This paper describes fossil remains of Promephitis lartetii (Mephitidae) from the Upper Miocene (MN 12–13) of Tuva, the Taralyk-Cher locality, which are represented by two nearly complete deformed skulls, mandibular rami, and maxilla, mandible fragments, and isolated teeth. The variability of taxonomically significant characters in the morphology of P4–M1 and the skull of P. lartetii has been studied. The stability of the taxonomic characters of the genus Promephitis has been analyzed.
The composition of the order Miomoptera is considered at the family level, and the system of the family Permosialidae is revised. Keys are provided to families of the order and to genera and species of the family Permosialidae, with synonymies and unified diagnoses of the genera and species of Permosialidae. The composition of the family is shown to remain uniform through its entire time interval, with the type genus always prevalent, and the only one recorded at its start (late Kungurian) and finish (Triassic). The geographical distribution of Permosialidae is noteworthy: widespread over Angarida and confined to that region except for a unique record from Australia.
New taxa of the spiriferid subfamily Howellellinae are described from the Lower Devonian beds of Northeastern Asia (Tas-Khayakhtakh, Ulakhan-Sis, Sette-Daban, and Selennyakh ridges): Afanasjevispirifer gen. nov. with the type species A. mercuriformis Kulkov, 1963; Aldanispirifer selennyakhensis sp. nov. and Talyndzhaspirifer gen. nov. with the type species T. latus sp. nov.
A new species of the conodont genus Palmatolepis—Pa. abramovae sp. nov. is described from the Makarovo Regional Substage of the Famennian Stage based on materials from four sections of the western slope of the South Urals (Bolshaya Barma, Akkyr, Ryauzyak, and Kuk-Karauk). The paper presents ontogenetic series of the described species and suggests its possible phylogenetic relationships. Pa. abramovae sp. nov. is a characteristic species of the Upper triangularis Zone.
Brachiopod shell imprints from the core samples from Borehole XC-1 (1012–1013 m), Shumnaya Formation, Botomian–Toyonian stages, Lower Cambrian, Siberian Platform were examined. The samples are represented by thin laminated bituminous mudstone. Imprints of phosphate brachiopod (lingulids and acrotretids) valves and casts of valves occur on the bedding surfaces of the samples. One sample contains a cluster of small fossils (60–220 µm) probably belonging to embryos or brephic valves of these brachiopods. Chemical analysis has revealed that the originally organic material of the valves was replaced by pyrite, most likely postmortem. At the same time, the fragments of the valves of adult lingulate brachiopods are composed of calcium phosphate.
The Khuvsgul phosphorites became the first model object of bacterial paleontology. During their study, techniques were developed for preparing samples for viewing on a scanning electron microscope and for screening the samples for the presence of identified fossil bacteria. Due to the wide variety of fossils found, different forms of bacteria preservation were identified, and the conditions of their formation were explored.
The development of bacterial paleontology has shaken some generally accepted scientific paradigms in research on the Archean–Proterozoic evolution of the Earth. Thus, bacterial and paleontological studies occasionally led to a revision of paleogeographical constructions. This paper discusses the main achievements of this rather young scientific discipline, including the finds of ancient prokaryotic and eukaryotic microorganisms and their connection with the early Earth’s environments, as well as the finds of fossilized microorganisms in carbonaceous chondrites (meteorites), which change our attitude toward the problems of panspermia and the origin of life.
A new genus Plesiomedetera gen. nov., is described from Late Eocene Baltic amber. The genus is placed in the extant subfamily Medeterinae and includes five recognized and two doubtful species, all poorly described by Meunier in 1907–1908 and never reported again. Plesiomedetera flammea (Meunier, 1907), comb. nov. and P. mustela (Meunier, 1907), comb. nov. are described and illustrated, and a key to recognized species of this genus is compiled. The other eight extinct genera from Baltic amber are briefly reviewed, belonging to extant subfamilies ?Diaphorinae, Dolichopodinae, Medeterinae, Peloropeodinae and Sciapodinae, and a key to these genera is compiled. The following new combinations (comb. nov.) are proposed: Plesiomedetera decora (Meunier, 1907), P. elegantula (Meunier, 1907), P. vana (Meunier, 1907), P. lasciva (Meunier, 1907), P. lepida (Meunier, 1907), Medeterites atterraneus (Nazarov, 1994), M. gestuosus (Meunier, 1907), M. gulosus (Meunier, 1907), M. latipennis (Meunier, 1907), Palaeoargyra planipedia (Meunier, 1907), Palaeomedeterus praeconcinnus (Evenhuis, 1994), P. concinnus (Meunier, 1907), P. tertiarius (Meunier, 1907), Prohercostomus ciliatus (Meunier, 1907), P. devinctus (Meunier, 1907), P. gracilis (Meunier, 1907), P. minutus (Meunier, 1907), P. morbosus (Meunier, 1907), P. smicrus (Meuffels et Grootaert, 1999) and P. inumbratus (Meunier, 1907). Sciara pusilla Meunier, 1899 is considered nomen nudum, rather than unplaced species of Dolichopodidae. Dolichopus smicrus Meuffels et Grootaert, 1999 (unnecessary new name) is placed in synonymy with Prohercostomus minutus. In all, 53 recognized, 5 doubtful and 10 unplaced species from Baltic amber are listed.
Phosphorites from the Pechenga Basin, with an age of 2.04 Ga, were produced by microorganisms. Phosphorites of the Pechenga Greenstone Belt were found in the form of numerous rounded, slightly deformed fragments (Fig. 1). The earliest Early Proterozoic (Pechenga) phosphorites show all the characteristics of a cyanobacterial mat—a prokaryotic benthic community united in a physical structure by the glycocalyx.
The results of a long-term electron microscopic study of Kamchatka geyserites are presented showing biological remains of unique preservation and a wide variety of cyanobacteria silicification types. The data obtained made it possible to consider the geyserites of Kamchatka as a model object for bacterial-paleontological studies.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：