Cryptocaryoxylon LEISMAN

Mantzouka, Dimitra, 2018, The First Report Of Cryptocaryoxylon From The Neogene (Early Miocene) Of Eurasia (Eastern Mediterranean: Lesbos And Lemnos Islands, Greece), Fossil Imprint 74 (1 - 2), pp. 29-36 : 30-33

Fossil Genus Cryptocaryoxylon LEISMAN

Cryptocaryoxylon lesbium MANTZOUKA sp. nov. Pl. 1, Figs. 1–6

H o l o t y p e. Designated here. Specimen DM17

(Repository: Natural History Collection of Vrisa – Cultural, Research and Education Centre of the National and Kapodistrian University of Athens), 3 slides (Repository: Museum of Geology and Palaeontology in the National and Kapodistrian University of Athens) .

P l a n t F o s s i l N a m e s R e g i s t r y N u m b e r.

PFN000086 (for new species).

E t y m o l o g y. The epithet, lesbium , is due to the origin of the described material (Lesbos Island, Greece).

T y p e h o r i z o n. Under Polichnitos Ignimbrite (PU unit), inside volcanic material.

A g e. Early Miocene.

T y p e l o c a l i t y. Damandri, Southeastern Lesbos ,

Greece.

D i a g n o s i s. Heteroxylous wood, growth rings present, diffuse porosity, numerous vessels per sq. mm; vessels generally in radial multiples of 2 to 4, single and in clusters, circular to oval in outline, tyloses present; exclusively simple perforation plates; alternate intervessel pits, polygonal; non-septate fibres; paratracheal axial parenchyma, scanty; apotracheal axial parenchyma in marginal bands of up to a width of 3 cells; rays numerous, exclusively heterocellular, short to medium sized; mostly biseriate and triseriate; no aggregate rays present; idioblasts numerous, associated with the ray parenchyma cells only; no crystals present.

D e s c r i p t i o n. Macroscopic description. The sample is from a small stem of diameter 2.5 cm which was enclosed in volcanic material. It is silicified, light, porous, whitish and red-brown with distinct growth ring boundaries that can be seen with the naked eye.

Microscopic description. Pith: of square/rectangular or polygonal shape (Pl. 1, Figs 5, 6). — Growth rings: distinct (Pl. 1, Fig. 1). — Wood: diffuse-porous (Pl. 1, Fig. 1). — Vessels: 40–100 (60–70) vessels/sq. mm.; 19 % solitary, 50 % in groups of two, 13 % in groups of 3, 2 % in groups of 4 and 16 % in clusters; tangential diameter 50 to 90 μm, mean: 70 μm; radial diameter of the solitary vessels 50 to 110 µm, mean: 80 μm; outline of solitary vessels round to oval (Pl. 1, Figs 1, 2); vessel walls thin; perforation plates exclusively simple; tyloses common (Pl. 1, Fig. 4); intervessel pits alternate and polygonal in outline, about 10 μm across (medium to large in size). — Rays: heterocellular (Pl. 1, Fig. 3) 1 to 3 cells wide (25–30 μm) (Pl. 1, Figs 2–4), commonly 2–3-seriate and 180–550 μm high, body of multiseriate rays composed of procumbent cells with one row of upright cells; no crystals observed; 13–20 (mean 15) rays per mm. — Axial parenchyma: scanty paratracheal with a tangential width of 15–25 μm, in marginal bands 1–3 cells wide (Pl. 1, Fig. 2). — Fibres: most probably non-septate — Idioblasts: associated with the ray parenchyma cells only (Pl. 1, Figs 2, 3); mean radial × tangential diameter of the idioblasts in transverse section: 12–30 × 25–50 μm; number of idioblasts per sq. mm (transverse section): 35–45.

