Structure of fossil dinosaur eggshell from the Aix Basin,France

At least four types of dinosaur eggshell are distinguished among samples of fossil eggshell from Late Cretaceous deposits of southern France. Recognition is based on shell microstructure, porosity, and shell thickness. Estimated values of water vapour conductance for these dinosaur eggshells are much greather than predicted for avian eggs, suggesting that the eggs were incubated under conditions of high humidity, such as would occur underground.     

Fungal sporocarps from the Carboniferous: An unusual specimen of Traquairia

Small spherical structures commonly termed sporocarps are widespread elements in Carboniferous permineralized peat. While sporocarps today are generally interpreted as fungal, their precise systematic affinities largely remain unknown. A specimen of the sporocarp-type Traquairia from the Lower Coal Measures (Lower Pennsylvanian) of Great Britain demonstrates a heretofore unknown feature in the form of a preformed aperture from which emerges a fascicle of radially oriented structures that are constricted sub-distally; transverse septa are present in the constricted areas of some of the structures. The outgrowths are morphologically similar to conidiophores bearing terminal conidia of certain extant fungi in the order Entomophthorales, and thus might suggest affinities of Traquairia with the Zygomycota. Alternatively, the outgrowths might represent sporulating hyphae of a parasitic or saprotrophic blastocladalean fungus or a peronosporomycete that used Traquairia as a nutrient source.     

Two unusual trepostome bryozoans from the Lower Carboniferous of the Karatau (south Kazakhstan)

Two bryozoan species from the Lower Carboniferous of south Kazakhstan are described. Both species are placed in the genusNipponostenopora Sakagami 1960. InNipponostenopora karatauensis n. sp., colonies have a pseudobifoliate form resembling true bifoliate colonies but lacking a mesotheca. Peculiarities of the internal structure of this species and ofN. bifoliata (Nikiforova) are discussed.     

An unusual phylogeography in the bushcricket Ephippiger ephippiger from Southern France

Pleistocene glaciations have played a major role in species divergence. The bushcricket Ephippiger ephippiger shows unusual patterns of intraspecific variation in multiple traits across Southern Europe. This is centred in Southern France, and evidence implies that it results from secondary contact after differentiation in Pleistocene refugia. However, the possible time scales involved, locations of the refugia and patterns of expansion remain obscure. This study sequenced the COII (507 BP) and cyt b (428 BP) mitochondrial genes to examine the intraspecific phylogeography of Western European samples of E. ephippiger. A minimum evolution tree revealed little resolution between described subspecies of E. ephippiger. Strikingly, populations from the Pyrenees and Mediterranean coastal region contained a complex genetic structure corresponding to major river valleys, independent of the traditional taxonomy. Samples of the subspecies E. e. vitium formed a distinct clade, perhaps supporting their taxonomic status. However, other forms (cruciger and cunii) were not genetically distinct, which is surprising given differences in their morphology and behaviour. The extent of the genetic divergence between Pyreneen valleys is unexpectedly deep, with average Tamura-Nei distances of around 14% (net distances of 11%) separating the main clades of coding COII sequences. Cyt b showed a similar pattern, but was confounded by some non-coding probable pseudogenes. If a conventional insect molecular clock is applied, these cryptic clades must pre-date the Pleistocene, and hypotheses for their history are discussed. However, mtDNA divergence in Ephippiger is not evolving in a clock-like manner, because a likelihood ratio test rejects clock assumptions for the COII sequences.     

The early evolution of feathers: fossil evidence from Cretaceous amber of France

The developmental stages of feathers are of major importance in the evolution of body covering and the origin of avian flight. Until now, there were significant gaps in knowledge of early morphologies in theoretical stages of feathers as well as in palaeontological material. Here we report fossil evidence of an intermediate and critical stage in the incremental evolution of feathers which has been predicted by developmental theories but hitherto undocumented by evidence from both the recent and the fossil records. Seven feathers have been found in an Early Cretaceous (Late Albian, ca 100 Myr) amber of western France, which display a flattened shaft composed by the still distinct and incompletely fused bases of the barbs forming two irregular vanes. Considering their remarkably primitive features, and since recent discoveries have yielded feathers of modern type in some derived theropod dinosaurs, the Albian feathers from France might have been derived either from an early bird or from a non-avian dinosaur.     

