Wood Flora Research Articles

A diverse assemblage of Late Eocene woods from Oregon, western USA

Well-preserved silicified woods from a site near the town of Post, Oregon, western USA, provide insights into the late Eocene vegetation and climate ca. 36 million years and data for comparing with both older and younger wood floras regionally and globally. The composition of this wood flora, taken into consideration along with taxa identified from silicified fruits and seeds of the same locality, provides a more complete picture of the former vegetation. We recognize woods belonging to the families Anacardiaceae (Pistacia terrazasae sp. nov.), Cannabaceae (Celtis popsii sp. nov.), Cercidiphyllaceae (Cercidiphyllum cf. alalongum R.A.Scott et E.A.Wheeler), Fagaceae (Fagus dodgeii sp. nov., Lithocarpoxylon ashwillii sp. nov., Lithocarpoxylon sp., Quercus sp.), Hamamelidaceae (Hamamelidoxylon crystalliferum sp. nov., H. cf. suzukii E.A.Wheeler et T.A.Dillhoff), Juglandaceae (Pterocaryoxylon sp.), Malvaceae (Wataria kvacekii n. sp.), Platanaceae (Platanoxylon cf. haydenii (Felix) Süss et Müll.-Stoll, Platanus sp.), Sapindaceae (Acer, 2 spp.), Trochodendraceae (Trochodendron beckii (Hergert et H.K.Phinney) R.A.Scott et E.A.Wheeler). This assemblage, which we refer to as the Post Hammer flora (UF 279), is comparable in age to the nearby Teater Road flora known mainly from fossil leaf impressions. Comparing the functional traits of the Hammer woods to the older Clarno Nut Beds woods attests to changing climate in the region, including an increase in seasonality.

Palaeobiogeographical implications of the first fossil wood flora from the Jurassic of Turkey

Palaeobiogeographical implications of the first fossil wood flora from the Jurassic of Turkey

A Chattian-Aquitanian wood flora from the West Siberian Plain: Implications for regional palaeobiogeography

A Chattian-Aquitanian wood flora from the West Siberian Plain: Implications for regional palaeobiogeography

Early Miocene paleoclimate in southern Patagonia inferred from fossil woods

Patagonia has a rich record of fossil woods that are a unique data store of paleoclimatic information. We studied the wood flora recovered from the Río Leona Formation (early Miocene) of southern Patagonia near El Calafate and Río Turbio localities, Santa Cruz Province, Argentina. The fossil wood assemblage was analyzed using various methodologies (anatomy analysis, Vulnerability and Mesomorphic indices, and the Coexistence Approach) to determine paleoclimate variables including mean annual temperature (MAT) and mean annual precipitation (MAP). The anatomy analysis developed by Wiemann et al. (1998, 1999) is based mostly on woods from the Northern Hemisphere. We applied those equations to extant woods from the southernmost region of South America to test their functionality and to compare them with the results obtained from the fossils. These equations gave limited results. Climate signals from fossil woods suggest a microthermal climate for the region with MAT of 8–12 °C and MAP of 80–170 cm/year. In addition, part of the results points towards an environment with water in abundance (i.e., Coexistence Approach and some wood characters influenced by the environment) and other results suggest wood tolerance to hydric stress (i.e., Vulnerability Index, Mesomorphy Index, and wood characters influenced by the environment). These suggest an environment with rainy and dry seasons, which is also supported by the presence of well-marked growth ring boundaries and false rings. These conditions can be found today in central Chile, a region that shares some vegetation elements with the Río Leona Formation and has a Mediterranean climate.

Palaeoclimate estimates based on the late Miocene to early Pleistocene wood flora of the Bengal Basin: an insight into the climatic evolution of southern Asia

To assess the pattern of climatic evolution during the late Miocene to early Pleistocene in the largest fluvio-deltaic sedimentary system on the Earth, the Bengal Basin (BB), a quantitative palaeoclimatic reconstruction was made, based on 20 fossil wood floras. Those floras show that moisture-loving taxa have decreased considerably since the Miocene, especially at the western margin of the basin. A quantitative reconstruction of climate parameters reveals that the late Miocene−early Pliocene was warmer and wetter than now, yet with spatial variability. Seasonality of temperature was low in the basin and subsequently increased during the late Pliocene−early Pleistocene. Monsoon intensity was weaker during the interval from the late Miocene to early Pleistocene than the present day. A comparison of the retrieved data with some earlier records from sites either influenced by Indian summer monsoon (ISM) or East Asian summer monsoon (EASM) or both, the two branches of the Asian summer monsoon (AM) provide insights into the temporal and spatial patterns of climate evolution in southern Asia during the late Neogene–Quaternary transition. In general, a drop in temperature and a weakening in ISM strength since the early Pleistocene correlate with the global cooling trend, though with spatial differences.

