Fossil water‐penny beetles (Coleoptera: Psephenidae: Eubrianacinae) from the Eocene of Europe,with remarks on their phylogenetic position and biogeography

Abstract: A species of water‐penny beetles is recorded from larval instars from the Middle Eocene Messel pit fossil site in Germany. This species clearly belongs to the psephenid subfamily Eubrianacinae, but its precise systematic affinities remain unclear. It is the second fossil species of this taxon recorded from Europe. The holotype of the first fossil species, Eubrianax vandeli Bertrand and Laurentiaux, 1963, is lost. The high number of fossil specimens from Messel allowed discussion of stratigraphic and spatial occurrence of the eubrianacine species in the Messel pit, but its larval ontogeny could not be unravelled. Because of the high number of fossils and their wide occurrence, it is inferred that the species from Messel gen. sp. 1 was an autochthonous faunal element of the Eocene Lake Messel, which might indicate that some parts of the former Lake Messel had a shore area with stones. The analysis of the phylogenetic position of both Eocene eubrianacine species showed that their phylogenetic placement cannot be resolved because preservational influences limit the evaluation of characters. The historical biogeography of Psephenidae and Eubrianacinae is analysed and discussed. The fossil record shows that psephenid beetles have fossil members occurring outside their current distribution range, so interpretations of their biogeography based only on extant members can be misleading.     

Taxonomic description of in situ bee pollen from the middle Eocene of Germany

The middle Eocene Messel and Eckfeld localities are renowned for their excellently preserved faunas and diverse floras. Here we describe for the first time pollen from insect-pollinated plants found in situ on well-preserved ancient bees using light and scanning electron microscopy. There have been 140 pollen types reported from Messel and 162 pollen types from Eckfeld. Here we document 23 pollen types, six from Messel and 18 from Eckfeld (one is shared). The taxa reported here are all pollinated by insects and mostly not recovered in the previously studied dispersed fossil pollen records. Typically, a single or two pollen types are found on each fossil bee specimen, the maximum number of distinct pollen types on a single individual is five. Only five of the 23 pollen types obtained are angiosperms of unknown affinity, the remainder cover a broad taxonomic range of angiosperm trees and include members of several major clades: monocots (1 pollen type), fabids (7), malvids (4), asterids (5) and other core eudicots (1). Seven types each can be assigned to individual genera or infrafamilial clades. Since bees visit only flowers in the relative vicinity of their habitat, the recovered pollen provides a unique insight into the autochthonous palaeo-flora. The coexistence of taxa such as Decodon, Elaeocarpus, Mortoniodendron and other Tilioideae, Mastixoideae, Olax, Pouteria and Nyssa confirms current views that diverse, thermophilic forests thrived at the Messel and Eckfeld localities, probably under a warm subtropical, fully humid climate. Our study calls for increased attention to pollen found in situ on pollen-harvesting insects such as bees, which can provide new insights on insect-pollinated plants and complement even detailed palaeo-palynological knowledge obtained mostly from pollen of wind-pollinated plants in the dispersed pollen record of sediments. In the case of Elaeocarpus, Mortoniodendron, Olax and Pouteria the pollen collected by the middle Eocene bees represent the earliest unambiguous records of their respective genera.     

Highly resolved early Eocene food webs show development of modern trophic structure after the end-Cretaceous extinction

Generalities of food web structure have been identified for extant ecosystems. However, the trophic organization of ancient ecosystems is unresolved, as prior studies of fossil webs have been limited by low-resolution, high-uncertainty data. We compiled highly resolved, well-documented feeding interaction data for 700 taxa from the 48 million-year-old latest early Eocene Messel Shale, which contains a species assemblage that developed after an interval of protracted environmental and biotal change during and following the end-Cretaceous extinction. We compared the network structure of Messel lake and forest food webs to extant webs using analyses that account for scale dependence of structure with diversity and complexity. The Messel lake web, with 94 taxa, displays unambiguous similarities in structure to extant webs. While the Messel forest web, with 630 taxa, displays differences compared to extant webs, they appear to result from high diversity and resolution of insect–plant interactions, rather than substantive differences in structure. The evidence presented here suggests that modern trophic organization developed along with the modern Messel biota during an 18 Myr interval of dramatic post-extinction change. Our study also has methodological implications, as the Messel forest web analysis highlights limitations of current food web data and models.     

