Dicotyledonous woods from the Upper Cretaceous of southern Illinois

Dicotyledonous woods from the Upper Cretaceous of Southern IllinoiS. Five species of fossil dicotyledonous wood are described from an Upper Cretaceous (Maestrichtian; locality in Alexander County, IllinoiS. U.S. A. Paraquercimum cretaceum has structure similar to the Fagaceae (evergreen Oak- Lithocarpus ) and Casuarinaceae and represents the earliest known occurrence of this structural type (large solitary pores and uniseriate and large multiseriale rays). Paraphyltanthoxyhin illirioisense and Icacinoxylon alternipunctata are species of genera represented at other Cretaceous and Early Tertiary localities In large diameter trees. Parabombacaceoxylon magniporosum has large diameter pores and scalariform perforation plates, a combination of characters that is extremely rare in the extant flora. Paraapocynaceoxylon barghoorni has a combination of characters represented in extant Apocynaceae. These five species lack growth rings, have high vulnerability indices (mean vessel diameter divided by mean number of vessels per square millimeter, and a relatively high proportion of ray parenchyma. They lack specialized wood anatomical characters, and a compilation of vessel element lengths in these and other Cretaceous woods indicates that short vessel elements (a derived character) were less frequent in the Cretaceous than in extant dicotyledonous trees.     

TREE RINGS: A NATURAL DATA-STORAGE SYSTEM

1. The wood of trees grown in temperate regions shows a periodicity in the form of rings which, with certain known exceptions, accurately reflects the annual cycle of the seasons. The wood thus has a built-in dating system. 2. Tree rings are not always the same width in successive years; the widths show a positive correlation with variations in environmental factors. 3. Trees in a given geographical area influenced by the same environmental conditions show similar patterns in their ring sequences and may thus be cross-dated. 4. Ring sequences from cross-dated trees may be used to construct long, accurate chronologies. This practice, the science of dendrochronology, is now so reliable that it is widely used in archaeology and has also served to calibrate the ¹⁴ dating method. 5. The extent of the variation in a ring sequence may be expressed in the form of a coefficient known as the mean sensitivity. 6. The climatic effects recorded in the growth rings are those which operate at certain crucial periods, such as the growing season. The effects are primarily those of rainfall and temperature; humidity is usually only secondary. 7. Damage by insects or fire may be dated by examination of ring sequences. 8. As tree-ring sequences correlate positively with contemporaneous meteorological data, they may be used in the reconstruction of past climates. This is the basis of extrapolatory dendroclimatology. 9. New isotope techniques have been developed which indicate the possibility of deducing the ambient temperature of the tree's environment whilst its wood was being formed. 10. Interpretative dendroclimatology aims to deduce from the features of a sample, or preferably from a number of samples of wood, the nature of the climate which influenced their development. 11. The wood of most growth rings is divisible into two zones, earlywood and late-wood. The former consists of larger, thin-walled cells while in the latter the cells are smaller and thick-walled. 12. Beams of light, X-rays and β-rays have been used in various instruments to determine the earlywood-latewood ratio. 13. The earlywood-latewood ratio is dependent upon genetic as well as climatic factors. Of the latter, summer rainfall is the most potent in producing latewood. 14. The ring-width data from a number of Recent and fossil wood specimens have been analysed to show that certain deductions may be made about the climate in which they were formed. 15. A histogram technique has been devised to show differences between wood specimens with otherwise similar coefficients. 16. Evidence has been produced in support of earlier work to the effect that ring-width sequences from different radii of a tree trunk have fundamentally similar features, thus demonstrating ‘circuit uniformity’. 17. The interpretation of the features of tropical woods is more complex. The mode of development of such a wood is the resultant of the interplay of genetical factors, endogenous rhythms and slight variations in environmental conditions. 18. There is evidence that endogenous rhythms are also involved in the development of woods in temperate as well as tropical regions.     

Mesozoic woods from India: Nomenclature review and palaeoclimatic implications

Nomenclature reappraisal, diversity pattern and palaeoclimatic implications of Jurassic, Triassic and Early Cretaceous pycnoxylic woods in India are undertaken in the present study. Among the fourteen generic names published previously, only eight are validly published and the rest are nomenclaturally illegitimate. About 51 species were reported under these genera to date. There is a gradual increase of species diversity of fossil wood from the Triassic to Early Cretaceous. The nature of the growth rings was applied to understand the palaeoclimate. The lack of distinct growth rings in the Triassic woods suggests absence of seasonality. The Jurassic woods with an inconsistency in growth rings and presence of growth interruptions suggest climate was seasonal and turbulent. During the Early Cretaceous, conifer dominated vegetation and with wider growth rings and gradual transition suggests warm environments with pronounced seasonality. The general increase in mean ring width from the Triassic to Early Cretaceous indicates ameliorating climatic conditions, particularly benign summer conditions.     

