Palaeogene leaf compressions of Taxodium mucronatum Ten. affinity from Pasekovo, Middle Russian Upland, Southern European Russia

Pre-print version.

Published in Scientia-CUCBA 5(1-2): 63-87. 2003. (ISSN 1665-8493)

Manuscript received 23.08.2003, accepted 27.11.2003.

Palaeogene leaf compressions ofTaxodium mucronatum Ten.

affinity from Pasekovo, MiddleRussian Upland, southern

European Russia

SERGEI V. [email protected]

V. L. Komarov B otanical Institute, Russian Academy of Sciences

St. Pete rsbu rg, 197 376, R ussia

BEN A. [email protected]

URS Corporation, 1400 Union Meeting Road, Suite 202

Blue Bell, PA 19422-1972, USA

VIACHESLAV YU. [email protected]

Department of Botany, St. Petersburg State Un iversity

St. Petersburg, 199034, Russia

current address: Guadalajara, Jalisco, Mexico

SUMMARY

Numerous leaf compressions of Taxodiumbalticum Sveshn. et Budants. were found in therecently discovered Late Eocene? – Early OligocenePasekovo brown-coal locality (41 mln. years) ofVoronbezh oblast’, Central Russia (Âèêóëèí, 1987;2002; Vickulin 1999 a, b). The fossil T. balticum isthe most ancient structurally verified amongstdiscovered ever since true Taxodium’s in Europe,

Pre-print version.



where this particular species was distributed withinthe time span of Eocene – Oligocene of Western,Central Russia and Germany. A detailed account ofcomparat ive leaf micromorpholo g y a ndstomatography of fossil and all 3 living species ofTaxodium is given. The seed cones and their scalescarry a prominent central spine on the outer surfaceshowing close similarity of the fossil with a mexicanspecies of T. mucronatum, whereas epidermalfeatures also reinforce affinities of fossil leaves of T.balticum towards T. mucronatum. In terms ofphytocenology T. balticum was in association withthe archaic ericaceous Epacridicarpum and hadrepresented the most ancient specific Late Eoceneversion of Taxodium – Nyssa – Alangiumassociation that was widely distributed throughoutthe Europe thereafter in Miocene.

RESUMEN

Hace poco se encontraron en la región deVoronezh, en la localidad carbonífera de Pasekovo,en Rusia central, numerosas impresiones deTaxodium balticum Sveshn. Et Budants. Del Eocenotardío? — principios del Oligoceno. El fósil de T.balticum es el más antiguo desde el punto de vistaestructural entre los verdaderos Taxodiumdescubiertos en Europa, donde esta especie estuvodistribuida dentro del periodo Eoceno — Oligocenodel oeste, Russia central y Alemania. Se hizo unestudio comparativo detallado de la micromorfologíay estomatografía de la hoja de fósil y de las tresespecies actuales conocidas. Los conos femeninos y

Pre-print version.



sus escamas poseen una espina central prominiente yen apariencia en fósil muestra similitud con laespecie mexicana Taxodium mucronatum, mientrasque las características de la epidermis refuerzantambién las afinidades de T. balticum con T.mucronatum. Con respecto a la fitocenología, T.balticum estuvo asociada con Epacridicarpum, unaericacea arcaica y habría representado la versiónespecífica más antigua del Eoceno tardío, en laasociación Taxodium — Nyssa — Alangium queestuvo bastante distribuida por Europa, tiempodespués, en el Mioceno.

ÐÅÇÞÌÅ

Ìíîãî÷èñëåííûå ôèòîëåéìû ëèñòüåâTaxodium balticum Sveshn. et Budants. áûëèí å ä àâ í î î á í à ð ó æ å í û â Ï à ñ å êî â ñ ê îìáóðîóãîëüíîì ìåñòîðîæäåíèè Âîðîíåæñêîé îáë.,(Öåíòðàëüíàÿ Ðîññèÿ), 41 ìëí. ëåò (Vickulin1999b). Èñêîïàåìûé T. balticum ÿâëÿåòñÿíàèáîëåå äîñòîâåðíûì è äðåâíèì èç ñòðóêòóðíîñîõðàíèâøèõñÿ ïðåäñòàâèòåëåé èñòèííûõTaxodium â Åâðîïå. Äàííûé ýîöåíîâî-îëèãîöåíîâûé âèä áûë ðàñïðîñòðàíåí âÇàïàäíîé, Öåíòðàëüíîé Ðîññèè è Ãåðìàíèè.Ï ð è â î ä ÿ ò ñ ÿ ä å ò à ë ü í û å ä à í í û å ï îñ ð à â í è ò å ë ü í î é - ñ ò î ì à ò î ã ð à ô è è èìèêðîìîðôîëîãèè ëèñòüåâ êàê èñêîïàåìîãî, òàêè âñåõ òðåõ ñîâðåìåííûõ âèäîâ Taxodium.Ñåìåííûå (æåíñêèå) øèøêè, èõ ùèòêè èìåþò íàâíåøíåé ïîâåðõíîñòè çíà÷èòåëüíî âûðàæåííûéöåíòðàëüíûé øèïèê, ÷òî ñâèäåòåëüñòâóåò î

Pre-print version.