First substantial Middle Eocene record of the Lithornithidae (Aves): A postcranial skeleton from Messel (Germany)

A postcranial skeleton of a representative of the palaeognathous Lithornithidae (Aves) is described from the Middle Eocene of Messel in Germany. The specimen is slightly smaller than Lithornis plebius from which it, however, differs in limb bone proportions. It constitutes the latest fossil record of the Lithornithidae in Europe, whose only other Middle Eocene record is a fragmentary tibiotarsus from North America.     

Faunes et paléoenvironnements des principaux sites archéologiques plio-pléistocènes de la formation de Nachukui (Ouest-Turkana, Kenya)

Faunas and paleoenvironments from main archaeological Plio-Pleistocene sites of the Nachukui Formation (West Turkana, Kenya). The Nachukui Formation is currently under archaeological investigation, especially within the Kalochoro (2.35 – 1.9 Myr) and Kaitio (1.9 – 1.65 Myr) Members. Six main archaeological sites have been excavated from this time period, which yield rich vertebrate faunas collected in situ or in close vicinity to the site. Paleontological studies help to precise the specific diversity for each site and increase our documentation for each Member with the discovery of new taxa. They allow to provide new informations about the biotope diversities exploited by Hominids and show a climatic tendency towards more humid environment between the Members. To cite this article: J.-P. Brugal et al., C.R. Palevol 2 (2003).     

Cyanobacteria and seasonal death: A new taphonomic model for the Eocene Messel lake

Two new observations lead us to reconsider the taphonomy of Messel. First, several horses as well as turtles indicate death at a specific season although they come from different horizons. Second, specific structures in the Sediments are very similar to those found in Neumark-Nord. There they could be related to Cyanobacteria. Blooms of Cyanobacteria may poison die surface water. From actual observations it is known that animals drinking such poison water collapse immediately and die mostly near or within the water soon. This model might explain why birds and bats are so frequent throughout the entire profile of Messel. Both drink from the water surface during flight. In contrast to volcanic exhalations, assumed so far, such algae blooms occur repeatedly and always during early summer and autumn. An erratum to this article is available at .     

Paleoecology of early middle Eocene bats from Messel,FRG. aspects of flight,feeding and echolocation

By their diversified flight apparatus Messel bats occupied specific flight niches similar to those of extant tropical bats. The small Palaeochiropteryx tupaiodon is considered to be most specialized for hunting close to the ground and for hovering inside dense vegetation. Contrarily, Hassianycteris spp. most likely were high and fast flyers in the open space.

The analysis of gut contents proves that Palaeochiropteryx spp. exclusively fed on small moths and caddis flies, i.e. slow and low flying insects. For P. tupaiodon this confirms the foraging strategy independently from wing morphology. Hassianycteris spp. preyed mainly on beetles or other insects with thick cuticules.

Inner ears of Messel microbats are less specialized compared to those of recent species. Especially P. tupaiodon shows no acoustical specialization with regard to its hunting habitat. Thus, we assume that during the early evolution of bats the development of different flight styles and wing shapes preceded acoustical refinements of the echolocation system.     

Eolacertidae: a new extinct clade of lizards from the Palaeogene; with comments on the origin of the dominant European reptile group – Lacertidae

We describe a new lizard taxon, Stefanikia siderea gen. et sp. nov., from the early-middle Eocene locality of Messel in Germany based on a nearly complete skeleton, which we studied using μCT methods. It shares many characters with the Eocene taxon Eolacerta, which is broadly distributed in the Eocene of central and Western Europe, but is much smaller and shows several important anatomical differences. The new discovery sheds light on the paleodiversity of these lizards in the Eocene of Europe, and the new family name Eolacertidae is proposed to encompass Eolacerta and Stefanikia. The relationships of Eolacerta have been intractable. Our phylogenetic analyses confirm that Eolacertidae is a member of the clade Lacertiformes and provide strong support for a sister-group relationship to Lacertidae. In some places, skin impressions are preserved, displaying the body scalation. As such, the exquisitely preserved specimens of Eolacertidae from Messel provide new insight into the morphology and ecology of lizards on the stem of Lacertidae, Europe’s dominant group of living reptiles.

http://zoobank.org/urn:lsid:zoobank.org:pub:DFD01563-A913-4286-B64B-E0912474FD08     

A new baurusuchid crocodyliform (Archosauria) from the Late Cretaceous of Patagonia (Argentina)