C o m p a r i s o n w i t h f o s s i l w o o d. See Table 1. The anatomical characteristics of sample DM17 to some degree resemble Laurinoxylon genus Type 1 ( Mantzouka et al. 2016), with idioblasts associated only with the ray parenchyma cells. The only feature (of great taxonomic

importance) not in accordance with the emended diagnosis of Laurinoxylon was the existence of axial parenchyma in marginal bands. The fossil Lauraceae include – with the exception of Laurinoxylon FELIX (previously also Laurinium UNGER , Ulminium UNGER and other genera) – many other genera, such as: Beilschmiedioxylon DUPÉRON- LAUDOUENEIX et DUPÉRON, Caryodaphnopsoxylon GOTTWALD, Cinnamomoxylon GOTTWALD, Cryptocaryoxylon LEISMAN , Mezilaurinoxylon WHEELER et MANCHESTER , Paraperseoxylon WHEELER et MANCHESTER and Sassafrasoxylon BŘEZINOVÁ et SÜSS ( Leisman 1986, Březinová and Süss 1988, Gottwald 1992, 1997, Wheeler and Manchester 2002, Dupéron-Laudoueneix and Duperon 2005). Based on the anatomical characteristics of modern Lauraceae wood as described by Richter (1981), we can say that the existence of marginal bands is the main characteristic of the tribe Cryptocaryeae NEES , so the fossil genus Cryptocaryoxylon is similar to our sample. A comparison of DM17 and the already described representatives of this genus has indicated some differences (see Tab. 1) which support the delimitation of a new species.

B o t a n i c a l a f f i n i t i e s. Cryptocaryoxylon lesbium has axial parenchyma in marginal bands of up to a 3-cell width. Marginal bands are also found in the Cryptocaryeae NEES tribe of the Lauraceae , thus the possible botanical affinities of our specimen include: Beilschmiedia , Endiandra , Potameia / Syndiclis , Triadodaphne , Cryptocarya , Ravensara , Licaria wilhelminensis . From the above-mentioned genera, we can exclude those which have different characteristics not in accordance with our sample: Endiandra contains species with idioblasts in the fibres, Potameia / Syndiclis and Triadodaphne don’t have idioblasts in ray parenchyma, Ravensara has only species which contain A type crystals and Licaria wilhelminensis has only 1-row of parenchyma in marginal bands. So our sample could be closer to the present day genus Cryptocarya and more precisely to the 20 % of species in this genus which have idioblasts in rays (only) and to an even more reduced percentage of species in this genus which have no crystals ( Richter 1981). Taking into account the work by Richter (1981) and the vessel diameters in our specimen, we could hypothesise that our sample is more similar to Cryptocarya species from Chile than Cryptocarya species from New Guinea.

Cryptocaryoxylon lemnium MANTZOUKA sp. nov. Pl. 1, Figs 7–15

H o l o t y p e. Designated here. Specimen DMLHM11 (Repository: Municipality of Moudros, Lemnos Island), 3 slides (Repository: Museum of Geology and Palaeontology in the National and Kapodistrian University of Athens).

P l a n t F o s s i l N a m e s R e g i s t r y N u m b e r.

PFN000087 (for new species).

E t y m o l o g y. The epithet, lemnium , is due to the origin of the described material (Lemnos Island, Greece).

T y p e h o r i z o n. Inside volcanic tuff (Romanou

Unit).

A g e. Εarly Miocene. T y p e l o c a l i t y. Moudros, Central-Eastern Lemnos

Island, Greece.

D i a g n o s i s. Heteroxylous wood, growth rings present, semi-ring/diffuse porosity, numerous vessels per sq. mm; vessels generally in radial multiples of 2 to 3, also single and in clusters, circular to oval in outline, tyloses present; exclusively simple perforation plates; alternate intervessel pits, polygonal; non-septate fibres; paratracheal axial parenchyma, vasicentric to aliform and banded parenchyma with up to 3-cell wide rows and seemingly marginal bands; numerous rays, exclusively heterocellular, short to medium sized; mostly biseriate and triseriate, but up to a width of 5 cells; no aggregate rays present; idioblasts numerous, associated with ray parenchyma cells and among the fibres; silica bodies (crystalliferous elements / aggregate grains) inside rays’ idioblasts.

D e s c r i p t i o n. Macroscopic description. Part of a silicified stump, 15 × 10 × 8 cm (Pl. 1, Fig. 7).

