Sonja Wedmann

The first fossil leaf insect: 47 million years of specialized cryptic morphology and behavior

Stick and leaf insects (insect order Phasmatodea) are represented primarily by twig-imitating slender forms. Only a small percentage (≈1%) of extant phasmids belong to the leaf insects (Phylliinae), which exhibit an extreme form of morphological and behavioral leaf mimicry. Fossils of phasmid insects are extremely rare worldwide. Here we report the first fossil leaf insect, Eophyllium messelensis gen. et sp. nov., from 47-million-year-old deposits at Messel in Germany. The new specimen, a male, is exquisitely preserved and displays the same foliaceous appearance as extant male leaf insects. Clearly, an advanced form of extant angiosperm leaf mimicry had already evolved early in the Eocene. We infer that this trait was combined with a special behavior, catalepsy or “adaptive stillness,” enabling Eophyllium to deceive visually oriented predators. Potential predators reported from the Eocene are birds, early primates, and bats. The combination of primitive and derived characters revealed by Eophyllium allows the determination of its exact phylogenetic position and illuminates the evolution of leaf mimicry for this insect group. It provides direct evidence that Phylliinae originated at least 47 Mya. Eophyllium enlarges the known geographical range of Phylliinae, currently restricted to southeast Asia, which is apparently a relict distribution. This fossil leaf insect bears considerable resemblance to extant individuals in size and cryptic morphology, indicating minimal change in 47 million years. This absence of evolutionary change is an outstanding example of morphological and, probably, behavioral stasis.

Direct and indirect fossil records of megachilid bees from the Paleogene of Central Europe (Hymenoptera: Megachilidae)

Aside from pollen and nectar, bees of the subfamily Megachilinae are closely associated with plants as a source of materials for nest construction. Megachilines use resins, masticated leaves, trichomes and other plant materials sometimes along with mud to construct nests in cavities or in soil. Among these, the leafcutter bees (Megachile s.l.) are the most famous for their behaviour to line their brood cells with discs cut from various plants. We report on fossil records of one body fossil of a new non-leafcutting megachiline and of 12 leafcuttings from three European sites—Eckfeld and Messel, both in Germany (Eocene), and Menat, France (Paleocene). The excisions include the currently earliest record of probable Megachile activity and suggest the presence of such bees in the Paleocene European fauna. Comparison with extant leafcuttings permits the interpretation of a minimal number of species that produced these excisions. The wide range of size for the leafcuttings indirectly might suggest at least two species of Megachile for the fauna of Messel in addition to the other megachiline bee described here. The presence of several cuttings on most leaves from Eckfeld implies that the preferential foraging behaviour of extant Megachile arose early in megachiline evolution. These results demonstrate that combined investigation of body and trace fossils complement each other in understanding past biodiversity, the latter permitting the detection of taxa not otherwise directly sampled and inferences on behavioural evolution.

New middle Eocene formicid species from Germany and the evolution of weaver ants

Two new species of weaver ant are described from the Eocene of Germany. Males and gynes of Oecophylla longiceps Dlussky sp. nov. are found in the middle Eocene (about 47 Ma) of Grube Messel, Germany. Males, gynes and two workers of O. eckfeldiana Dlussky sp. nov. are recorded from the middle Eocene (about 43 Ma) of Eckfeld maar, Germany. The two new species are among the oldest records of the extant genus Oecophylla. First adaptations for moving in the forest canopy are present in the workers of O. eckfeldiana. Even more specialized adaptations for arboreal life are found in the workers of O. brischkei from Baltic amber. The coexistence of two species in Baltic amber and in the Bembridge marls suggests that in these cases different ecological niches were realised by sympatric species. Comparisons of the queens from different fossil and extant species indicate morphological trends, partly connected with increasing fertility. Most likely Oecophylla originated in the early Paleogene in the Palaearctic realm, radiating strongly during the climatic changes of the Eocene—Oligocene transition.

Phylogeographic Analysis Elucidates the Influence of the Ice Ages on the Disjunct Distribution of Relict Dragonflies in Asia

Unusual biogeographic patterns of closely related groups reflect events in the past, and molecular analyses can help to elucidate these events. While ample research on the origin of disjunct distributions of different organism groups in the Western Paleartic has been conducted, such studies are rare for Eastern Palearctic organisms. In this paper we present a phylogeographic analysis of the disjunct distribution pattern of the extant species of the strongly cool-adapted Epiophlebia dragonflies from Asia. We investigated sequences of the usually more conserved 18 S rDNA and 28 S rDNA genes and the more variable sequences of ITS1, ITS2 and CO2 of all three currently recognised Epiophlebia species and of a sample of other odonatan species. In all genes investigated the degrees of similarity between species of Epiophlebia are very high and resemble those otherwise found between different populations of the same species in Odonata. This indicates that substantial gene transfer between these populations occurred in the comparatively recent past. Our analyses imply a wide distribution of the ancestor of extant Epiophlebia in Southeast Asia during the last ice age, when suitable habitats were more common. During the following warming phase, its range contracted, resulting in the current disjunct distribution. Given the strong sensitivity of these species to climatic parameters, the current trend to increasing global temperatures will further reduce acceptable habitats and seriously threaten the existences of these last representatives of an ancient group of Odonata.

