In the course of life development, just a small number of key evolutionary events were registered that inspired global biosphere changes. The explosive development of terrestrial vegetation and the ...appearance of forest ecosystems in the Devonian period was one of such events. Land colonization started by bryophytes, and their ancestors required the appearance and development of various root systems. Roots evolved separately and independently in several main directions, rapidly expanding their functionality. Numerous paleosol horizons and their complexes were studied in the middle reaches of Tsilma River on the Middle Timan Ridge in the red-colored mid- and upper Devonian sediments. The palynological data testified to highly diverse terrestrial flora in this area. The ancient soils contained in situ roots of various types. This work was aimed at morphological description of the discovered root systems. At present, the taxonomy of Devonian root systems is at the stage of primary data accumulation. As a result of the studies, three morphological types of root systems belonging mainly to grass-like plants have been identified in paleosols. There are no descriptions of such objects in paleobotanical literature. Morphological types of root systems are correlated with geomorphological features of the studied territory.
The "last" tentaculitoids Marshall, J. E. A; Tel'nova, O. P
Palynology,
12/2017, Volume:
41, Issue:
sup1
Journal Article
Peer reviewed
An earliest Famennian (Late Devonian) record of tentaculitoids (an extinct 'class' of small calcareous conical shells) preserved as palynomorphs is documented from Sosnogorsk in the Komi Republic of ...Russia. These were preserved in considerable abundance in a near-shore shallow lagoon subjected to marine flooding with euxinia. Four forms of nowakiid tentaculitoids plus related aberrant forms are documented. They represent evidence for survival of the nowakiids into the earliest Famennian and hence post-date the Frasnian-Famennian mass extinction. It is hypothesised that the Frasnian and younger occurrence of tentaculitoids as palynomorphs may relate to a changing balance of carbonate and organic matter in their shells driven by the environmental conditions of the Frasnian-Famennian mass extinction.
The results of bio- and lithostratigraphic study of Sargaevo deposits in the Tsil’ma River basin are discussed. The palynological data used for biostratigraphic subdivision of the section provide ...grounds for defining the miospore assemblage corresponding to the regional miospore Cristatisporites pseudodeliquescens Zone. It is established that deposits of the Sargaevo regional stage are distributed almost through the entire Tsil’ma River basin. They are characterized by distinct lithological features and may serve as a stratigraphic reference unit in field investigations.
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The results of biostratigraphic study of Givetian–Frasnian rocks of the Tsil’ma River basin (Middle Timan) are presented. The biostratigraphic division of the sections is based on palynological ...data: five palynocomplexes are distinguished in the Valsa, Tsil’ma, Ust’-Chirka, Ust’-Yarega, and Kraipol’e formations and are correlated with coeval palynocomplexes of adjacent of territories. The features of miospore associations from continental and coastal marine facies are identified. The clear cycle of origination of geological bodies corresponding to the formations is established at this territory.
The results of sporoderm studies for Paleozoic spores are obtained for the first time on a nanotomographic scanner. They are comparable to the results obtained on a scanning electron microscope (SEM) ...and transmitting electron microscope (TEM), verifying the interpretation of structures of the external and internal structure of the sporoderm for the objects studied. A nanotomographic scanner enables us to carry out complex studies of different sporoderm projections and to visualize the relationships and arrangement of its components without damaging the integrity of the object and losing unique Paleozoic material. Application of a nanotomographic scanner also reduces the time taken for object preparation for examination on a SEM or TEM. The nanosculpture of the exosporium of Devonian
Kryshtofovichia africani
Nikitin megaspores is revealed to show its two-layer structure, with the thicknesses and locations of the layers established.
This paper describes the optimization of a workflow incorporating experimental implementation of information tools into paleopalynological research. It is proposed to streamline the work of expert ...palynologists by using an intelligent “deep learning” algorithm, utilizing identification resources such as atlases and photographic plates, by developing an adaptive database.
Lignin of Ancient Plant Fossils Telnova, O. P.; Marshall, J. E. A.; Kocheva, L. S. ...
Paleontological journal,
12/2022, Volume:
56, Issue:
9
Journal Article
Peer reviewed
A comprehensive study of dispersed Early Carboniferous seeds has been carried out to test the possibilities of using chemosystematics for Paleozoic fossils. This has involved their morphology; the ...ultrastructure of ion thinned sections and their material. The results of analysis of the FTIR and EPR spectra indicate that the key structural unit of the substance is the phenyl propane structure. The presence of relict lignin (
p
‑coumaric type) was established by structural-chemical analysis using pyrolytic chromatomass-spectrometry. Lignins of this type are unknown in modern plants. The concentration of phenoxyl radicals is 2–3 orders of magnitude higher in the samples than in modern lignins.
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