Fossil ghost ranges are most common in some of the oldest and some of the youngest strata

Biologists routinely compare inferences about the order of evolutionary branching (phylogeny) with the order in which groups appear in the fossil record (stratigraphy). Where they conflict, ghost ranges are inferred: intervals of geological time where a fossil lineage should exist, but for which there is no direct evidence. The presence of very numerous and/or extensive ghost ranges is often believed to imply spurious phylogenies or a misleadingly patchy fossil record, or both. It has usually been assumed that the frequency of ghost ranges should increase with the age of rocks. Previous studies measuring ghost ranges for whole trees in just a small number of temporal bins have found no significant increase with antiquity. This study uses a much higher resolution approach to investigate the gappiness implied by 1,000 animal and plant cladograms over 77 series and stages of the Phanerozoic. It demonstrates that ghost ranges are indeed relatively common in some of the oldest strata. Surprisingly, however, ghost ranges are also relatively common in some of the youngest, fossil-rich rocks. This pattern results from the interplay between several complex factors and is not a simple function of the completeness of the fossil record. The Early Palaeozoic record is likely to be less organismically and stratigraphically complete, and its fossils -- many of which are invertebrates-may be more difficult to analyse cladistically. The Late Cenozoic is subject to the pull of the Recent, but this accounts only partially for the increased gappiness in the younger strata.     

The original colours of fossil beetles

Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group.     

History of ichnology

William Buckland not only was an eccentric scientist either liked or disliked by his peers but, in the early 1800s, was also the foremost authority on coprolites. The latter were a source of considerable amusement to some of his friends.     

Ichnologic note

The brittle star Taeniaster bohemicus was found in association with the trace fossil Asteriacites lumbricalis in the Upper Ordovi‐cian of central Bohemia. Morphological features of the trace, coupled with spatial interrelationships between trace and body fossils, provide evidence that the brittle star represents the trace‐maker of this Asteriacites. The cubichnial burrows probably represent negative phototaxis among the ophiuroids.     

Palerasnitsynus gen. n. (Trichoptera, Psychomyiidae) from Burmese amber

Palerasnitsynus ohlhoffigen. et sp. n. is described fromBurmese amber of late Albian (Lower Cretaceous) age. This is the first record of the family Psychomyiidae from Burmese amber, and the earliest fossil record of the family. The genus Palerasnitsynusgen. n. differs from all other known psychomyiid genera by the absence of fork III in the forewings.     

Ichnologic note

Palaxius salataensis, an anomuran microcoprolite, is described from Cretaceous deposits of the MIT Guyot in the northwest Pacific, about 1500 km southeast of Japan. This is the first report of the ichnogenus in this area and the first report of the ichnospecies in Cretaceous deposits. The range of P. salataensis is thus very long, from Permian to Cretaceous.     

天山哈密翼龙化石围岩风化机理初步分析

哈密翼龙及其3D蛋与胚胎化石的发现,具有重要的科学价值。然而,这些化石在离开原始埋藏环境之后,就会出现粉化剥落等严重自然风化现象。本文拟利用XRF等多种方法对代表性化石的赋存围岩样品进行分析检测,以探讨其风化破碎机理。分析表明,化石围岩为含泥砾的砂岩,含有蒙脱石等黏土类矿物,胶结物为钙质和盐类,且围岩中含有大量的Cl^-、NO₃^-、Na⁺和Mg²⁺等可溶盐。因此,本文指出围岩产生风化的主要机制是当湿度发生变化时,盐胶结溶解,同时围岩中的可溶盐溶解重结晶产生的巨大结晶压力,以及蒙脱石等矿物吸水膨胀产生巨大的挤压力,促使围岩在巨大内部应力等综合作用下逐渐粉化脱落,最终导致围岩彻底破碎。基于以上认识,也给出了化石的保护建议。     

Tomographic techniques for the study of exceptionally preserved fossils

Three-dimensional fossils, especially those preserving soft-part anatomy, are a rich source of palaeontological information; they can, however, be difficult to work with. Imaging of serial planes through an object (tomography) allows study of both the inside and outside of three-dimensional fossils. Tomography may be performed using physical grinding or sawing coupled with photography, through optical techniques of serial focusing, or using a variety of scanning technologies such as neutron tomography, magnetic resonance imaging and most usefully X-ray computed tomography. This latter technique is applicable at a variety of scales, and when combined with a synchrotron X-ray source can produce very high-quality data that may be augmented by phase-contrast information to enhance contrast. Tomographic data can be visualized in several ways, the most effective of which is the production of isosurface-based 'virtual fossils' that can be manipulated and dissected interactively.     

Fossil insect evidence for the development of raised mire at Thorne Moors, near Doncaster

Fossil insects contained within a monolith of peat taken from Thorne Moors, to the northeast of Doncaster, UK, were studied. The changing entomofauna demonstrates clearly the development of raised mire from fen woodland. Many of the trees emerging from the peat have been severely burnt and the role of fire in the destruction of the woodland is considered. A number of species recovered from the lower peats are now extinct in Britain; others have extremely limited distributions in Europe today.     

Fossil wood of the Juglandaceae: Some questions of taxonomy,evolution, and phylogeny in the family based on wood anatomy

Some problems in the taxonomy of the Juglandaceae are discussed based on wood anatomy; the identification of fossil juglandaceous wood is considered. Data on fossil wood of the Juglandaceae are summarized; a key for identification of wood anatomy in modern and fossil Juglandaceae is compiled. Wood anatomical characters in members of the family are discussed in the light of major evolutionary trends in the secondary xylem of dicots, and a comparative characterization of members of the family is developed. A hypothesis is proposed that the subfamily Engelhardioideae is the most primitive member of the Juglandaceae based on wood anatomy, the tribe Juglandeae and subfamily Platycaryoideae are slightly more highly specialized, and the tribe Hicorieae is the most advanced. Evolutionary relationships between the members of the Juglandaceae are reviewed based on wood anatomy.