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A – F , DB.D1 Xylotype 1: A , Diffuse porous wood, vessels solitary and in radial multiples, growth ring boundary present, XS, DMNH 23796; B , Scalariform perforation plates, with less than 10 bars, RLS, DMNH 23798; C , Alternate intervessel pits, TLS, DMNH 23797; D , Procumbent ray parenchyma cells, RLS, DMNH 23796; and E–F , Narrow rays with tendency to form aggregate rays, TLS, DMNH 23796. G – K , DB.D1 Xylotype 2, DMNH 23799: G , Diffuse porous wood, vessels exclusively solitary, XS; H – I , Scalariform perforation plates, with more than 20 closely spaced fi ne bars, RLS, TLS, respectively; J , Heterocellular ray with procumbent, square and upright cells, RLS; and K , Rays of two sizes, uniseriate and more than 6-seriate, TLS. L – P , DB.D1 Xylotype 3, cf. Platanoxylon , DMNH 23800: L , Diffuse porous wood, vessels predominantly solitary, very wide rays, and apotracheal parenchyma in short uniseriate lines, XS; M , Axial parenchyma in short uniseriate lines, fi ber wall thickness medium to thick, XS; N , Procumbent ray parenchyma cells, RLS; O , Marginal cells of multiseriate rays of similar size as body cells, TLS; and P , Tall and wide rays, narrow rays rare, TLS. Scale bars = 200 μm in A , E , G , K – L , and P ; 100 μm in F , J , and N – O ; and 50 μm in B – D , H – I , and M .
Source publication
Silicified woods are common in the upper D1 (Paleocene – Puercan and Torrejonian) and D2 (Eocene – Wasatchian) sequences of
the Denver Basin. Almost all derive from angiosperms. Woods from the upper D1 sequence are the second set of angiosperm woods
described from Paleocene strata of the Rocky Mountain region. Wood assemblages from the upper D1 seq...
Contexts in source publication
Context 1
... with exclusively solitary vessels (Fig. 2G), scalariform perforation plates with more than 20 bars ( Fig. 2H-I), vessel-ray parenchyma pits that are not enlarged, rays of two distinct sizes (Fig. 2K), multiseriate heterocellular K), multiseriate heterocellular K rays, little axial parenchyma, and vessels <200 µm that are not more than 40 per mm 2 , occur in the extant families ...
Context 2
... with exclusively solitary vessels (Fig. 2G), scalariform perforation plates with more than 20 bars ( Fig. 2H-I), vessel-ray parenchyma pits that are not enlarged, rays of two distinct sizes (Fig. 2K), multiseriate heterocellular K), multiseriate heterocellular K rays, little axial parenchyma, and vessels <200 µm that are not more than 40 per mm 2 , occur in the extant families Clethraceae, Icacinaceae, and Thea- ceae (Ternstroemia). Distinctly ...
Context 3
... with exclusively solitary vessels (Fig. 2G), scalariform perforation plates with more than 20 bars ( Fig. 2H-I), vessel-ray parenchyma pits that are not enlarged, rays of two distinct sizes (Fig. 2K), multiseriate heterocellular K), multiseriate heterocellular K rays, little axial parenchyma, and vessels <200 µm that are not more than 40 per mm 2 , occur in the extant families Clethraceae, Icacinaceae, and Thea- ceae (Ternstroemia). Distinctly bordered fi ber pits, which characterize the aforementioned families, were not observed. ...
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... combination of diffuse porous woods with narrow, frequent vessels ( Fig. 2L), large near-homocellular rays ( Fig. 2N-P), and apotracheal parenchyma ( Fig. 2M) suggests that this wood type represents Platanaceae. As is characteristic of all other Cretaceous and early Tertiary platanoid woods that occur in North America, this wood has rays wider than present-day temperate Platanus species but consistent with ...
Context 5
... combination of diffuse porous woods with narrow, frequent vessels ( Fig. 2L), large near-homocellular rays ( Fig. 2N-P), and apotracheal parenchyma ( Fig. 2M) suggests that this wood type represents Platanaceae. As is characteristic of all other Cretaceous and early Tertiary platanoid woods that occur in North America, this wood has rays wider than present-day temperate Platanus species but consistent with those of the southeast Asian P. kerrii. This ...
