Two fossil wood species Celastrinoxylon celastroides and Ficoxylon cretaceum are reported and described for the first time from the Farafra Oasis in Egypt. They are compared to earlier descriptions of these species from Egypt and other parts of Africa.
of a tissue in extant plants can be measured i n vivo ( e.g. Ellmore & Ewers 1985 ; Sperry et al. 1988 ; Zwieniecki & Holbrook 1998 ; Hajek et al. 2016 ), this kind of experimental studies is obviously impossible for fossilwoods. In previous analyses devoted to fossils, derivations of the
& Escapa 2015 , 2016 ). The Cretaceous-Cenozoic of the Northern Hemisphere with its well-documented climate changes ( e.g. , Upchurch & Wolfe 1987 ; Graham 1999 ; Bowen 2007 ; Linnert et al. 2014 ; Anagnostou et al. 2016 ) and its relatively abundant fossilwood record provides opportunities for
We describe a new species, Gleditsioxylon jiangsuensis (Leguminosae), a new record of Robinia zirkelii (Platen) Matten, Gastaldo & Lee (Leguminosae), and a new record of Moroxylon xinhuaensis Yin, Liu & Cheng (Moraceae) from the early Miocene strata of Sihong County in Jiangsu Province, eastern China. Gleditsioxylon jiangsuensis sp. nov. is the first report of Gleditsioxylon fossil wood from China. These fossil woods, combined with paleontological records, may indicate that the boundary between the subtropical and the temperate zones in eastern China during the early Miocene was located north of its modern location.
In 1907 Halle (1911) collected a diverse wood assemblage from the organic clays and lignites of the Forest Bed on West Point Island. This wood assemblage provides a reliable basis for determining the local arboreal component of the vegetation comprising the Forest Bed community. Five wood types have been recognised from Halle's collection as belonging to the Cupressaceae and Podocarpaceae. A reinvestigation of the only dicotyledonous angiosperm wood collected from this bed found that it resembled most closely Weinmannia L. of the Cunoniaceae. Together these remains represent an increased diversity of wood types derived from the arboreal component of thc vegetation, relative to previous studies. Gymnosperms are likely to have comprised the overstorey with angiosperms forming a closed canopy, interpreted as a broadleaf-gymnosperm temperate-type rainforest. The results agree with arecent palynological study of the same deposits, which concluded that the vegetative composition of the Forest Bed is a unique variant of the continuum of the Nothofagus Blume-Podocarpaceae rainforests that existed on middlehigh latitude landmasses across the Southern Hemisphere during the Late Tertiary.
Angiosperm woods occur throughout Upper Cretaceous (84–66 million years old) continental strata of Big Bend National Park, Texas, USA. Vertebrate remains occur along the same stratigraphic levels, providing a rare opportunity to reconstruct associations of sedimentary facies, wood remains, and vertebrate remains. The wood collection sites span a vertical stratigraphic succession that corresponds to an environmental transect from poorly-drained coastal salt- or brackish water swamps to progressively better drained freshwater flood-plains lying at increasingly greater distance from the shoreline of the inland Cretaceous sea and at higher elevations. The eight dicot wood types of the Aguja Formation differ from the five types of the Javelina Formation, paralleling a change from a fauna dominated by duckbill and horned dinosaurs to a fauna dominated by the large sauropod, Alamosaurus. These woods increase the known diversity of Cretaceous woods, and include the earliest example of wood with characteristics of the Malvales. The lower part of the upper shale member of the Aguja contains numerous narrow axes, some seemingly in growth position, of the platanoid/ icacinoid type, and of another wood that has a suite of features considered primitive in the Baileyan sense. Duckbill dinosaur remains are common in the facies with these woods. In contrast to other Cretaceous localities with dicot wood, Paraphyllanthoxylon is not common. Dicotyledonous trees are most abundant at the top of the Aguja and the lower part of the Javelina Formations in sediments indicating well-drained inland fluvial flood-plain environments. One locality has logs and insitu stumps, with an average spacing of 12–13 metres between each tree, and trees nearly 1 metre in diameter. To our knowledge this is the first report of anatomically preserved in situ Cretaceous dicot trees. Javelinoxylon wood occurs at all levels where remains of the giant sauropod Alamosaurus occur. The vertebrate faunas of the late Cretaceous of New Mexico and Texas are said to comprise a ʻsouthernʼ fauna distinct from the ʻnorthern faunaʼ of Alberta and Montana. The wood remains are consistent with such provincialism. It has been suggested that dicots were not commonly trees in the late Cretaceous of the northern part of the western interior of North America. The Big Bend woods provide direct evidence for dicot trees having more than a subordinate role in Cretaceous vegetation at lower latitudes. Most of the dicot wood types of Big Bend are characterized by high proportions of parenchyma, over 50% in one type. Whether these high proportions of parenchyma are correlated with the higher CO2 levels of the Cretaceous and /or the pressures exerted by aggressive browsing by large dinosaur herbivores is unknown.
