A late Eocene wood assemblage from the Crooked River Basin, Oregon, USA
Author
Wheeler, Elisabeth A.
Author
Manchester, Steven R.
Author
Baas, Pieter
text
PaleoBios
2023
2023-11-01
40
14
1
55
http://dx.doi.org/10.5070/p9401462457
journal article
10.5070/P9401462457
0031-0298
10913330
KETELEERIA FARJONII
SP
. NOV.
FIG. 2A–G
Diagnosis—
Growth rings distinct. Gradual transition from earlywood to latewood. Intertracheary bordered pits primarily uniseriate, occasionally biseriate, on radial walls. Axial parenchyma absent to rare. Rays exclusively uniseriate, average ray height medium (
sensu
IAWA Committee 2004
, 5‒15 cells), ray tracheids absent to rare, cross-field pits cupressoid to taxodioid, 2‒4 pits per cross-field, horizontal end walls of ray parenchyma pitted. Axial canals with thick-walled epithelial cells present; radial canals absent.
Holotype
—
UF 278-84891
, estimated maximum diameter
4 cm
.
Occurrence—
Dietz Hill (
UF
278).
Etymology—
Named for Aljos Farjon, THE expert on all things coniferous.
Description—
Growth rings distinct. Gradual transition from earlywood to latewood (
Fig. 2A‒C
). Aver- age tangential diameter of longitudinal tracheids 24 (
SD
=4.7), range 13–33 µm; intertracheary bordered pits primarily uniseriate, occasionally biseriate, on radial walls (
Fig. 2E, F
).
Figure 1. A.
Oblique northerly view of Dietz Hill, site UF278. White tuff capping the hill yielded radiometric age of 36.21±0.26 Ma (n=26) (
Manchester and McIntosh 2007
). Woods and fruits and seeds derive from the same tuff. Google Earth imagery.
B.
Index map of Oregon. Yellow rectangle showing the location of satellite image in C.
C
. Paleobotanical localities in the vicinity of Post, Oregon, in the Crooked River valley. Yellow line marks the approximate contact between the Clarno Formation (Tc) and overlying John Day Formation (Tjd) based on the geologic mapping of
Waters (1968)
. Quaternary deposits in the Crooked River floodplain and localized Plio-Pleistocene igneous intrusions not shown (see
Waters 1968
for detail). Late Eocene localities: UF279 Post Hammer site; UF278 Dietz Hill (subject of this treatment), UF254 Brummers Spring, UF256 Teater Road leaf locality. Early Oligocene locality: UF258. Crooked River leaf site (
Chaney 1927
,
Meyer and Manchester 1997
).
Axial parenchyma not observed with certainty (
Fig. 2A‒C
).
Rays uniseriate (
Fig. 2D
); 2‒18 cells, average 8 (
SD
=4) cells; 176 (
SD
=87) µm high, 67‒358 µm; only ray paren- chyma observed (
Fig. 2E–G
); end walls of ray parenchyma nodular (
Fig. 2G
); horizontal walls of ray parenchyma apparently pitted (
Fig. 2G
); cupressoid/taxodioid pits, 2‒4 pits per cross field, mostly two. (
Fig. 2E‒G
).
Ray tracheids apparently absent. Normal and traumatic axial canals present with rather thick-walled epithelial cells (
Fig. 2A‒C
). Radial canals absent.
Comparisons with extant and fossil woods—
The only extant conifer with axial resin canals (normal and traumatic), but without radial resin canals is
Keteleeria
.
Other features we observed in
UF
278-84891 are consistent with its assignment to this genus: cupressoidtaxodioid cross-field pits, nodular end walls of ray parenchyma (e.g.,
Phillips 1948
,
Lin et al. 2000
,
Lin et al. 2002
,
Itoh et al. 2022
).
Today,
Keteleeria
(three to five species) is native to the broadleaved evergreen forests of Central and South
China
,
Laos
,
Vietnam
, and
Taiwan
(
Farjon 1990
,
Shu 1999
,
POWO 2023
). It is another example of an Asian endemic that had a more extensive range in the past. Its distinctive seeds are known from the Eocene and Oligocene of North America (
Meyer and Manchester 1997
,
Manchester et al. 2009
), as well as the Oligocene-Miocene of Europe (
Manchester et al. 2009
).
Figure 2.
Pinaceae
.
Keteleeria farjonii,
UF
278-84891.
A‒C.
Distinct growth rings, gradual transition from earlywood to latewood, traumatic resin canals, TS.
D
. Uniseriate rays, TLS.
E, F
. Intertracheary pitting mostly uniseriate, rays composed of ray parenchyma cells, RLS.
G
. Mostly two pits per cross-field, difficult to determine if taxodioid or cupressoid; n to left of nodular end wall; p above pitted horizontal walls, RLS. Scale bars=500 µm in A; 200 µm in B; 100 µm in C, D; E; 50 µm in F; 20 µm in G.
Shi et al. (2022)
reviewed the record of fossil woods resembling
Keteleeria
and described a new species
Keteleerioxylon changchunense
Shi, Sun, Meng et Yu (2022)
from the early Cretaceous of
China
. There are three other reports of
Keteleerioxylon
I.A.
Shilkina (1960)
from the Cretaceous, Oligocene, Pliocene, Miocene of
Russia
(
Shilkina 1960
,
Blokhina and Bondarenko 2005
,
Blokhina et al. 2006
). However, those woods and the Miocene
Keteleeria
wood described from the Miocene of
Japan
(
Choi et al. 2010
) differ from
UF
278-84891 in
having cells that resemble ray tracheids. Such cells appear absent from this Dietz Hill wood. Given that it has a combination of features only seen in extant
Keteleeria
,
we are assigning it to the genus.