Context 6
... combination of diffuse porous woods with narrow, frequent vessels ( Fig. 2L), large near-homocellular rays ( Fig. 2N-P), and apotracheal parenchyma ( Fig. 2M) suggests that this wood type represents Platanaceae. As is characteristic of all other Cretaceous and early Tertiary platanoid woods that occur in North America, this wood has rays wider than present-day temperate Platanus species but consistent with those of the southeast Asian P. kerrii. This sample's preservation was not good ...
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... 23796 has a higher vessel frequency, shorter rays, and more frequent biseriate rays than DMNH 23798 and DMNH 23797, which have nearly exclusively uniseriate rays. DMNH 23796 has some rays arranged so as to resemble aggregate rays ( Fig. 2E-F). Tentatively, we are con- F). Tentatively, we are con- F sidering these differences between samples to be comparable to those seen within wood of a single extant species. The combination of scalariform perforation plates ( is not common among extant angiosperms; usually simple perforations and alternate pits, and scalariform ...
Citations
... Platanaceous fossil woods are known from North America, Europe, and East Asia, largely from the Cenozoic, but also from the Late Cretaceous (Brett 1972;Suzuki 1976;Wheeler et al. 1977;Scott & Wheeler 1982;Wheeler & Manchester 2002;Wheeler & Michalski 2003;Gregory et al. 2009;Oakley & Falcon-Lang 2009;Sakala et al. 2010Sakala et al. , 2018Továrková et al. 2011;Koutecký et al. 2019;Iamandei et al. 2020). The combination of features of these woods includes diffuse-porous wood, small diameter vessels, high vessel frequency, perforation plates exclusively scalariform or scalariform and simple, vessel-ray pits similar to intervessel pits, and mostly large homocellular multiseriate rays. ...
A new record of Cretaceous platanaceous wood, Platanoxylon sp., is described from Keshan, Heilongjiang Province, Northeast China. The features indicating it belongs to Platanoxylon include: growth rings distinct, wood diffuse-porous, vessels numerous, solitary and in short radial or tangential multiples, perforation plates exclusively scalariform, intervessel pits opposite, elliptical, horizontally elongated, vessel-ray pits similar to intervessel pits, some fibers with distinctly bordered pits, axial parenchyma diffuse, rays mostly large homocellular multiseriate, rarely uniseriate, and crystals often in ray cells. Fossil platanaceous woods are common in the Northern Hemisphere. Yet, Platanoxylon sp. is China’s first report of fossil Platanaceae wood. It is also China’s first record of Cretaceous angiosperm wood. This wood and compression floras indicate that the Platanaceae were in northern China from the Late Cretaceous to the Eocene.
... Brown (1962), for example, observed that "Ficus" planicostata, which Knowlton (1917) recognized as the dominant element of the Vermejo flora (see also Ash & Tidwell 1976), crossed the K-Pg boundary with little or no change. Likewise, this species is known to have been a principal component of the neighboring flora of the Denver Basin both before and after the K-Pg mass-extinction event, as is wood (Paraphyllanthoxylon) with a strong lauraceous affinity Wheeler & Michalski 2003). Upchurch (1995) observed that lauraceous dispersed cuticle, which exhibits a positive taphonomic bias (Nichols & Johnson 2008;Manchester 2018, pers. ...