Fossil Woods from Late Cretaceous of Heilongjiang Province,Northeast China,and Their Palaeoenviromental Implications

Three species of fossil coniferous woods, Cupressinoxylon jiayinense Wang R. F., Wang Y. F. et Chen Y. Z., Taxodioxylon cryptomeria Schonfeld and Protopiceoxylon amurense Du N. Z. from late Cretaceous of Heilongjiang Province,Northeast China, were described. Their wood structural characters showed their affinities to the extant Cupressus, Cryptomeria and Keteleeria respectively. The data from fossil woods, fossil foliage and pollen assemblage of late Cretaceous in the same region showed that the flora consists of conifers and broad-leaved trees and most elements were subtropic or warm-temperate, only a few of them were temperate vegetation. At the same time, the occurrence of fungi filaments in the wood of Cupressinoxylon fiayinense might suggest a type of humid and warm environment. All of these evidences indicated that a humid warm temperate or subtropic paleoclimate had existed in Heilongjiang Province during Late Cretaceous.     

黑龙江晚白垩世化石木及其古环境研究

描述了3种出自黑龙江省嘉荫县晚自垩世的化石木:嘉荫柏型木(Cupressinoxylon jiayinense WangR.F.,Wang Y.F.et Chen Y.Z.)、柳杉型木(Taxodioxylon cryptomeria Schonfeld)和黑龙江原始云杉型木(Protopiceoxylon amurense DU N.Z.)。它们分别与现存的柏木属(Cupressus)、柳杉属(Cryptomeria)和油杉属(Keteleeria)有较近的亲缘关系。综合化石本研究与其现存近缘3属的地理分布区的环境分析和已有的植物叶大化石及孢粉的研究成果,黑龙江嘉荫地区晚自垩世的植被类型为针阔叶混交林,植物群由松柏类和阔叶树种组成,大多数是亚热带-暖温带分子,少量是温带分子。同时,嘉荫柏型木中真菌菌丝的侵入生长指示湿热生境的存在。上述证据表明黑龙江省嘉荫县晚自垩世为温暖、湿润的亚热带-暖温带气候。     

A Method To Distinguish Between Woods Produced By Evergreen And Deciduous Coniferopsids On The Basis Of Growth Ring Anatomy: A New Palaeoecological Tool

A method is outlined in which woods produced by deciduous and evergreen coniferopsids may be distinguished from one another on the basis of a quantitative analysis of growth ring anatomy. In this method the diameter of successive tracheid cells was measured across growth rings in modern coniferopsid woods, viewed using standard transverse anatomical sections. The cumulative algebraic sum of each cell's deviation from the mean was then calculated for each growth ring increment and plotted as a zero-trending curve (CSDM curve). Deciduous conifer and ginkgo species dominantly possess symmetrical or left-skewed CSDM curves whilst evergreen conifer species dominantly possess right-skewed CSDM curves. These data suggest that in most cases it may be possible to distinguish between evergreen and deciduous fossil coniferopsid species using wood anatomical characteristics, thus providing important insight into coniferopsid palaeoecology. key words : growth rings, conifer wood, palaeoclimate, evergreen, deciduous.     

Permian wood from western Henan, China: implications for palaeoclimatological interpretations

Two new species of Araucarioxylon and one new species of Protophyllocladoxylon are described from the Permian of western Henan, China. The stratigraphic position of the fossil woods is discussed in detail, mainly based on the recent findings of animal and plant fossils, and palynomorphs. Interesting is the fact that in North China only the Late Permian wood has growth rings; the specimens from older deposits do not. The presence of growth rings in secondary wood at the close of the Permian shows climatic change, suggesting that aridization most probably took place during that period in the vast area of North China.     

辽西义县下白垩统沙海组木化石新材料

辽西地区下白垩统沙海组是我国北方地区重要的白垩纪木化石产出层位,其产出的木化石数量丰富、类型多样.尽管前人开展了部分研究,但目前对沙海组木化石植物群组成特征的认识仍相对薄弱.本文报道了辽西义县上石洞沟地区沙海组产出的木化石新材料,共鉴定出2属3种,分别为:Phyllocladoxylon cf.eboracense(H...     