Three new wood types from the Late Cretaceous and one from the Paleocene of Big Bend National Park, Texas, U.S.A. add to our knowledge of North American Late Cretaceous and Paleocene plants. Sabinoxylon wicki sp. nov. provides further evidence of similarities in late Campanian-early Maastrichtian vegetation of Texas, New Mexico, and northern Mexico. This species is characterized by mostly solitary vessels, scalariform perforation plates, vessel-ray parenchyma pits similar to intervessel pits, vasicentric tracheids, and two size classes of rays. Storage tissue accounts for close to 50% of its wood volume. Another of the new Cretaceous wood types, referred to as Big Bend Ericalean Wood Type I, has more than 40% ray parenchyma. Both Big Bend Ericalean Wood Type I and Sabinoxylon have a combination of characters that occurs in the order Ericales (sensu APGII). The third new Cretaceous wood type is from a small axis (less than 3 cm diameter), and has a combination of features that is the most common pattern in extant eudicots (vessels solitary and in radial multiples randomly arranged, simple perforation plates and alternate intervessel pits, and heterocellular rays). The Paleocene wood (cf. Cunonioxylon sensu Gottwald) differs from all other North American Paleocene woods and has characteristics found in the predominantly Southern Hemisphere family Cunoniaceae. The characteristics of these new Big Bend woods contribute to a database for fossil angiosperm woods, and allow for comparison of incidences of selected wood anatomical features in Northern Hemisphere Cretaceous woods from Albian to Maastrichtian time as well as comparison with extant woods. Cretaceous woods as a whole differ from Recent woods in having higher incidences of exclusively solitary vessels, scalariform perforation plates, and wide rays (>10-seriate), and lower incidences of ring porosity, wide vessels (>200 μm), vessels in groups, non-random arrangements of vessels, and marginal parenchyma. The occurrence of relatively high percentages of storage cells (>40%) in some Cretaceous trees is noteworthy; the ability to produce wood with varying amounts and arrangements of parenchyma is likely to be a contributing factor to the success of angiosperm trees in a wide variety of environments.
A new species of Moroxylon, M. xinhuaensis Yin, Liu & Cheng, with wood anatomical features found in modern Morus (Moraceae), is described from the Neogene of Xinhua, Yuanmou Basin, Yunnan Province, southwest China. This wood represents the first fossil wood of Morus reported from Asia. It provides additional data for evaluating relationships between the Neogene floras of Europe and eastern Asia.
Early Miocene fossil woods of Gebel Ruzza, Egypt, were examined and two new records (Cynometroxylon schlagintweitii and Afzelioxylon welkitii) for Egypt are reported. A hot wet palaeoclimate is suggested for the Early Miocene collection site. The literature on fossil dicot woods from Egypt is summarised.
Fossil wood was collected from an in situ upright tree encased in the late Oligocene mudstone sediments exposed in the Tirap Mine, Makum Coalfield, Tinsukia district, Assam. The wood belongs to Careya of the Lecythidaceae. This genus is reported for the first time from Paleogene sediments. Its presence supports the occurrence of tropical evergreen to deciduous forests in the region during the depositional period.