Juniperoxylon acarcae Akkemik 2021, sp. nov.
Creators: name: Akkemik, Unal
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Pinopsida
Pinales
Cupressaceae
Juniperoxylon
Juniperoxylon acarcae

description: Juniperoxylon acarcae Akkemik sp. nov.
Figs. 2-5
Holotype. AGUD08.
Repository. The Department of Forest Botany, Faculty of Forestry, Istanbul University-Cerrahpasa, Istanbul, Turkey.
Etymology. The epithet “ acarcae ” originates from the surname of Dr. N. Neslihan Acarca Bayam who worked on the petrified woods in the Galatian Volcanic Province for her PhD in Turkey. It was the first PhD on petrified woods in Turkey.
Plant Fossil Names Registry Number: PFN001814
Type locality. Aşağıgüney Village of the city of Beypazarı in the province of Ankara (AGU). This region is called Galatian Volcanic Province (GPV) (Fig. 1).
Age. Early Miocene.
Type horizon. Hançili Formation.
Diagnosis: Growth ring boundaries distinct with 2-3 rows of flattened latewood tracheids. False rings commonly present. Transition from earlywood to latewood indistinct. Tracheids generally circular, and intercellular spaces clearly obvious and occur throughout the wood. Normal axial resin canals absent. Axial parenchyma appears both diffuse (in the transition from earlywood to latewood and within the latewood itself) and tangentially zonate. Rays uniseriate, and sometimes partly biseriate. Ray height is 1-6 (max.16) cells. Tracheidal pits on tangential walls common and 1-2 seriate, irregular or slightly alternate. The rays with one cell height conspicuously longer. Transverse end walls of axial parenchyma cells are nodular and smooth. Ray tracheids absent. End walls of ray parenchyma cells nodular and smooth, horizontal walls of rays sparsely pitted. Tracheid pitting in radial walls of the earlywood is uniseriate and biseriate, opposite, frequent, contiguous, and sometimes spaced. Cross-field pitting is cupressoid with 2–3 (-5) pits per cross-field.
Description: Wood anatomical characteristics of the specimen of Juniperoxylon were given as follows:
Transversal section: Growth ring boundaries distinct with 2-3 rows of flattened latewood tracheids. False rings commonly present (Fig. 3: a-c). Transition from earlywood to latewood gradual and indistinct. Tracheids generally circular, and intercellular spaces clearly obvious and occur throughout the wood. Normal axial resin canals absent. Axial parenchyma presents and both diffuse (in the transition from earlywood to latewood and within the latewood itself) and tangentially zonate (Fig. 3: b (arrows)-c).
Tangential section: Rays exclusively uniseriate, and sometimes partly biseriate (Fig. 3: d). Ray height is 2- 6 (max.16) cells (Fig. 3: d-e and Fig. 4: a). Tracheidal pits on tangential walls commonly present, and uni- to biseriate, irregularly spaced or slightly alternate (Fig. 3: e-f). The rays with one cell height conspicuously longer (Fig. 3: d-e). Transverse end walls of axial parenchyma cells are nodular and smooth (Fig. 4: b-d).
Radial section: Ray tracheids absent. Tracheid pitting in radial walls of the earlywood is uniseriate and biseriate, opposite, frequent, contiguous (Fig. 4: e-f), and sometimes spaced (Fig. 5: c). Crassulae sometimes presents (Figure 4: f). End walls of ray parenchyma cells nodular and smooth, and horizontal walls of rays sparsely pitted (Figure 5: a-d). Indenture rarely visible (Figure 5d). Cross-field pitting is cupressoid with 2–3 (-5) pits per cross-field (Fig. 5: e-g).
Discussion: According to the discussion by Ruiz and Bodnar (2019), the features of distinct growth ring boundary, narrow latewood band, common spaces among tracheid, presence of pits on tangential walls of tracheids, presence of diffuse and/or zonate axial parenchyma, cupressoid or taxodioid type of cross field pits, low height of rays, generally nodular end walls of axial parenchyma, and homocellular rays are the main characteristics of Juniperoxylon. Due to having very close wood anatomical characteristics with Ruiz and Bodnar (2019) ’s description, the present fossil specimen was identified as Juniperoxylon. Based on the differences in the characteristics of the fossil species (Table 1), the following identification key was prepared to find the exact place of the present Juniperoxylon species:
1A. Ray tracheids present
2A. Cross-field pits 4-6 cupressoid; end walls of axial parenchyma cells smooth; radial tracheidal pitting spaced and contiguous> Protojuniperoxylon ischigualastense Bonetti, 1966 emend. Bodnar & Artabe, 2007
2B. Cross-field pits 1-3 cupressoid and taxodioid; end walls of axial parenchyma nodular; radial tracheidal pits sparse> Juniperoxylon rhenanum van der Burgh 1973
1B. Ray tracheids absent
3A. Axial parenchyma absent or scarce, if present, diffuse; Ray parenchyma horizontal walls smooth; 4-6 pits per cross-field; radial tracheidal pitting spaced and contiguous> Protojuniperoxylon maidstonense (Stopes, 1915) Eckhold, 1923
3B. Axial parenchyma common.