The Cretaceous-Paleogene (K-Pg) mass-extinction event had a profound effect on global vegetation, with a major turnover. The post-extinction flora is typified by a recovery succession dominated by fern spores (Cyathidites and Laevigatosporites). Dispersed spores of the genus Cyathidites in this fern-spore spike interval are commonly assumed to have been produced by tropical tree ferns. However, Anemia-like schizaeaceous foliage is also known to have produced Cyathdiites (psilate, Lygodium-like trilete spores) in the Paleogene. Within the Sugarite coal zone in the Raton Formation, which contains both the K-Pg boundary and the fern-spore spike, Anemia-like schizaeaceous foliage currently classified as A. elongata (Newberry) Knowlton is associated with Cyathidites spores. As no other fern megafossil that has been collected from the Sugarite coal zone is known to have both survived the K-Pg mass-extinction event and to have been capable of producing spores of the dispersed spore genus Cyathidites, it is hypothesized that A. elongata produced these spores. A. elongata is found alongside species with a strong affinity to Lauraceae, which dominates the post-extinction dicot angiosperm flora in the Raton Basin. Lauraceous pollen typically is not preserved in the fossil record. Therefore, the orthodox concept of an earlier, fern-dominated recovery interval followed by a later phase of angiosperm recovery, which is principally based on palynology, is questioned. Reevaluation of the classic model for plant recovery in the Raton Basin, which was based upon the pattern of plant recolonization of the Krakatau islands following the 1883 volcanic eruption, provides support for the novel concept that recolonization by Lauraceae may have preceded or, more conservatively, coincided with recolonization by schizaeaceous (Cyathidites-producing) or thelypteridaceous (Laevigatosporites-producing) ferns.
... MTD ¼ mean tangential diameter of vessel lumina (range); V/mm 2 ¼ vessels per square mm (range); B/ PP ¼ bars per perforation plate (maximum bars per plate); IVP ¼ intervessel pitting type; S ¼ scalariform; O ¼ opposite; A ¼ alternate; V Shape ¼ vessel outline in transverse section; Ang ¼ angular; Ov ¼ oval; C ¼ circular; RW ¼ ray width in cells (maximum ray width in cells); Unk ¼ unknown; * ¼ charcoalified samples, MTD and V/mm 2 estimated. Xylotype 2 from the Paleocene of the Denver Basin (Wheeler and Michalski, 2003), but it has two distinct sizes of rays and sheath cells in the raysdfeatures that do not occur in Vasunum cretaceum. ...
The fossil record of Cretaceous angiosperm wood is skewed toward the latest part of the period; most described taxa are based on specimens from Campanian or Maastrichtian sediments. The low percentage of pre-Campanian angiosperm woods relative to other flowering plant organs may reflect a taphonomic bias or the existence of relatively few woody angiosperm taxa until the last part of the Cretaceous. The discovery of three fossil angiosperm wood taxa in the Turonian Moreno Hill Formation of New Mexico offers additional data on the occurrence of secondary xylem in early angiosperms. These wood fossils represent a common Cretaceous wood taxon plus two new angiosperm wood types, and increase the number of known pre-Campanian wood types by 10–20%. Analyses of thin sections from a large (>50 cm diameter) silicified log at a locality in the lower Moreno Hill Formation reveal it is Paraphyllanthoxylon arizonense Bailey, a wood taxon known from Cenomanian and Maastrichtian to Paleocene sites in the American Southwest. Paraphyllanthoxylon arizonense represents large trees that may belong to Laurales. Several other sizeable logs in the same area are also likely to be P. arizonense. In contrast, two taxa from a stratigraphically higher site in the Moreno Hill have not been previously described and are each represented by only one specimen. These two new wood types, based upon small, phosphatic axes (5–7 cm in diameter), differ from Paraphyllanthoxylon in their smaller diameter vessels and scalariform perforation plates. The unique combinations of character states of these phosphatic specimens indicate that they are new genera. Although the taxonomic affinities of Herendeenoxylon zuniense gen. et sp. nov. are uncertain, it is possible that it belongs to the Ericales. The affinities of the other new wood type, Vasunum cretaceum gen. et sp. nov. are unknown. The presence of three angiosperm wood taxa in the Moreno Hill Formation is noteworthy because exposures of terrestrial Turonian deposits are uncommon. The large diameter and apparent abundance of P. arizonense in the lower member of the Moreno Hill Formation suggest that these trees were dominant members of woodland or forest habitats of the ancient coastal lowlands. The small diameters and scarcity of the other two wood types suggest that they came from shrubs or small trees that were not common.
... Silicified wood occurs in upper D1 Paleocene strata and in the overlying Eocene D2 beds [9]. The Cherokee Ranch fossil forest lies within the upper part of the D1 sequence, just below the upper boundary paleosol. ...
