Reisia rieki, Deregnaucourt & Wappler & Anderson & Béthoux, 2017
|
publication ID |
https://doi.org/ 10.4202/app.00345.2017 |
|
persistent identifier |
https://treatment.plazi.org/id/03B4B660-FF8F-FF9C-FCB8-A8CFFC3239BF |
|
treatment provided by |
Felipe |
|
scientific name |
Reisia rieki |
| status |
sp. nov. |
Reisia rieki sp. nov.
Figs. 1–3 View Fig View Fig View Fig .
Etymology: Named after Edgar Frederick Riek (1920–2016), who described the earliest collections of Molteno insects in three papers in the mid-1970’s.
Type material: Holotype: PRE/F/17569 (positive and negative imprints). Paratypes: PRE/F/16442 (negative and positive imprints) and PRE/F/17499 (negative imprint); all from the type locality.
Type locality: Kapokkraal (locality code “Kap 111”; see Anderson and Anderson 1984), Karoo Basin, South Africa .
Type horizon: Molteno Formation, Carnian, Triassic.
Material.— Type material and specimen PRE/F/10616 (negative and positive imprints) from the Aasvoëlberg locality (locality code “Aas 411”; see Anderson and Anderson 1984), Carnian (Triassic), Molteno Formation, Karoo Basin, South Africa .
Diagnosis.—MP area moderately developed (as opposed to small” in Reisia gelasii and R. nana , and “large” in R. sogdianus ; unknown in R. rubra ); sparse crossveins network as opposed to dense in R. sogdianus ); main portion of Irp 1+2 –rp 3+4 and RP3/3a straight (regularly bent in all other species of Reisia , but unknown in R. nana ); clear origin of RP3b (no clear differentiation of RP3b in R. sogdianus ); RP2, Irp 1+2 –rp 3+4 and RP3a with a strong bending near their end (putative apomorphy; unknown in R. nana ); RP2 with a few, very distal branches (as opposed to more basal origin, as in R. rubra and, to some extent, in R. gelasii — unknown in R. nana and R. sogdianus ).
Description.—General features: wing total length and maximum width unknown, about 108–118 mm, and 15–17 mm, respectively; anterior wing margin slightly thicker near the apex (i.e., in the area where a pterostigma occurs in extant relatives); area between the anterior wing margin and ScP large, with many crossveins, distally broadened in the pterostigmal area”; in the area between the anterior wing margin and RA (distal to the nodus), crossveins stronger than in other areas; occurrence of a Sn; in the area between RA and RP1, occurrence of a distinctively oblique crossvein known only in the holotype; see asterisk on Fig. 1A View Fig and Fig. 3 View Fig ); RP+MA divided into RP and MA basal to the nodus; RP divided into RP1+2 and RP3+4 opposite Sn; RP1+2 divided into RP1 and RP2 shortly before wing mid-length; Irp 1 –rp 2 (convex) occupying a large area filled with convex branches (of Irp 1 –rp 2) and supplementary concave intercalaries, all sub-parallel; RP3+4 divided into RP3 and RP4 basal to the fork of RP1+2; areas between RP1+2/2, Irp 1+2 – rp 3+4 and RP3+4/3/3a each with a single row of cells; RP3 divided in RP3a and RP3b, without obvious further forks; RP2, Irp 1+2 –rp 3+4 and RP3a strongly bent close to the posterior wing margin, which they reach at a nearly right angle; large area between RP3a and RP3b; occurrence of Irp 3 – rp 4, simple; areas between RP3/3b, Irp 3 –rp 4 and RP4/4a/4aa each with a single row of cells; RP4 dichotomously divided, with three orders of branching for RP4a and RP4b (RP4baa and RP4bab visible); a single row of cells occurs between RP3+4/4 and MA; MA simple; MA and MP parallel, area between these two veins with a single row of cells, longer than broad; MP with no evident fork, but delimiting a large area filled with several concave MP branches and convex intercalary veins, subparallel; CuA with numerous branches (convex) and intercalary veins (concave) between them; some of these intercalaries are forked and additional, convex intercalaries occur between them.
Specimen PRE/F/17569 ( Figs. 1A View Fig , 2A View Fig , 3 View Fig ): right wing, median part preserved; preserved length 61 mm, maximum width 16.6 mm; basal part of the wing partly distorted, with ScP most probably concealed by RA (the termination of ScP not visible, occurrence of the nodal crossvein cannot be verified); apex and base of the wing missing.
Specimen PRE/F/16442 ( Figs. 1B View Fig , 2B View Fig ): fragment of a left wing; preserved length 36.2 mm, width of 16.9 mm; apex and first half of the wing missing; specimen slightly larger than others.
Specimen PRE/F/10616 ( Figs. 1C View Fig , 2C View Fig ): fragment of the apex of a right wing; preserved length 29.5 mm, maximum width 13 mm; distal part of RP2 preserved, with few, short branches.
Specimen PRE/F/17499 ( Figs. 1D View Fig , 2D View Fig ): fragment of the distal third of a right wing; preserved length 43.2 mm, maximum width 13.8 mm.
Remarks.—Because of the elaborate system of intercalary veins it proved impossible to identify CuP and AA branches with certainty in the only specimen displaying this area ( Figs. 1A View Fig , 2A View Fig ). For similar reasons, the delimitation of CuA is uncertain.
We hypothesise that all specimens herein documented belong to a single species. Although they are very incomplete, there are sufficient portions in common to allow comparison in venation and size. A good match was obtained for the specimens PRE/F/17569 ( Figs. 1A View Fig , 2A View Fig ) and PRE/F/16442 ( Figs. 1B View Fig , 2B View Fig ) based on the RP1–RP2 and RP4a–RP4b forks. Considering these specimens altogether, the specimen PRE/F/17499 ( Figs. 1D View Fig , 2D View Fig ) perfectly matches them (in particular the outline, and the peculiar, straight course of RP2, Irp 1+2 –rp 3+4, and RP3/3a). Finally, the specimen PRE/F/10616 ( Figs. 1C View Fig , 2C View Fig ) is very similar to the specimen PRE/F/17499, but also complement the specimen PRE/F/16442 (with a minor difference in size, the latter being the largest of the set). The range of intra-specific variability is unknown in related species (all are known from singletons but one, R. guillaumei , known thanks to two incomplete specimens), but the observed differences are minimal. In conclusion there is no ground to assume that the specimens belong to different species. Until new specimens are discovered and constitute a challenge to this proposition, it should be considered valid.
The species possesses a long RP +MA stem basal to the arculus ( Figs. 1A View Fig , 2A View Fig ), a trait distinctive of Triadotypomorpha (see above). Our diagnosis demonstrates that this species differs from those previously known. Its size is similar to that of other Reisia species, as far as it can be inferred from the limited data on these species.
Stratigraphic and geographic range.—Putatively early Carnian, Late Triassic ( Anderson and Anderson 1983); Karoo Basin, Molteno Formation, localities Kapokkraal and Aasvoëlberg (respective locality codes “Kap 111” and “Aas 411”; see Anderson and Anderson 1984), South Africa.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.