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.     

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.     

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。     

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.     

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.     

Illicioxylon, an Element of Gondwanan Polar Forests? Late Cretaceous and Early Tertiary Woods of Antarctica

The Late Cretaceous and early Tertiary sediments from the northernPeninsula region of Antarctica yield a rich assemblage of fossilwood with well preserved anatomy. Wood specimens of a previouslyrecognized morphotype are described. The woods are characterizedby diffuse porous wood, mainly solitary vessels with long scalariformperforation plates, scalariform and opposite vessel-ray pitting,generally uniseriate and biseriate heterogeneous rays, and tracheidswith obvious uniseriate, circulate, bordered pits. These fossilspecimens show greatest anatomical similarity to the organ genusIllicioxylon Gottwald and extant members of the Illiciaceae.The occurrence of illiciaceous-like wood in Gondwana suggeststhat the distribution of this family may have been more widespreadin the geological past and that a relatively warm temperateclimate prevailed over the northern Peninsula region of Antarcticaduring the Late Cretaceous and early Cenozoic. Copyright 2000Annals of Botany Company Fossil, wood, Illiciaceae, Illicioxylon, Illicium, Cretaceous, Tertiary, Gondwana, Antarctica     

Radiation précoce des coniferes Taxodiaceae et bois affines du Jurassique de France

Three Jurassic fossil-wood taxa from France have been investigated, Taxodioxylon lemoignei n.sp. from the Oxfordian, Prototaxodioxylon romanensis Philippe from the Pliensbachian, and P. sp. from the Hettangian. Wood of this type, prior to the Late Cretaceous, is reviewed. The Oxfordian wood shows a structure characteristic of a Taxodiaceae, previously unknown before the Late Cretaceous. It is well differentiated from contemporaneous woods of Cupressaceae. The systematic position of the Liassic forms, with mixed type of pitting, remains more arguable. These taxodiaceous woods, along with known reproductive structures, reinforce the idea that this family was well separated from Cupressaceae already in the Middle Jurassic. *** Fossil wood, Jurassic, France, Taxodiaceae.     

ANGIOSPERM WOOD FROM THE UPPER CRETACEOUS OF CENTRAL CALIFORNIA: PART II

Three species of fossil wood representing two genera are described. The specimens are from a collection of woods from the Upper Cretaceous Panoche formation of central California. Tetracentronites panochetris sp. nov. resembles angiosperm wood in ray structure and vascular pitting but lacks vessels. Plataninium platanoides sp. nov. is similar to the wood of Platanus, and the evidence presented points to a direct relationship. The resemblance between Plataninium cali-fornicum sp. nov. and the woods of certain Icacinaceae is discussed, but evidence of relationship is inconclusive.     

New species of <Emphasis Type="Italic">Piceoxylon</Emphasis> Gothan (Pinaceae) from the Cretaceous and Paleogene of the northwestern Kamchatka Peninsula

New fossil species of Piceoxylon (Pinaceae), P. talovskiense sp. nov. and P. kamtschatkiense sp. nov., are described on the basis of wood anatomy from the Cretaceous and Paleogene (respectively) of the Talovka River basin in the northwestern Kamchatka Peninsula. The Late Cretaceous P. talovskiense sp. nov. shows wood characters of modern Picea. The wood anatomy of the Paleogene Piceoxylon kamtschatkiense sp. nov. is somewhat similar to those of modern Picea sitchensis and P. jezoensis. Fossil woods of Piceoxylon have been found in the Kamchatka Peninsula for the first time.     

A report on biocompounds from palm fossil of India

The occurrence of a large number of fossil woods having resemblance in anatomical features with the modern palm genus, Phoenix L in Deccan Intertrappean fossil flora of Maastrichtian-Danian age (i. e. Late Cretaceous and Earliest Tertiary (65-67 my)) indicates the most primitive record of date palm. Present discovery of biocompounds from fossil wood of Phoenix collected from Deccan Intertrappean having affinity with the biocompounds known from modern plant further exemplify the earliest documentation of Phoenix in Indian peninsula.     

Fossil Woods From Williams Point Beds, Livingston Island, Antarctica: A Late Cretaceous Southern High Latitude Flora

The wood flora from Williams Point, Livingston Island, contains 12 wood types of gymnosperm and angiosperm origin. Recent collections of material have increased the biodiversity of a postulated species-rich vegetation. The gymnosperm wood can be readily assigned to four form-genera: Araucarioxylon Kraus, Araucariopitys Jeffrey, Podocarpoxylon Gothan and Sahnioxylon Bose and Sah. This indicates a diversity of coniferous araucarian and podocarp trees alongside woods of uncertain affinity ( Sahnioxylon ; Bennettitales). Two angiosperm morphotypes are assigned to the organ genera Hedycaryoxylon Su¨ss (Monimiaceae) and Weinmannioxylon Petriella (Cunoniaceae). The remaining four taxa of angiosperm wood cannot be confidently placed in extant families as they exhibit features that suggest relationships with the Magnoliidae, Hamamelidae and Rosidae. This paper presents the first comprehensive taxonomic revision of the wood flora from Livingston Island and discusses the palaeoecology that prevailed at a latitude of about 60 degrees south during the Late Cretaceous. Newly described taxa are Araucarioxylon chapmanae sp. nov., Araucariopitys antarcticus sp. nov., Podocarpoxylon chapmanae sp. nov., P. verticalis sp. nov., P. communis sp. nov., Weinmannioxylon ackamoides sp. nov., Antarctoxylon livingstonensis gen. et sp. nov., A. multiseriatum gen. et sp. nov., A. heteroporosum gen. et sp. nov. and A. uniperforatum gen et sp. nov.     