An extensive fossil forest discovered in 2010 on private property in central Colorado, USA, has not previously been described in scientific literature. Horizontal partial logs originated as fluvially transported driftwood. A preliminary study of petrified wood specimens reveals evidence of a complex mineralization sequence that involved multiple episodes of mineral deposition, combined with diagenetic transformation of silica minerals. Specimens from two logs have opalized cell walls. However, minerals filling the cell interiors of these specimens vary. Vessel lumina are filled with chalcedony or crystalline quartz; tracheid lumina may contain opal or chalcedony. Specimens from 5 other logs contain quartz/chalcedony, but relict textures suggest cell walls were originally mineralized with opal that was later converted to microcrystalline silica. Pyrite, calcite, and iron oxides were observed as minor constituents in some specimens, providing additional evidence that fossilization occurred in multiple stages, with temporal and spatial variations in physical and chemical conditions causing episodic precipitation of various minerals within the buried wood. Trace element analyses suggest that Fe is the main source of fossil wood color.
... Fossil woods with this combination of features include Metcalfeoxylon, which is common in the Late Cretaceous of New Mexico and Texas (Wheeler et al., 1995), Mexico (Estrada-Ruiz et al., 2010) and an Early Eocene wood from Colorado (Wheeler and Michalski, 2003) that had some features seen in the Late Cretaceous Parabombacaceoxylon from Southern Illinois (Wheeler et al., 1987). These North American fossil woods have abundant diffuse-in-aggregates axial parenchyma, and wider and taller rays than Upatoi Wood Type 5. ...
This paper is the first in a series describing a diverse assemblage of charcoalified angiosperm woods from the Cretaceous (early to mid-Santonian) Eutaw Formation at Upatoi Creek, Georgia, USA. In our study, we separated ‘twigs’ from more ‘mature’ woods and further subdivided the latter material into specimens showing scalariform and simple perforation plates. Here, we report on thirteen ‘mature’ specimens with scalariform perforation plates. For such a small sample size, there is a remarkable diversity, with seven more or less distinct wood types present including two new taxa: Gregoryoxylon georgiaensis gen. et. sp. nov. and Chaloneroxylon pagei gen. et. sp. nov. The seven wood types are similar to most previously reported specimens from the Turonian–Santonian interval, i.e., they are diffuse porous, with predominantly solitary vessels, heterocellular rays, and only diffuse and/or scanty paratracheal parenchyma. None of the seven Upatoi wood types has a combination of features that allows unequivocal assignment to a single extant family. Chaloneroxylon may represent a record of the Magnoliaceae; of the other unnamed wood types, one has features found in the asterid orders Cornales and Ericales, while two possibly are referred to the Malpighiales. The affinities of the remaining three wood types, including Gregoryoxylon, are uncertain. The cryptic affinity of these woods is significant in itself, reflecting their Cretaceous age, a time when extant families were still rapidly diversifying.
... For example, GH 5.3 and GH 5.6 represent samples from trees 3 and 6 at the GH 5 locality. The use of wood types (xylotypes) parallels the morphotype system that has been used for Cretaceous leaves (e.g., Johnson, 1996) and for Paleocene woods from the Denver Basin (Wheeler and Michalski, 2003), and is based on Page's method for characterizing a large assemblage of Cretaceous angiosperm woods (Page, 1979(Page, , 1980(Page, , 1981. A similar approach was adopted by Chapman and Smellie (1992) who used descriptive paleotaxa names (e.g., Coniferwood-Cretaceous-spacedpits), rather than species names, for Cretaceous woods from the Antarctic Peninsula. ...
Conifer wood types from the Upper Cretaceous Aguja and Javelina Formations and the Paleocene Black Peaks Formation of Big Bend National Park, Texas, are briefly described. The Big Bend conifer woods represent the largest assemblage of late Cretaceous conifer wood thus far described from the western interior of North America, and include samples with characteristics of the Araucariaceae and Cheirolepidiaceae, and Cupressaceae and Podocarpaceae. Cupressaceae/Podocarpaceae types of the Maastrichtian Javelina Formation have, on average, narrower rings than those of the Campanian Aguja Formation, consistent with the drier climate already proposed for the Javelina Formation. Angiosperm wood assemblages differ between the lower shale and upper shale members of the Aguja Formation, the Javelina Formation, and the Black Peaks, so do the conifer assemblages. The Big Bend conifer woods differ from those described from other western interior localities and document more variation in growth ring types than previously recognized for the whole of the northern hemisphere Late Cretaceous. The sizes of some logs and width of their growth rings suggest that some trees might have reached diameters of 1 m in approximately 80 years. Woods of the Cupressaceae/Podocarpaceae type show that the strategy of having juvenile wood with narrower tracheids and less distinct growth rings than in mature wood occurred in the Late Cretaceous. The incidence of compression wood in mature trunk wood is relatively high and may reflect either unstable substrates or frequent storms with high winds.