A new baurusuchid, Wargosuchus australis gen. et sp. nov., coming from the Bajo de La Carpa Formation, Neuquén Province (Argentina), is described. This new taxon is based on a fragment of snout and a portion of the cranial roof. Wargosuchus differs from other crocodyliforms by possessing a deep median groove on the frontals, a contact between nasals and frontals extremely reduced, a large depression for the olfactory bulbs, three large foramina surrounding the large, smooth perinarial depression, and a hypertrophied, conical last premaxillary tooth followed by a large paracanine fossa. The finding of Wargosuchus in Patagonia (Argentina), a taxon with a strong resemblance to Brazilian baurusuchids, reinforces the hypothesis of a similar biota between both regions by the Late Cretaceous. Wargosuchus and Cynodontosuchus represent the only Argentinian mesoeucrocodylians to be included within Baurusuchidae. This finding extends the number of crocodyliforms from the Bajo de la Carpa Formation, which, in turn, corresponds to the most taxonomically diverse one in Argentina.     

Acoustic telemetry survey of the dusky grouper (Epinephelus marginatus) in the Marine Reserve of Cerbère-Banyuls: informations on the territoriality of this emblematic species

The Marine Reserve of Cerbère-Banyuls represents a refuge for dusky grouper populations (Epinephelus marginatus). Density survey and observation of the reproductive behavior of this species have been conducted there for the last 30 years. However, information on the behavior or habitat utilization for this species during winter time is limited. We conducted acoustic telemetry surveys from September 2005 to June 2006 in the Marine Reserve of Cerbère-Banyuls for a dusky grouper population. Six groupers were tagged and followed within the integral reserve and in the adjacent partial reserve. The results from the tracking of these individuals indicated that the largest dusky groupers are sedentary fishes with a high degree of site fidelity and a high sensitivity to variations of environmental conditions such as storms. This together with the life history characteristics of this species encourages the conservation and the protection of essential habitats of this species. Acoustic tracking coupled to the use of a fixed Kernel can be proposed to follow fish populations. To cite this article: J. Pastor et al., C. R. Biologies 332 (2009).     

Pythons in the Eocene of Europe reveal a much older divergence of the group in sympatry with boas

Extant large constrictors, pythons and boas, have a wholly allopatric distribution that has been interpreted largely in terms of vicariance in Gondwana. Here, we describe a stem pythonid based on complete skeletons from the early-middle Eocene of Messel, Germany. The new species is close in age to the divergence of Pythonidae from North American Loxocemus and corroborates a Laurasian origin and dispersal of pythons. Remarkably, it existed in sympatry with the stem boid Eoconstrictor. These occurrences demonstrate that neither dispersal limitation nor strong competitive interactions were decisive in structuring biogeographic patterns early in the history of large, hyper-macrostomatan constrictors and exemplify the synergy between phylogenomic and palaeontological approaches in reconstructing past distributions.     

New enantiornithine bird (Aves, Ornithothoraces) from the Late Cretaceous of NW Argentina

A new enantiornithine bird, Intiornis inexpectatus gen. et sp. nov, is described here. It is based on a partial hind limb found in beds of the Upper Cretaceous Las Curtiembres Formation (Campanian), North-West Argentina. The new taxon is referred to the family Avisauridae on the basis of its cranially convex third metatarsal. Several features suggest close relationships between Intiornis and the avisaurid Soroavisaurus, from the Lecho Formation (Maastrichtian; North-West Argentina). Intiornis was the size of a sparrow, thus representing the smallest Enantiornithes known from South America. The new species shows adaptations for a perching mode of life. Moreover, the hypothesis suggesting that the flying pterosaur reptiles decrease in taxonomic diversity due to competitive interaction with birds is discussed. The new species shows adaptations for a perching mode of life. Moreover, the hypothesis suggesting that the flying pterosaur reptiles decrease in taxonomic diversity due to competitive interaction with birds is discussed.     

