Pliocene Wood of Larix from Southern Primorye (Russian Far East) O

Home , Keteleeria, Korfa Bay, Larix olgensis

ISSN 0031-0301, Paleontological Journal, 2007, Vol. 41, No. 11, pp. 1054Ð1062. © Pleiades Publishing, Ltd., 2007.

Pliocene Wood of Larix from Southern Primorye (Russian Far East) O. V. Bondarenko Institute of Biology and Soil Science, Far East Division, Russian Academy of Sciences, pr. Stoletiya Vladivostoka 159, Vladivostok, 690022 Russia e-mail: [email protected] Received December 19, 2007

Abstract—A new fossil larch species, Laricioxylon blokhinae, showing the wood anatomy of modern Larix olgensis A. Henry and L. leptolepis (Siebold et Succ.) Gord. is described. The taxonomic and structural diversity of larch species is reviewed, based on fossil wood remains from the Pliocene of southern Primorye.

DOI: 10.1134/S0031030107110044 Key words: Larix, Pinaceae, wood anatomy, Pliocene, southern Primorye.

INTRODUCTION Eastern Division of the Russian Academy of Sciences), collection IBSS, no. 20a. Fossil wood is often the only paleobotanical macro- In view of the heterogeneous nature of wood anat- fossil known from the Pliocene of the Russian Far East, omy, entailed by diverse functions of the tissue, the since remains of leaves and reproductive structures are anatomical sections were made in three mutually per- not usually preserved in the coarse alluvial deposits of pendicular planes (transverse, radial, and tangential). this age. We used the technique of preparing sections of fossil- At present, a single, but extremely rich locality for ized wood that was slightly carbonized and fossilized Pliocene wood is known in southern Primorye: Pav- (Gammerman et al., 1946). After preliminary treatment lovka lignite field. It is restricted to the Pavlovka group of the wood specimens (softening and consolidation), of depressions, situated 35 km northeast of the town of transparent thin sections were produced by hand, using Ussuriisk. The locality contains numerous and often a razor blade. In total, 730 thin sections were made and large (branches, stumps with butts, and even complete studied. The sections were studied microscopically and trunks) wood remains with well-preserved anatomy. microphotographs of anatomical structures were taken The fossil wood comes from small-pebble conglomer- by using “Mikmed” LOMO biological light micro- ates of the upper part of the cross-bedded sandstones scopes. and pebble gravels of the Suifun Formation. The forma- Resolutions tion is either Pliocene ( …, 1994) or TAXONOMIC AND STRUCTURAL DIVERSITY Eopleistocene in age (Pavlyutkin, 1998). Fossil leaves OF LARCHES ESTABLISHED ON THE BASIS are lacking in the beds. However, siltstone lenses have OF FOSSIL WOOD yielded spores, pollen grains, and plant debris com- posed of fossil fruits, seeds, and unidentifiable needles. On the basis of anatomical characters, 35 taxa of Pollen grains of the Pinaceae, including larch, are fossil wood have been determined. They belong to prominent in the palynological assemblage (Pavlyutkin 18 modern genera (Abies Mill., Keteleeria Carr., Picea et al., 1988; Resolutions…, 1994). A. Dietr., Larix Mill., Microbiota Kom., Biota (D. Don) Endl., Ulmus L., Quercus L., Betula L., Micromeles Decne., Malus Mill., Pyrus L., Padus Mill., Cerasus MATERIALS AND METHODS Mill., Acer L., Eleutherococcus Maxim., Fraxinus L., and Sambucus L.) and four fossil genera (Pseudotsug- The fossil wood of the new species was found in the oxylon Blokh. et Bondar., Piceoxylon Gothan, Lari- Pavlovka lignite field, Pavlovskii-2 open-cast coal cioxylon Greguss, and Populoxylon Mädel-Angeliewa) mine. The remains are dark brown and slightly lignitic, of 11 families (Pinaceae Lindl., Cupressaceae Gray, 6Ð23 cm in length and 3Ð18 cm in diameter. The growth Ulmaceae Mirb., Fagaceae Dumort., Betulaceae Gray, rings are 0.5Ð1.7 (3Ð5) mm wide and are readily distin- Salicaceae Mirb., Rosaceae Adans., Aceraceae Juss., guishable to the naked eye. The fossil wood remains are Araliaceae Juss., Oleaceae Hoffmanns. et Link, and housed at the Institute of Biology and Soil Science (Far Caprifoliaceae Adans.) (Bondarenko, 2006).

