New Triassic dasyleptids (Insecta: Archaeognatha: Monura)

Workshop zur Geologie und 1 2 Paläontologie der Trias Alexei S. Bashkuev & Jürgen Sell 3–4 May, 2013, Euerdorf 1 Borissiak Paleontological Institute Russian Academy of Sciences, 117997 Moscow, Russia, e-mail: [email protected] 2 Sammlung Mainfränkische Trias, 97717 Euerdorf, e-mail: [email protected]

Dasyleptidae, or monurans, an extinct group of apterygote bristletail-like insects, were previously only known from the Upper Carboniferous and Lower to Middle Permian, when they were a typical faunal element of the Palaeozoic sea shores and swamps. Recently, Bechly & Stockar (2011) described Dasyleptus triassicus from the Ladinian (Middle 2 1 Triassic) Meride Limestone of Monte San Giorgio in Switzerland (3). It was the first Mesozoic

3 record of the group, but not the sole one known so far. Numerous dasyleptid remains, were also found in the Upper Buntsandstein deposits of Lower Franconia (Bashkuev et al., 2012) (2) and Vosges Mountains (1). They share many characters, as far as their preservation allows to tell, and belong probably to the same species.

Triassic records of dasyleptids in Europe: Dasyleptus triassicus Bechly et Stockar, 1 – Vosges: ‘Grès à Voltzia’ Fm, Upper Buntsandstein About 40 specimens were collected mainly by the second author during the holotype 2 – Franconia: uppermost Röt Fm early Anisian last several years in the worked-out quarry at Hammelburg, Lower Franconia, 3 – Monte San Giorgio: Meride Limestone, late Ladinian in the oberen Dendritenschichten (Myophoria beds, Röt Formation), about 2 m below the Buntsandstein/Muschelkalk boundary. This horizon is one of the richest in fossils in Buntsandstein of Franconia: diverse insects occurred here along with conchostracans, decapods, triopsids, lingulids, bivalves, fish (particularly Saurichthys) and tetrapod remains.

SMTE 5825/2–593 A pair of undescribed dasyleptids in the private collection of Dr. L. Grauvogel-Stamm. ‘Grès à Voltzia’ Fm of Vosges. Photo by D. Shcherbakov, 2008

The new species is most similar to the Dasyleptus triassicus, and slightly differs from it in the shorter

Muschelkalk Grenzgelbkalkstein terminal filament, which is in all specimens

Strohgelbe Kalke examined not longer than abdomen, as well as in

Hammelburg body and leg segments proportions.

bank Legs distinctly broadened (flattened?), but there is Obere Obere cx – coxa, fl – flagellum, fm – femur, msn,

Dendritenschichten mtn – meso- and metanotum, oc – eye, no such a contrast between this and the Palaeozoic

pmx – maxillary palp, pn – pronotum, pt – species, as indicated by D. triassicus. These and

Buntsandstein pretarsus (claw), st – abdominal styli, tb – other characters are in need of further analysis. Röt 4 Subformation tibia, tf – terminal filum, tr – trochanter, ts

– tarsus, I–XI – abdominal terga Rotes Zwischelmittel

genitalia

SMTE 5825/2–593, SEM images A mass grave, comprising about 20 specimens of Dasyleptus sp. SMTE 5825/2–584; Obere Dendritenschichten of Hammelburg

A B Various specimens of Dasyleptus sp. nov. from Hammelburg A) SMTE 5825/2–663 C B) SMTE 5825/2–664 C) SMTE 5825/2–436 D) SMTE 5825/2–364

D

fm tb ts A wing referred to the Palaeozoic protorthopterous pt family Psoropteridae (D.S. Aristov, pers. comm.) 5 mm

Acknoledgements. We thank Prof. A.P. Rasnitsyn and Dr. D.E. Shcherbakov (PIN) for comments Bashkuev A., Sell J., Aristov D., Ponomarenko A., Sinitshenkova N., & Mahler H. 2012. Insects from the Buntsandstein of Lower Franconia and Thuringia. Paläontol. Z. 86: 175–185. and discussion, Michael and Larissa Henz, Horst Mahler (SMTE), and Dr. Danil Aristov (PIN) for Bechly G.& Stockar R. 2011. The first Mesozoic record of the extinct apterygote insect genus Dasyleptus (Insecta: Archaeognatha: Monura: Dasyleptidae) from the Triassic of Monte their additional help. The study is supported by the Russian Foundation for Basic Research, San Giorgio (Switzerland). Palaeodiversity. 4: 23–37. project N. 13-04-01839 and the President RF Support of Young Scientists, no. МК-6619.2013.4