áëèçêîé ñâÿçè èñêîïàåìîãî âèäà ñ ñîâðåìåííûììåêñèêàíñêèì T. mucronatum. Ïðèçíàêèýïèäåðìàëüíîãî ñòðîåíèÿ ëèñòüåâ òàêæåïîä÷åðêèâàþò ñõîäñòâî T. balticum è T.mucronatum. Ôèòîöåíîëîãè÷åñêè, T. balticumâõîäÿ â àññîöèàöèþ ñ àðõàè÷íûì ýðèêîèäíûìEpacridicarpum, ïðåäñòàâëÿë ñîáîé íàèáîëååäðåâíþþ - ïîçäíåýîöåíîâóþ, èç èçâåñòíûõôèòîàññîöèàöèé Taxodium – Nyssa – Alangium,êîòîðàÿ íåêîãäà áûëà øèðîêî ðàñïðîñòðàíåíà ïîâñåé Åâðîïå è ïîëó÷èëà îñîáîå ðàçâèòèå ïîçäíåå– â ìèîöåíå.

Key words: Conifers, Taxodium, stomata, leafcut ic le , microm orphology/stomatography,Eocene/Oligocene.

INTRODUCTION

The fossil leaves of Taxodium as compressionsare found from Upper Cretaceous to Miocenesediments all over the Northern Hemisphere. Itremained in Europe until the Pliocene. However inmodern times Taxodium has been confined only inNorthern and Central America. In the fossil recordTaxodium was known since Late Cretaceous(Ñâåøíèêîâà 1967; Aulenback & LePage 1998). Anumber of representatives of the family Taxodiaceae,to which Taxodium belongs, remained in Europeuntil Pliocene, but current distribution of the abovefamily within the Northern Hemisphere is restrictedwithin two major continents: 1) by Eastern Asia,

Pre-print version.



where species of Glyptostrobus, Metasequoia,Cryptomeria, Cunninghamia, Scyadopitis andTaiwania occupy very limited areas, and 2) NorthernAmerica wi t h T a x o d i u m , S e q u o i a andSequoiadendron (Aulenback & LePage op. cit.;Graham 1999; Ma & Gu 2000; Vickulin 2000a, b;Vickulin et al. 1995, 2003). Additionally, theSouthern Hemisphere is presently occupied by theonly Taxodiaceous genus – Athrothaxis, though inthe fossil record of of eastern Otago, New Zealandsuch a taxa as Sequoiadendron is also known (Pole1995).

Taxodium balticum Sveshn. et Budants.,described earlier from Russia and Germany is animportant component of the Late Eocene – EarlyOligocene transitional Haselbah-Svetlogorsk-Pasekovo type of paleofloras (Âèêóëèí 1987; Mai1996; Mai & Walther 1978, 1985; Vickulin 1999b).Initially, it was described by I. N. Sveshnikova and L.Yu. Budantzev from Early Oligocene outcrops at theBaltic sea coast near small cities of Svetlogorsk andOtradnoe of Kaliningrad district of Western Russia(Ñâåøíèêîâà è Áóäàíöåâ 1960; Ñâåøíèêîâà1963a, b). Among fossil remains that had beenoriginally recognized were such vegetative remains,as imprints of terminal branches with structurallypreserved leaf-cuticles, and female cones/scales witha prominent spike-like outgrowths. Cone scalescovered with a distinctive spine-sculpture were a key-feature that allowed authors to describe new species(Ñâåøíèêîâà è Áóäàíöåâ, op. cit.). Later, in 1963,preliminary paleocarpological data on Kaliningradfossil floras were published by P. I. Dorofeev (1963).

Pre-print version.



His article was published without any illustrations ofexamined species, inclusively noted such nomennudum as T. paleomucronatum Dorof. Part of thefemale cone scales with distinctive scale sculptureand spines was described by Dorofeev usingtrinominal name – Taxodium distichum miocenumHeer. After revising of materials collected bySveshnikova, Budantzev and Dorofeev (collectionsare stored in Komarov Botanical Institute), S. V.Vickulin found them identical (unpublishedobservations 1987). The identity of the Taxodiumfemale cone-structures in different collections ofSveshnikova, Budantzev and Dorofeev was confirmedby paleocarpologists K. P. Proskurin (pers. comm.1988) and O. N. Arbuzova (pers. comm. 1995).Neither Sveshnikova and Budantzev, nor Dorofeev in1950 – 1970 had a complete and reliable herbariumreference material for all 3 extant Taxodium species.Herbarium specimens of T. ascendens Brongn. andT. mucronatum Ten. were not available in KomarovInst. at the time and fossil findings were compared byall above authors only with a more commonly knownspecies of T. distichum (L.) Rich.

In 1978, German paleobotanists D. Mai and H.Walter had described identical Taxodium remainsfrom Early Oligocene of Haselbach flora near Leipzig(Germany) using nomen T. balticum (Mai & Walter1978, 1985). Mai was personally acquainted withTaxodium-remains from collections of Dorofeev,Sveshnikova and Budantzev (pers. comm. 1980).Mai and Walter (op. cit.) had described fossilTaxodium’ leafy branchlets, female cone scales withspines, seeds and finely preserved leaf epidermal

Pre-print version.



structures with stomata, which were adduced toconfirm taxonomical diagnosis (Tab. 1). Germanauthors had specified that Eocene-Early OligoceneTaxodium relates closely to mexican T. mucronatum,not to a T. distichum.

Phylogenetic interrelations and taxonomy of thefamily Taxodiaceae, incl. Taxodium, were studied bya number of authors, involving different approachesof molecular biology, cytogenetics, micro- andmacromorphology of seeds, bark, leaves, etc(Aulenback & LePage 1998; Brunsfeld et al. 1994;Chaw et al. 1997; Cross 1939a, b, 1940; Gadek et al.2000; Hart 1987; Hida 1957; Hilu & Liang 1997;Kaiser 1953; Kusumi et al. 2000; Page 1990; Philips1941; Price & Lowenstein 1989; Schlarbaum et al.1983; Soltis et al. 1992; Stefanovic et al. 1998; Takaso& Tomlinson 1990; Tsumura et al. 1999). Howevercomparative leaf micromorphology is still poorlyknown for fossil and recent species; present study isthe first detailed SEM comparative investigation ofthe Late Eocene Taxodium leaf micromorphologywith the all three modern Nearest Living Relativesfrom North America.