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PLIOCENE WOOD OF LARIX FROM SOUTHERN PRIMORYE (RUSSIAN FAR EAST) 1055

Of all gymnosperms in the wood remains of the Pav- (a) Abies lovka group of depressions, the Pinaceae is the most Laricioxylon 13% Keteleeria representative family both at the generic and specific 30% 6% levels. Quantitatively, members of the family constitute 72.5% of all determined specimens of fossil wood. Fig- ure 1 shows the proportions of pinaceous genera in the Pliocene dendroflora of the Pavlovka group of depres- Pseudotsugoxylon sions by the number of species (Fig. 1a) and specimens 6% of fossil wood (Fig. 1b): Larix and Laricioxylon taken Picea Larix Piceoxylon 19% together are the most representative genera both at the 13% 13% specific level (seven species, Table 1) and in numbers. (b) Abies Keteleeria There is no consensus on the number of species of 4% 1% larches currently occurring in Primorye. Koropachin- Pseudotsugoxylon 3% skii (1989) mentioned only two species: Larix cajan- Laricioxylon derii Mayr and L. olgensis A. Henry, the latter with a 33% very limited range (Table 1). Other authors have Picea referred to three (Kolesnikov, 1946), two (Dylis, 1961), 25% and four (Gukov, 1976) species present in the same region. All Pliocene wood showing the anatomy of larch is relatively easily differentiated from each other by a Larix Piceoxylon combination of structural elements (Table 2). 24% 10%

The wood anatomy of fossil wood remains of Larix Fig. 1. Proportions of genera of the Pinaceae in the Pliocene gmelinii (Rupr.) Rupr. is identical (even in finest detail) dendroflora of the Pavlovka group of depressions: (a) num- to that of modern L. gmelinii and differs from other ber of species; (b) number of specimens of fossil wood. larches in the presence of triseriate pitting on radial walls of tracheids and in the number and type of pits (both piceoid and taxodioid pits are present) on cross- Miocene of the Korfa Bay of the Kamchatka Peninsula fields. and L. sichotealinense Blokh. from the Upper Oli- gocene of the Siziman Bay of the Khabarovsk Region All anatomical characters of the fossil wood of (Blokhina, 1985), respectively. L. olgensis completely coincide with those of modern L. olgensis. The characteristic features are large pits on The fossil wood of L. aff. chelebaevae is distinct radial and tangential walls of tracheids, high uniseriate from other Pliocene larch wood remains by the occa- rays, and numerous pits on cross-fields. sional occurrence of helical thickenings on walls of vertical tracheids, the highest (up to 8 cells) biseriate Laricioxylon pavlovskiense Blokh. et Bondar. is regions in uniseriate rays, and smaller pits on radial characterized by a peculiar combination of characters walls of tracheids. of three modern species: Larix occidentalis Nutt., L. gmelinii, and L. olgensis. Among numerous bi- and The fossil wood of L. aff. korfiense is characterized uniseriate pits, triseriate pits also occur on radial walls by smaller pits on radial walls of tracheids, less numer- of tracheids; the maximum number of pits occurs on ous pits on cross-fields, large pits on tangential walls of cross-fields (up to 10). tracheids, and high uniseriate rays. The fossil wood described below, Laricioxylon L. aff. sichotealinense has the smallest (merely 6Ð µ blokhinae sp. nov., combines the wood anatomical 7.5 m) pits on tangential walls of tracheids, not characters of modern Larix olgensis and L. leptolepis numerous pits on cross-fields, and very high uniseriate (Siebold et Zucc.) Gord. It differs from other fossil rays. wood showing the anatomy of larch from the Pliocene All fossil larch wood from the Pliocene of the of the Pavlovka group of depressions in the larger pits Pavlovka group of depressions are characterized by (30Ð36 µm) on radial walls of tracheids, large pits on (1) numerous, predominantly biseriate, pits on radial tangential walls of tracheids, very high uniseriate rays, walls of tracheids, (2) large pits on radial (27Ð30 (36) µm and numerous pits on cross-fields. in diameter) and tangential (7Ð12 µm) walls of trache- Several kinds of fossil wood from the Pliocene of ids, (3) numerous (6–10) piceoid pits on cross-fields the Pavlovka group of depressions show a considerable (taxodioid pits are found only in Larix gmelinii), and similarity to wood from older deposits (Table 1). Thus, (4) high uniseriate pits (up to 30Ð40 (47) cells). Pliocene Laricioxylon aff. chelebaevae Blokh., L. aff. Among similar modern larches (Table 1), Larix korfiense Blokh., and L. aff. sichotealinense Blokh. are occidentalis and L. lyallii Parl. currently have a North similar to L. chelebaevae Blokh. (Blokhina, 1996b) and American range, L. gmelinii and L. sibirica Ledeb. have L. korfiense Blokh. (Blokhina, 1996a) from the Middle a Siberian range, L. leptolepis has a Japanese range, and