A NEMESTRINID FLY (INSECTA: DIPTERA: NEMESTRINIDAE: CF. HIRMONEURA) FROM THE EOCENE MESSEL PIT (GERMANY)

The Nemestrinidae or tangle-veined flies are a small group of brachycerous flies with about 300 extant and fossil species (Evenhuis, 1994). Many of them are large to medium-sized flies with a densely pilose body. They have a unique wing venation with a compound diagonal vein which is an apomorphic character for Nemestrinidae (Yeates, 1994). The diagonal vein comprises elements of veins R, M, and Cu and it crosses the wing obliquely. Adult nemestrinids often occur in open areas and many feed on the nectar of flowers (Richter, 1997). Nemestrinid larvae appear to be internal parasitoids of Orthoptera (grasshoppers) and can even control the population numbers of Acridoidea (Orthoptera: Caelifera); however, the species of Hirmoneura Meigen, 1820 develop in larvae of scarabaeid beetles (Richter, 1997). As far as is known, the female places the eggs in the hosts habitat and the first-instar larvae actively search out their host. Larval development takes about 40 days, but there may be a long diapause (inactive period) before 20 to 30 days of pupation take place. Adults live for about 25 to 45 days (Richter, 1997). Extant Nemestrinidae occur worldwide, but some subgroups show a very disjunct distribution (Bernardi, 1973). Centers of their diversity are in the Palaearctic, Australian, Neotropical, and Afrotropical regions (Bernardi, 1973). Particularly in southern Africa, long-proboscid nemestrinid flies are well known for their spectacular pollination associations with a wide range of plant species with tubular flowers (e.g., Goldblatt and Manning, 2000). These plants have mostly odorless flowers with an elongate floral tube that is typically 35 to 60 cm long, and many species are pollinated solely by specially adapted long-proboscid flies (Goldblatt and Manning, 2000). The fossil record of Nemestrinidae is quite extensive. An up-to-date list is given in Ansorge and Mostovski (2000). The oldest nemestrinoids were already …

Morphological and Behavioral Convergence in Extinct and Extant Bugs: The Systematics and Biology of a New Unusual Fossil Lace Bug from the Eocene

The bug Gyaclavator kohlsi Wappler, Guilbert, Wedmann et Labandeira, gen. et sp. nov., represents a new extinct genus of lace bugs (Insecta: Heteroptera: Tingidae) occurring in latest early Eocene deposits of the Green River Formation, from the southern Piceance Basin of Northwestern Colorado, in North America. Gyaclavator can be placed within the Tingidae with certainty, perhaps it is sistergroup to Cantacaderinae. If it belongs to Cantacaderinae, it is the first fossil record of this group for North America. Gyaclavator has unique, conspicuous antennae bearing a specialized, highly dilated distiflagellomere, likely important for intra- or intersex reproductive competition and attraction. This character parallels similar antennae in leaf-footed bugs (Coreidae), and probably is associated with a behavioral convergence as well.

New Palaeogene horntail wasps (Hymenoptera, Siricidae) and a discussion of their fossil record

The phylogenetic placement of siricid hymenopterans and especially the relationships among Siricidae are not resolved, and are in need of further investigation. The fossil record helps to illuminate the evolutionary history of this group. In this paper, Xoanon? eocenicus sp. nov. is newly described from the Eocene Fossillagerstätte Grube Messel (Germany). Although several characters of the wing venation of this fossil are similar to the extant genus Xoanon, there remain some doubts concerning the generic placement. A newly found fossil is attributed to Urocerus ligniticus (Piton, 1940) from the Paloecene Fossillagerstätte Menat (France) and provides more morphological information on this species. An overview of the fossil record of Siricidae in the strict sense is given and the state of knowledge on the different fossils is reviewed.

NEW MEGAPODAGRIONID DAMSELFLIES (ODONATA: ZYGOPTERA) FROM THE PALEOGENE OF EUROPE

Abstract Three fossil taxa of megapodagrionid damselflies are described and figured from the Paleogene localities in Europe on the basis of isolated wings. Eckfeldia superstes (Wappler, 2003) gen. nov. is described from the laminated mudstones of middle Eocene age from Eckfeld Maar, Germany. Furagrion jutlandicus (Henriksen, 1922) gen. nov. is recorded from the laminated claystones of lowermost Eocene age from the Ølst and Fur-Formation, Denmark, and an undetermined megapodagrionid damselfly is recognized from middle Eocene strata. Taphonomy and color preservation in the fossils are briefly considered. Characters used for phylogenetic analyses in extant and fossil Megapodagrionidae are discussed. The biogeographic and paleoecological implications of the new European fossils are briefly discussed.

First record of a fossil larva of Hemerobiidae (Neuroptera) from Baltic amber

A fossil larva of Hemerobiidae (Neuroptera) is recorded for the first time from Baltic amber. The subfamilial and generic affinities of this larva are discussed. It is assumed that it may belong to Prolachlanius resinatus, the most common hemerobiid species from the Eocene Baltic amber forest. An updated list of extant species of Hemerobiidae with described larvae is provided.

The oldest ‘amphipterygid’ damselfly of tropical affinities in the Paleocene of Menat (Zygoptera: Eucaloptera)

Abstract The new damselfly genus and species Valerea multicellulata is described from the Paleocene of Menat (France), a Lagerstatte with many fossil insects, plants and vertebrates with high paleontological value. Aquatic insects are very scarce in this outcrop, this damselfly being the fourth described Odonata. Its closest modern relatives belong to the Amphipterygidae or the Devadattidae, families with very narrow tropical extant distributions. This new fossil allows us to confirm the tropical affinities of the odonatan fauna of the Menat paleolake communities. It also shows that the amphipterygids were clearly more widespread during the Paleogene than today, probably in relation to the worldwide warm and equable climate in the Paleocene. http://zoobank.org/urn:lsid:zoobank.org:act:3F631097-DE0B-40FA8227-9C12F55DBAB4