Based on the results of leaf physiognomic studies, it is generally acknowledged that the Raton Basin in south-central Colorado and northeastern New Mexico hosted a tropical rainforest during the early Paleocene. However, this interpretation is problematic because the canopy-forming foliage of this forest was predominately lauraceous, and lauraceous foliage is almost invariably entire-margined. Thus, it may be necessary to look to other, taxonomy-based paleotemperature proxies to test megathermal paleotemperature estimates based solely on leaf physiognomic analyses of predominately lauraceous datasets. In this study, the pantropical fern Cyclosorus sensu lato (s.l.) is reported from the upper coal zone of the Raton Formation. The presence of this fern in the understory of a predominately lauraceous canopy suggests megathermal conditions in the early Paleocene.
Fossil woods are common in the Late Cretaceous through early Eocene rocks of the Denver Basin, Colorado. The overwhelming majority of these woods are dicotyledonous angiosperms. A new locality for fossil woods, Cherokee Ranch, in the upper D1 stratigraphic sequence (Denver Formation) is described, and evidence for it being late Paleocene is reviewed. Most Cherokee Ranch woods resemble previously described Denver Basin angiosperm woods, but there is one new type of wood attributed to the family Lauraceae. A new genus, Ubiquitoxylon, is proposed for woods with the combination of features commonly seen in the Cherokee Ranch woods. Denver Basin Paleocene woods differ from Paleocene wood assemblages to the north (Wyoming and Montana), where conifer woods are common and angiosperms are rare. The width and spacing of the water-conducting vessels and the lack of distinct growth rings in almost all of the Cherokee Ranch woods suggest that these trees did not experience water stress, and there was no pronounced seasonality.
Premise of research. Over the past 3 decades, angiosperm woods have been reported from the Campanian to the Maastrichtian of southern Laramidia, including Coahuila and Chihuahua, Mexico; Big Bend National Park, Texas; and the San Juan Basin, New Mexico. Recent investigations of the upper Campanian (76.5 to >72.5 Ma) Jose Creek Member of the McRae Formation, south-central New Mexico, indicate an abundance of well-preserved silicified woods, representing one of the most diverse Cretaceous wood floras in the world. In this report, we describe four new angiosperm wood types. Methodology. The fossil woods described here were collected from the upper Campanian of south-central New Mexico, along the northeastern flank of the Caballo Mountains and in the adjacent Cutter Sag, and were studied using thin sections. The potential affinities of these McRae woods were determined by comparison with fossil and extant woods. Pivotal results. The woods reported here comprise one magnoliid and three eudicots with varying levels of comparability to extant taxa. Laurinoxylon rennerae sp. nov. belongs to Lauraceae and has a combination of features found in multiple extant genera variously referred to as Cinnamomeae Nees, Laureae Maout & Decaisne, or Lauroideae Burnett/core Lauraceae. Turneroxylon newmexicoense gen. et sp. nov. is a eudicot with many similarities to Dilleniaceae but differs in having narrower rays. Mcraeoxylon waddellii gen. et sp. nov. has a suite of features seen in several families of Malpighiales, Myrtales, and Oxalidales. McRae angiosperm wood type 1 has a suite of features found in genera of Dilleniales, Ericales, and Malpighiales.
Conclusions. All wood types, with the exception of M. waddellii, have minimum axis diameters of >10 cm (12–50 cm), indicating that they represent trees. This reinforces previous evidence for the presence of small to large angiosperm trees in the Jose Creek Member and underscores the importance of woody angiosperms in vegetation of the southern Western Interior during the Campanian-Maastrichtian.
