Palaeodictyopterida is remarkable insect superorder, which formed a significant part of the diversity of upper Palaeozoic insects, but disappeared by the end of the Permian. The main synapomorphy of the superorder is the piercing-sucking mouthparts in the form of a rostrum consisting of five styles. This rostrum was probably used to pierce on plant tissue and for the juice sucking. The same type of mouthparts shared by adults was present also in larvae of Palaeodictyopterida. The external copulatory organs of the superorder members was also showed some morphological interests. The male genitalia consist of a pair of gonostyli and two penial lobes, similarly to the genitalia of recent Ephemeroptera. The female genitalia of Palaeodictyopterida are developed in a form of the ovipositor that can be compared with the endophytic ovipositor of some recent Odonata. This morphological features support placement of Palaeodictyopterida as sister group of Odonatoptera + Panephemeroptera. The main aim of the work was to describe new representatives of the order Megasecoptera, the second largest group of Palaeodictyopterida. Wing venation of Megasecoptera exhibits a reduction of the longitudinal and transverse veins in comparison with the order Palaeodictyoptera. Other body structures were examined mainly in the...

On five key sites of the Lower Palaeozoic of the Železné hory Mountains (Bačalský rybník, Bačalský mlýn, Palác, Rabštejn and Deblov) the detailed research involving the compilation of schematic lithostratigraphic profiles (exluding site Deblov) was conducted. Individuals of ichnotaxa Zoophycos that have maximum Middle Cambrian age were described on the site Palác. This is the third oldest finding in the world. Ichnotaxa Zoophycos was further described on the site Bačalský rybník, where they are exposed quartz siltstones, the equivalent of the Dobrotiv of the Barrandian area. Ichnofossils abundant in the study area are Skolithos, Pragichnus, to a lesser extend Phycodes and Monocraterion. Skolithos on the site Rabštejn occurs in extreme size (until 90 cm). On the site Deblov community of Skolitos ichnofacies on the area measuring hundreds of square meters were described. There was also performed ichnological imaging which showed proportional representation of each ichnotaxa. Study samples for microprobe showed differences in structure and chemistry of ichnofabrics up filling and surrounding environment.

For two centuries, questions about the origin of terrestrial plants and their impacts on the Earth systemhave occupied palaeobotanists. This essay attempts to synthesise the state of research to date, and outlineareas where major questions remain. Fossil evidence for land plants first appears in rocks of MiddleOrdovician age (~ 470 Ma), but it was not until the Devonian that vascular plants became the dominantgeobiological agents on the continents. Plants began as small organisms, lacking any vascular tissues,and essentially confined to wetlands. Key developments in their reproductive biology and the evolutionof mycorrhizal symbiosis subsequently enabled early plants to exploit a broader range of environments,enhancing water uptake and absorption of nutrients. In turn, the evolution of plant roots has significantlyimpacted terrestrial landscapes. The Devonian rise of plants led to a modification of the weathering rateand a sharp increase in the rate of mudrock production. This was driven by the impacts that plants exerted on watercourses, with the creation of meandering rivers and deltas that retained fine siliciclasticmaterials. This increase in weathering rate, combined with the development of leaves and the intensification of photosynthesis also had consequences for the carbon cycle and atmosphere, reducing the levelof CO2 and increasing that of O2 in the atmosphere. The increased proportion of oxygen and creation ofcombustible material is also thought to have led to the planets first wildfires, whilst the decrease in CO2lowered global temperatures. Via a complex set of feedbacks, these modifications may even have drivena series of anoxic events in the oceans, generating one of the five major mass extinctions at the end ofthe Devonian. / Paleobotanik är studien om fossiliserade växter. Då växter ursprungligen först saknades från jordens ytahar deras utveckling och kolonisering av kontinenterna (för 450 miljoner år sedan) haft många effekter.Ursprungligen var de första landväxter små och liknande modernt gräs. Deras små rötter begränsadedem till närvaron av vattenkällor (hav, flod, träsk…). En symbios med svampen (kallad mykorrhizalsymbios) underlättade landväxtens upptag av näring samt utvecklingen av djupare rötter, vilket ocksåunderlättade deras upptag av vatten. Då landväxter nu kunde migrera till torrare landskap har antaletlandväxter ökat med tiden. Det växande antalet landväxter var viktigt för bildningen av exempelvis kol,vilket är slutprodukten av dött växtmaterial som begravts och utsatts för höga tryck och temperaturförhållanden. Den geologiska perioden Karbon (359–299 miljoner år sedan) namngavs tack vare av denenorma andelen kol som kan dateras tillbaka till denna tid. Genom fotosyntes kan växter även absorbera CO2 och frigöra syre, och på så vis förändra atmosfärenssammansättning. På grund av högre syrehalter i atmosfären blev bränder ett allt vanligare fenomen eftersom det försågs med växter och syre som bränsle, som i sin tur även förbättrade bevarandet av frönoch växtvävnader i form av träkol. Oavsett om det är växtens frigöring av syre, minskning av CO2 (som är en växthusgas) eller genombränder, har uppkomst av landväxter haft en stor inverkan på atmosfärens sammansättning, och därföräven klimatet. På grund av en hastig nedgång av temperatur och syrehalt i haven mellan 450–375 miljoner år sedan (från 40 till 25 °C), utrotades nästan 75% av allt djurliv. Upphovet av denna massutrotning, genom försämringen av vattenkvalité, och uppkomsten av syrefritt vattenmiljöer tros bero på näringsläckage av jordar orsakat av ett ökat tillstånd av alger som spreds i samband med landväxters rotutveckling.

The late Paleozoic deposits of the Czech Republic are famous for their rich occurence of silicified stems. Despite the fact they have been often described and are well-known among scientists and collectors, their modern evaluation is lacking. This work summarizes results of recent anatomical and paleoenvironmental studies of silicified stems of the Intra Sudetic and Krkonoše Piedmont basins, where are these fossils found very frequently. Based on field research and review of public and private collections, the presence of silicified remnants was proved in several stratigraphic units. Firstly, this work deals with silicified stems of calamitaleans, which are known from the Ploužnice Horizon of the Krkonoše Piedmont Basin, and some gymnosperms. Based on anatomical studies of the secondary xylem and other related features there were found two species of calamitaleans: Arthropitys cf. bistriata and Calamitea striata. Secondly, the more abundant Agathoxylon - type of wood was divided into two groups, which are assigned to cordaitaleans, and conifers. The palaeoenvironmental conditions were partly reconstructed according to sedimentary structures and also according to cordaitaleans - conifers ratio in each wood-bearing layer. Powered by TCPDF (www.tcpdf.org)

The history of research on the Late Paleozoic amphibians at Faculty of science of Charles University in Prague coincides with the 50th of the last century, when it was acquired rich collection material from field collection prof. Špinar. This is connected with the necessity of cataloging and processing of this material. The catalog alone contains large amounts of material, 3,237 pieces of items that will be the basis for subsequent research directions in the fields of morphology, anatomy, taxonomy, biomechanic and more. The most numerous species in collections is discosauriscus austriacus.