Towards improving the assessment of rainforest carbon: Complementary evidence from repeated diameter measurements and dated wood

We explore whether a growth-ring analysis can produce additional information about carbon budgets in tropical forests. Such forests are characterized by a high number of species and by trees that rarely have anatomically distinct annual growth rings, which hampers the application of dendrochronological tools in carbon balance assessments in the tropics. We use forest inventory data and archived annual diameter measurements from the Luki Biosphere Reserve in the southwestern margin of the Congo Basin forest massif. In addition, dated wood data are available from the same location thanks to tag nail traces that allow for the measurement of growth increments over a period of 66 years.We find that precise increment measurements based on dated wood are advisable for small subsets of many less abundant species and for functional species groups characterized by slow growth. The dated wood approach shows that many understory trees with non-periodical rings remain in a steady state for long periods of time. These results suggest a dated wood approach is advisable for studies of growth trajectories of individual trees that might be of importance for carbon assessments in degraded forests.     

Tetracentron Wood from the Miocene of Noto Peninsula,Central Japan,with a short revision of homoxylic fossil woods

A vesselless fossil wood was discovered in the Miocene Yanagida Formation in the Noto Peninsula, central Japan. This fossil has distinct growth rings with gradual transition from the early- to the latewood ; tracheids, which are called 'usual traeheids' here, constitute the ground mass of the wood and have typical scalariform bordered pits on radial walls in the earlywood and circular sparse pits on those in the latewood ; rays are 1\2-4 cells wide and heterogeneous with low to high uniseriate wings; axial parenchyma strands are scattered in the latewood. This wood has a peculiar feature; sporadic radial files of broad tracheids whose tangential walls have crowded alternate bordered pits. The radial walls have crowded half-bordered pits to ray cells, but no pits to the usual tracheids. Among all of the extant and extinct angiosperms and gymnosperms, these unusual tracheids occur only in Tetracentron. From these features, we refer the fossil to the extant genus Tetracentron, and name it T. japonoxylum. A revision of homoxylic woods is made for comparision with the present fossil. Tetracentron japonoxylum is the only fossil wood of Tetracentron.     

Javelinoxylon,an Upper Cretaceous dicotyledonous tree from Big Bend National Park,Texas, with presumed malvalean affinities

Well-preserved petrified woods from the Maastrichtian of Big Bend National Park, Texas, with a combination of characters seen in the Malvales are described as Javelinoxylon multiporosum gen. et sp. nov. One log is over 70 cm in diameter and is riddled with termite galleries; this specimen provides additional documentation for the occurrence of dicotyledonous trees in the Late Cretaceous. These woods have structure different from any other known Cretaceous dicotyledonous wood and are advanced in the Baileyan sense as vessel elements are relatively short, perforations are exclusively simple, vessels are commonly in long radial multiples, and rays are storied. This is the earliest record for woods with storied structure. The occurrence of large dicotyledonous trees with advanced wood structure in Big Bend suggests there were differences between the Late Cretaceous vegetation of the northern Rocky Mountains and the Big Bend region.     

Two Fossil Woods from Heilongjiang Sheng of China

Two fossil coniferous woods, Xenoxylon latiporosum (Cramer) Gothan and Protopiceoxylon amurense sp. nov. found in Heilongjiang Sheng of China are described in this paper. The diagnosis of Protopiceoxylon amurense sp. nov. is as follows: Growth rings distinct. The transition from the early wood to the late wood slightly abrupt. Tracheids of the early wood square to rectangular in the transverse section. Bordered pits on the radial walls of early wood traeheids 1-2-seriate, opposite, circular with round apertures. The erassula well marked. Walls of the late wood traeheids much thickened. Rays uniseriate and partly biseriate, 1–45 cells high. The highness of the biseriate part is often more than 2/3 that of the ray. Transverse walls of ray cells rather densely pitted and the tangential walls with marked nodular thickenings. The pitting of the cross-field is small, simple or taxodioid type. The axial wood parenchyma absent. The axial resin canal, both traumatic and normal, present, separate or gathered in tangential rows. Epithelial cells with thickwalls are more than 10 in number. The affinities of the two woods are discussed. The age of the fossil woods is assigned to Late Jurassic to Early Cretaceous. It is inferred that they grew in the then north subtropical warm temperate zone and on a hilly area with an elevation of 1000 metres approximately.     

Wie wachsen Tropenbäume? Jahrringe als Ausdruck von Klimabedingungen und Lebensform

Growth of tropical trees is largely depending on the seasonality of the local climate. In many trees growing in areas with a distinct dry season, cambial activity ceases resulting in the formation of annual rings. In very humid mountain rainforests, trees stop to grow already after short rainless periods. By a combination of increment measurements and wood anatomical analyses, the climatic control of wood formation can be assessed. Intra‐annual wood density variations and content of various stable isotopes enable the climatological interpretation of the “wood signals”.     