PALEONTOLOGICAL JOURNAL Vol. 41 No. 11 2007

1056 BONDARENKO Central and eastern Siberia, northern Inner Mongolia, northeastern China slopes of the Sikhote-Alin, and Valentin between the Vladimir bays Central Honshu (Japan) Idaho (United States) and British Columbia (Canada) As number 1 cade Range (United States) As number 3 As number 1 al and geographical ranges Nutt. Montana, Washington, Nutt. As number 4 (Siebold (Siebold A. Henry Marine coast and eastern A. Henry As number 2 A. Henry As number 2 (Rupr.) (Rupr.) (Rupr.) (Rupr.) (Rupr.) Ledeb. and central Siberia Western Parl. Mountains and Cas- Rocky gmelinii olgensis olgensis leptolepis occidentalis gmelinii olgensis sibirica lyallii leptolepis occidentalis gmelinii

Larix Rupr. Larix Larix Larix et Zucc.) Gord. Larix Larix Rupr. Larix Larix Larix et Zucc.) Gord. Larix Larix Rupr. Larix Laricioxylon chelebaevae Middle Miocene, Korfa Middle Miocene, Korfa Kamchatka Peninsula Bay, As Upper Oligocene, Siziman Region Khabarovsk Bay,

Related fossil species Related modern species chelebaevae korﬁense sichotealin-

species name occurrence species name geographical range Blokh. Laricioxylon Laricioxylon Blokh. Blokh. Laricioxylon ense 1Ð Ð 6Ð Ð 2 3 24 Ð Ð 10 Number of specimens in the collection

sicho- chele- korﬁ- A. Henry 31 Ð Ð (Rupr.) (Rupr.) blokhinae pavlovski-

aff. aff. aff. Blokh. species Blokh. Fossil wood Fossil gmelinii olgensis

Blokh. et Bondar. Blokh. Fossil wood of larches from the Pliocene of the Pavlovka group of depressions and related fossil modern species. Geologic of larches from the Pliocene Pavlovka wood Fossil Larix Rupr. Larix Laricioxylon sp. nov. Bondarenko O.V. Laricioxylon ense Laricioxylon baevae Laricioxylon ense Laricioxylon tealinense 2 3 4 5 6 1 7 No. Table 1. Table

PALEONTOLOGICAL JOURNAL Vol. 41 No. 11 2007 PLIOCENE WOOD OF LARIX FROM SOUTHERN PRIMORYE (RUSSIAN FAR EAST) 1057 aff. Blokh. sichotealinense Laricioxylon korﬁense Blokh. Laricioxylon aff. aff. Blokh. chelebaevae Laricioxylon character occurs very rarely; (?) no data. character occurs very aff. aff. Laricioxylon pavlovskiense Blokh. et Bondar.