FLORA OF THE LOWER CRETACEOUS CEDAR MOUNTAIN FORMATION OF UTAH AND COLORADO. PART III: ICACINOXYLON PITTIENSE N. SP

Icacinoxylon pittiense, a new species of angiospermous wood from the Lower Cretaceous Cedar Mountain Formation of Utah is described and compared with similar fossil and modem woods. It is distinguished from other species of Icacinoxylon by its thick-walled fiber-tracheids with their walls making up at least 50% of the total diameter of the cells, conspicuous bordered pits with obliquely crossing extended apertures on both the tangential and radial walls of its fiber-tracheids, scalariform perforation plates with as few as four or greater than 30 bars, transitional opposite to scalariform pitting on its vessel walls, thick-walled ray cells, and distinct sheath or border cells in its rays. Icacinoxylon pittiense is the first species of this genus to be reported from Cretaceous sediments. This wood is of special interest because very few angiosperm woods have been reported from lower Cretaceous strata.     

Influence of environmental factors on the wood structure of living and fossil trees

The mechanism of wood development records in varying degree the effects of both external and internal factors that are operating at the time of development. As a result, fossil woods spanning the last 370 million years represent a unique palaeo-environmental data-store. Data concerning external factors that can be reclaimed consist of: presence or absence of growth rings; ring widths; relative proportions of earlywood and latewood and the nature of the transition between them; “false” and “frost” rings and evidence of damage by animals or fire; occurrence of reaction wood. These effects have to be seen against a background of the influences of the internal factors. The development of wood involves the action of plant growth regulators. The production of an entire season’s growth of wood depends on a supply of photosynthate, partly stored from the previous year, and the remainder directly from photosynthesis during the current one. In any population of trees of the same species there will be genetic variation which will lead to differences in the wood formed by the individual trees even if they have all grown in a largely similar environment. However the external factors exert a much greater influence than the internal ones. Our earliest fossil woods (Upper Devonian) show either seasonless growth patterns or, if weak rings are perceptible, then the increments are extensive. This is consistent with the palaeo-equatorial position of all recorded Devonian woods. In the Carboniferous a few sites (marginal in the tropical belt?) show subdued (weak) growth rings. By the time of the Gondwana glaciation strong rings are shown in high southern latitudes, but most surprisingly there are sizeable increments well inside the palaeoantarctic circle. This phenomenon persists into the Mesozoic where lack of growth rings shows consistency with positions within the palaeo-equatorial latitudes. However occurrence of Cretaceous high latitude wood growth demonstrates that given an adequate ambient temperature, forest growth was possible close to both poles. It is shown that this is consistent with the total energy flux known to occur now in high latitudes.     

ANGIOSPERM WOOD FROM THE UPPER CRETACEOUS OF CENTRAL CALIFORNIA. III

Five species representing five genera are described. The specimens are part of a collection of woods from the Upper Cretaceous Panoche Formation of central California. Lardizabaloxylon cocculoides sp. n. resembles wood of those species of Cocculus of the Menispermaceae lacking included phloem. Carpinoxylon ostryopsoides sp. n. is similar to the wood of the Coryleae of the Betulaceae, particularly Ostryopsis. Riboidoxylon cretacea gen. et sp. n. is similar to the wood of Ilex of the Aquifoliaceae and also falls within the range of variation of the woods of the two closely related families, the Grossulariaceae and the Escalloniaceae. Mulleroxylon eupomalioides sp. n. falls well within the range of variation of the woods of the Magnoliaceae.     

Comparative wood anatomy ofCoriaria

Wood anatomy ofCoriaria was surveyed to clarify generic features on the basis of 14 species collected from various regions of the World to cover the whole range of geographic distribution and habitual variation. Wood anatomy ofcoriaria is considerably uniform, and the species share a combination of the following features: 1) pores are thin-walled, polygonal in outline and mostly in multiples; 2) vessel elements and libriform fibers are very short; 3) perforation plates are exclusively simple; 4) intervessel pits are alternate; 5) vascular tracheids are present; 6) wood parenchyma is vasicentric and sometimes confluent; 7) rays are heterogeneous and large. Its species differ in several characters, such as distinctness of growth rings, pore size, pore patterns, type and abundance of wood parenchyma, and distinctness of storied structure. Comparisons among species indicate that the species of the Northern Hemisphere show a tendency toward having semi-ring porosity, while those of the Southern and Western Hemisphere have diffuse porosity. The other infrageneric variations appear to be related to different habits of the species rather than to geographic distribution. Small trees mostly have confluent and vasicentric parenchyma composed of fusiform cells and distinctly storied tissues, while shrubs and herbs have less abundant parenchyma which is vasicentric and comprises strands of two to four cells and indistinctly storied tissues.     

