Palaeorehniidae Zeuner, 2022

Archibald, S. Bruce, Gu, Jun-Jie & Mathewes, Rolf W., 2022, The Palaeorehniidae (Orthoptera, Ensifera, “ Zeuneropterinae ”), and new taxa from the early Eocene Okanagan Highlands, western North America, Zootaxa 5100 (4), pp. 559-572 : 560-565

Family Palaeorehniidae Zeuner stat. nov.

Palaeorehnia in the Hagloidea , Zeuneropterinae in the Stenopelmatoidea . Cockerell (1908) discussed the similarities of Palaeorehnia Cockerell to other taxa but did not assign it to a higher taxon within the Ensifera , nor did he publish a drawing of it, only low-resolution photographs (1909).

Zeuner (1937) grouped Palaeorehnia and Jurassobatea Zeuner (Jurassic of Germany) as the Palaeorehniinae, a subfamily of the Gryllacrididae . Palaeorehnia included P. maculata (Scudder) from the Priabonian shale at Florissant, Colorado, USA ( Scudder 1890; Cockerell 1908, 1909; Kevan and Wighton 1983) and P. scotica .

Sharov (1962) treated P. maculata and Jurassobatea as Haglidae incertae sedis and erected the genus Zeuneroptera Sharov for P. scotica , maintaining the subfamily name Palaeorehniinae. As it no longer contained Palaeorehnia, Kevan and Wighton (1983) proposed the replacement name Zeuneropterinae (in Gryllacrididae ), consisting only of Zeuneroptera . They assigned their new genus Albertoilus Kevan and Wighton to the Prophalangopsidae (Hagloidea) and suggested that P. maculata belongs to it as well.

Zeuner, Sharov, Ragge (1955) and others in much of the Twentieth Century had differing arrangements of the superfamilies of Ensifera and their compositions, understanding the relationships of Zeuneroptera and Palaeorehnia to each other and within the Ensifera in a variety of ways. For brief reviews of the history of this thought, e. g., see Kevan and Wighton (1981, 1983) and Gorochov (2001).

The current generally accepted view has Palaeorehnia in the Hagloidea and Zeuneropterinae (as Zeuneroptera and Albertoilus ) in the Stenopelmatoidea (Gorochov 1995, but see Béthoux 2012, who makes an argument for Zeuneroptera in the Prophalangopsidae ). Gorochov (2001) thought that the Zeuneropterinae might be close to the Anostostomatidae (Mimnermidae) , especially its subfamily Cratomelinae , although with uncertainty as to it belonging the Stenopelmatoidea .

In Gorochov’s diagnosis of the Stenopelmatoidea (1995, page 186), CuA+CuPaα, CuPaβ, CuPb, and 1A are long and at a low angle to the posterior margin (“parallelization”), ending in the distal quarter of the wing as is reconstructed in the Zeuneropterinae . This is contra his Hagloidea concept (1995, page 107) where these four veins meet the posterior margin farther from the wing apex at a steeper angle (and see Gorochov 1988, 2001) as in the reconstruction of Cockerell’s P. maculata wing of Zeuner (1939: plate 2; plate 22, Fig. 1 ; plate 25, Fig. 1 ).

Reassessment of superfamily assignments. The angles and ending points of CuA+CuPaα, CuPaβ, CuPb, and 1A in Palaeorehnia , Zeuneroptera and Albertoilus , have, however, been estimated based on reconstructions of partial wings, none of which completely preserves those veins to their ends. To evaluate the assumption that these veins conform with Gorochov’s Hagloidea in Palaeorehnia , we examined modern high-resolution photographs of the part and counterpart of Cockerell’s holotype ( Fig. 1A–1C ). In these, the line thought to be a portion of the posterior wing margin can now be seen to be a part of a displaced, upturned vein in a folded section as in the similarly folded basal posterior region of the Ypopteron nicola type specimen ( Fig. 4 ). Zeuner’s reconstruction (1939) then incorrectly rotates the wing clockwise, increasing the angles of these four veins to the non-existent portion of the posterior margin, therefore, ending too basally on the wing margin for Palaeorehnia to be associated with the Stenopelmatoidea ( Fig. 1D ). While there is not a sufficient portion of the posterior margin preserved to act as a landmark with which to orient the wing, it should be rotated counterclockwise by some unknown amount from Zeuner’s reconstruction and from that in Fig. 1E , and it is equally likely that the angles of these veins match those in Zeuneroptera and Albertoilus .

This interpretation is also suggested by a new, high-resolution photograph of a second, unpublished fossil tegmen in the University of Colorado (Boulder) collections (UCM-18757: Fig 1E, F ) labelled “ Palaeorehnia maculata Ckll (apparently) Florissant T. Duce”. It is quite damaged and is somewhat smaller than the P. maculata wing, although this might be explained by sexual dimorphism. Its preserved venation is similar enough to that of the P. maculata holotype that it is likely closely related or perhaps even conspecific as the tentative identification on the label indicates. The basal branching of RA and RP is notably like that of the P. maculata type specimen. The posterior margin of the wing and CuPaβ, CuPb, and 1A are not preserved, but the distal portions of the branches of CuA+CuPaα appear long, at a low angle to the wing length.