Fossil Woods from the Middle Miocene (Río Correntoso Formation) of Patagonia (Northern Santa Cruz Province, Argentina)

We collected nine samples from the middle Miocene of Patagonia, in outcrops of the Rio Correntoso Formation (Rio Zeballos Group) in north Santa Cruz Province, Argentina. Fossil woods have variable preservation and some are poorly preserved. Six samples are silicified, and three are totally carbonized. Two taxonomic units were confidently described, Cupressinoxylon sp., a conifer with Cupressaceae or Podocarpaceae affinity and Nothofagoxylon scalariforme with Nothofagus subgenus Nothofagus affinity of the Nothofagaceae. Other samples are indeterminate angiosperms and conifers. Growth rings of two samples indicate seasonality and galleries with frass and coprolites found in an indeterminate conifer are similar to those made by coleoptera and acari. The assemblage taxonomic composition is similar to other Miocene wood floras of Patagonia with conifers and Nothofagaceae.

Fossil woods from the Lower Cretaceous Tres Lagunas Formation of central Patagonia (Chubut Province, Argentina)

Silicified fossil woods are common in the Tres Lagunas Formation (Lower Cretaceous) of central Patagonia. This region has a poor record of Early Cretaceous fossil woods. A collection of 23 fossil woods is studied. Fossil wood anatomy is described and compared in detail. The wood flora is composed of conifers. Most of the samples have Araucariaceae-like wood anatomy. The samples are placed into seven taxonomic units: three fossil-species of Agathoxylon, two more taxonomic units related to Agathoxylon, one taxonomic unit consistent with Cupressinoxylon? and one fossil-species of Brachyoxylon. This study indicates a dominance of conifers, particularly Araucariaceae, during the Early Cretaceous of this zone of central Patagonia which partially does not coincide with the taxonomic proportions of previous studies of coeval pollen and plant macrofossils.

Fossil woods from the Eocene–Oligocene (Río Turbio Formation) of southwestern Patagonia (Santa Cruz province, Argentina)

ABSTRACTOver 80 samples of fossil woods were collected from numerous outcrops of the Río Turbio Formation, southwestern Patagonia. Preservation of the woods is variable and only about half of these samples could be identified to genus level. The assemblage consists of six types of conifers and four types of dicotyledons, one of them a new species of Caldcluvioxylon (Cunoniaceae). We provide an emended diagnosis of Caldcluvioxylon. A previously described fossil wood from this stratigraphic unit, thought to have affinity with Proteaceae, was re-examined and is described herein as Scalarixylon romeroi sp.nov. Other families recognized in the Río Turbio Formation wood assemblage are Araucariaceae, Podocarpaceae, and Nothofagaceae. Differences in the taxonomic composition of the upper and lower members of the Río Turbio Formation are consistent with the age difference between them according to recent isotopic dating. The diversity of fossil wood is also consistent with the fossil leaves and pollen from each stratigraphic level and most of the taxa are shared with coeval Antarctic fossil wood floras.

Geology and woods of a new fossil forest from the Early Miocene of Gokceada (Turkey)

DOI : 10.26650/forestist.2019.412545 In Gokceada, metamorphic, sedimentary and volcanic rocks from the period covering the Paleozoic to the Upper Miocene periods have formed outcrops over time. A newly identified fossil forest site in Gokceada covers an area of approximately 1.5 square kilometers of land situated near the coastline. Silicified trees in the area from the early Miocene period were observed to present three phases of pyroclastic deposition, namely: the complete silicification phase, the half silicification phase and the coal phase. The purpose of this study is to present the paleobiology and paleoecology of the wood flora and the geological formation of the fossil forest site, and to evaluate this information in terms of paleoclimatology. Sixteen (16) petrified pieces of wood thought to have originated from the upper slopes and found on the sea shore were collected, with three planes of thin sections taken from each one. A total of 12 types of woods were identified, as follows: three conifers (Cupressinoxylon, Sequoioxylon and Pinoxylon) and nine angiosperms (Alnoxylon, Carpinoxylon, Ostryoxylon, Palmoxylon type 1 and 2, Fagoxylon, Quercoxylon sect. Ilex, Laurinoxylon and Platanoxylon). The wood composition in Gokceada is similar to that of the wood flora of the Miocene in Lesvos, showing the presence of riparian, well-drained lowland and coastal trees.