sp. nov. sp. nov. (30Ð36) blokhinae Laricioxylon

ÐÐÐÐÐÐ olgensis

A. Henry Larix ÐÐÐÐ+ÐÐÐÐ +++++++ +++++++ +++++++ gmelinii

9Ð12 6Ð8(10) 7Ð10(12) 12 6Ð7.5(9) 9Ð12 6Ð7.5 (Rupr.) Rupr. (Rupr.) Larix m 18Ð27(30) (14)18Ð28(30) (12)18Ð28 (14)17Ð24(30) 15Ð24(27) 15Ð24(30) (15)18Ð21(27) m (4.5)6Ð8(9) 4.5Ð6 5Ð8 5Ð7 4.5Ð6 6Ð7.5 5Ð7 µ µ m µ Comparative anatomy of fossil larch wood from the Pliocene of southern Primorye anatomy of fossil larch wood Comparative biseriate bi- or triseriatetriseriateshortlong + + + 1Ð3 11 + 1Ð12 Ð 4Ð25 Ð 2Ð5 +Ð 11Ð20 Ð 1Ð10 5Ð26 + 1Ð5 2Ð14 + Ð 1Ð6 10Ð24 Ð + 10Ð28 1Ð19 + piceoid taxodioid +Ð Anatomical characters uniseriate biseriatetriseriate pit diameter, ++ +ÐÐ ++ Ð ++ Ð ++ +Ð ++ Ð ++ Ð ++ Ð height (number of cells)number of biseriate regionsnumber of epithelial cells 1Ð26 1Ð3number of epithelial cells 8Ð10(12)arrangement in rays 1Ð35(42) 1Ð3(6) 8Ð9(11) 8Ð10(12) 1Ð35(47)uniseriate ends: 7Ð10(13) 7Ð10 1Ð6 1Ð25(30) 7Ð9(10)number of pits (5)6Ð9 pit diameter, 1Ð27 Ð 8Ð11 5Ð7 1Ð30(46) 1Ð6(7) 1Ð8 7Ð12 1Ð35(44) 1Ð6(7Ð8) 6Ð9 1Ð7 8Ð12 1Ð6(7Ð8) 6Ð8 1Ð6(7Ð10) 1Ð6 6Ð10 1Ð6 1Ð6 1Ð6 type of pits Note: (+) character is present, (Ð) absent, (++) (+Ð) character prevails, character is occasionally present, (+ÐÐ) Pits on radial walls of tracheids: Pits on radial walls Pit diameter on tangential walls Pit diameter on tangential walls of tracheids, on walls Helical thickenings tracheids of vertical Uniseriate rays: resin canals: Vertical Horizontal resin canals: Pits on cross-ﬁelds: Table 2. Table