We further evaluated the angle of these veins in Zeuneroptera , whose sole fossil is missing its distal posterior portion. Sharov’s reconstruction (1962: Fig. 402, redrawn here as Fig. 2A ) presumes a quite wide wing with the reconstructed portions of CuPaβ, CuPb, and 1A straightening in the missing portion from their curves in their preserved portions. In this interpretation, these veins are long as in the Stenopelmatoidea .

This missing portion could, however, have been narrower than Sharov speculated, and if these veins continue their curvature as in his drawing of their preserved portions (we have not seen the fossil or its modern photographs; access to collections at the Natural History Museum, London, is restricted during the COVID-19 pandemic), then they terminate more basally, not as in the Stenopelmatoidea (Fig, 2B). Both reconstructions are possible, and so the angles and termination points of these veins are unknown.

In the partial tegmen of Albertoilus , CuA+CuPaα, CuPaβ and possibly CuPb (but possibly not 1A?) appear to be angled low to the margin and most likely long ( Fig. 3C ).

Although there are three fossil tegmina known of the new genus Republicopteron , none have the distal portions of these four veins preserved. Their preserved portions suggest, however, that they are long. In the holotype SR 00- 04-06 part of the anterior margin is preserved with which to align the fossil, indicating that at least MA, MP, and CuA+CuPaα are long, oriented at a low angle to the length of the wing .

In the more complete tegmen of the new genus and species Ypopteron nicola , the termination points of these veins are more proximal than in the Stenopelmatoidea and are like those of many Prophalangopsidae : only two of five branches of CuA+CuPaα end in the distal quarter of the wing, and CuPaβ ends mid-wing ( Fig. 4 ). Note that the distal portions of the basal branch of CuA+CuPaα, CuPaβ, CuPb, and the anal veins are upturned by a fold of the wing as in the P. maculata holotype.

These four veins then might or might not conform with Grochov’s diagnosis of the Stenopelmatoidea in Palaeorehnia and Zeuneroptera , probably do in Albertoilus and Republicopteron , and do not in Ypopteron . By the strong similarity of all other aspects of the venation of these five genera listed in our emended diagnosis below, we group them as a taxon of unknown superfamily affinity, suspecting that these veins might have a range of lengths among them, perhaps varying from the hagloid-type to the stenopelmatoid-type. If this is so, it would be in concordance with Gorochov (1995), who considered the venation of Zeuneropterinae to be intermediate between the Stenopelmatoidea and Hagloidea .

Like the Prophalangopsidae , CuA+CuPaα has numerous branches in the Zeuneropterinae , further excluding it from the Stenopelmatoidea (including the Anostostomatidae ), where there are no more than two (Gorochov 1995, 2001).

With the restoration of Palaeorehnia to the taxon, its name reverts to Palaeorehniinae. As it is not then associated with any family, we raise it to the family level and treat it as the Palaeorehniidae Zeuner stat. nov., defining it by emending Gorochov’s diagnosis (1995, part 1, page 126) of the Zeuneropterinae as follows.

Emended diagnosis. The tegmen of Palaeorehniidae have venation most like that of female Prophalangopsidae (e.g., CuPb and 2A rather equally bowed away from 1A basally), but may be distinguished from them most easily by the following.

1: CuPaα ( Fig. 3 , red) not aligned with CuPa ( Fig. 3 , dark blue), angled toward M before its branching, toward anterior margin ( Y. nicola : weakly; all others: more so) [all Hagloidea : CuPaα aligned with CuPa, subparallel to M before M branching, directed toward posterior margin];

2: basal branch of CuA+CuPaα ( Fig. 3A , light blue) not aligned with free CuA [ Prophalangopsidae : almost always aligned, but see discussion];

3: CuPaα oblique to CuA+CuPaα not aligned ( Fig. 3 , purple), these, with free CuA ( Fig. 3 , green) form a “Y rotated counterclockwise [ Prophalangopsidae : CuPaα aligned with CuA+CuPaα distal basal branch as in character state 2; these, with free CuA form an “X”];

4: as a consequence of 1 and 3, space posterior to M+CuA ( Fig. 3 , yellow), twice or more width of space posterior to M immediately distal to it ( Fig. 3 , orange) [ Prophalangopsidae : similar width, but narrowing distal to branching of M ( Fig. 3 , light brown) in many];

Type and included genera. Type genus: Palaeorehnia ; included genera: Zeuneroptera , Ypopteron , Albertoilus , and Republicopteron .

