High peak and average power Yb-doped ps-pulse fiber amplifiers are of high demand for different micromachining tools. Most of commercial lasers are designed for operation near 1030 nm, which is due to high gain at this wavelength. An ultimately high peak power of ∼ MW just after the fiber amplifier and ∼3.8 GW after pulse compression [1] was achieved in lasers operated near 1030 nm by utilization of rod-type photonic crystal fibers (PCF). However, such fibers have a well-known problem: they could not be spliced with standard fibers, and also it must be kept perfectly straight. As a result, lasers based on PCF lose most of the advantages of fiber lasers – reliability, compactness and a low production cost.

Ostriches (Struthionidae) are iconic Old-World giant flightless birds. The two living African species represent only a small part of ancient struthionid diversity, which comprises a number of fossil taxa, including the largest known birds of Northern Hemisphere – Pleistocene giants Pachystruthio. In comparison with most other birds, ostriches have an extensive fossil record, mostly represented by eggshell fossils, which are rather common in many Neogene to Quaternary localities of Africa and Eurasia. The global Old-World diversity of the fossil ostrich eggshell is here for the first time analyzed and put together with bone fossil record as well as current palaeoenvironmental and stratigraphic/biochronological data. The available fossil record indicates a complicated geographical pattern of ostrich evolutionary history during the Miocene, Pliocene and Pleistocene of Africa and Eurasia, with a number of evolutionary transformations and proposed dispersal events (both out-of-Africa and out-of-Eurasia). The evolution of ostriches is further put into a context of the overall environmental and faunal evolution, and paleontology-based hypotheses of the origin of modern taxa are developed.

Analysis of the results of involvement of eggshell structure and egg morphology traits in the cladistic analysis of dinosaur (primarily, theropod) phylogeny revealed the subjective character of trait state assessment upon the construction of a matrix. The example of two groups of elongated dinosaur eggs (Elongatoolithidae and Prismatoolithidae) has been used to demonstrate that the motivation to confirm the correctness of the theropod (taxa that generated the eggs) cladogram often resulted in a biased interpretation of trait modality – for instance, to the detection of avian traits in the structure of eggshell, eggs, and nests. We showed that it was actually impossible to demonstrate the presence of these traits in the material studied. It has been noted that uncritical attitude to the matrix leads to a loss of important biological information, including the information related to the patterns of morphogenesis evolution.

Different aspects of using eggshell structure in description of fossil eggs and in phylogenetic analysis are critically discussed. One of the lines of discussion is that correct identification of the so-called squamatic ultrastructure (important feature of the spongy layer in ornithoid type of eggshell) is a key point for the results of the analysis. The complex biocrystalline nature of the so-called squamatic ultrastructure is under particular consideration. The other line concerns the use of parataxonomy and the role of structural typifications (eggshell basic types and morphotypes) as an adequate concise language for fossil egg description. The importance of these questions is illustrated on the examples of the last finds of Cretaceous eggs from the territory of the Gobi Desert in Mongolia. Finally, some recommendations for the future development of paleoology are proposed. Development of the accessible photobase of all described oogenera and oospecies, with comparable illustrations of the eggs, eggshell surface and eggshell structure, is an important step in this direction.