PALEONTOLOGICAL JOURNAL Vol. 41 No. 11 2007 1058 BONDARENKO

Plate 1

4 7

5 6

1 10 11 9

2 13 14

PALEONTOLOGICAL JOURNAL Vol. 41 No. 11 2007 PLIOCENE WOOD OF LARIX FROM SOUTHERN PRIMORYE (RUSSIAN FAR EAST) 1059

L. olgensis is an endemic of the Sikhote-Alin. Pliocene 20 cells. Piceoid pits 1–6(7–8) per cross-field, 5–8 µm finds of Laricioxylon pavlovskiense, L. aff. chelebae- in diameter. vae L. korfiense Larix , and aff. , resembling the modern Description. The wood consists of tracheids, occidentalis L. lyallii and in wood anatomy, confirm the ray tracheids, ray parenchyma, and epithelial cells of supposition made by Blokhina (1984) that larches resin canals. related to modern North American species possibly grew in the Russian Far East during the Neogene, but Earlywood tracheids are large, thin-walled, with disappeared in the post-Pliocene time. large lumina, radially elongated, rectangular and polyg- In addition, the majority of Pliocene wood remains onal (Pl. 1, figs. 1, 2). Uniseriate pits are circular and of larch show the anatomical wood characters of the slightly oval, horizontally elongated, with included cir- modern Larix olgensis and/or L. gmelinii (Table 1). cular and oval apertures, respectively; they are in dif- This fact, along with finds of fossil wood of L. olgensis fuse or close arrangement, or crowded along the length and L. gmelinii, testifies to the probable presence of of the tracheid (Pl. 1, figs. 4–6). Circular pits are 18– µ × these species in southern Primorye in the Pliocene and 24(28Ð30) m in diameter, and oval pits are 18Ð21 µ the possibility of their introgressive hybridization with 24Ð30(36) m in size. Biseriate pits are opposite, circu- other ancient larches (Bondarenko and Blokhina, lar and slightly oval, horizontally elongated, with 2003). Dylis (1961), Bobrov (1972, 1978), and Gukov included circular and oval apertures, respectively; they (1976) found in Primorye hybrids with the participation are in diffuse or close arrangement, or crowded along of L. olgensis: L. lubarskii Suk. and L. komarovii the length of the tracheids (Pl. 1, figs. 3, 5). Circular pits µ × B. Kolesn. Unfortunately, so far the wood anatomy of are 18Ð24(30) m in diameter, and oval pits are (14)18 µ hybrid larches has not been studied. 21(24Ð28) m in size. Crassulae are present between biseriate pits. On radial walls of latewood tracheids, only uniseriate pits occur, which are circular, 12Ð15 µm SYSTEMATIC PALEOBOTANY in diameter, in a very diffuse arrangement along the Family Pinaceae Lindley, 1836 length of the tracheid. Last latewood tracheids lack pits. Pits on tangential walls of tracheids are abundant, uni- Genus Laricioxylon Greguss, 1967 and biseriate, 7Ð10(12) µm in diameter. Uniseriate pits Laricioxylon blokhinae O.V. Bondarenko, sp. nov. are in diffuse arrangement along the length of the trac- Plate 1, figs. 1–14 heid; biseriate pits are more or less opposite or alternate µ Etymology. In honor of N.I. Blokhina, a fossil (Pl. 1, fig. 10). There are 1Ð6(7Ð8) piceoid pits 5Ð8 m wood anatomist. in diameter per cross-field (Pl. 1, figs. 12, 13). Holotype. IBSS, no. 20a/135, fossil wood, Pri- Growth rings are distinct, 0.5Ð1.7(3Ð5) mm wide, morye, Mikhailovskii district, Pavlovka lignite field, mostly consisting of earlywood tracheids. The transi- open-pit coal mine Pavlovskii-2, Suifun Formation, tion from earlywood to latewood is abrupt; occasion- Pliocene; Pl. 1, figs. 1–14. ally, it becomes more gradual in the widest rings. Late- Diagnosis. Growth rings distinct. Pits on radial wood occupies only about one-fourth to -one-fifth of walls of tracheids rarely uniseriate, predominantly bis- the growth ring. Latewood tracheids are thick-walled, eriate, opposite. Crassulae present. Circular pits 18Ð rectangular or strongly flattened in radial direction, 24(28Ð30) µm in diameter, and elliptic pits (14)1821 × with nearly slitlike lumina (Pl. 1, figs. 1, 2). 24Ð30(36) µm in size. Pits on tangential walls of trac- Rays are numerous, of two types: uniseriate and heids uniseriate and biseriate, 7Ð10(12) µm in diameter. multiseriate, the latter type is with horizontal resin Uniseriate rays 1Ð35(47) cells high, occasionally with canals. The height of uniseriate rays is 1Ð35(47) cells 1Ð6 biseriate layers. Inner walls of ray tracheids (Pl. 1, fig. 9), biseriate regions occasionally present, smooth. Vertical and horizontal resin canals encircled 1−6 cells long. Ray tracheids are arranged in 1Ð2(3) rows with 7Ð10(13) and (5)6Ð9 thick-walled epithelial cells, along ray margins (Pl. 1, figs. 11–13), or, more rarely, respectively. Horizontal resin canals occur in biseriate in one or two rows in the middle part of the ray. They rays; uniseriate ends equal (up to 1Ð8 cells long) or also form separate rays with 1Ð3(4) rows (Pl. 1, fig. 14). unequal: short ends of 2Ð5 cells, and long ends of 11Ð Ray tracheids are low, with smooth interior and uneven

Explanation of Plate 1 Figs. 1Ð14. Laricioxylon blokhinae sp. nov., holotype IBBS, no. 20a/135: (1) transverse section, wide growth ring, a gradual earlywood/latewood transition, ×35; (2) transverse section, narrow growth rings, an abrupt earlywood/latewood transition, note vertical resin canals in latewood, ×47; (3) radial section, biseriate pits on tracheid walls, ×206; (4) radial section, large uniseriate pits on tracheid walls, ×206; (5) radial section, uniseriate and biseriate pits on tracheid walls, ×206; (6) radial section, uniseriate pits on tracheid walls, ×206; (7) tangential section, horizontal resin canal in a biseriate ray with short equal uniseriate ends, ×206; (8) tangential section, horizontal resin canal in a biseriate ray with unequal uniseriate ends, ×206; (9) tangential section, long uniseriate ray, ×206; (10) tangential section, pits on tracheid walls, ×206; (11) radial section, marginal ray tracheids, ×206; (12) radial section, eight piceoid pits on cross-fields, ×330; (13) radial section, pits on cross-fields, pitted walls of ray cells, ×206; (14) radial section, ray tracheids in two rows, ×206. Primorye, Pavlovka lignite field, open-cast coal mine Pavlovskii-2, Suifun Formation, Pliocene.