Discussion. In Prophalangopsidae , the basal branch of CuA+CuPaα (see character state 2 of the diagnosis) is shifted basally in Gorochov’s (1996, Fig. 5A ) drawing of the tegmen of Karatailus micropterus Gorochov and appears shifted slightly distally in a specimen of a male Ashangopsis daohugouensis Lin et al. (see Gu et al. 2010, Fig. 9.2), but is aligned with the free CuA in the female specimen (Fig. 9.4). The basal branch of CuA+CuPaα appears not aligned in Prophalangosis obscura (Walker), see Liu et al. (2009, Fig. 1 , their CuA2), but we believe this to be due to creasing of the wing; in a specimen that we examined, this basal branch originates at the distal end of the free CuA as in the above diagnosis, although it appears at a slightly different angle from it, also because of creasing of the wing.

Two genera thought at times to belong to the Zeuneropterinae have been transferred to the Tettigoniidae : Lithymnetes (Théobald) 1937 (Oligocene, France, now Archepseudophylla Nel et al. ) ( Nel et al. 2008), and Eodecticus Pongrácz (Miocene, Croatia) ( Zeuner 1939 and see Gorochov 1995). Wang et al. (2019) transferred Hylophalangopsis chinensis Lin and Huang from the Prophalangopsidae to the taxon, however, while it agrees with character state 2 of our diagnosis (basal branch of CuA+CuPaα not aligned with free CuA), it disagrees with it and agrees with Prophalangopsidae by character states 1, 3, and 4. Although this wing resembles those of Prophalangopsidae in these ways, MA, MP, CuA+CuPaα, CuPb, CuPaβ appear probably long as in Stenopelmatoidea , not Hagloidea . A thorough analysis and placement of it to higher taxon is outside of the scope of this paper, but we are confident that it is not a member of the Palaeorehniidae .

In Prophalangopsidae , details of the branching of CuA+CuPaα vary within species and even between the left and right wings of an individual ( Gu et al. 2009, Wang et al. 2017). We presume this is also true in the Palaeorehniidae ; therefore, we do not include these in Table 1 (as above, however, that this vein has more than two branches is informative).

We suspect that perhaps two or more of the genera of Palaeorehniidae should be synonymized and some of the character states listed in Table 1 considered species-level differences. We refrain from doing so here as premature because except for Republicopteron , they are only known from single specimens (UCM-18757 is only tentatively associated with P. maculata ) and all are fragmentary.

The three specimens assigned to R. douseae are consistent in the character states listed in table 1. Although the length of CuA+CuPaα before its first branching varies to some degree, it is always long, distinct from that of all other Palaeorehniidae . All three wings have dark membranes. The holotype has some spots, but much fewer than those of P. maculata . The two paratypes do not bear such spots, but this might be an artefact; compare the part and counterpart of P. maculata ( Fig. 1A and 1B ). The photograph and drawing of the tegmen of A. cervirufi by Kevan and Wighton (1983) are not very informative as to colouration, but they described the wing as bearing reasonably well developed maculations that are not definite in shape, although this pattern could also be an artefact. In Zeuner’s description of Z. scotica (as P. scotica ), he makes no mention of colouration, and we know of no description or illustration of this. The wing of Y. nicola appears infuscate throughout, although preservation of the membrane varies across it.

Figures

FIGURE 1. Palaeorehnia maculata holotype wing, A–E: A, closeup of the basal posterior portion of the counterpart, showing 1A and portions of it folded up over the wing and portions of unknown veins distally (cf. veins of upturned portion in Ypopteron nicola, Fig. 4); B, photograph of the part showing preserved colouration; C, photograph of the counterpart; D, reproduction of the drawing of Zeuner (1939: plate 25, Fig. 1); E, new drawing from the photographs (in same rotational orientation as D); tentative Palaeorehnia maculata, University of Colorado (Boulder) collections UCM-18757, F and G: F, photograph; G drawing. Scale bars for A and B–F are 1 cm.

FIGURE 2. Reconstructions of the distal missing portion of the wing of Zeuneroptera scotica, venation of the fossil in black with reconstructed missing venation in green: A, reconstruction of Sharov (1962, Fig. 402); B, new reconstruction. No scale bar on original.

FIGURE 3. Diagnostic character states of the wing of Palaeorehniidae (see text); comparative Prophalangopsidae (A) and Palaeorehniidae (B, C): A, Aboilus tigris Gorochov, female, redrawn from Gorochov (1996, Fig. 2c); B, Republicopteron douseae specimen SR 21-005-001; C, tegmen of Albertoilus cervirufi, redrawn from Kevan and Wighton, with distal fragment positioned as in their drawing (1983, Fig. 1b). Scale bar for B, see Fig. 7; for C, see original; original of A has no scale bar.

FIGURE 4. Ypopteron nicola, new genus and species, holotype Q-1010, Quilchena: A, photograph; B, drawing. Scale bar = 1 cm.

FIGURE 5. Republicopteron douseae, new genus and species, holotype SR 00-04-06, Republic: A, photograph; B, drawing. Scale bar = 1 cm.