Siphloplecton macrops ( Pictet-Baraban & Hagen, 1856 )

Staniczek, Arnold H. & Godunko, Roman J., 2016, Revision of fossil Metretopodidae (Insecta: Ephemeroptera) in Baltic amber — Part 3: Description of two new species of Siphloplecton Clemens, 1915, with notes on the re-discovered lectotype of Siphloplecton macrops (Pictet-Baraban & Hagen, 1856), Zootaxa 4103 (1), pp. 1-24 : 2-4

Siphloplecton macrops ( Pictet-Baraban & Hagen, 1856)

Figures 1 A–C

For complete list of synonyms see Staniczek & Godunko 2012: 59

Material. Lectotype. Male imago in Baltic amber (Eocene), MNB, MB.I.5150., specimen provided with 7 different labels ( Fig. 1 A, i–vii) that read as (“//” denotes line break):

(i) n◦ 14 Palingenia macrops // Tab. VI Fig 2

(ii/1: front side) Holotyp // Paläontologisches Museum Berlin // Siphloplecton macrops // ( Pictet, 1856) // Orig. Pictet-Baraban & Hagen, 1856 // S. 74, Taf. 6, Fig. 2 // Slg. BERENDT // b.w.

(ii/2: rear side) war ausgeliehen an // Illies, 1966; // zerstört zurück 1990

(iii) Hololectotype

(iv) MB.I.5150

(v) G. Demoulin detrev., 19567 // Siphloplecton // macrops // (PICTET) // ♂ imago

(vi) 7350 // Palingenia // macrops

(vii) 7350

S. macrops was described in 1856 from a type series of 11 specimens from the Berendt collection (see Fig.1 A, label (i) that most probably dates back to the original description). Demoulin (1968) in his revision of Siphloplecton noted that out of the original type series only 3 specimens had survived in 1968. Georg Demoulin could identify the male imago that had been figured in Pictet-Baraban & Hagen (1856). He redescribed and refigured this specimen ( Demoulin 1968, fig. 38) and designated it as “hololectotype” ( Fig. 1 A, labels (iii), (v)) in an addendum that he attached to his original publication (see also Staniczek & Godunko 2012). Obviously, this specimen was forwarded to him by J. Illies (Schlitz) who had discovered it among fossil Plecoptera in the amber collection of MNB and took it on loan in 1966 (see Fig.1 A, label (ii/2 )).

During our own investigations of Berendt’s mayfly collection at the MNB in 2004 and 2008 this specimen was not traceable, so we assumed it might be lost ( Staniczek & Godunko 2012). However, during our ongoing investigations at the MNB the lost lectotype was finally found in November 2012 apart from the mayfly amber collection in a different, remotely located repository.

Our subsequent study of the rediscovered lectotype revealed that the specimen today appears to be even more damaged than described by Demoulin (1968). The initial single piece of amber with the embedded body of S. macrops obviously split at some point, and there are four separate remaining pieces ( Fig. 1 B, i–iv). Two small pieces ( Fig. 1 B, i and ii) do not contain any inclusions. In the third, bigger amber fragment ( Fig.1 B, iii) some parts of left legs are visible. The biggest amber fragment ( Fig. 1 B, iv) contains parts of right foreleg, right forewing, prothorax, distal part of mesothorax, and slightly damaged head (arrow in Fig. 1 B points to location of head that is enlarged visible in Fig. 1 C).

Description of preserved body parts of lectotype. Measurements (in mm): Length of left foreleg (right foreleg partly preserved, poorly visible): femur—2.25; tibia—2.10; tarsi* (* = preserved part): segment 1—1.35; left middle leg: femur*—2.03; tibia*—0.80; tarsi: segment 1*—0.52; segment 2*—0.40; segment 3—0.33; segment 4—0.23; segment 5—0.20; left hind leg: femur—1.80; tibia*—0.73.

Very damaged specimen in relatively dark amber. Head light brown; eyes large, well preserved, medially contiguous; ocelli and antennae uniformly yellow to light brown, with irregular dirty brownish maculation ( Fig. 1 B, C).

Only small part of right forewing is preserved (central C, Sc, RS fields preserved on approx. 1/2–1/3 of wing length); transversal veins not visible. Only small distal part of mesothorax with mesonotal suture preserved, stretched backwards medially as typical for Siphloplecton . Right foreleg partly preserved, but part of tibia and first tarsal segment covered with “Verlumung” and poorly visible; only traces of tarsal segments and claws are preserved; tarsomere borders not visible. Left foretibia with hardly visible spines anteriorly.

Due to the poor preservation of the lectotype it is not possible to determine any distinguishing characters of S. macrops . For this reason, we confirm the restriction of the name S. macrops to this lectotype specimen and corroborate our previous descriptions of several new species from specimens formerly attributed to S. macrops (for additional details see Staniczek & Godunko 2012: 62–63).

Figures

FIGURE 1. Siphloplecton macrops (Pictet-Baraban & Hagen, 1856), MNB, MB. I. 5150, lectotype, male imago: A—preserved amber pieces in storage box together with labels i – vii (top right corner shows rear side of label ii; B—four biggest pieces, only pieces iii and iv include parts of specimen, arrow points to location of head; C—head in dorsal view.

FIGURE 2. Siphloplecton barabani Staniczek & Godunko, 2012, MNB, Nr. 268, female imago (photographs): A—total lateral view, right side; B—left side, lateral view; C—head and thorax in lateral view (right side); D—head and thorax in ventral view; E—abdominal segments VII (with subgenital plate) to X in ventrolateral view.