Enantiornithes is the most speciose clade of Cretaceous birds, but many taxa are known from isolated postcranial skeletons. Two embryonic enantiornithine bird skeletons of Gobipipus reshetovi gen. et sp. nov. from the Upper Cretaceous (Campanian) Barun Goyot Formation of the Gobi Desert in Mongolia provide new insights into the anatomy, radiation, and mode of development of early avialans. In recent times, both enantiornithine and ornithuromorph birds are known from the Barun Goyot Formation as well as from the Djadokhta and Nemegt Formations. The 80-million-year-old Gobipipus skeletons encased within eggshells shows several features characteristic of enantiornithine birds. The wing skeleton and shoulder girdle show morphological features indicating that Gobipipus achieved sophisticated powered flight. Gobipipus reshetovi gen. et sp. nov. is quite distinct from the sympatric enantiornithine species Gobipteryx minuta from the same strata in many anatomical features. Phylogenetic analysis of 26 avialan ingroup taxa based on distribution of 202 characters indicate that Gobipipus is a basal member of enantiornithine birds along with Confuciusornis and shares more characters with ornithuromorphs than previously recognized. The embryonic nature of Gobipipus specimens sheds new light on the developmental history of enantiornithine birds. The well-ossified bones of the fore- and hind limbs, and fusion of many skeletal elements indicate a precocial mode of development in Gobipipus. Apparently Gobipipus hatchlings could walk away from the ground nests as soon as they emerged from their eggs. The asymmetry of egg poles are unique features of Gobipipus eggs (oogenus Gobioolithus) among Cretaceous avialans. The microstructure of the shell in Gobioolithus eggs with the embryos of Gobipipus is typical avian (of ornithoid basic type) and less ratite-like in morphology of the spongy layer than is that in the other possible egg-remains of enantiornitine birds (oofamily Laevisoolithidae).

SummaryFieldwork on the distribution, habitat preferences and status of birds was conducted in the Bikin River basin, northern Ussuriland, south-east Russia, during May–July 1992,1993,1995,1996 and 1997. The results of this survey combined with data collected during 1960–1990, show the area to be of high conservation priority and one of the most important for the conservation of Blakiston's Fish Owl Ketupa blakistoni, Chinese Merganser Mergus squamatus, Mandarin Duck Aix galericulata and Hooded Crane Grus monacha. This paper reports on all of the 13 threatened and near-threatened breeding species of northern Ussuriland, with special emphasis on their occurrence and status in the Bikin area. Three more species, included in the Red Data Book of Russia, are also briefly discussed. Maps show the distribution of the breeding sites of the species discussed. The establishment of a nature reserve in the lower Bikin area is suggested as the only way to conserve the virgin Manchurian-type habitats (wetlands and forests), and all 10 species of special conservation concern. Monitoring of the local populations of Blakiston's Fish Owl, Chinese Merganser and Mandarin Duck in the middle Bikin is required.

MIKHAILOV K. E.: Classification of fossil eggshells of amniotic vertebrates. Acta Palaeont. Polonica, 36, 2, 193-238. Fossil avian and reptilian eggs and eggshells, from the Cretaceous of Mongolia and USSR (Kazakhstan, Zaisan basin) as well as samples of dinosaurian and the Eocene avian eggshells from USA, China, France and Argentina were studied. Methodological, terminological and biomineralization aspects of eggshell structure are discussed. Considered are different classifications of eggshell according to the structural levels of eggshell matter organization (texture. general histostructure, superficial morphology). Basic types, morphotypes, types of pore system and types of surface ornamentation are the main structural categories employed in the systematic description of fossil material. About 18 groups of fossil eggshells referred to turtles, geckoes, crocodiles, and to 14 families or dinosaur and bird oological remains are described. Their composition, occurence, paleobiology and systematics are shortly presented.

CONTENTS I. I n t r o d u c t io n ..........................................................................................................................................53' II. D ata of SEM s t u d i e s .................................................................................................................. ......57 A. Prim ary spherite ........................................................................................................................57 B. Eisospherite .................................................................................................................................58C. Secondary s p h e r i t e ....................................................................................................................59» D. Tabular structure and “fish-bone p a tte rn ” s t r u c t u r e ................................................ ......60 E. “Real” structure .................................................................................................................. ......61 P . E xtern zone .................................................................................................................................63III . D is c u s s io n ........................................................................................................................................ ......63IV. System atic and phylogen etical a s p e c t s ............................................................................... ..... 64 References ......................................................................................................................................... 67 Streszczenie .................................................................................................................................... 69-