Recently discovered leaf c ompressions/impressions and shoot fragments of fossil Taxodiumfrom the Late Eocene-Early Oligocene Pasekovo floraof European Russia (Âèêóëèí 1987; Vickulin 1999a,b; Vickulin et al., 2002) are under treatment in thepresent paper in terms of comparative SEM/LM leafmicromorphology and stomatography. TertiaryTaxodium remains are described here as T. balticumfollowing Walter and Mai (1978), and close similarityof treated fossil species with a living T. mucronatum

Pre-print version.



is proved based primarily on comparative leaf cuticlemicromorphology. Distinctive elongated seeds ofTaxodium from the Pasekovo-locality were describedhere as so called paleocarpological species – T. heerii. Fossil remains are considered at thebackground of morphological comparisons with all 3species of North American NLR. Integrated macro/micromorphological and paleocarpological data,together with ongoing paleopalynological studies(palinological evidence will be considered shortly as aseparate paper) allow us to consider Early Tertiary T.balticum to be closely related with a semi-evergreenmexican Montezuma-Cypress – T. mucronatum Ten.Preliminary brief notes on the fossil species of T.balticum were recently published (Vickulin et al.2002).

MATERIALS AND METHODS

Fossil sites and specimens: new fossilTaxodium remains were derived from Paleogeneflora of Pasekovo. This fossil flora was discovered atthe brown coal pit locality near village Pasekovo(49°45N N, and 39°48N E), Central Russian Upland,Mikhailovsky district, Voronezh oblast’, EuropeanRussia; it contains cone scales, seeds, lignified wood,various evergreen and deciduous leaf impression/compression with exceptionally well preserved“paper” leaf-cuticles of Gymnosperms andAngiosperms, that show rare anatomical detail forPaleogene plants (Vickulin 1999a, b; Âèêóëèí 2002).Sediments containing plant remains are rankedwithin the interval Late Eocene-?Early Oligocene, so

Pre-print version.



flora may be referred to Eocene/Oligocene boundaryinterval and may represent pre “Grande Coupure”time (37 Ma), due to S. V. Vickulin’ and stratigrapherfrom Voronezh University – V. P. Semenov’assumptions (Ñåì¸íîâ 1965, 1972; Vickulin 1999a,b).Macrofossils of Taxodium were splitted from coallayers in the field as well as later in the lab and coal-samples for palinological analyses of Pasekovobrown-coals have been collected by S. V. Vickulin in1984, 1985, 1988 (samples 21-40, coll. 1392). Fossilseeds described in our paper are derived fromadditional paleocarpological collection fromPasekovo drill-hole, which was received by K. P.Proskurin and P. I. Dorofeev from geologist Yu. I.Iosifova (coll. 462, bore-hole) in 1985. Collection ofP. I. Dorofeev from Svetlogorsk and Otradnoe sites ofEarly Oligocene, Kaliningrad oblast’, Western Russiawas also considered. All mentioned specimens aredisposed at the Laboratory of Paleobotany of the V.L. Komarov Botanical Institute of the RussianAcademy of Sciences.

Extraction of fossil leaves andmaceration of the cuticle: The leaf and shootsimprints, covered with a coalified organic substancei.e. “phyto-leima” [=Greek term of A. N.Kryshtofovich, which means “plant remain”=synonimous to Engl ish l i terature “leafcompression”] and small shoot fragments, more than50 samples, some of which were taken in the fieldoutcrop as a monolith rock to prevent fast oxidationand drying of fossil samples for subsequentmaceration, extraction and preparation in the

Pre-print version.



laboratory conditions. Leaf cuticle samples wereprepared from selected specimens using routine andstandard paleobotanical methodology for SEM andLM leaf investigations (for exhaustive references see:Alvin 1970; Alvin & Boulter 1974; Boulter 1970, 1971;Cutler et al. 1982; Kerp 1990; Kerp & Krings 1999;Ñâåøíèêîâà 1978; Vickulin 1999a, b; Âèêóëèí2002; Vikulin et al. 2002; Vickulin et al. 2003). Afterinitial preparation: pre- cleansing with Hydrofluoricacid (HF) and maceration using HNO3 + KClO3

Schultze solution, fossil cuticle layer was neutralizedusing 10% alkaline solution (KOH, NaOH, orNH4OH). Further, samples were mounted on stubsand Sputter-coated with a nanno-thin gold layer foran appropriate electric conductivity duringsubsequent SEM analyses. Cuticles of living Coniferswere treated according to Boulter (1970, 1971) andSveshnikova (1978) using standard dilution ofChromium trioxide solution (20%, or 10%) as theonly macerating agent to prevent over-maceration oftiny stomatal lignified T-piece polar bodies (alsoknown as polar lamellae). SEM investigations of theleaves were conducted by S. V. Vickulin and BenLePage at the Komarov Botanical Institute usingSEM JEOL 35-c facility at the Lab. of ScanningElectron Microscopy.

Sampling of Nearest living relatives(NLR): Initially, herbarium samples of extantTaxodium distichum and T. ascendens from theirnatural growth sites were received with the kindcooperation of New York Botanical Garden directorthe late Dr. Arthur Cronquist in early 1980-ties.