PALEONTOLOGICAL JOURNAL Vol. 41 No. 11 2007 1060 BONDARENKO Blokh. – 4–14 Laricioxylon koﬁense (Blokhina, 1996a) 2003) Laricioxylon primorskiense and Snezhkova, Blokh. (Blokhina data. Gord. …, 1992) Atlas Greguss, 1955, 1963; Greguss, Larix leptolepis (Budkevich, 1956, 1961; (Budkevich, A. Henry sp. nov. and wood of related modern and fossil species and wood sp. nov. darov, 2000) darov, Blokhina, 1998; (Budkevich, 1961; (Budkevich, Blokhina and Minkhai- Larix olgensis Laricioxylon blokhinae sp. nov. ÐÐ+ÐÐÐ 7Ð10(12) 6Ð9(12) (5)6Ð9(10) (6)9 ? Laricioxylon blokhinae m (12)18Ð28(30Ð36) (18)21Ð27(30) 20Ð24 (15)18Ð24(30)m 15Ð24 5Ð8 4Ð5 ? 5 5Ð7 µ µ m µ characters Anatomical Comparative anatomy of fossil wood of anatomy of fossil wood Comparative biseriatebi- or triseriatetriseriateshortlong Ð +piceoid Ðtaxodioid 2Ð5 11Ð20 + + + + Ð 1Ð10 17Ð28 Ð + Ð 2Ð13 1Ð4 + Ð Ð + 7Ð16(25) Ð 3Ð8 + +Ð Ð + 1Ð4 Ð + Ð + uniseriatebiseriate pit diameter, + ++ + ++number of pits pit diameter, + + 1Ð6(7Ð8) + ++ 1Ð6(8) + + 1Ð6(7) 1Ð6(8Ð9) 1Ð6 height (number of cells)number of biseriate regionsnumber of epithelial cells 1Ð35(47) 1Ð6number of epithelial cellsarrangement in rays 7Ð10(13) (5)6Ð9 1Ð36uniseriate ends: 1Ð2(5) 8Ð10(12) 8Ð10(12) 1Ð30(37)type of pits 8Ð12 ? 6Ð12 1Ð30(40) 7Ð10 Ð 1Ð30(40) 6Ð10 8Ð10(12) 1Ð6(11) 6Ð10(12) Note: (+) character is present, (Ð) absent, (++) (+Ð) character prevails, character is occasionally present, (?) no Pits on radial walls of tracheids: Pits on radial walls Pits on cross-ﬁelds: Pit diameter on tangential walls Pit diameter on tangential walls of tracheids, on walls Helical thickenings tracheids of vertical Uniseriate rays: resin canals: Vertical Horizontal resin canals: Table 3. Table