4A. Zonate axial parenchyma present
5A. Cross-field pits only taxodioid; 2-6 pits per cross-field; end walls of axial parenchyma smooth or irregularly pitted; ray height 1-14 cells; horizontal end walls of rays smooth or rarely pitted> Juniperoxylon breviparenchmatosum Watari & Nishida 1973
5B. Cross-field pits only cupressoid, and 1-6 per cross-field.
6A. Horizontal walls of rays smooth; ray width uniseriate and rarely partly biseriate; end walls of axial parenchyma smooth or nodular; radial wall pitting uniseriate, rarely bi-to triseriate pits opposite, and spaced> Juniperoxylon pachyderma (Göppert, 1850) Kräusel, 1949
6B. Horizontal walls of rays distinctly pitted.
7A. Radial wall pitting exclusively uniseriate, horizontal walls of rays distinctly pitted; ray width uniseriate; transversal end walls of axial parenchyma smooth> Juniperoxylon pottoniense (Stopes, 1915) Kräusel, 1949
7B. Radial wall pitting uni-to biseriate; transversal end walls of axial parenchyma nodular
8A. Tracheidal pits on radial walls often frequent and contiguous; rays uni- to biseriate; crassulae rarely present, end walls of axial parenchyma nodular and smooth; end walls of rays nodular and smooth; horizontal walls of rays sparsely pitted> Juniperoxylon acarcae Akkemik sp.nov.
8B. Spacing of radial tracheidal pits sparse; rays uniseriate; crassulae present; ray parenchyma horizontal walls distinctly pitted> Juniperoxylon juniperoides (Kownas, 1951) Huard, 1966
4B. Zonate axial parenchyma absent, axial parenchyma only diffuse.
9A. Axial parenchyma scarce; ray heights 2-34 cells; ray parenchyma horizontal walls distinctly pitted; 1-2 (3-4) pits per cross-field; radial tracheidal pitting spaced but not contiguous> Juniperoxylon zamunerae (Bodnar et al., 2015) Ruiz & Bodnar 2019
9B. Axial parenchyma present, abundant, and diffuse; ray height up to 18 cells.
10A. Ray parenchyma horizontal walls smooth; end walls of axial parenchyma cells nodular; ray heights 1-5 cells> Juniperoxylon wagneri Süss & Rather 1998
10B. Ray parenchyma horizontal walls sparsely or distinctly pitted; Ray heights up to 18 cells.
11A. Horizontal walls of ray parenchyma sparsely pitted; rays uniseriate and occasionally biseriate; axial parenchyma abundant; crassulae present> Juniperoxylon schneiderianum Dolezych 2016
11B. Horizontal walls of ray parenchyma distinctly pitted; rays uniseriate; axial parenchyma present; crassulae absent> Juniperoxylon turonense Houlbert, 1910
According to the identification key and the given characteristics in Table 1, the new fossil Juniperoxylon species has differences from all former fossil species.
Juniperoxylon zamunerae (Bodnar et al., 2015) Ruiz & Bodnar, 2019 differs from the new species in having scarce and diffuse axial parenchyma, and 2-34 cells height of rays.
Protojuniperoxylon maidstonense (Stopes, 1915) Eckhold, 1923 differ from the present specimen in having scarce axial parenchyma and predominantly uniseriate tracheidal pitting on radial walls, and 4-6 cupressoid pits per cross-field (Bodnar and Artabe, 2007).
Juniperoxylon wagneri Süss & Rather 1998, Protojuniperoxylon ischigualastense Bonetti, 1966 emend. Bodnar & Artabe, 2007, and J. schneiderianum Dolezych, 2016 differ from the new specimen in having only diffuse axial parenchyma.
Juniperoxylon breviparenchmatosum Watari & Nishida, 1973 differs from the new species in having only taxodioid type cross-field pits.