Epidermal anatomy of Barthelopteris germarii from the Upper Carboniferous and Lower Permian of France and Germany

The epidermal anatomy of Barthelopteris germarii, a late Paleozoic seed fern, is described on the basis of material from the Upper Stephanian of Central France. A number of features are described for the first time for this species. Some have never been reported for late Paleozoic pteridosperms. Although our material is in most respects very similar to previously described material of B. germarii from Germany, there are also some striking differences, especially the peltate glandular trichomes that are very common in the French but completely absent in the German material. Their presence is most probably an ecological adaptation as in many modern plants. This and other epidermal and gross-morphological features (e.g., the presence of papillae on subsidiary cells of the stomata, anastomosing venation) indicate that B. germarii was well adapted to stressed conditions. Of more general interest is the preservation of the material. There appears to exist a clear relationship between the preservation of anticlinal walls and the thickness of the parenchymatic mesophyll; anticlinal walls are very well preserved where parenchyma was thin. Therefore, the absence of anticlinal walls in fossil cuticles, which has often been used as a taxonomic character, is not necessarily a primary feature.     

Lageniastrum macrosporae (fossil Volvocales, Lageniastraceae nov. fam.), an endophyte in megaspores from the Carboniferous of the French Massif Central

Sublagenicula nuda lycophyte megaspores from the upper Visean of central France frequently host a colonial green alga as an endophyte. This association was first recorded more than 100 years ago by the French paleobotanist B. Renault, who introduced the name Lageniastrum macrosporae for the alga. However, the biological significance of the discovery was not fully assessed until recently. The L. macrosporae-S. nuda association represents the oldest compelling fossil evidence for algal endophytes in land plants, and the only example to date of an alga residing in the interior of spores of vascular cryptogams. Here we present a detailed re-evaluation and photographic documentation of the surviving original specimens from the Visean of Combres/Lay and Esnost. Moreover, a newly discovered specimen from the Stephanian of central France represents the first record of this association from the Upper Carboniferous. An emended diagnosis for L. macrosporae Renault, 1896 is provided, and a lectotype and paralectotype are designated. Although L. macrosporae displays a striking suite of morphological characters found in members of the extant chlorophyte family Volvocaceae (especially the genus Volvox), the peculiar biology of the fossil necessitates establishment of a new family, for which the name Lageniastraceae is proposed. Considerations of the adaptive advantages for the alga of occupying the interior of megaspores are offered. These include the possible effectiveness of the spores in protection during periods of desiccation and against plankton-feeding animals, and use of the spores as potential vectors for dispersal from one isolated body of water to another by spore-feeding animals.     

A new Carboniferous bivalve from Gondwana

The dawning of the Late Palaeozoic glaciations affected faunas of Gondwana and induced endemism. Deposits of that epoch occur in Argentina and Australia, and they yield the oldest record of some endemic taxa. The new bivalve genusAmosius n. gen. described here comes from the lower strata of theLevipustula levis Zone (Serpukhovian) of central Patagonia, where it is associated with the oldest Carboniferous glacial deposits.      

A cysteine proteinase cDNA from Trypanosoma brucei predicts an enzyme with an unusual C-terminal extension

A cDNA for a Trypanosoma brucei cysteine proteinase has been cloned and sequenced. The deduced protein can be divided into four domains, based on homologies with other cysteine proteinases: the pre-, pro- and central regions show considerable homology to the cathepsin L class of mammalian enzymes, whilst the long C-terminal extension distinguishes the trypanosome enzyme from all mammalian cysteine proteinases reported. This 108 amino acid extension, which includes 9 contiguous prolines near the junction with the central domain, appears likely to be processed in part to produce the mature enzyme, and may be involved in targeting the protein within the cell. The trypanosome genome contains more than 20 copies of the cysteine proteinase gene arranged in a long tandem array.     

A new fossil cebine from hispaniola

An incomplete mandibular fragment of a cebine monkey from an early Holocene Haitian cave deposit adds to the small but growing list of fossil Antillean primates. The jaw is of the correct size to belong to the same taxon as the partial maxilla of “Saimiri” bernensis from the Dominican Republic. Both finds probably represent a single species whose proximate ancestry lay closer to Cebus than to Saimiri, although more evidence will be required to substantiate this. No close relationship of the Hispaniolan fossils to the Jamaican platyrrhine Xenothrix is indicated. How monkeys managed to penetrate the West Indies is a biogeographical puzzle of the first order. Geographical vicariance events, island-hopping, and purposeful or inadvertent introduction by humans seem rather implausible devices. On the whole, long-distance, over-water rafting from the Americas remains the most likely mechanism for past land vertebrate immigration into the Caribbean.     

