I photographed this very interesting little critter in 2013 at a German private collection (coll. Carsten Gröhn, no. 1623), which will be inherited by the Centrum für Naturkunde at the University of Hamburg. The insect is preserved as an inclusion in Eocene Baltic amber, which is a fossil conifer resin that is about 34-37 million years old. It is only 2.5 mm long, thus likely representing an early nymphal instar. It belongs to the wingless insect order Zygentoma (silverfish), which is a small group of only 470 species that are classified in seven families. They are very rarely found as fossils (Mendes & Wunderlich 2013), but this specimen is an even more remarkable scientific novelty, which is here revealed for the first time. Therefore, please allow me to get a bit technical for the specialists.
The animal certainly belongs to a new genus and species and either represents the first record of the family Nicoletiidae in Baltic amber, or even an undescribed new family of silverfish, which is characterized by the following combination of characters: The body is elongate and slender (as in Lepidotrichidae, Nicoletiidae, and Maindroniidae); the thorax lacks pronounced paranotal lobes (as in Nicoletiidae and Maindroniidae); abdominal urosternites II-VIII are supplied with pairs of stylets (unlike the articulated styli in Lepidotrichidae, Tricholepidiidae, and Maindroniidae) and II-VII with eversible vesicles (as in Lepidotrichidae, Tricholepidiidae, and Nicoletiidae); the tarsus is three-segmented (unlike Lepidotrichidae and Tricholepidiidae); scales are totally absent (unlike Ateluridae and Lepismatidae); the head is globular and hypognathous (as in Tricholepidiidae), and is distinctly longer and larger than the prothorax (as in Maindroniidae); lateral eyes seem to be present (unlike Nicoletiidae, Ateluridae, and Protrinemuridae); the maxillary palps are very long and five-segmented; the labial palp is short with an ovoid distal segment (unlike Maindroniidae); the antennae seem relatively short (maybe incomplete) and robust with elongated distal segments (contrary to the filamentous annulated antennae of most other silverfish, but maybe due to early ontogenetic stage). The median appendage (paracercus) is incomplete or broken, which is sometimes found in living silverfish (e.g., Maindroniidae and Nicoletiidae).
Interestingly, this unique combination of characters includes a strange mixture of archaic and derived features that does not fit well with the assumed evolutionary relationships within silverfish (compare Koch 2003). Such incongruent or homoplastic characters represent a notorious problem for modern phylogenetics and contradict the evolutionary prediction of a perfectly nested hierarchy, which is so often championed by the apostles of Darwinism as one of their best arguments.
- Koch M 2003. Towards a Phylogenetic System of the Zygentoma. pp. 122-125 in: Klass K-D (ed.). Proceedings of the 1st Dresden Meeting on Insect Phylogeny: “Phylogenetic Relationships within Insect Orders“ (Dresden, September 19-21, 2003). Entomologische Abhandlungen 61(2), 119-172.
- Mendes LF, Wunderlich J 2013. New Data on thysanurans preserved in Burmese amber (Microcoryphia and Zygentoma Insecta). Soil Organisms 85(1), 11-22.