The Neogene wood flora of Yuanmou, Yunnan, southwest China

ABSTRACT The Pliocene fluvio-lacustrine sediments of the Yuanmou Basin, Yunnan, near the southeastern part of Qinghai-Tibet Plateau, China, have yielded diverse and abundant assemblages of fossilized mammals and woods. The Yuanmou fossil woods reveal a wood flora with the highest diversity in the Cenozoic wood in China. The woods can play an important role in understanding palaeofloristics and in reconstructing palaeoclimate of southeastern China. In this study, we describe ten angiosperm taxa and three gymnosperm taxa namely: Castanopsis makinoi (Ogura) Suzuki & Terada (Fagaceae), Cedreloxylon cristalliferum Selmeier (Meliaceae), Dalbergioxylon biseriatensis sp. nov. (Fabaceae), Lagerstroemioxylon yuanmouensis Cheng, Li, Jiang & Wang (Lythraceae), Lithocarpoxylon microporosum sp. nov., Lithocarpoxylon sp. (Fagaceae), Paraalbizioxylon sinica sp. nov., P. yunnanensis sp. nov. (Fabaceae), Pterocaryoxylon huxii sp. nov. (Juglandaceae), Zelkova wakimizui (Watari) Watari (Ulmaceae), Abies sp. (Pinaceae), Cephalotaxus sp. (Cephalotaxaceae), and Picea sp. (Pinaceae). Nearest living relative (NLR) comparisons of these taxa, coupled with previously identified taxa, suggest that altitudinal vegetation zones were present in the Yuanmou region during the Pliocene: (i) subtropical evergreen and deciduous mixed broad-leaved forest dominated by Pterocarya/Juglans, Albizia/Acacia, Bischofia and allied taxa at lower elevations, (ii) subtropical evergreen broad-leaved forest dominated by Quercus/Lithocarpus and Castanopsis at middle altitudes of mountains around the basin, and (iii) evergreen coniferous forest of Abies, Picea and other genera at the higher elevations of the mountains. Based on the habits of the NLRs, the prevailing climate was probably humid subtropical and thus differed from the present-day hot and dry climate supporting savanna. It is suggested that subtropical forest was predominant in Yunnan, while tropical rainforest occurred in southwest Asia and India during the same period. The uplift of the mountains near the Qinghai-Tibet plateau in western Yunnan presumably acted as a barrier to block warm and humid air from the Indian Ocean, which influenced the dispersal and distribution of plants.

Fossil wood flora from the Siwalik Group of Arunachal Pradesh, India and its climatic and phytogeographic significance

The plant fossil records from the Siwalik Group of Arunachal Pradesh, India are far from satisfactory due to remoteness and dense vegetation of the area. We report seven fossil woods of which three belong to the Middle Siwalik (Subansiri Formation), while the rest are from the Upper Siwalik (Kimin Formation). The modern analogues of the fossils from the Middle Siwalik are Lophopetalum littorale (Celastraceae), Afzelia-Intsia and Sindora siamensis (Fabaceae) and from the Upper Siwalik are Miliusa velutina (Annonaceae), Calophyllum tomentosum and Kayea (Calophyllaceae) and Diospyros melanoxylon (Ebenaceae). The dominance of diffuse porosity in the fossil woods indicates a tropical climate with low seasonality (little variation) in temperature, while a high proportion of large vessels and simple perforation plates in the assemblage infer high precipitation during the deposition of the sediments. The aforesaid inference is in strong agreement with the previous quantitative reconstruction based on fossil leaves. Several modern analogues of the fossil taxa are now growing in low latitudes possibly due to an increase in seasonality (increased variation) in temperature caused by the rising Himalaya.