云南中新世杉科化石木研究

利用光学显微镜和扫描电镜首次对云南省楚雄州晚中新世石灰坝组石鼓村层的钙化木材进行了解剖学研究.鉴定出两种类型的木材:柳杉型落羽杉型木(Taxodioxylon cryptomeripsoides Schonfeld)和杉木型落羽杉型木(Taxodioxylon cunninghamioides Watari).二者分别与现代柳杉属和杉木属具有最接近的亲缘关系.根据这两种杉科化石木现存最近亲缘种的生态环境,并综合其他资料,推测该地区在晚中新世为温暖湿润的亚热带气候环境.     

New records of Early Cretaceous petrified wood in Yumen,northwestern Gansu Province,China and their palaeoclimatic implications

Several fossil woods from Early Cretaceous sediments in Yumen City in northwestern North China Block, China, have been described. They belong to two fossil wood taxa, Piceoxylon yumeniense Zhou, Peng, Deng, Zhang and Yang n. sp. and Protophyllocladoxylon chijinense Zhou, Peng, Deng, Zhang and Yang n. sp. The well-preserved specimens yield secondary xylem with distinct growth rings. Piceoxylon yumeniense exhibits cross-field with taxodioid pits as well as two distinct xylem ray types. The bi- to triseriate rays are characterised by one or two horizontal resin canals with unequal uniseriate ends. Protophyllocladoxylon chijinense Zhou, Peng, Deng, Zhang and Yang n. sp. shows window-like cross-field pits, which are occasionally cupressoid and have uniseriate xylem rays. These fossil wood records improve our understanding of the fossil diversity, floral composition and palaeoclimate of the Xiagou Formation. Palaeoclimatic analysis of the palaeoxylogical assemblage indicates that the northwestern Gansu region predominantly exhibited a warm and wet climate condition, while a brief cooling event may have occurred in the region during the Early Cretaceous.     

More Malpighiales: Woods of Achariaceae and/or Salicaceae from the Deccan Intertrappean beds,India

The families Achariaceae and Salicaceae (Malpighiales) are characterized by wood anatomical ranges that partly overlap. Formerly these families were treated together in the polyphyletic Flacourtiaceae and a much more narrowly circumscribed Salicaceae. Here we attribute two recently collected fossil woods from the Deccan Intertrappean Beds to the clade that contain these two families, i.e., the Parietal Clade of the Malpighiales. The new genus Elioxylon shares features with several extant genera of Achariaceae and Salicaceae, but does not completely match with any of them. A new record of Hydnocarpoxylon indicum Bande & Khatri is a good match for extant Hydnocarpus Gaertn. (Achariaceae). Elioxylon and Hydnocarpoxylon share an absence of parenchyma, the presence of septate fibres and 1–3 seriate heterocellular rays with long uniseriate margins consistent with Achariaceae and Salicaceae. Elioxylon has mixed simple and scalariform perforations, whereas Hydnocarpxylon has exclusively scalariform perforations. Other Deccan fossils formerly attributed to “Flacourtiaceae” in the literature are critically discussed and mostly excluded from Achariaceae and Salicaceae. Elioxylon and Hydnocarpoxylon from the Maastrichtian ‐ Danian of India are the oldest fossil records of the Parietal Clade of the Malpighiales. With their occurrence on the Indian plate during its northward journey from Gondwana to Laurasia, these fossils provide further support for an ‘out‐of‐India’ hypothesis for Achariaceae and/or Salicaceae. “Baileyan trends” in vessel perforation plate and vessel grouping evolution are apparent in the phylogeny of the Parietal Clade.     

PALEOCENE DICOTYLEDONOUS TREES FROM BIG BEND NATIONAL PARK,TEXAS: VARIABILITY IN WOOD TYPES COMMON IN THE LATE CRETACEOUS AND EARLY TERTIARY,AND ECOLOGICAL INFERENCES

