The fossil woods and leaves of the Fossil Forest Piedra Chamana represent a diverse assemblage of plants dating to 39 Ma (late Middle Eocene). The fossils are preserved in an ashfall and overlying lahar deposits near the small village of Sexi in the northern Peruvian Andes (central Cajamarca). The assemblage includes dicot wood types and leaf morphotypes, as well as a diversity of monocot material. The ~30 dicot wood types are referred to the families Acanthaceae, Anacardiaceae, Apocynaceae, Combretaceae, Cordiaceae, Dipterocarpaceae, Euphorbiaceae, Fabaceae, Lechythidaceae, Lythraceae, Malvaceae, Melastomataceae, Muntingiaceae, Rubiaceae, Rutaceae, and Sapindaceae. Described herein are descriptions of the first 17 wood types that have been assigned to the families Acanthaceae through Lythraceae; descriptions of the additional wood types will appear in a later paper. The paleovegetation can be characterized as lowland tropical forest with a dry aspect based on preliminary analysis of floristic affinities and wood anatomical characteristics of the fossils.
Eighty-two silicified fossil woods were collected from Miocene formations on the western coast of the Yamagata Prefecture, Japan. Twenty-two taxa (5 conifers and 17 dicotyledons) were identified. Five new species (Chamaecyparis parathyoides, Pterocarya parvipora, Populus soyaensis, Schima protowallichii, Lagerstroemia odaniense) and two species not previously known from the Miocene of Yamagata are described. This brings the number of fossil wood taxa from the Miocene of Yamagata to 39. Warm temperate elements such as Keteleeria, Liquidambar, Distylium and Lagerstroemia were found in the formations studied. The fossil wood assemblages from four Miocene formations (except Onisakatoge Formation from which only one sample was collected) suggest that the woody flora changed gradually during the Miocene from a mixture of cool and warm temperate elements to a warm temperate assemblage. These changes agree well with the vegetation changes during the Miocene in Japan; from the Aniai type to the Daijima-type.
Ninety–four fossil woods were collected from the Upper Triassic Jogyeri Formation of the Nampo Group in the County of Cheongyang-gun, Chungcheongnam- do Province, Korea. Eight of the specimens were preserved well enough to identify them down to species or genus. All were coniferous woods. On the basis of their detailed anatomical features, four specimens were identified as Xenoxylon phyllocladoides Gothan and the other four as Agathoxylon sp. Therefore six taxa of fossil woods, Cedroxylon regulare Göppert, Xenoxylon phyllocladoides Gothan, X. latiporosum (Cramer) Gothan, X. japonicum Vogellehner, Phyllocladoxylon heizyoense Shimakura and Agathoxylon sp., have now been reported from the Early Mesozoic Daedong Supergroup in the Korean Peninsula.
Sassafrasoxylon gottwaldii sp. nov. is a new taxon for fossil wood with a suite of features diagnostic of Sassafras Nees & Eberm. of the Lauraceae. The fossil wood described is from Late Cretaceous (Santonian- Maastrichtian) sediments of the northern Antarctica Peninsula region. This new species of Sassafrasoxylon Brezinová et Süss resembles the species of extant Sassafras in being distinctly ring-porous, having vessel elements with simple perforation plates and very occasional scalariform plates with relatively few bars in the narrowest latewood vessels, alternate intervascular pitting, marginal (initial) parenchyma bands and paratracheal vasicentric parenchyma in the latewood, multiseriate rays and oil and /or mucilage cells. The fossils were found as isolated pieces of wood and therefore it is not certain whether the parent plant was Sassafras-like in all characters. Consequently the fossils have been placed in an organ genus rather than in extant Sassafras. This is the oldest record of an organ with features closest to extant Sassafras and may suggest that Sassafras first appeared in Gondwana and later radiated into the Northern Hemisphere. The distribution of extant Sassafras in North America and East Asia may represent a relict of a geographically more widespread taxon in the past.
Three fossil woods, collected from Late Jurassic–Early Cretaceous of Gebel Kâmil in southwestern Egypt, were studied anatomically, and identified as Xenoxylon saadawii sp. nov. of the family Protopinaceae.
A fossil wood with features similar to those of the Oligocene Hovenia palaeodulcis Suzuki (Rhamnaceae) from Japan is described from the late Eocene Florissant Fossil Beds National Monument, Colorado, U.S.A. This is the first report of fossil wood of this Asian genus in North America and is further documentation of Tertiary exchange between East Asia and North America. The affinities of Chadronoxylon florissantensis, the most common angiosperm wood at Florissant, are reevaluated; its combination of features suggests relationships with two families in the Malpighiales, the Salicaceae and Phyllanthaceae. Chadronoxylon is compared with Paraphyllanthoxylon Bailey. The Eocene P. hainanensis from China has notable differences from the original diagnosis of Paraphyllanthoxylon, but shares features with Chadronoxylon warranting transfer of P. hainanensis to Chadronoxylon and the creation of Chadronoxylon hainanensis (Feng, Yi, Jen) Wheeler & Meyer, comb. nov.