First record of fossil Trachycarpeae in Africa: three new species of Palmoxylon from the Oligocene (Rupelian) Gebel Qatrani Formation, Fayum, Egypt

Based on a survey of the fossil wood flora of Gebel Qatrani (Rupelian, Fayum, Egypt), three new species of palm stem are described: Palmoxylon araneus Nour-El-Deen, El-Saadawi & Thomas sp. nov., Palmoxylon elsaadawii Nour-El-Deen & Thomas sp. nov. and Palmoxylon qatraniense Nour-El-Deen, El-Saadawi & Thomas sp. nov. The specimens are the first petrified palm wood to be reported from the deposits in the upper sequence of the Gebel Qatrani Formation. They are characterized by fibrovascular bundles with two vessels, the presence of a ground parenchyma sustained growth, fibrous bundles, globular echinate phytoliths, radiating parenchyma, and multiseriate scalariform thickening of metaxylem elements. Palaeoclimatic inferences and comparisons with similar fossil stems are discussed for each of the three taxa. Comparisons with extant palms allow identification of these species to tribal (Trachycarpeae) and subfamilial (Coryphoideae) levels. They are the first representatives of tribe Trachycarpeae on the African continent. An attempt is also made to explain migration events and discuss the current and fossil distribution of the tribe in Africa.

Conifer fossil woods from the Santa Marta Formation (Upper Cretaceous), Brandy Bay, James Ross Island, Antarctica

Conifer fossil woods from the Santonian to lower Campanian Santa Marta Formation are anatomically studied in detail. The wood flora is dominated by conifers, mainly Araucariaceae. Conifer fossil woods represent 84% of the samples (26 of 31) of the assemblage. The remaining samples are dicotyledon woods which are not included in this study. Woods are mostly calcified and preservation is often excellent. Fossil woods include three species of Agathoxylon, Phyllocladoxylon antarcticum, Cupressinoxylon hallei and a new species of Cupressinoxylon, C. rotundum Pujana sp. nov. The conifer-dominated forests are consistent with the pollen and macrofloras previously described from sediments of the same stratigraphic unit. This fossil wood assemblage contributes to understand the floristic changes that took place in the Cretaceous forests.

The Cairo Petrified Forest revisited

The study of the wood flora of the Oligocene Cairo Petrified Forest (CPF) protected area is resumed here after five years. The study added seven Fabaceae species Afzelioxylon welkitii, Copaiferoxylon matanzensis* -Caesalpinoideae, Andiroxylon aegyptiacum* sp. nov.-Faboideae, Dichrostachyoxylon palaeonyassanum*, D. royaderum*, D. zirkelii* and Mimosoxylon tenax -Mimosoideae as new records to the area and five (asterisked) as new records to Egypt; one of which is new to science. Descriptions and illustrations are given for these five asterisked species. Descriptions of the other reported species were given in earlier publications mentioned in the text. Affinities and comparisons are given for the studied species. Climatic interpretations based on the anatomical features of all the CPF fossil taxa are presented. Moreover, the relationships and comparisons with the nearest living relatives are discussed.

On the Fossil Wood Flora of Wadi Ankebieh, Egypt, with Two New Records

On the Fossil Wood Flora of Wadi Ankebieh, Egypt, with Two New Records

Late Miocene wood flora associated with the Yuanmou hominoid fauna from Yunnan, southwestern China and its palaeoenvironmental implication

The Upper Miocene Xiaohe Formation of the Yuanmou Basin in Yunnan Province, southwestern China, is famous for its hominoid fauna and is important for studying the Late Cenozoic human and mammal evolution. Abundant fossil wood was found associated with this fauna, which provided important evidence for palaeoenvironmental reconstruction of the basin. Among the fossil wood, two different taxa have been identified namely, Quercoxylon sp. (Fagaceae) and Pterocarya sp. (Juglandaceae). Based on the habitats of their Nearest Living Relatives (NRLs), it is suggested that upland subtropical evergreen broad-leaved forest dominated by Quercus/Lithocarpus was common around the basin, while a lowland deciduous broad-leaved forest dominated by Pterocarya was present on the river bank of the basin during the Late Miocene.

