Archaeonebria inexspectata Schmidt & Scholz & Kavanaugh 2019, sp. n.
Creators: name: Schmidt, Joachim
name: Scholz, Stefan
name: Kavanaugh, David H.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Archaeonebria
Archaeonebria inexspectata

description: Archaeonebria inexspectata Schmidt & Kavanaugh, sp. n.
Type material. Holotype: Male in Baltic amber; Coll. Carsten Gröhn in the collection of the Geological-Palaeontological Institute of the University of Hamburg (GPIH), now in the Centrum of Natural History, Hamburg (CeNak), with collection number „ GPIH no. 4980, coll. Gröhn no. 7919”. For better investigation of the fossil, the stone was cut in two pieces, with one piece bearing the Nebriini fossil, and has a size of approx. 24 x 6 x 7 mm (irregularly cut) (= „ GPIH no. 4980, coll. Gröhn no. 7919a”, Fig. 1); the remaining piece has a size of approx. 35 x 20 x 16 mm (irregularly cut) (= „ GPIH no. 4980, coll. Gröhn no. 7919b”).
Preservation status: The amber is clear but pervaded by several flowlines and partly covered by very fine surface cracks; the embedded Nebriini fossil is extensively covered by flowlines and bubbles adjoining the beetle body (Figs 2–3) and thus, hardly visible using light microscope. The exoskeleton of the specimen and its negative imprint on the inclusion wall is well preserved and could therefore be imaged in detail using micro-CT (Figs. 4–6, 31, 32, 34), as well as the aedeagal median lobe, except for the weekly sclerotized structures (Figs 42-49).
Syninclusions: One Nematocera fly and a dirt particle in the „ GPIH no. 4980, coll. Gröhn no. 7919a” piece, an additional Nematocera fly in the „ GPIH no. 4980, coll. Gröhn no. 7919b” piece.
Paratype #1: Female in Baltic amber; deposited in the University of California, Museum of Palaeontology, Berkeley, CA, with specimen number UCMP 403984.01, and locality number IP 15208 (Fig. 9). Size of the piece approx. 31 x 20 x 8 mm.
Preservation status: The amber is clear, pervaded by very few flowlines, partly covered by very fine surface cracks; the embedded Nebriini fossil is partly covered by milky coating and a small bubble adjoining the dorsal surface of the beetle body (Fig. 7). Parts of the metatarsi are cut and thus lost. The exoskeleton of the Nebriini fossil and its negative imprint on the inclusion wall are moderately well preserved and could therefore be imaged in most details using micro-CT (Figs. 11–13). Traces of the fossilized gonocoxites could also be imaged.
Syninclusions: One Trichoptera, three Nematocera flies (two of which are preserved in mating position), one Coleoptera: Scirtidae, stellate hairs, dirt particles.
Paratype #2: Female in Baltic amber; no. CCHH #952- 1 in the collection of Christel and Hans Werner Hoffeins, Hamburg, Germany (later to be deposited at the Senckenberg Deutsches Entomologisches Institut, Müncheberg, Germany) (Fig. 16). Size of the piece approx. 13 x 7.5 x 7 mm.
Preservation status: The amber is clear, partly pervaded by very few flowlines; the embedded Nebriini fossil is partly covered by milky coating adjoining head and elytra (Fig. 14), and extensively covered by milky coating and small bubbles adjoining the ventral surface of the beetle body (Fig. 15). Left antennomeres 9–11 and right metatarsomere 5 are cut and thus lost. The fossilized exoskeleton of the specimen is in parts shrunken and thus dissociated from the inclusion wall (Fig. 19). However, most details of diagnostic importance of the external morphology could be reconstructed based on both, the remains of the fossilized exoskeleton and the negative imprint of the beetle body on the inclusion wall, using micro-CT (Figs 18–20, 29) including the gonocoxites (Figs 50–53).
Syninclusions: No syninclusions except for a few dirt particles.
Paratype #3: Female in Baltic amber, deposited in the amber collection of the Senckenberg Deutsches Entomologisches Institut, Müncheberg, Germany (SDEI) (Fig. 23). Size of the piece approx. 24 x 14 x 5 mm.
Preservation status: The amber attached to the embedded Nebriini fossil is pervaded by several flowlines, dorsally and ventrally of the fossil; its ventral surface is almost fully covered by milky coating (Fig. 22). Due to the extensive flowlines, micro-CT scans resulted in low contrasts between amber and fossil particularly on its dorsal surface (Fig. 24).
Syninclusions: Two Nematocera flies, wing remains of an additional Nematocera fly, stellate hairs, dirt particles.
Description. Color: All specimens appear unicolored dark throughout, with pronotum and elytra markedly shiny. No metallic reflection is evident.
Microsculpture: Not visible on any part of the male holotype, and on the head surfaces of any of the female paratypes; on pronotum and elytra of females with very finely impressed small transverse meshes (visible at magnifications of> 60x).
Measurements: Standardized body length 6.4 (holotype, paratype #1) to 7.2 mm (paratype #3). Length of aedeagal median lobe 0.94 mm (holotype). For additional measurements see Tab. 2.
Proportions, given for holotype; paratype #1; paratype #2; paratype #3:
PW/HW = 1.36; 1.34; 1.41; 1.43.
PW/PL = 1.59; 1.65; 1.62; 1.65.
PW/PWb = 1.03; 1.07; 1.08; 1.13.
PWb/PWa = 1.36; 1.27; 1.28; 1.22.
EW/PW = 1.06; 1.22; 1.18; 1.18.
EL/EW = 1.50; 1.50; 1.46; 1.47.
EL/FL = 2.00; 2.10; 2.05; 2.16.
LPL3/LPL2 (min–max) = 1.21–1.23; 1.19–1.24; not measurable in paratype #2; 1.26–1.28.
EL/AedL = 4.15 (holotype).
Variation: The pronotum is less transverse, and its extension is larger, in the male holotype than in the three female specimens. In the female paratype #3 the pronotum is less constricted towards the base than in the other specimens, and its legs are slightly shorter.
Etymology. The species epithet, inexspectata, is a Latin adjective meaning “unexpected”, referring to unexpected occurrence of a nebriine carabid in Baltic amber.
description: Published as part of Schmidt, Joachim, Scholz, Stefan & Kavanaugh, David H., 2019, Unexpected findings in the Eocene Baltic amber forests: Ground beetle fossils of the tribe Nebriini (Coleoptera: Carabidae), pp. 350-370 in Zootaxa 4701 (4) on pages 353-365, DOI: 10.11646/zootaxa.4701.4.2, http://zenodo.org/record/3558175