Pre-print version.



Furthermore, herbarium material was complementedwith the samples for all 3 extant species fromsoutheastern USA (Ben A. LePage collections in2000) and from Mexico (T. mucronatum, Jalisco, –V. Yu. Shalisko’ collections during 2002) as well asfrom US arboretums (S. V. Vickulin collections in1992, 1997, 1999). Selected samples were prepared toobtain the leaf cuticle. Examination of this materialhad included LM and SEM studies to reveal leaf-micromorphology to be compared with the fossil leafcompression.

RESULTS AND DISCUSSION

SYSTEMATIC BOTANY & PALEOBOTANY

Family Taxodiaceae Warming 1884Genus Taxodium Rich. 1810

Living species of Taxodium: all threemodern species of Taxodium are Northern Americanendemics (Watson 1985; McVaugh 1992) and can befound growing naturally in swamps or other wet,marshy areas. Deciduous trees of T. distichum (L.)Rich. and T. ascendens Brongn. are inhabitants ofswamp and marshy areas at the southeast of theUnited States, where they are constantly or partlyflooded from year to year. The area of distribution ofanother species – T. mucronatum Ten., isdisjunctively separated and these semi-evergreentrees occur in Mexico and Guatemala along rivers,streams or bodies of standing water. Though twospecies from the United States are overlapping ingeographical range, T. distichum has a more

Pre-print version.



northern distribution. It is represented by trees of upto 40-50 m tall and has numerous soft linear leavesof 7-17 mm length, and 1-1.25 width, which arearranged distichously on annually deciduousbranchlets (brachiblasts). In contrary – trees of T.ascendens are commonly smaller, leaves onbranchlets are tightly apressed, 5-10 mm length,distorted and subulate, adjoining or even imbricatedto rigid shoots. Mexican T. mucronatum plants arehuge trees of 20-30 m height. This species ischaracterized by linear, slightly coriaceous 10-15(20)mm length, 1.25 mm width leaves on deciduousbranchlets (figs 4, 5), that fall out at the second yearof vegetation. As in two above species from theUnited States, young permanent shoots are coveredwith leaves, in case of T. mucronatum these leavesare 2-4 mm length. Mature female cones of extantTaxodium species are consisting of about 15-25peltate coriaceous scales, commonly with tuberoses(figs 30, 31). Mexican T. mucronatum conescharacterize with explicit spine on terminal part ofscales, that spine is absent in other two species ofTaxodium.

Fossil species: Taxodium balticum Sveshn. et Budants.,

Bot. Zhurn. (#@H. /JD>.) 45(6): 872 - 874. Tab. 1, fig.1-10; Tab. 2, fig. 1-5; Tab. 3, fig. 1-6; Tab. 4, fig. 1-9;Tab. 5, fig. 1-9; Tab. 6, fig. 1-6; fig. in text 1b, 2. 1960.Sveshnikova 1963, Tr. BIN AN SSSR (GD. #3= !=EEEC) 8(4): 224, Tab. 9, fig. 7 - 15; Mai und Walther,1969 Über eine neue Tertiärflora im Haselbach, Taf.3, fig. 4 – 9; Mai und Walther, 1978 Abhandl. Mus.

Pre-print version.



Mineral, Geol. 28: 23, Tab. 14, Fig. 1 -7, Tab. 16, fig.1- 11.

Synonimes: T. palaeomucronatum Dorof. DANSSSR ()!= EEEC) 152: 983. 1963. nomen nudum. T.distichum miocenum Heer, Mioz. Balt. Flora: 18 - 20.Tab. 2, fig. 1 - 26; Tab. 3, fig. 6, 7. 1869. Dorofeev,Bot. Zhurn. (#@H. 0JD>.) 61(10): 1367. Tab. 1, fig. 5 –14; Tab. 2, fig. 18 - 21. 1976. T. heerii Dorof. Ibid.:1371, Tab. 4, figs 9 – 12; Fig. 1, 1 – 8, Fig. 2, 1.

Holotype: Lower Oligocene, Svetlogorsk(Rauschen), Kaliningrad oblast’, Russia, sample 300(female cone), coll. 462, Laboratory of Paleobotany,BIN RAN.

Isotypes: sample 23/58 (shoot), sample 570(microstrobiles), coll. 462, Laboratory ofPaleobotany, BIN RAN.

The type of T. paleomucronatum from LowerOligocene of Svetlogorsk and Otradnoe, Kaliningradoblast’, Russia is stored in Laboratory ofPaleobotany, BIN RAN (coll. 462). Place ofdepository for T. distichum miocenum from theLower Oligocene of Rauschen, Germany (nowSvetlogorsk, Kaliningrad oblast’, Russia) is unknownexactly, possibly it was lost during the II world war.

As was noted by the earlier publications, thediagnosis of Early Tertiary European Taxodiumbalticum Sveshn. et Budants. should becomplemented with a stomatographical andcarpological – seed data which reinforce affinity ofthis fossil species with a living Central-Americanspecies T. mucronatum.

T. balticum is known from several Eocene -Oligocene localities of European Russia (Svetlogorsk

Pre-print version.



of Kaliningrad oblast’; Pasekovo of Voronezh oblast’)and Germany (Haselbach Flubsande, Klausa, Profen,Tagebau Bornaost, Tagebau Peres, TagebauSchleenhain, Tagebau Profen). Morphologicalfeatures of remains from both Russian and Germanlocalities correspond in general detail: vegetativeshoot leaves are flat, 6-10 mm long, 1.2-1.7 mm wide,linear-lanceolate with acute apices, acuminate leafbases and well expressed medial vein (figs 1-3).Leaves going apart from shoot at angle of 35°-45°.They are arranged in a spiral course, distichously-alternate.