Juniperoxylon rhenanum van der Burgh, 1973 differs from the new species in having 1-3 cupressoid and taxodioid cross-field pits, space of radial tracheidal pits, much longer rays (1–40 cells), and crassulae formation.
The closest fossil species are Juniperoxylon pachyderma (Göppert, 1850) Kräusel, 1949, J. juniperoides (Kownas, 1951) Huard, 1966, and J. pottoniense (Stopes, 1915) Kräusel, 1949. These three fossil species have only spaced radial tracheidal pits. The new fossil species has both spaced and contiguous radial tracheidal pits. J. pachyderma and J. juniperoides have also crassulae formation, and J. pottoniense has exclusively uniseriate pits on radial walls of tracheids.
Based on these differences, the specimen was described as a new Juniperoxylon species and named Juniperoxylon acarcae Akkemik sp. nov. The descriptions of Juniperus from Hoçaş Fossil site (Akkemik et al., 2016) and from Aşağıgüney Fossil site (Acarca Bayam et al., 2018) were compared with the new species and results showed that they both had very similar features. It can be concluded that the new species, Juniperoxylon acarcae Akkemik sp.nov. has an area through the valley between Beypazarı- Aşağıgüney Village and Seben-Kozyaka Village (Fig. 1).
Affinities: The fossil Juniperoxylon descriptions (e.g.Vaudois and Privé, 1971; Bodnar and Artabe, 2007; Kłusek, 2014; Akkemik et al., 2016; Dolezych, 2016, Acarca Bayam et al., 2018) revealed that this type of wood is closely related to modern Cupressaceae due to the the presence of “ abietinean tracheid pitting, distinctly pitted ray cell walls, axial parenchyma and cupressoid cross-fields ”.
In Cupressaceae, normal resin canals and helical thickenings are also absent. When some fossil species such as J. zamurense are related to different modern genera, Chamaecyparis Kurz., Cupressus L., Fitzroya Lindl. and Juniperus (Ruiz and Bodnar, 2019), the new species, Juniperoxylon acarcae, is closely related to the modern Juniperus. A comparison of the features of the new fossil species with the five modern Juniperus species in Turkey, which are native, and two similar species given in Esteban et al. (2004), which are Juniperus saltuaria Rehder et E.H. Wilson from south of China and Tibet and Juniperus thurifera L. from the western Mediterranean Basin, showed the highest similarities. However, Juniperus foetidissima Willd. has both cupressoid and taxodioid cross-field pits, and Juniperus saltuaria has not marginal and metatraheal axial parenchyma, therefore, these two species slightly differ from the fossil species and the other five modern Mediterranean species (Table 2). Wood features demonstrated that both fossil and modern species are rather close to each other, and therefore, the fossil species may be evaluated as a possible ancestor of the modern species in the Mediterranean basin.
Possible growing site conditions: The described Juniperoxylon acarcae Akkemik sp. nov. is a forest tree of the Galatian Volcanic Province (GVP). The new species was one of the elements within a rich woody flora of GVP (Akkemik et al., 2016; Acarca Bayam et al., 2018). The early Miocene trees of Pinus L., Juniperus, Cedrus Trew., Ulmus L., Zelkova Spach., Liquidambar L., and Acer L., grow under the conditions of VU0, and VU5 to VU 7 in GVP. These vegetation units (VU) classify that VU0 is subtropical, moist or dry light forests, VU5 is well-drained lowland forests, VU6 is well-drained upland forests, and VU7 is well-drained (lowland and) upland conifer forest.
The Juniperoxylon acarcae stems are autochthonous in the field. The other autochthonous early Miocene trees are Quercus Sect. Ilex, palms (later they were identified as Palmoxylon sp. cf. Trachycarpus by Iamandei et al., 2018), Liquidambar and Salix /Populus in Hoçaş Fossil Site (Akkemik et al., 2016). Because these fossil woods are found in their original positions in the field, to interpret their life conditions is more satisfactory. The presence of these riparian and lowland trees may suggest that the growing area of Juniperoxylon acarcae trees was a forest having an open, well-drained lowland growing conditions.
description: Published as part of Akkemik, Unal, 2021, A New Species Of Juniperoxylon From The Early Miocene Of Northwestern Turkey, pp. 15-26 in Acta Palaeontologica Romaniae 17 (1) on pages 18-25, DOI: 10.35463/j.apr.2021.01.02, http://zenodo.org/record/10520760