Wood of Connaroxylon dimorphum (Connaraceae, Oxalidales) from the Deccan Intertrappean Beds of India (KPg Boundary 65–67 MY BP) is described. It is characterized by parenchyma-like fiber bands alternating with normal fibers, septate and nonseptate fibers, vessel-ray pits with strongly reduced borders, uniseriate rays of square and upright cells, and radial tubules in the center of ray cells that are arranged in a herringbone pattern. The overall wood anatomy strongly resembles Melastomataceae p. p., Lagerstroemia p. p. (Lythraceae) and Connarus (Connaraceae). However, the shared radial tubules of Connarus and the fossil strongly tilt the evidence of botanical affinities towards this genus. This would represent the second and by far the oldest fossil wood record of the Connaraceae, also considerably older than the earliest fossil records of the family’s other plant parts, and one of the oldest fossils of the order Oxalidales.
This paper describes a new species of fossil wood, Wataria yunnanica Li et Oskolski, from the Dajie Formation of the middle Miocene in southern Yunnan province, China. This species shows the greatest similarity to the modern genus Reevesia Lindl. from the subfamily Helicteroideae of Malvaceae. The fossil specimen is ascribed to the genus Wataria Terada & Suzuki based on its combination of ring-porous wood and the presence of tile cells. It differs from other Wataria species because vessel groups are common in its latewood. This is the first record of Wataria in China. Other species of this genus have been reported from Oligocene and Miocene deposits in Japan, and from Miocene deposits in Korea. The occurrence of ring-porous wood in the Dajie Formation suggests that there may have been a seasonal (probably monsoonal) climate in southern Yunnan during the middle Miocene.
Fossil woods are abundant in the Cretaceous Yezo Group in Hokkaido, Japan, in strata of Albian to Santonian ages. From 144 dicotyledonous samples, fourteen species representing 10 genera were identified: Castanoradix cretacea gen. et sp. nov., C. biseriata gen. et sp. nov., Frutecoxylon yubariense gen. et sp. nov., Hamamelidoxylon obiraense sp. nov., Icacinoxylon kokubunii sp. nov., I. nishidae sp. nov., Magnoliaceoxylon hokkaidoense sp. nov., Nishidaxylon jezoense gen. et sp. nov., Paraphyllanthoxylon cenomaniana sp. nov., P. obiraense sp. nov., Plataninium jezoensis sp. nov., P. ogasawarae sp. nov., Sabiaceoxylon jezoense gen. et sp. nov. and Ulminium kokubunii sp. nov. All 14 species are new and four of the 10 genera are new. Five genera (lcacinoxylon, Magnoliaceoxylon, Paraphyllanthoxylon, Plataninium and Ulminium) already are known from the Cretaceous and Tertiary, one (Hamamelidoxylon) previously is known only from the Tertiary. The species distribution by age is: Albian: one species; Cenomanian: four species in four genera; Turonian: ten species in eight genera; Coniacian: six species in five genera; Santonian: eight species in seven genera. The two specimens of Icacin oxylon kokubunii from the Albian are the oldest records of dicotyledonous woods in Japan.
Silicified woods from near the town of Ocú on the Azuero Peninsula, Panama were first reported by Stern and Eyde in 1963; however, the significance of these fossils has been largely overlooked. Well-characterized fossil floras from Central America can be used to test hypotheses related to the historical biogeography and paleoclimate of the Neotropics. We describe 10 new wood types and one palm based on 22 samples from Oligo-Miocene deposits. Affinities at the family/order level include Fabaceae, Lauraceae, Moraceae, Sapotaceae, Euphorbiaceae, Arecaceae, Sapindales, Ericales, and Humiriaceae. The fossil woods are fragmentary and have not been found in-place, but the size and angularity of the specimens suggests minimal transport from the site of growth. We compared these woods with calcareous woods from the Lower Miocene Cucaracha Formation and silicified woods from the upper Miocene Alajuela Formation using Rare Earth Element (REE) analysis to test the hypothesis that the Ocú woods were preserved under uniform conditions and not reworked. Although the results were ambiguous with respect to the original hypothesis, we note that the REE concentrations in silicified woods are much lower than in calcareous woods. We used comparative analysis of wood anatomical features to draw conclusions about the paleoclimate from the fossil flora. All the dicot woods are diffuse porous and none have distinct growth rings; some have very wide vessels at low frequencies. These features are typical of canopy trees in tropical lowland forests. Nonmetric multidimensional scaling of wood anatomical characters from a variety of communities and ecological categories showed that the anatomy of the Ocú woods is most similar to that found in tropical rainforests. Based on the combination of taxonomic identity and functional anatomy, we interpret these fossils as evidence for humid to perhumid megathermal climate in Panama during the late Paleogene-early Neogene.