Angiosperm wood from the Upper Cretaceous (Coniacian) of British Columbia, Canada

Abstract

Fossil angiosperm wood was collected from shallow marine deposits in the Upper Cretaceous (Coniacian) Comox Formation on Vancouver Island, British Columbia, Canada. The largest specimen is a log at least 2 m long and 38 cm in diameter. Thin sections from a sample of this log reveal diffuseporous wood with indistinct growth rings and anatomy similar toParaphyllanthoxylon. Occasional idioblasts with dark contents in the rays distinguish this wood from previously knownParaphyllanthoxylonspecies and suggest affinity with Lauraceae. The log also includes galleries filled with dry-wood termite coprolites. This trunk reveals the presence of tree-sized angiosperms in what is now British Columbia, and the association of dry-wood termites with angiosperm woods by the Coniacian (89 Ma). To understand the significance of this discovery, we reviewed the record of Cretaceous woods from North America. Our analysis of the distribution of fossil wood occurrences from Cretaceous deposits supports the conclusion that there was a strong latitudinal gradient in both the size and distribution of angiosperm trees during the Late Cretaceous, with no reports of Cretaceous angiosperm trees north of 50°N paleo-latitude in North America. The rarity of angiosperm wood in the Cretaceous has long been used to support the idea that flowering plants were generally of low-stature for much of the Cretaceous; however, large-stature trees withParaphyllanthoxylon-like wood anatomy were widespread at lower–middle paleo-latitudes at least in North America during the Late Cretaceous. Thus, the presence of a largeParaphyllanthoxylonlog in the Comox Formation suggests that Vancouver Island has moved significantly northward since the Coniacian as indicated by other geological and paleobotanical studies.

Late Paleocene woods from Cherokee Ranch, Colorado, U.S.A.

“…Recently, one of us (EAW) examined slides of the holotype of Paraphyllanthoxylon arizonense and additional samples collected at and near the type locality. The rays in all samples have thin-walled cells, lack obvious marginal rows of upright and square cells, and usually have square cells intermixed with procumbent cells in the body of the ray (Wheeler and Lehman, 2009;Jud et al, 2017). Rays in the "phyllanthoid" Denver Basin woods, including these Cherokee Ranch woods, do not have those ray features.…”

“…This combination of features characterizes many Late Cretaceous to late Eocene fossil woods from the Northern Hemisphere. If oil cells are present as well, then the wood can be assigned to the Lauraceae (Laurel family) (Metcalfe and Chalk, 1950;Richter, 1987;Mantzouka et al, 2016;Jud et al, 2017). If the diagnostic feature of oil cells is absent, then it is usually impossible to confidently assign such woods to a single family because this combination of features occurs not only in the Lauraceae (order Laurales), but in other families in other orders, e.g., Anacardiaceae, Burseraceae, Kirkiaceae (order Sapindales), Lamiaceae, and Verbenaceae (order Lamiales).…”

A new fossil assemblage shows that large angiosperm trees grew in North America by the Turonian (Late Cretaceous)

“…We evaluated the significance of the size of the specimen by comparing it with other Cretaceous occurrences from around the world for which we could obtain diameter estimates. We augmented the data set of North American occurrences presented by Jud et al ( 37 ) with updated diameter estimates, and we included occurrences from other continents.…”

Hidden termite coprolites revealed by Synchrotron microtomography inside Eocene–Oligocene filled wood-borings from the Malzieu Basin, Lozère, southern France

“…are known since the Early Cretaceous to the Holocene (Rogers 1938;Corbett & Burrell 2001;Sutherland 2003;Nuorteva & Kinnunen 2008;Pires & Sommer 2009;Colin et al 2011;Boucher 2012;Jud et al 2017), this report consists of the first evidence of Eocene-Oligocene termite borings containing coprolites in Europe. The fragments of pellet-filled borings were analysed using a non-destructive imaging technique useful for the observation of inner and hidden structures: propagation phase-contrast X-ray synchrotron microtomography (PPC-SRμCT).…”