1, Ax2.

7- six long secondary longitudinal veins in CuA–A space (region not well preserved in part, but six appears most likely);

8- MA smoothly, sinuately curved twice toward anterior margin and MP, CuA deeply curved;

9- MP, CuA sub-parallel, remain close at termination on margin (where preserved, highly likely throughout) without secondary longitudinal veins between them.

These distinguish Republica from:

Eodichroma Cockerell by 3 [13 Ax2 to nodus], 5 [simple], 7, [less, apparently 3–4], 8, 9;

Parazacallites Nel by 2 (near Ax1), 3 [11, aligned], 5 [simple], 6 [2], 7 [less: 3 preserved, perhaps another?], 9 [diverge, but no secondary longitudinal veins between];

Solveigia Zessin by 1 [forewing L/W ~3.0, N/ W 2.0], 3 [7 preserved, probably 1–2 more, second row 2 preserved, aligned], 4 [1 cell wide], 5 [simple], 6 [none], 7 [less: apparently 3], 8, 9;

Ejerslevia Zessin by 4 [1 cell wide], 5 [simple], 7 [less, apparently 4], 8, 9;

Wolfgangeuphaea Ferwer & Nel: 2 [near Ax1], 4 [1 cell wide], 5 [simple], 9 [diverge distally];

Labandeiraia Petrulevičius et al. by 5 [see discussion], 9 [ L. riveri , see notes, below] and:

L. americaborealis Petrulevičius et al. and L. browni Bechly et al. : 6 [none];

L. riveri Bechly et al. :1 [forewing L/ W 3.4], 6 [none].

Note: some character states cannot be compared when only the hind wing is known due to forewing-hind wing differences or where the relevant region is missing, e.g., the distal half of the Parazacallites wing; others that do not appear in descriptions and were not illustrated cannot be assessed, e.g., character state 8 in Wolfgangeuphaea, character state 5 in L. riveri , and the presence of secondary crossveins between Ax1 and Ax2 and the general density of secondary longitudinal veins in L. browni and L. riveri ( L. browni contradicts character state 9 from the published photograph; however, the published photograph of L. riveri is unclear in this regard).

Type species. Republica weatbrooki new species, by monotypy.

Description. As for its only species.

Etymology. The genus name is the Latinized form of Republic, the town where the only known specimen was found. Gender, feminine.

Range and age. Tom Thumb Tuff Member of the Klondike Mountain Formation at Republic, Washington, U.S.A., exposure B4131 ; latest Ypresian .

Position of Republica . Republica belongs to the Euphaeida and Epallagoidea of Bechly (1998) and to the Euphaeidae by the combination of (as Epallagidae : Bechly 1996, 1998, Petrulevičius et al. 2007): the distal side of the quadrangle and sub-quadrangle (discoidal bracket: “db” of Fig. 1 ) is thick, with reversed obliquity; densely reticulate venation; CuA sigmoidally and smoothly curved; curved intercalary veins between CuA and the hind margin; antenodal crossveins numerous [ Zacallitidae : less numerous]; and the quadrangle is longer than wide [ Zacallitidae : as long as wide].

It is assigned to the subfamily Eodichromatinae by Ax1 and Ax2 being distinctly bolder than the secondary antenodal crossveins ( Petrulevičius et al. 2007); other character states listed by Bechly (1998) and Petrulevičius et al. (2007) that separate the subfamilies cannot be evaluated by preservation. We assign it to the tribe Eodichromatini ( Eodichroma , Parazacallites , Labandeiraia ., Solveigia , Ejerslevia , and Wolfgangeuphaea) by the presence of secondary antenodals between ScP and RA, absent in the other tribe of Eodichromatinae , the Litheuphaeini ( Litheuphaea Fraser ). Eodichroma is poorly known; a drawing of its single fossil wing was never published, only a poor-quality photo ( Cockerell 1923, fig. 2; reproduced by Berry 1924, figure 1 of his plate LXIII), and the specimen is now lost ( Bechly 1998).

The wing of Republica is morphologically closest to those of Labandeiraia as in the diagnosis of Petrulevičius et al. (2007): it has more than 20 antenodal crossveins; the arculus very close to Ax2; an elongate, narrow quadrangle (inferred in Republica: MP +CuA, between the quadrangle and sub-quadrangle is not preserved); most likely six long secondary longitudinal veins in the CuA–A space (this region not well preserved in part in Republica , but six appears reasonable); more than two rows of cells between C and RA distal to the pterostigma and between RA and RP1 below it. The absence of the pterostigmal brace vein cannot be established as region poorly preserved. Further to the diagnosis, as in Labandeiraia, MA smoothly curves several times.

Republica differs from the diagnosis of Labandeiraia ( Petrulevičius et al. 2007) as the anal area is not so broadened; however, this broadening is based on the wider hind wings. The distinctive transverse cells of the anal region appear present in the forewing of L. riveri in figure 5 of Bechly et al. (2020) confirming their presence in a narrower forewing of that genus. Republica lacks these elongate cells. Republica also differs by shorter secondary longitudinal veins between main veins. In Labandeiraia MA and CuA diverge toward the wing margin with long secondary longitudinal veins between them, while they are sub-parallel, remaining close in Republica . Although the space between MA and CuA is poorly preserved in the sole specimen of Republica , there appears to be no room for a secondary longitudinal vein between them.

Republica is further separated from Labandeiraia by both rows of antenodal, postnodal crossveins with many branching, some connected by horizontal crossveins (diagnostic character state 5). One is, however, branched in L. americaborealis specimen 31.665A ( Petrulevičius et al. 2007, fig. 1C), and three in L. europae , paratype MM 1255 ( Petrulevičius et al. 2007, fig. 2A)], but we consider these few cases minor, not as in Republica , where there are many.

We make the assumption that the Republica wing is a forewing, as wherever the wings of Eodichromatini are known to be forewings or hind wings, the hind wing is broader to much broader and/or more triangular, deeper in the middle than the forewing. Even when the hind wing is not as extremely broad as it is in Labandeira species (see Petrulevicius et al. 2007), it is triangular, not smoothly curved along the posterior margin as in the Republica wing. If the Republica wing were a hind wing, it would differ much more distinctly from other Eodichromatini in this way. To be conservative, however, we treat it as a presumed forewing.

Figures

FIGURE 1. Republica weatbrooki Holotype SR 06-59-08. A, photograph; B, drawing. Both to scale, 5 mm; db, discoidal bracket, see text.