PALEONTOLOGICAL JOURNAL Vol. 41 No. 11 2007 PLIOCENE WOOD OF LARIX FROM SOUTHERN PRIMORYE (RUSSIAN FAR EAST) 1061 and occasionally strongly sinuous external walls. Bor- are often difficult to differentiate. Nonetheless, the dered pits are present on radial walls of ray tracheids. presence of predominantly biseriate pits on radial walls Vertical resin canals with 7Ð10(13) thick-walled of tracheids, smooth internal walls of ray tracheids, epithelial cells are predominantly situated in latewood. numerous pits on cross-fields, abrupt earlywood/late- Resin canals are 40Ð100 µm in diameter, circular and wood transition, and arrangement of horizontal resin oval, radially elongated (Pl. 1, fig. 2). Horizontal resin canals only in biseriate rays with sharply uneven unise- canals are with (5)6Ð9 thick-walled epithelial cells, riate ends allow me to assign the wood under study to oval, elongated along the ray, 36Ð48 µm in diameter; they the genus Larix. are situated in biseriate rays with equal (1Ð14 cells) or Greguss (1967) proposed to use the generic name sharply unequal uniseriate ends: the short end consists Laricioxylon for fossil wood remains showing the anat- of 2Ð5 cells, and the long end consists of 11Ð20 cells omy of modern larches. Since the wood under study is (Pl. 1, figs. 7, 8). not identical to any modern or fossil larch, it should be Comparison. The fossil wood under study most considered as a new fossil species, Laricioxylon blokhi- closely resembles the wood of modern Larix olgensis nae sp. nov., with a certain similarity to the wood of and L. leptolepis (Table 3). It differs from the wood of modern Larix olgensis and L. leptolepis. L. olgensis mostly by the absence of triseriate rays with Material. IBBS, nos. 20a/3, 20a/4, 20a/6, 20a/9, horizontal resin canals. In addition, it has slightly larger 20a/29, 20a/30, 20a/31, 20a/33, 20a/40, 20a/44, 20a/48, pits on radial walls of tracheids and cross-fields, shorter 20a/50, 20a/52, 20a/54, 20a/55, 20a/57, 20a/101, 20a/135 uniseriate ends of multiseriate rays, and smaller num- (holotype), 20a/150 and IBBS, nos. 20b/5, 20b/16, ber of epithelial cells lining horizontal resin canals. 20b/23, 20b/32, 20b/49. In total, 24 specimens were The fossil wood under study differs from the wood studied. of L. leptolepis in the larger pits on radial and tangential walls of tracheids, more numerous pits, and in the ACKNOWLEDGMENTS absence of taxodioid pits on cross-fields, as well as in the longer uniseriate ends of multiseriate rays and less I am grateful to N.I. Blokhina for the valuable dis- numerous epithelial cells lining horizontal resin canals. cussion during the study and to K.P. Novikova (IBBS) Among fossil wood, some similarities are found in for printing photographs. The study was supported by Laricioxylon primorskiense Blokh. from the Upper the Presidium of the Russian Academy of Sciences and Miocene of the Erkovetskii brown coal field in the Presidium of the Far East Division, Russian Academy Amur Region (Blokhina and Snezhkova, 2003) and of Sciences, grants no. 06-I-P11-022 (Program Scien- L. korfiense from the Middle Miocene of the Korfa Bay tific Grounds of Biodiversity Conservation in Russia) of the Kamchatka Peninsula (Blokhina, 1996a). and no. 06-I-P18-081 (Program Origin and Evolution The wood under study differs from L. primorskiense of the Biosphere), and the Russian Foundation for in the larger pits on radial and tangential walls of trac- Basic Research, project no. 05-04-49907. heids, higher uniseriate rays, biseriate regions in uniseriate rays, numerous epithelial cells lining vertical resin REFERENCES canals, slightly smaller number of pits per cross-field, 1. Atlas of Wood and Wood Fibers for Paper, Ed. by and greater diameter of such pits (Table 3). E. S. Chavchavadze (Klyuch, Moscow, 1992) [in Rus- The Pliocene wood differs from the wood of L. kor- sian]. fiense in the prevalence of biseriate pits on radial walls 2. N. I. Blokhina, “Wood of Laricioxylon shilkinae of tracheids, greater diameter of such pits, higher unis- (Pinaceae) from the Upper Oligocene of the Siziman eriate rays, and shorter biseriate regions in uniseriate Bay (Khabarovsk Krai),” Bot. Zh. 69 (11), 1498Ð1501 pits, less numerous epithelial cells lining horizontal (1984). resin canals, and more numerous pits on cross-fields 3. N. I. Blokhina, “A New Fossil Species of Larix (Based (Table 3). on Wood) and the Problem of the Origin of Siberian and Remarks. The presence of normal vertical and Daurian Larches,” in Komarov Readings (Dal’nevost. horizontal resin canals with thick-walled epithelial Nauchn. Tsentr Akad. Nauk SSSR, Vladivostok, 1985), cells testifies to the affinity of the wood under descrip- No. 32, pp. 3Ð13 [in Russian]. tion to the formal genus Piceoxylon, which embraces 4. N. I. Blokhina, “Fossil Larch Wood (Larix, Pinaceae) fossil wood remains showing characters of modern from the Middle Miocene of the Korfa Bay (Kam- Picea, Larix, Pseudotsuga Carr., and, in part, Ketelee- chatka),” Bot. Zh. 81 (6), 91Ð101 (1996a). ria Carr. 5. N. I. Blokhina, “New Species of Laricioxylon Wood from the Middle Miocene of the Korfa Bay, Kamchatka,” However, Keteleeria should be excluded because of Paleontol. Zh., No. 1, 124Ð128 (1996b) [Paleontol. J. 30 lacking horizontal resin canals. The wood of Pseudot- (1), 119Ð123 (1996b)]. suga differs in the presence of helical thickenings on 6. N. I. 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