The Budden Canyon Formation is a Cretaceous unit spanning the Valanginian–Turonian interval in northern California. This marine unit includes plant-fossiliferous near-shore sequences, with richest plant fossil occurrences in the...
moreThe Budden Canyon Formation is a Cretaceous unit spanning the Valanginian–Turonian interval in northern California. This marine
unit includes plant-fossiliferous near-shore sequences, with richest plant fossil occurrences in the Hauterivian–Aptian. The Lower Chickabally
Member (Barremian–early Aptian, ca. 125 Ma) hosts a rich flora preserved anatomically in carbonate concretions, near the town of Ono. The
material is dominated by conifers: wood, foliage, cones and dispersed seeds. We characterize the anatomy of a coniferous trunk. The wood
exhibits axial and radial resin canals with thick-walled epithelial cells, distinct growth rings, and conspicuous early to late wood transition.
Axial tracheids bear radial uniseriate and opposite biseriate pitting. Rays are uniseriate with biseriate portions, with scarce ray tracheids and
taxodioid cross-field pitting. Traumatic resin canals form extensive tangential bands. The axial and radial resin canals indicate pinaceous
affinities for the Ono wood, but several characters make it different from most extant Pinaceae. The specimen is most similar to Picea Dietrich,
from which it differs in cross-field pitting. Among fossil Mesozoic genera, the Ono wood is similar to Palaeopiceoxylon Kräusel and Protocedroxylon
Gothan, and to the Pinuxylon-Laricioxylon-Piceoxylon group, but is not entirely consistent with any of these genera. Pinaceous affinity
of the Ono wood is consistent with presence in the Budden Canyon Formation of several types of pinaceous foliage and ovulate cones that
are, however, not assignable to any extant genus in the family. Together, these indicate the presence in the unit of stem-group Pinaceae
that await reconstruction as whole plants