Microscopic description. Growth rings: distinct (Pl. 1, Fig. 8). — Wood: semi-ring/diffuse-porous (Pl. 1, Fig. 8). — Vessels: 14–16 vessels/sq. mm.; 30 % solitary, 50 % in groups of two, 10 % in groups of 3 and 10 % in clusters; tangential diameter of the solitary vessels 90 to 120 μm, mean: 100 μm; radial diameter of the solitary vessels 100 to 150 μm, mean: 120 μm; outline of solitary vessels round to oval (Pl. 1, Figs 8, 9); vessel walls thin; perforation plates simple (Pl. 1, Fig. 15); tyloses common (Pl. 1, Figs 8, 10); intervessel pits polygonal, alternate about 8–10 μm (medium in size) (Pl. 1, Fig. 11). — Rays: heterocellular (Pl. 1, Figs 11–14) up to 5 cells wide (20–60 μm) (Pl. 1, Fig. 10), and 200– 600 μm high (mean: 350 μm) (Pl. 1, Figs 11, 12), body of multiseriate rays composed of procumbent cells with one row of upright and/or square marginal cells (Pl. 1, Fig. 14); silica bodies (crystalliferous elements) observed inside the rays’ idioblasts (Pl. 1, Figs 11–14); 7–9 rays per mm. — Axial parenchyma: vasicentric paratracheal to aliform with up to 3-cell wide rows (Pl. 1, Figs 8, 9) seemingly marginal bands of parenchyma (Pl. 1, Figs 8, 10) — Fibres: most probably non septate. — Idioblasts: associated with the ray parenchyma cells and among the fibres (Pl. 1, Figs 11–14); mean radial × tangential diameter of the idioblasts in transverse section: 13–43 × 20–50 μm; number of idioblasts per sq. mm (transverse section): 15–23.

C o m p a r i s o n w i t h f o s s i l w o o d. See Table 1. Our specimen belongs to the Lauraceae . The following characteristics of the specimen DMLHM11 are similar to Laurinoxylon Type 2b ( Mantzouka et al. 2016): wood semi- -ring-diffuse porosity, growth ring boundaries distinct, vessels mainly in radial multiples of 2–3, often solitary but rarely in clusters, simple perforation plates and polygonal alternate intervessel pits medium size (8–10 μm), tyloses common, paratracheal axial parenchyma vasicentric (to aliform), rays up to 5-seriate (mainly 2-seriate), heterocellular, body of multiseriate rays composed of procumbent cells with one row of upright and/or square marginal cells, silica bodies (crystalliferous elements) observed inside rays’ idioblasts and idioblasts associated with ray parenchyma and also among the fibres .

Our sample also has features not in accordance with the Laurinoxylon emended diagnosis, such as: a) paratracheal axial parenchyma vasicentric-aliform of up to 3-seriate bands wide, b) axial parenchyma being seemingly in marginal bands and c) the occurrence of idioblasts in rays (abundant) and in fibres (sporadic) along with the existence of silica bodies inside rays’ idioblasts. The combination of features described above leads us to assign our specimen to Cryptocaryoxylon . The same result is obtained if we take into account Richter’s classification ( Richter 1981, 1987) based on the correlation of vessel-ray parenchyma pits and diameter classes of the intervessel pits, according to which our sample, DMLHM11, belongs to class b (with intervessel pits 8–12 μm, with vessel-ray pits variable in shape, round to oval, to elongate horizontally, vertically or diagonally).

DMLHM11 was compared with C. gippslandicum LEISMAN ( Leisman 1986) from the Tertiary of eastern Victoria but there are differences concerning the intervessel pits’ size, the apotracheal parenchyma, the exact location of the idioblastic cells, and the existence of siliceous inclusions in the material from Lemnos ( Tab. 1).

Although the age of the findings in Nut Beds (Middle Eocene) is not particularly similar to ours (Early Miocene), we compared our specimen with Cryptocaryoxylon hancockii , C. radiporosum and C. meeksii and although there are a lot of similarities it seems that DMLHM11 is not identical with any of the latter species ( Tab. 1). The major differences between Cryptocaryoxylon lemnium and C. hancockii are found in growth rings, vessel grouping, size and numbering, and intervessel pits’ size. Cryptocaryoxylon lemnium and C. radiporosum differ in growth rings, vessel grouping, size and numbering, intervessel pit size, rays’ width and exact location of idioblasts. A comparison of C. lemnium and C. meeksii revealed differences in vessel size (radial diameter), apotracheal parenchyma, rays’ width, exact location of idioblasts and the existence of crystalliferous elements (silica bodies). Although there are also some “blobs” inside the rays’ idioblasts in Cryptocaryoxylon radiporosum , which resemble silica bodies of C or even B type sensu Richter (1981) ( Wheeler and Manchester 2002: 71, fig. 19F), they most probably represent residues of oils/extracts in the cells (Dr. Wheeler pers.com.). There are also differences when compared with C. oleiferum ( Ramos et al. 2015) especially related to the idioblasts occurrence and crystals type (the sporadic occurrence of A type crystals inside rays’ idioblasts in C. oleiferum was confirmed by Dr. Ramos, pers. com.).