Identification of fossil Taxodium at the entirebasis of external vegetative features is very difficult.Major part of such identifications lacking cuticles andis usually described as T. dubium (Sternb.) Heer.Another species of Taxodium based on vegetativeremains is T. tinajorum Heer, which possess leavesof the bigger size (#J*">P,& 1983) (fig. 1).

COMPARATIVE LEAF MICROMORPHOLOGY AND

STOMATOGRAPHY O F LIVING AND FOSSIL SPECIES

Using stomatography and leaf cuticlemicromorphology as an identification tool todesignate extant and fossil Taxodium species isfeasible (Tab. 1).

Living species: The leaves are hypostomatic.Epidermis of adaxial and abaxial leaf surfacesconsists of the cells with a similar shape. Stomata areconcentrating mostly in the lower epidermis in

Pre-print version.



several rows. Trichomes and macro-papillae areabsent.

1) T. mucronatum – presumably more ancientsemi-evergreen mexican species possesses thick andmassive walls of epidermal cells, considerably thickerthan in other two deciduous species from South-Eastof USA. Stomatal set is encyclocytic. Epidermal cellsin stomata rows are angular, with slightly curvedanticlinal cell walls. Epidermal cells between stomatarows (main epidermis) mostly orthogonal, with alength equal to width or 2 times prevail over it. Thisspecies has well-developed thick cuticle. (Figs 8, 13-16).

2) T. distichum – possesses sub-encyclocyticstomata, epidermal cell walls are thin. Epidermalcells in stomata rows have smooth, rounded edges,their anticlinal walls are more curved than in T.mucronatum. Cuticle is less developed than in T.mucronatum, thin. (Figs 21-22).

3) T. ascendens – is characterized even moreunstable stomatal type in comparison with T. distichum. Epidermal cell walls are of the samethickness as in previous species, but epidermal cellsof main epidermis differ in form. T. ascendens differsfrom the two other living species by elongated cells ofepidermis, spindle-form with acuminate edges.Cuticle is thin. (Figs 17-20).

Fossil species: leaf epidermis of T. balticumfrom Pasekovo consists of quadrangular cells with alength equivalent to width or rather exceeding it.Longitudinal walls of epidermal cells are straight.Leaves are amphistomatic or hypostomatic,

Pre-print version.



epidermis of lower leaf surface consists of cells andstomata complexes analogous to ones of uppersurface. Stomata are amphicyclic, encyclocytic,usually with 4-5, rarely 6 subsidiary cells. Stomatalcomplexes are not randomly scattered, but aredistributed in two rows at the both sides of leafcentral vein. Stomata apertures are oriented athwartto leave axis, parallel orientation is very rare. T.balticum demonstrates 2-3 times smaller mainepidermis cells in comparison with recentrepresentatives of the genus. (Figs 6, 7, 9-12).

Eocene – Oligocene cuticles of T. balticumfrom Germany were documented by D. Mai and H.Walter (1978, 1985). They also had described leaveswith 2 stomatal rows possessing encyclocyticstomata. The average stomatal complex: 31 :mlength and 19 :m width. The dimensions of the cellsof main epidermis varies within 37-80 :m (length),14-25 :m (width). Length/width varies within 1:2 -1:4 ratio. Epidermis within stomatal rows is smaller,quadrangular, it’s stomatal size is about 20 × 20 :m.

Recent assumptions of S. V. Vickulin that T.balticum from Pasekovo and Haselbach is somewhatsimilar to living T. mucronatum from Mexico(%48J:4> 1987; Vickulin et al. 2002) have reinforcedearlier suggestions of D. Mai and H. Walter (1978,1985), and added further micromorphologicalevidence regarding above matter. Instead, anotherfossil species based on vegetative remains is T.dubium, which is much closer to living species fromUSA – T. distichum.

Pre-print version.



Analyses of the leaf compression of structurallypreserved fossil Taxodium allow us to specify twodistinctive types of extinct Taxodium in terms ofthe leaf surface micromorphology. Thus, moreancient evergreen Early-Tertiary type with a thickercuticle (T. balticum-type), relates to living T.mucronatum. In contrast, deciduous type from LateTertiary (T. dubium-type) with a thinner cuticle anda less stable organization of stomatal sets (sub-encyclocytic stomata) is closer to living species of T.distichum / T. ascendens – group.

The pattern of stomatal sets orientation easilydiffer Taxodium from other closely-related taxawithin Taxodiaceae. Living and fossil Taxodiumspecies are characterized by prevailing orthogonalorientation of the stomatal sets (aperture slit)towards the leave axis (figs 6-8), which differs themfrom relative representatives of fossil and livingGlyptostrobus, possessing stomatal sets in irregularposition and arrangement of subsidiary cells withinthe stomatal sets. Another genus with similarleaf/shoot macromorphology – Sequoia has stomatalapertures usually oriented parallel towards the leaveaxis (Vickulin et al. 2003). It’s noteworthy, that incupressoid leaves of Upper Cretaceous Taxodiumwallisii Aulenback et LePage (Aulenback & LePage1998) as well as those of T. ascendens (unpublishedSEM observations of B. LePage & S. Vickulin 2001),the stomata are also oriented more or less parallel tothe long-axis of the leaf. Amongst another distinctivefeatures of Taxodium leaf surface micromorphologyone need to mention a better expressed orthogonaltips of major epidermal cells in realtion to

Pre-print version.



