Thaites ruminiana,

Jong, Rienk De, 2017, Fossil butterflies, calibration points and the molecular clock (Lepidoptera: Papilionoidea), Zootaxa 4270 (1), pp. 1-63: 37

publication ID

http://doi.org/ 10.5281/zenodo.583183

publication LSID

lsid:zoobank.org:pub:2D00AFF5-4FE2-4EC1-A328-C8670CFB8D6D

persistent identifier

http://treatment.plazi.org/id/03AA87D3-2864-FFF3-F7F0-FDA3FDF1B7E4

treatment provided by

Plazi

scientific name

Thaites ruminiana
status

 

ruminiana  . Thaites ruminiana Scudder, 1875 

Figs. 14–16

Papilionidae  : Parnassiinae  : Parnassiini  .

France, Bouches-du-Rhône, Aix-en-Provence; late Oligocene –early Miocene.

Depository: PMUZ (holotype).

Published figures: Demoulin (1975: Fig. 2View FIGURE 2); Leestmans (1983: Figs 1–4View FIGURE 1View FIGURE 2View FIGURES 3 – 4); Murata (1998: Figs 12View FIGURES 11 – 13 –15); Scudder (1875: Pl. III Figs 1View FIGURE 1, 3View FIGURES 3 – 4, 6–10).

This specimen is only partly preserved; most of the venation and much of the pattern is discernible. Although Scudder usually is very accurate in his figures and descriptions, his figure of the left underside of the fossil (pl. III Fig. 9) must be incorrect in that it shows two subcostal veins in the forewing. In his reconstruction of the venation (Pl. III Fig. 1View FIGURE 1) the normal, single subcostal vein is depicted. The radial formula is: 1, 2+3, 4+5, with R2 and R3 separate close to the apex. Posterior margin of cell quadrifid, an apomorphy of Papilionidae  . A cubital spur, another apomorphy of Papilioninae  , is not apparent. Hindwing with single anal vein, an apomorphy of Papilionidae  . Starting from the assumption that the radial formula 1, 2, 3+(4+5) belongs to the groundplan of the Papilionidae  , the fossil cannot belong to the ancestry of any taxon in this family where the plesiomorphic condition has been retained. With slight variations, this is the case for all papilionid genera except for Parnassius  and Hypermnestra  . Therefore, only these genera can be considered as close relatives of Thaites ruminiana  . Parnassius  and Hypermnestra  are thought to be sister groups by Hancock (1983), Omoto et al. (2004) and Nazari et al. (2007), the ancestor of which has lost R3 by fusion with R2; in some Parnassius  species a further fusion seems to take place in a terminal anastomosis of R1 and R2. Thaites  fits in quite well here, as sister group of both. According to Hancock (1983) Thaites  is an offshoot of the ancestral line of Parnassiini  , which is unlikely, as is his opinion that Archon  belongs here, although it has retained the plesiomorphic radial vein arrangement. In the Parnassiini  sensu Nazari et al. (2007) the tribe consists of Parnassius  and Hypermnestra  only, with which the fossil shares the apomorphic condition of the radial vein venation. Consequently, the fossil should be placed as sistergroup of Parnassiini  sensu Nazari et al. (2007). However, Nazari et al. (2007) had included the fossil in their phylogenetic analysis of the morphology and molecular characters of extant species (see also under Doritites bosniaskii  and Praepapilio colorado  ). In the analysis it appeared as an offshoot of the Parnassiini  lineage, before it split into Parnassius  and Hypermnestra  . For the calibration of the clock such a switch of a taxonomic assignment may be of little consequence, since it concerns a sister group, but yet it is preferable to have relationships explicitly stated. New information, such as more or other molecular data or additional taxa, may prompt another rearrangement of genera and then the date of the calibration point should be clear.

For the sake of historical completeness but without impact on the discussion above, the following information is provided. Principally because of similarities in wing pattern apparently based on symplesiomorphies, Scudder (1875) considered the fossil a close relative of Thais rumina (Linnaeus)  , now allocated in the genus Zerynthia  , hence the name. Stichel (1907) and Verity (1947) assigned the fossil to the tribe Zerynthiini  , without much comment. Bricoux (1975) followed Verity (1952) in considering Thaites ruminiana  as the ancestor of Zerynthia rumina  , what is most unlikely because of the venation issues as explained above. Demoulin (1975) is of the opinion (based on venation) that the fossil is a precursor of Parnassius  ; he does not mention Hypermnestra  .

With two other papilionid fossils, this fossil was used for calibration by Condamine et al. (2012), see discussion under Praepapilio colorado  .