A new genus of Mantispidae (Insecta: Neuroptera) from the Eocene of Germany, with a review of the fossil record and palaeobiogeography of the family

A new mantispid genus and species Symphrasites eocenicus gen. sp. nov. is described from the Middle Eocene of the Messel Pit fossil site, Germany. It has been placed, with confidence, in the subfamily Symphrasinae, the fossils of which were previously unknown. A review of the known fossil species of Mantispidae is provided, and their systematic placements are discussed. Liassochrysa stigmatica Ansorge & Schlüter, 1990 is assigned to Mantispidae, and therefore Liassochrysidae is a new synonym of Mantispidae; a second, more complete specimen of Mesomantispa sibirica Makarkin, 1997 is described from the Early Cretaceous Baissa locality, Russia; Mantispidiptera Grimaldi, 2000 is excluded from the family; Vectispa Lambkin, 1986 is referred to subfamily Mantispinae; and the assignment of Whalfera Engel, 2004 to Rhachiberothidae is validated. The origin and palaeobiogeography of the mantispids are briefly discussed: the concept of ousted relicts – which assumes that former widely distributed taxa were replaced with groups originating in the tropics – is assumed to best explain the present distribution of the family.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 701–716.     

Mode of life of fan-hand-like Scoliocrinus according to functional form and syntopy with two other irregular crinoids from the Middle Devonian of the Rhenish Massif (Germany)

For a long time, the highly aberrant crinoid Scoliocrinus was known only from the Lower Givetian Eifel area (western Rhenish Massif) as a single oblique calyx with only two out of five radials having an arm facet. Several almost complete crowns of a new species in the Middle Givetian Finnentrop area (eastern Rhenish Massif) have two fan-like arms (in the A and E rays), and a horizontal large anal tube. The probable mode of life of Scoliocrinus is analysed by (a) functional morphology mainly of the arms, (b) criteria of minimised faecal recycling, (c) biostratinomic association with two new species of another aberrant, but four-armed new crinoid genus thus suggesting original syntopy with Scoliocrinus. It is concluded that the construction of Scoliocrinus is probably an adaptation to prevailing unidirectional (tidal?) currents in biostromal reef biotopes. This is supported by rather similar crinoid occurrences in a Lower Givetian biostromal reef-related region in the western Rhenish Massif, with the genotype of Scoliocrinus and a newly assigned third species of Scoliocrinus (arm and probable part of the calyx), as well as four-armed species. The new forms are described as Scoliocrinus ubaghsi nov. sp., Scoliocrinus gerolsteinensis nov. sp., Trapezocrinus scheeri nov. gen., nov. sp., and Trapezocrinus hilperti nov. gen., nov. sp.     

First report of a green toad (Bufo viridis sensu lato) in the Early Pleistocene of Spain: Palaeobiogeographical and palaeoecological implications

For the first time unequivocal fossil remains of a green toad (Bufo viridis s.l.) are described in the Iberian Peninsula. The fossils come from the Cueva Victoria site, a late Early Pleistocene (ca. 1.1–1.2 Ma) karstic filling in semi-arid southeastern Spain (Murcia region). By extension, other remains from two other Early Pleistocene Spanish localities, Barranco León D (ca. 1.3 Ma) and Almenara-Casablanca 3 (ca. 1.1 Ma), are cautiously attributed to the group B. viridis. The B. viridis group was previously reported with some uncertainty to the west of its current distribution area in Western Europe (Spain and France) in the Pliocene (Bufo cf. viridis) and less probably in the Early Miocene (Bufo aff. viridis). Since no osteological differences have been established between the recently described extant species of B. viridis s.l. (e.g. Bufo balearicus, Bufo siculus, Bufo boulengeri, B. viridis sensu stricto and Bufo variabilis) no precise palaeobiogeographical relationships can be drawn for the Spanish fossils. However, the occurrence of a third species of bufonid toad during the Pleistocene in the South of the Iberian Peninsula raises some interesting ecological questions in relation to the local disappearance of the green toad, which can be hypothetically linked to the intensification of the Pleistocene glacial/interglacial climate dynamic or to probable competition with another toad, Bufo calamita.     

Steady-state kinetic behaviour of two- or n-enzyme systems made of free sequential enzymes involved in a metabolic pathway

The overall rate of functioning of a set of free sequential enzymes of the Michaelis–Menten type involved in a metabolic pathway has been computed as a function of the concentration of the initial substrate under steady-state conditions. Curves monotonically increasing up to a saturation plateau have been obtained in all cases. The shape of these curves is sometimes, but not usually, close to that of a hyperbola. Cases exist in which the overall rate of reaction becomes quasi proportional to the concentration of initial substrate almost up to the saturation plateau, which never occurs with individual enzymes. Increasing the number of enzymes sequentially involved in a metabolic pathway does not seem to generate any particularly original behaviour compared with that of two-enzyme systems. To cite this article: G. Legent et al., C. R. Biologies 329 (2006).