Glyptostrobus (Ma et al. in press). The latter hasrounded cell tips, whereas Sequoia possesseselongated cells with acuminate tips.

FEMALE CONES AN D SCALE FRAGM ENTS OF FOSSIL

TAXODIUM

Female cones and their scale fragments wereinvestigated from Pasekovo flora by K. P. Proskurinand S. V. Vickulin (Âèêóëèí 1987; Âèêóëèí et al.1986). Cone scales carry specific surface sculpturewith an arch of barb-like tubercles on outer surface ofthe cone-scale and acute upright central spine (figs23, 29, 30). High central spine is so well-developedthat Svetlogorsk, Pasekovo and Haselbah specimensof T. balticum resemble in this respect the taxa ofAraucaria and Cryptomeria. Such type of scalesculpturing is characteristic for most female conescale rests of T. balticum described from Svetlogorskcollections ()@D@L,,& 1963, 1975, 1976), which werealso revised in this study, and from Haselbach (Mai &Walter 1978). Among fossil Taxodium species basedprimarily on the seed-cones, similar scale sculpture isknown for T. tavdense Dorof. (Oligocen, Tumenoblast’, Russia). P. I. Dorofeev properly consideredboth of this Tertiary species to be close to mexican T.mucronatum, which is the only recent species withwell developed spines on mature female cones (figs26, 28, 31, 32).

Besides female cone scales of T. balticum,Pasekovo collection posesses Taxodium seeds, thathave elongated sphenoid form and match to“carpological” species of T. heerii Dorof. (figs 24, 25),

Pre-print version.



type of which originates from Oligocene fossil localityof Otradnoe, Kaliningrad oblast of Wesrtern Russia,though Pasekovo seeds are smaller in comparisonwith the type. Pasekovo seeds are of 6.5-7.6 mmlength and 3.5-4.0 mm width, sphenoid, rarely oval,with a recess on a rounded tip. The form andproperties of hilum are similar to that of T. heerii.

EOCENE-OLIGOCENE PALEOFLORISTICS OF TAXODIUM

FORMATIONS IN EASTERN AND CENTRAL EUROPE

The Late Eocene – Early Oligocene floristicassociation of Pasekovo (Middle Russian Upland)was composed of Taxodium, Nyssa, Sequoia,Glyptostrobus, Protosequoia, A l a n g iu m ,Rhodomyrtophyllum and Nectandra, which issignificantly different from modern associations ofTaxodium representatives in Northern America.Species of T. distichum and T. ascendens usuallygrow in plant communities with Nyssa aquatica, N.sylvestris, N. ogeche (Eyde, Manchester 1997;Graham 1999), forming a number of forestformations – e. g. dismal swamps, mostly flooded atthe major part of the year. Montezuma cypress – T.mucronatum can be found in the Gallery forest,growing both with temperate (Platanus, Populus,Salix, Acer) and sub-tropical elements (Rzedowski1994). In the sense of phytocenology Taxodiumassociations from Pasekovo flora represent specificextinct East-European formations, which differ fromthose of modern genus representatives (Vickulin etal. 2002; Êðèøòîôîâè÷ et al. 1956; Èëüèíñêàÿ1957; Äîðîôååâ 1976; Mai & Walter 1978). The fossil

Pre-print version.



T. balticum is the most ancient structurally verifiedamongst discovered ever since true Taxodium’s inEurope, where this species was distributed in Eocene– Oligocene of Germany, Kaliningrad oblast’ ofWestern Russia and within the Middle RussianUpland (Pasekovo brown-coal mine of Voronbezhoblast’). Within all above mentioned Tertiary Floras,T. balticum had been occurred jointly with species ofApocynophyllum (A. firmum, A. helveticum) ofMyrtaceous afinities, deciduous species of entire-margined and dentate leaves of Nyssa, relative to N.sylvatica and N. aquatica, and with ericaceousaffinity species of Epacridicarpum rossicumProskurin et Vickulin (Ïðîñêóðèí è Âèêóëèí 1990)Association of T. balticim and Epacridicarpum is themost ancient specific version of Taxodium – Nyssa –Alangium association that was widely distributedthroughout the Europe later in Miocene (Âèêóëèí1987; Eyde, Manchester 1997). T. balticum andericaceous Epacridicarpum from Pasekovo florapresumably began their origin in some primevalEarly Paleogene or Late Cretaceous Europeanassociations.

Regular plant assemblages from Eocene-Oligocene localities of Central and Eastern Europe(Messel, Heizetal, Zeitz complex, Stare Sedlo,Ukraninan Ekaterinopolie, sites of Volyn’ andBelgorod-Kursk-Voronezh areas) comprise variousevergreen etire-margined leaves of primitive Quercuss. l. (Cyclobalanopsis, Lythocarpus, etc.),Castanopsis and other archaic Fagaceae, variousspecies of Lauraceae, Myrsinaceae and some archaicextinct conifers (i.e. Doliostrobus, Araucarites).

Pre-print version.