A new Late Cretaceous (late Campanian to early Maastrichtian) wood flora from southern Patagonia

The Cerro Fortaleza Formation, in southernmost Patagonia (Argentina), contains a unique Late Cretaceous (Campanian) flora and fauna. This formation is characterized by lithified fluvial sands, overbank mud deposits, and paleosols deposited in fluvial, fluvial–palustrine, and coastal plain environments from the northeastern margin of the Austral (Magellanes) Basin. The overlying and underlying formations have been dated as Campanian and Maastrichtian, respectively. Therefore, the Cerro Fortaleza Formation putatively falls within the late Campanian–Maastrichtian. This formation is known for its diverse fauna including dinosaurs, fishes, and turtles. Furthermore, poorly preserved leaf impressions from indeterminate conifers and cycads have also been discovered but not yet described.Fossil wood taxa from the Cerro Fortaleza Formation yields a diverse flora of gymnosperm wood but only two genera of angiosperm wood. Gymnosperm genera identified in this study include Agathoxylon, Planoxylon, Taxodioxylon, Cupressinoxylon, and Podocarpoxylon; and angiosperm genera identified include Hedycaryoxylon and Nothofagoxylon. This is the first record of Planoxylon, Taxodioxylon, Cupressinoxylon, and Hedycaryoxylon from Argentina. Additionally, this is the oldest occurrence of Nothofagoxylon in Argentina. Both the angiosperm and gymnosperm wood samples possess distinct growth rings, providing strong evidence for seasonal growth regimes in the region. All of the wood genera from the Cerro Fortaleza Formation, except Planoxylon, have also been described from Late Cretaceous sediments of the Antarctic Peninsula. Thus, the presence of these taxa in both regions supports Late Cretaceous plant dispersal between them. Despite sharing the same taxa, the floras from the Cerro Fortaleza Formation and the Antarctic Peninsula exhibit strikingly different relative abundances. The ratio of gymnosperm to angiosperm wood in the Cerro Fortaleza Formation is 75:25; whereas coeval floras from the Antarctic Peninsula are ~25:75. The floral differences between these locations may be a relict from a widespread older flora that included Antarctica, regional floristic variations or a result of different depositional and/or taphonomic controls in discrete paleoenvironments.

A new species of Protophyllocladoxylon from the Upper Cretaceous (Cenomanian–Turonian) portion of the Winton Formation, central-western Queensland, Australia

Leaf floras in fluvial–lacustrine sediments of the Upper Cretaceous (Cenomanian–Turonian) portion of the Winton Formation suggest a community with co-dominance of angiosperms, conifers, ginkgo and other seed plants. To date wood floras associated with the Winton Formation have not been examined in detail. Winton Formation wood has been presumed to comprise araucarian, podocarp and taxodiaceous components, but this has been based largely on the identification of other plant macro and microfossils. Here we describe a new species of podocarp fossil wood from the genus Protophyllocladoxylon based on eleven specimens of silicified wood found as surface material at two broadly coeval sites in the Cenomanian–Turonian portion of the Winton Formation: QM L311 and Bladensburg National Park. The new species is characterised by the presence of araucaroid tracheid pitting and phyllocladoid oopores, the absence of oculipores, and the paired arrangement of the oopores within the crossfields. The recognition of Protophyllocladoxylon in the Winton Formation supports previous palynological frequency counts that suggest a dominance of podocarp conifers.

Fossil woods from the Lower Cretaceous (Albian) of Kamchatka Peninsula, Russian Far East

Three coniferous fossil wood taxa are described from the Kedrovka Formation (Albian) of Kamchatka Peninsula, Russian Far East: Protocedroxylon gregussii (Shilkina) Shilkina & Chudajberdyev, Taxaceoxylon sp. and Xenoxylon phyllocladoides Gothan. This wood flora is quite peculiar when compared to coeval wood floras from the same area. It yields the first safe report of Taxaceoxylon fossil wood from the Lower Cretaceous of Asia. The record of Xenoxylon phyllocladoides represents the latest stratigraphic occurrence of this species and the first from Russia. Taxaceae-like fossil wood record is reappraised and shown to be consistent with recent cladistic results, suggesting a boreal origin and a link to the Pinaceae. The palaeoecology of the Kedrovka Formation wood flora is investigated. The peculiarities of the flora might be explained by an oceanic palaeoclimate.

475 Fossil wood flora of western India and its palaeoecological and phytogeographical significance

475 Fossil wood flora of western India and its palaeoecological and phytogeographical significance