Jakub Sakala

Twig with attached leaves, fruits and seeds of Decodon (Lythraceae) from the Lower Miocene of northern Bohemia, and implications for the identification of detached leaves and seeds

Abstract A twig fragment with attached verticillate leaves and capsules with intact seeds was recovered from the Lower Miocene lignitic clay in the Bilina strip mine (northern Bohemia). The seeds correspond to those known in dispersed condition as Decodon gibbosus (E.M. Reid) E.M. Reid in Nikitin, while the foliage matches that which has been called Ficus multinervis Heer, and sometimes Apocynophyllum helveticum Heer. While the determination of the seeds is safe, the identity of the isolated foliage may be less secure. Therefore the name Decodon gibbosus is given preference to designate the whole plant. This fossil species differs from the only extant species D. verticillatus (L.) Ell. of eastern North America by narrower triangular shape of seeds in transverse section, the thicker spongy layer of the testa on the dorsal side, and by long petiolate leaves that are more variable in shape (from narrow linear-lanceolate to broadly lanceolate) with more densely spaced secondaries and intersecondaries. The leaf cuticular structure matches that of the glabrous form of D. verticillatus. The associated plant assemblage suggests aquatic to swampy environment typical of the extant relative.

Early Miocene conifer macrofossils from the Most Basin (Czech Republic)

A systematic overview of the conifer macrofossils (leaves, cones, seeds and wood) from the Lower Miocene of the Most Basin (Czech Republic) is presented and nine natural units (botanicalspecies)aredefined,belongingtothreespeciesof PinusL.andonespeciesof Pseudolarix GORDON, QuasisequoiaSRINIVASAN&FRIISemend.KUNZMANN, TaxodiumRICHARD, Glyptostrobus ENDLICHER, TetraclinisMASTERSand CupressospermumMAIemend.KUNZMANN.Seedsofthelatter taxon have been firstly described from the Most Basin. Different organs are rarely directly attached (pollen/seeds cones attached to a twig, a cone scale with seeds), but rather found in direct (close) or indirect (distant) association. The conifers are also characterized in environmental context as elementsofseveraldifferentvegetationtypes.

Silicified wood from the Czech part of the Intra Sudetic Basin (Late Pennsylvanian, Bohemian Massif, Czech Republic): systematics, silicification and palaeoenvironment

Silicified trunks, colloquially called “araukarity”, are plentiful plant fossils of the Late Pennsylvanian in the Czech part of the Intra Sudetic Basin (ISB) in NE Bohemia. They are predominantly embedded in Žaltman Arkoses, a unit of fluvial sediments deposited during Barruelian, Late Carboniferous. This unit is a part of the Odolov Formation with the richest outcrops in the area of “Jestřebí hory” (Hawk Mts.). Since GOEPPERT (1857) firstly described these fossils as species Araucarites brandlingii and A. schrollianus, interpreting both as conifer woods close to the Araucariaceae, they have later never been re-examined or studied as a whole by any modern analytical methods. As the original material of GOEPPERT was unavailable to our study, we re-evaluated the previous taxonomical assignments on the basis of newly collected material and supplemented a detailed description of their mineral matter (petrography, mineralogy). Following the modern classification, A. brandlingii (= Dadoxylon brandlingii) describes the wood of cordaites, and Araucarites schrollianus (= Dadoxylon saxonicum syn. Dadoxylon schrollianum) is a name of conifer wood, but our systematical study proves only the presence of cordaites. The pycnoxylic stems were silicified in alluvia without apparent influence of volcanic material. Data from sedimentary structures were used for reconstructions of palaeostreams. The weathering of feldspars is presumed as a source of silicification amplified by the oscillation of water table under seasonally arid periods within Late Pennsylvanian/Early Permian long climate cycles. This mode of permineralization is responsible for frequently poor preservation and high recrystallization of these fossils. Their mineral mass consists of pure highly crystalline quartz without other SiO2 phases. Cathodoluminescence (CL) microscopy and spectroscopy revealed a polyphase process of silicification including influence of thermal fluids which healed cracks in previously silicified mass. It is possible that all these facts responsible for poor preservation of anatomical features of Dadoxylon wood type have precluded its more detailed taxonomical study for more than one century.

Late Cretaceous flora of James Ross Island (Antarctica) - preliminary report

Fossil plants from Late Cretaceous strata (Hidden Lake Formation and Santa Marta Formation) of James Ross Basin exposed in the northern part of the James Ross Island are preliminary described. Both formations contain plant mega fossils, petrified wood, and charcoalified mesofossils. Fossil plants from the Hidden Lake Formation are represented by leaf impressions of pteridophytes (Microphyllopteris, Delosorus, Lygodium), conifers (Elatocladus, Brachyphyllum, Pagiophyllum, Araucaria, Podozamites vel Lindleycladus), Bennettitales vel Cycadales (Zamites vel Dioonites sp.) and angiosperms (Cinnamomoides, Dicotylophyllum ssp., Proteophyllum, Juglandi- phyllum vel Dicotylophyllum). Fossil wood can be attributed to the very broadly defined morphogenus Antarctoxylon Poole & Cantrill.