Pasekovo-Haselbach Eocene/Oligocene boundaryfloras represent essentially distinct type of mixedvegetation. Apparently, that type of vegetation, whichremains had been deposited as a brown coal leafpaper-layers of Pasekovo, was Taxodium-Nyssaswamps with an ample presence of evergreenthermophilous species. Swamp aspect is indicated aswell by high frequencies of pollen of Nyssa,Cupressaceae, Taxodium, Cyriliaceae, Polypodiaceaein Early Oligocene coals (Âèêóëèí 2002). Thisvegetation had persisted until retreat of theFennoscandian epicontinental sea of Tethys inOligocene and concomitant general cooling; later inMiocene evergreens sufficiently decreased along withintrusion of warm-temperate so called Turgaicspecies of Sorbus, Populus, Acer and other temperateboreal taxa from Trans-Ural region, which firstly forPaleogene came to the south of European Russiathrough newly appeared Turgay-isthmus (Budantzev1992; Âèêóëèí 1987, 2002; Vickulin 1999a, b).Oligocene-Miocene floras of Kazakhstan and WesternSiberia belong entirely to the temperate coniferous-broad-leaved type with the east Asian dominantelement. The migrational spread of temperate borealflora from Western Siberia and Northern Kazakhstanwas temporarily blocked by the Western Siberian Seaand the Turgai Straits until this sea barrierdisappeared in early Oligocene. In the latest Eocenethe West Siberian Sea rapidly became shallow, and itis practically disappeared by the mid-Oligocene. Dueto above paleogeographical and climatic events,Siberian mesophilic elements rapidly began their

Pre-print version.



westward spreading and dispersal within theEuropean Upper Tertiary floras.

ACKNOWLEDGEMENTS

Thanks are due to a number of individuals whohave contributed in various aspects of this study,including L. Yu. Budantzev, P. I. Dorofeev, K. P.Proskurin, I. A. Iljinskaja, O. N. Arbuzova, T. F.Abramova, L. A. Kartseva (all from KomarovBotanical Institute, St. Petersburg, Russia), R.Ramírez Delgadillo for help in photography of the T.mucronatum female cones, S. Carvajal for generalassistance, comments on the manuscript and helpwith the translation of a summry to Spanish (bothfrom Instituto de Botánica, Universidad deGuadalajara, México).

LITERATURE CITED

Alvin, K. L. & M. C. Boulter. 1974. A controlledmethod of comparative study of taxodiaceous leafcuticles. Bot. J. Linn. Soc. 69(4): 277-286.

Alvin, K. L. 1970. The study of fossil leaves by SEM.Scan. Elec. Microsc. 3: 121-218.

Aulenback, K. R. & B. A. LePage. 1998. Taxodiumwallisii sp. nov.: first occurrence of Taxodiumfrom Upper Cretaceous. Int. J. Plant Sci. 159(2):367-390.

Pre-print version.



Boulter, M. C. 1970. Lignified guard cell thickeningsin the leaves of some modern and fossil species ofTaxodiaceae (Gymnospermae). Biol. J. Linn. Soc.2: 41-46.

Boulter, M. C. 1971. Fine details of some fossil andRecent conifer leaf cuticles. In Heywood V. H.Scanning Electron Microscopy. Academic press,London and New York. Pp. 211-236.

Brunsfeld, S. J., P. S. Soltis, D. E. Soltis, P. A. Gadek,C. J. Quinn, D. D. Strenge & T. A. Ranker. 1994.Phylogenetic relationships among the genera ofTaxodiaceae and Cupressaceae: evidence fromrbcL sequences. Syst. Bot. 19(2): 253-262.

Budantzev, L. Yu. 1992. Early stages of formation anddispersal of the temperate flora in the borealregion. Bot. Rev. 58(1): 1-48.

Chaw, S-M., A. Zharkikh, H. M. Sung, T-C. Luu & W-H. Li. 1997. Molecular phylogeny of extantGymnosperms and seed plant evolution: analysisof nuclear 18s rRNA sequences. Mol. Biol. Evol.14(1): 56-68.

Cross, G. L. 1939. A note on the morphology of thedeciduous shoot of Taxodium distichum. Bull.Torrey Bot.Club 66(3): 167-172.

Cross, G. L. 1939. The structure and development ofthe apical meristem in the shoots of Taxodiumdistichum. Bull. Torrey Bot. Club 66(7): 431-452.

Cross, G. L. 1940. Development of the follage leavesof Taxodium distichum. Amer. J. Bot. 27(7): 471-482.

Cutler, D. F., K. L. Alvin & D. L. Price. 1982. Theplant cuticle. Linn. Soc. Symp. Ser. 10. Academicpress, London and New York. Pp. 1- 461.

Pre-print version.



Eyde, R. H., S. R. Manchester. 1997. Fossil recordand ecology of Nyssa (Cornaceae). Bot.Review63(2): 97-123.

Gadek, P. A., D. L. Alpers, M. M. Heslewood & C. J.Quinn. 2000. Relationships within Cupressaceaesensu lato: a combined morphological andmolecular approach. Amer. J. Bot. 87(7): 1044-1057.

Graham, A. 1999. Late Cretaceous and Cenozoichistory of Northern American vegetation, northof Mexico. Oxford University Press. Pp. 1-350.

Hilu, K.W., H. Liang. 1997. The matK gene: sequencevariation and application in plant systematics.Amer. J. Bot. 84(6): 830-839.

Kaeiser, M. 1953. Microstructure of the wood of threespecies of Taxodium. Bull. Torrey Bot. Club80(5): 415-418.

Kerp, H, M. Krings. 1999. Light microscopy ofepidermis. In Jones, T. P., N. P. Rowe. FossilPlants and Spores: Modern Techniques. TheBritish Geological Society, London. Pp. 52-56.

Kerp, H. 1990. The study of fossil Gymnospermsby means of cuticular analysis. Palaios 5(6):548-569.

Kusumi, J., Y. Tsumura, Y. Yoshimaru & H. Tachida.2000. Phylogenetic relationships in Taxodiaceaeand Cupressaceae sensu stricto based on matKgene, chlL gene, trnL-trnF IGS region, and trnLintron sequences. Amer. J. Bot. 87(10): 1480-1488.

Pre-print version.