A new Carboniferous equisetale from western Gondwana

Upper Paleozoic sphenopsids from western Gondwana are little known. New finds were made from the Upper Carboniferous of the San Juan province (Argentina). The specimens include vegetative and fertile characters that allow the definition of a new genus and species: Gondwanites subtilis. They are characterized by slender branches bearing whorls of very thin, simple or divided leaves. Simple fertile organs are borne in whorls just below the verticel of leaves. The presence of dichotomized leaves and bractless fertile organs in the new taxon suggests its probable primitive condition.     

A bryozoan buildup from the Lower Carboniferous of North Wales

A carbonate buildup dominated by trepostome Bryozoa is described from Dinantian (Asbian) strata near Llandudno in North Wales. A three-phase ecological succession is recognised within the buildup: (i) a basal diverse community with fenestrate, ramose, encrusting trepostome and cystoporate bryozoans in a mud rich wackestone; (ii) a bulk facies, dominated by encrusting and foliaceous, trepostome bryozoans in a fine packstone, and (iii) a thin capping phase, dominated by unilaminar, encrusting trepostome bryozoans in a slightly coarser lithology, including skeletal debris derived from the mound top and possible flanking beds. The buildup probably had topographic relief and developed in a shallow marine environment. The internal tripartite zonation reflects the growth of the structure into a shallower, higher energy regime, with the capping beds being deposited just below wave base. The buildup developed to the north of St. George's Land, on a carbonate shelf edge bordering the deeper basinal facies of the Irish Sea Basin. Dinantian, Asbian, buildup, trepostome Bryozoa, Foraminifera, corals, calcareous algae, Carboniferous, North Wales .     

Polygonal ornament in the conodont Siphonodella: an internal record

Polygonal 'pit' ornamentation has been reported from a wide range of conodont genera, typically distributed semi-continuously over the upper surface. Observations using the Scanning Electron Microscope (SEM) on the interior of Siphonodella have revealed polygonal pitting over the external surface of inner lamellae. The importance of this observation for the development of Siphonodella is discussed. ▭ Siphonodella, polygonal ornament, microstructure, growth.     

Female collared flycatchers learn to prefer males with an artificial novel ornament

We experimentally investigated whether learning from previousexperiences can lead to the establishment of a new mate preferencein a wild population of birds. During year one (2001), 63 femalecollared flycatchers (Ficedula albicollis) bred together withmales that we had provided with a novel trait, a red stripeon their white forehead patch (a sexually selected trait). Somecolor patterns of birds are largely determined by a few genes,and this experiment was designed to mimic the occurrence ofmutations in such genes. In the subsequent year (2002), we foundthat females with previous experience with red-striped maleswere more likely to pair with red-striped males (76%) than withcontrol males. By contrast, naïve females (i.e., with noprevious experience with red-striped males) were not more likelyto pair with red-striped males (44%) than with control males.Females paired with red-striped males produced more offspringthan females paired with control males, suggesting that maleswith the novel trait had become favored by selection. Thus,female collared flycatchers appear to quickly learn to associatea novel trait with a suitable mate that, in turn, leads to assortativemating between local mates (i.e., males with the new trait andfemales with previous experience of the new trait). Our resultsprovide support for the notion that learning may play an importantrole when the co-evolution of preferences and preferred traitstakes different routes in different populations of the samebird species.     

A Partially Permineralized Lepidophloios from the Early Upper Carboniferous of Scotland

A terminal shoot of Lepidophloios with both external morphologyand anatomy preserved is described. It is compared to the compressionspecies L. scoticus and the permineralized species L. scottiiand L. wuenschianus, all from the Lower Carboniferous of Scotland.It is characterized by the leaves having been abscissed rightup to the stem apex and by the occurrence of deflected and overlappingleaf cushions near the apex. These features are in contradictionwith current concepts about the growth of these plants. Lepidophloios, anatomy, arborescent lycopod, Carboniferous, leaf growth, terminal shoot     

A fossil Selaginella from the Permian of New South Wales

Selaginella harrisiana ap. nov. is described from the Permian (Kungurian) Upper Coal Measures at Victoria Pass, N.S.W. It resembles Selaginella selaginoides in its leafy parts but has a long leafless rhizome recalling Asteroxylon. The present evidence suggests that the herbaceous and arborescent ly copsids are taxonomically remote.