OLIGOCENE ANGIOSPERM WOODS FROM NORTHWESTERN BOHEMIA, CZECH REPUBLIC

Two species of fossil angiosperm wood are described from the Oligocene of northwestern Bohemia in the Czech Republic. One specimen from Kadan–Zadni vrch Hill is identified as Cercidiphylloxylon kadanense Prakash et al. Because of its superior preservation, the specimen is designated as an epitype to the original holotype specimen of the species and genus. Cercidiphylloxylon kadanense is known only from the locality of Kadan–Zadni vrch Hill, and it represents the oldest fossil wood of true Cercidiphyllum Sieb. & Zucc. Three other wood specimens from Zichov are attributed to Liquidambaroxylon speciosum Felix. Modern wood of some species of Cercidiphyllum Sieb. & Zucc., Liquidambar L., Altingia Noronha, Corylopsis Sieb. & Zucc., Distylium Sieb. & Zucc., and Hamamelis L. was examined to determine how to distinguish the wood of Cercidiphyllum (Cercidiphyllaceae) from similar woods of Hamamelidaceae. The number of bars in the scalariform perforation plates of the vessels is about 40 in Cercidiphyllum, and about 20 in the Hamamelidaceae. Rays are variable, even at intra-specific level, and are not suitable for distinguishing these woods. These criteria were found to be useful in evaluating affinities of the fossil woods.

Cenomanian angiosperm wood from the Bohemian Cretaceous Basin, Czech Republic.

The first permineralized angiosperm wood from the Cenomanian of the Bohemian Cretaceous Basin (Czech Republic) is described. The wood is diffuse porous, with vessels solitary and in radial multiples of 2–5, perforation plates are exclusively simple, and tyloses abundant. Rays are usually 4–7-seriate and heterocellular, narrower rays are rare. The fossil is designated as Paraphyllanthoxylon aff. utahense Thayn, Tidwell et Stokes. Other occurrences of Paraphyllanthoxylon are reviewed and the equivocal botanical affinity of the taxon is discussed.

A new species of Antarctoxylon: a contribution to the early angiosperm ecosystem of Antarctica during the late Cretaceous

Abstract A new species of Antarctoxylon is described from the Coniacian Hidden Lake Formation of James Ross Island as A. mixai Sakala, sp. nov. This angiosperm fossil wood shows a unique combination of features in having indistinct growth ring boundaries, scalariform perforation plates with about 30 bars and rays both narrow (1–6-seriate) and very wide (up to 18-seriate). Its systematic affinities and exact living relative at the specific, generic or even familial level cannot be specified. Along with Weinmannioxylon nordenskjoeldii from James Ross Island and the angiosperm woods from the Williams Point on Livingston Island, this record provides further evidence of the earliest record of arboreal angiosperms in Antarctica.

Silicified Angiosperm wood from the Dangu locality (Ypresian of the Gisors region, Eure, France) : the problem of root wood

The problem of root wood is discussed. Based on several specimens of silicified wood from the Dangu locality (Lower Eocene of the Paris Basin), the authors have attempted to explain variations in the wood structure by the origin of the studied woods within the tree. A new species with two new forms is also established.

USING IDIOBLASTS TO GROUP LAURINOXYLON SPECIES: CASE STUDY FROM THE OLIGO-MIOCENE OF EUROPE

Several specimens of Lauraceae fossil wood from the Cenozoic of Greece (southern part of Lesbos), the Czech Republic (Kadaň-Zadni Vrch Hill and Jachymov), and Hungary (Ipolytarnoc) were studied. When considering whether they belonged to the speciose fossil wood genus Laurinoxylon, we reviewed the literature and data from InsideWood on fossil and modern woods. As a result, we propose criteria for excluding a fossil Lauraceae wood from Laurinoxylon and list the species that should be excluded from this genus. The criteria (filters) proposed to exclude a genus from having relationships with Laurinoxylon are: A. Axial parenchyma features: A1. Marginal axial parenchyma, A2. Aliform to aliform-confluent paratracheal parenchyma. B. Ray features: B1. Rays higher than 1 mm, B2. Exclusively homocellular rays, B3. Rays more than 5 cells wide, B4. Rays storied. C. Porosity features: Ring-porous. D. Idioblasts: Absence of idioblasts. Based on the distribution of idioblasts, we recognize four groups in Laurinoxylon (Type 1 - with idioblasts associated only with ray parenchyma cells, Type 2a - with idioblasts associated with both ray and axial parenchyma, Type 2b - with idioblasts associated both with rays and present among the fibres, and Type 3 - with idioblasts associated with ray and axial parenchyma and also among the fibres) and list the extant genera with features of those groups. Such grouping helps with interpreting the relationships of fossil lauraceous woods with extant genera. We discuss the Oligocene–Miocene European species that belong to these Laurinoxylon groups, noting that some warrant reassignment to different genera or even families. Future studies are needed to determine whether new genera should be established to accommodate these species. We propose the new combination Cinnamomoxylon variabile (Prive-Gill & Pelletier) Mantzouka, Karakitsios, Sakala & Wheeler.