B o t a n i c a l a f f i n i t i e s. Richter (1981, 1990) clarified the existence of axial paratracheal and marginal parenchyma. He described the occurrence of paratracheal, mostly abundant vasicentric to aliform, often confluent with multiseriate bands 2–6(–10) cells wide ( Richter 1981: tab. 7, fig. 17a) in Beilschmiedia , Endiandra , Potameia / Syndiclis and Triadodaphne , the existence of paratracheal mostly sparse to slightly vasicentric multi-seriate bands 2–4(–8) cells wide ( Richter 1981: tab. 7, fig. 17b) in Cryptocarya and Ravensara and the occurrence of paratracheal incomplete to closed vasicentric bands of exclusively one-line in Licaria wilhelminensis as well as marginal (or seemingly marginal), fine, up to three cell wide bands in L. subbullata (Richter and Dallwitz 2000–onwards: Commercial timbers: descriptions, illustrations, identification, and information retrieval. Version: 25th June 2009; http://delta–intkey.com.); the latter two species are apparently synonyms according to The Plant List (Version 1.1., published on-line in 2013; http://www. theplantlist.org/ (last visit 13. 9. 2017 )). The occurrence of aliform to aliform-confluent paratracheal parenchyma has been observed in Hypodaphnis and Eusideroxylon (and/or Potoxylon , since some Eusideroxylon species have been moved to Potoxylon , and possibly Litsea garciae and L. sandakanensis ) ( Richter 1981).

Taking into account the latter characteristics along with the fact that SiO 2 was observed in Beilschmiedia , Endiandra , Potameia , Triadodaphne inaequitepala , Cryptocarya , Mezilaurus , Licaria wilhelminensis , Litsea , Dehaasia , Endlicheria , Anaueria and Clinostemon ( Richter 1981: tab. 11) we came to the conclusion that the closest modern genus is Cryptocarya which (according to Richter 1981) has the following characteristics: simple perforation plates, intervessel pits of 9–11 μm in diameter, large distinct bordered pits in fibres which are horizontally layered, paratracheal vasicentric to aliform or to confluent parenchyma, terminal bands of parenchyma, (2–)3–5(–7)-celled rays, rays with a maximum height of 0.4–0.75–1.5 mm, idioblasts mainly in rays but also in fibres, crystals of A type and SiO 2 of “agglomerate” type C (found only in 15 % of its species).

According to Carlquist (2001) the existence of SiO 2 (silica bodies) is of relevance to wood anatomists because its presence is often of diagnostic value as only a minority of dicotyledonous woods contain visible silica accumulations. Representatives of the Lauraceae which contain silica according to the latter author are: Cryptocarya , Licaria , Mezilaurus , Ocotea .

Regarding silica bodies, the function as load-bearing structures, as strengthening elements when in connection with Young’s modulus or perception as a beneficial element is still under research ( Mosbrugger 1990, Channing and Edwards 2013). Future research into the occurrence of silica dioxide crystals and druses in fossil woods would help clarify what had been the function of these elements and their complexity.

From study of the wood anatomy in DMLHM11 we recognizedthatthe occurrenceof SiO 2 (mainly “agglomerate” type C sensu Richter 1981) is mainly restricted to the interior of rays’ idioblasts. This diagnosis, along with the previously described characteristics of our sample, leads us to assign our specimen to Cryptocaryoxylon . The result is also the same if we consider the classification by Richter (1981, 1987) based on a correlation of the vessel-ray parenchyma pits with diameter size classes of the intervessel pits. According to this classification our sample DMLHM11 belongs to class b (with intervessel pits 8–12 μm, with vessel-ray pits variable in shape, round to oval, to elongate horizontally, vertically or diagonally).