Paraphyllanthoxylon abbottii n. sp. and cf. Plataninium haydenii Felix from the Paleocene Black Peaks Formation, Big Bend National Park, Texas, are the first Paleocene dicotyledonous woods described from North America. Both represent wood types common in the Cretaceous. There are 30 logs of Paraphyllanthoxylon abbottii; it is rare that a single locality has such as large number of petrified dicotyledonous logs with a similar structural pattern, and the variability in mature wood structure can be documented. Paraphyllanthoxylon abbottii has a combination of features that occurs in many dicotyledonous families, but it is most similar to genera of Burseraceae. The Big Bend Paraphyllanthoxylon trees lack distinct growth rings, which suggests they grew in a climate without marked seasonality; they have high (10–74) vulnerability indices; such high values occur in extant tropical trees. The type species of Paraphyllanthoxylon, P. arizonense Bailey was reexamined, and its quantitative features are described. Aplectotremas Serlin of Albian age from the Edwards Limestone has anatomy like Paraphyllanthoxylon, and most probably is wood from a tree. The wood designated cf. Plataninium haydenii Felix resembles extant Platanaceae but differs in having exclusively scalariform perforation plates. Comparison of this wood with other platanoid woods suggests that in platanoid woods there has been a shortening of vessel elements and a decrease in the frequency of scalariform perforation plates from the Cretaceous through the Tertiary. These changes are consistent with the Baileyan model for specialization in tracheary elements.     

Deviations in skeletons of radiolarians

Deviations in the skeleton structure of radiolarians are extremely rare in the fossil record. They are known from the Devonian to Recent. This is a very ancient and periodically repeated phenomenon, which should be regarded as a regularity or “lost chance” rather than exotic or accident. Emergence of deviant “mutants” in radiolarians is probably connected with two main causes, i.e., disturbance during reproduction and mutations in particular modules. From the point of view of the morphogenesis of skeletal structures, deviancy facilitates the recognition of relatively “weak” modules–blocks in the general skeleton pattern, which are subject to structural changes. Nonheritable deviant variants have been revealed in skeletons of 61 radiolarian in all of three subphyla of the phylum Radiolaria: Polycystina, Phaeodaria, and Collodaria. Three deviant types are recognized: multiplicative, posterioric and supplemental.     

Evidence of fungal activity in silicified gymnosperm wood from the Eocene of southern Patagonia (Argentina)

Evidence of fungal activity expressed as typical decay patterns is described from silicified podocarpaceous wood from the Eocene of Patagonia, Argentina. Decay features consist of tracheids of the secondary xylem that are degraded, resulting in thin-celled, lignin-free, translucent, circular to elliptical areas, some of which have cells devoid of all cell wall components including lignin, hemicellulose, and cellulose, and other areas that show only partial simultaneous decay of all cell wall layers. These patterns conform to the white rot and its variant white pocket rot decay patterns produced by basidiomycetes and ascomycetes in gymnosperm and angiosperm wood in modern terrestrial ecosystems. Coagulated opaque bodies in the lumen of some cells and enlarged secondary walls may represent host reactions to infection or remains of metabolic products of fungal enzymatic activity. Similar decay patterns and reaction features have been described from fossil woods ranging in age from the Devonian to the present. This record expands the fossil record of wood rot fungi and underscores their importance as drivers of biological cycles in ancient terrestrial ecosystems.     

华南地区新生代木乃伊化木化石研究进展*

中国木化石资源虽然很丰富, 但研究程度相比叶片化石要低得多, 且主要集中在中国北部和西南地区, 研究领域大多局限于分类学方面, 而木化石分析与古气候、古生态等领域的交叉和系统研究还很少。大多数情况下木化石的保存方式都为石化或矿化保存, 而木乃伊化保存的木化石则非常罕见。木乃伊化保存的化石在植物分类、系统演化及古气候研究等方面具有独特而重要的价值。近年来, 本团队在华南地区发现大量木乃伊化保存的新生代木化石, 它们分别产自广西南宁盆地晚渐新世邕宁组、广西桂平盆地中新世二子塘组以及广东茂名盆地晚更新世地层中。本文总结了这些木乃伊化保存的木化石的研究进展, 包括多样性组成、古植被、古气候及古生态等特征, 并对木兰属、蒲桃属和枫香属的植物地理史进行了讨论。综合分析植物群组成特征和木材生长轮以及木化石中具有气候指示意义的解剖结构特征, 推测广西南宁盆地晚渐新世时期生长着常绿(少数落叶)阔叶林, 为温暖湿润的亚热带季节性气候; 广西桂平盆地中新世时期生长着常绿—落叶、阔叶—针叶混交林 (阔叶为主), 为温暖湿润的亚热带气候; 广东茂名盆地晚更新世生长着常绿—落叶、阔叶—针叶混交林, 为温暖湿润的亚热带至热带季风气候。这是中国低纬度地区首次系统研究木乃伊化保存的木化石, 为新生代植物群的系统演化和古环境分析等提供了重要的木化石依据。