Upper Cretaceous woods from the Olmos Formation (late Campanian-early Maastrichtian), Coahuila, Mexico

? Premise of the study: The Olmos Formation was part of a system of deltas that existed in the southern portion of the Western Interior of North America during the Campanian-Maastrichtian. The paleofloristic composition from the northern portions of the Epicontinental Sea is relatively well known, but less intensive exploration in the south has precluded more detailed floristic comparison across the entire latitudinal span of the Sea. The Olmos Formation flora, with more than 100 different leaf morphotypes so far recognized and several wood types, has the most diverse Cretaceous fossil plant assemblage in Mexico and represents a valuable opportunity for comparative studies. ? Methods: The fossil woods here described were collected in the Coahuila State, Mexico. The samples were studied using standard thin section technique and identified by comparison with fossil and extant material. ? Key results: We described four new genera (Olmosoxylon, cf. Lauraceae; Coahuiloxylon, ?Anacardiaceae, ?Burseraceae; Muzquizoxylon, Cornaceae; and Wheeleroxylon, Malvaceae s.l.) and three xylotypes of angiosperms. ? Conclusions: Some of the genera present in the Olmos Formation such as Javelinoxylon and Metcalfeoxylon have been described from geologic units in the USA (San Juan Basin, New Mexico and Big Bend National Park, Texas), suggesting similarity in the taxonomic composition of the floras that inhabited southern portions of the western margin of the Campanian-Maastrichtian Epicontinental Sea. Other species, however, have only been reported for the Olmos Formation, indicating some degree of local floristic differentiation among the assemblages that inhabited the southern portion of the Western Interior.     

ANGIOSPERM WOOD FROM THE UPPER CRETACEOUS OF CENTRAL CALIFORNIA: PART I

This paper is the first in a series about a collection of 40 Upper Cretaceous woods from central California. The wood is in the form of fragments of stems and roots embedded in nodules of collophane rich in microorganisms, pollen, and spores. Two new species are described: Ulminium pattersonensis and Ulminium mulleri. Evidence presented indicates that these two specimens are similar to woods of the Lauraceae and fall well within the range of variation of woods of that family. Because the taxonomy of the Lauraceae is in need of revision, meaningful comparisons of fossil plant parts with modern taxa were found to be unfeasible.     

广西弄岗五桠果叶木姜子群落木质藤本空间格局及其与树种间的关系

木质藤本是生物多样性的重要组成,木质藤本通过影响支持木进而影响群落的结构和功能,但在生物多样性丰富的北热带喀斯特森林中,木质藤本与支持木的关系鲜为人知。以喀斯特季节性雨林的五桠果叶木姜子（Litsea dilleniifolia）群落为研究对象,对木质藤本的密度、分布格局及其与主要树种的关系进行调查研究,分析木质藤本对树木的影响。结果显示：（1）五桠果叶木姜子群落内木质藤本平均密度为0.0913株/m²,木质藤本在0-20m空间尺度整体表现为聚集分布,且随着尺度增大,聚集强度逐渐减弱;不同径级木质藤本在不同尺度上的分布格局不同。（2）木质藤本对不同径级、不同种类、不同聚集强度的支持木选择表现以下体征：随着支持木径级增加,木质藤本攀附的比例和每木藤本数有增加趋势,且木质藤本胸径与支持木胸径呈极显著正相关;附藤率较高的支持木有紫葳科（Bignoniaceae）种类和东京桐（Deutzianthus tonkinensis）,单木附藤数量多的是南方紫金牛（Ardisia thyrsiflora）;物种的聚集强度与附藤率、附藤数量呈负相关。（3）木质藤本的密度与支持木死亡率关系不显著,而物种的附藤率与死亡率呈极显著负相关。以上结果表明,木质藤本密度在原生性喀斯特季节性雨林中并不高,且木质藤本对支持木具有选择性,但其对五桠果叶木姜子群落的死亡率并未产生显著影响。该研究可为喀斯特原生性季节性雨林的物种共存、极小植物种群保育提供理论依据,也可为石漠化区域的植被修复提供科学参考。     

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.     

中国浙江新昌化石木研究

本文介绍了发现于中国东南沿海地区浙江省新昌县中生代地层中的一种化石木新种———新昌南洋杉型木 (AraucarioxylonxinchangenseDuansp .nov .)。这种化石木保存在早白垩世馆头组中、下部的紫红色泥砂岩中 ,分布在新昌县城西部 ,南北绵延 2 5公里、东西宽约 2公里的狭长地区。由于在化石木产区曾发现过多种植物化石 ,因而确定了该区在早白垩世时期处于我国的欧洲 中国植物区内 ,属亚热带 热带气候区 ,种种迹象表明此时气候有些干旱。同区发现的松柏目叶化石 ,其气孔构造与南洋杉科有一定的亲缘关系 ,这一点似乎与化石木之属可以对应。