Ma Q.-W. & F.-Q. Gu. 2000. Comparative studies onmorphological features of some genera inTaxodiaceae. Chinese Bull. Bot. 17 (Special issue):161-164.

Ma Q.-W., C.-S. Li, S. V. Vickulin & F.-L. Li. In press.Epidermal structures of Chinese endemicGlyptostrobus pensilis C. Koch (Taxodiaceae).Bot. J. Linn. Soc.

Mai, D. H. 1996. Tertiare VegetationsgeschichteEuropas (Vol. 1: Buntsandstein, Vol. 2: Keuperand Index). G. Fischer Verlag, Jena. Pp. 691.

Mai, D. H. & H. Walther. 1978. Die Floren derHaselbacher Serie im Weißelster-Becken (BezirkLeibzig, DDR). Abhandl. Staatl. Mus. Mineral.Geol. Dresden. 28: 1-200.

Mai, D. H. & H. Walther. 1985. Die obereozänenFloren des Weißelster-Beckens und seinerRandgebiete. Abhandl. Staatl. Mus. Mineral. Geol.Dresden. 33: 1-176.

McVaugh R. 1992. Taxodiaceae. In Flora Novo-Galiciana. Vol. 17. Gymnosperms y Pteridophytes.University of Michigan Herbarium. Pp. 104-106.

Pole, M. 1995. Late Cretaceous macrophloras ofeastern Otago, New Zealand: Gymnosperms. Aust.Syst. Bot. 8(6): 1067-1106.

Price, R. A. & J. M. Lowenstein. 1989. Animmunological comparison of the Sciadopityaceae,Taxodiaceae, and Cupressaceae. Syst. Bot. 14(2):141-149.

Rzedowski, J. 1994. Vegetación de México. EditorialLimusa, México, D. F. Pp. 1-432.

Pre-print version.



Schlarbaum, S. E., Johnson L. C. & Tsuchiya T. 1983.Chromos o m e s t u d i e s o f M etasequoi aglyptostroboides and Taxodium distichum. Bot.Gaz. 144(3): 559-565.

Soltis, P. S., D. E. Soltis & Ch. J. Smiley. 1992. AnrbcL sequence from a Miocene Taxodium (BaldCypress). Proc. Natl. Acad. Sci. USA 89(1): 449-451.

Stefanovic, S., M. Jager, J. Deutsch, J. Broutin & M.Masselot. 1998. Phylogenetic relationships ofconifers inferred from partial 28S rRNA genesequences. Amer. J. Bot. 85(5): 688-697.

Takaso, T. & P. B. Tomlinson. 1990. Cone and ovuleontogeny in Taxodium and Glyptostrobus(Taxodiaceae – Coniferales). Amer. J. Bot. 77(9):1209-1221.

Tsumura, Y., N. Tomaru, Y. Suyama & S. Bacchus.1999. Genetic diversity and differentiation ofTaxodium in the south-eastern United Statesusing cleaved amplified polymorphic sequences.Heredity 83: 229–238.

Vickulin, S. V. 1999a. Palaeogene leaf compressionsof myrtaceous affinity from Pasekovo, MiddleRussian Upland, southern European Russia. Bot.J. Linn. Soc. 131(1): 65-98.

Vickulin, S. V. 1999b. The Eocene and earlyOligocene floras of the Russian Plain and theirrelation to the palaeofloras of Central Europe.Acta Palaeobot. Suppl. 2: 429 – 445. Proceedings5th European Palaeobotanical and PalynologicalConference (June 26 –30. 1998, Krakow).

Pre-print version.



Vickulin, S. V. 2000a. Ultrastructural andmicromorphological studies of fossil cuticles fromthe Tertiary of Russia and some allied territories ofthe former Soviet Union. In: The SixthQuadrennial Conference of the Internat. Org. ofPaleobot., I.O.P.C. – VI, China.

Vickulin, S. V. 2000b. New data on Taxodium,Sequoia, Protosequoia and Glyptostrobus (leafcuticles, seeds & pollen) from the Upper Eocene ofCentral Russia. In The Sixth QuadrennialConference of the Internat. Org. of Paleobot., I. O.P. C. – VI, China.

Vickulin, S. V., B. A. LePage, V. Y. Shalisko & S.Carvajal. 2002. Early Tertiary Taxodium Rich.(Taxodiaceae) from Eurasia: comparativemorphological and sequence analyses usingnearest living relatives from North America. In S.Carvajal (Ed.). Avances en la investigacioncientifica en el CUCBA – 2002. XIII SemanaNacional de la Investigation Cientifica.Universidad de Guadalajaara, Jalisco, Mexico. Pp.273 – 275.

Vickulin, S. V., Q.-W. Ma, S. G. Zhilin & C.-S. Li.2003. On cuticular compressions of Glyptostrobuseuropaeus (Taxodiaceae) from Kaydagulformation Lower Miocene of Central Kazakhstan.Acta Bot. Sinica 45(6): 673-680.

Pre-print version.



Vikulin, S. V. & S. G. Zhilin 1993b. The scanningelectron microscope study of stomatal-complexconfiguration in Cupressaceae and its implicationsto transitional species from Creatceous to Tretiary.Proceedings of the Fifteenth InternationalBotanical Congress (Yokohama, Japan; September3, 1993); workshop: International Task Force onMesozoic Coniferous Woods, Abstracts, 5.Yokohama: Botanical Congress.

Vikulin, S. V. & S. G. Zhilin. 1993a. Evolutionary andstratigraphical significance of the Taxodiaceaetransitional taxa from the Cretaceous to Paleogenefloras of FSU. Proceedings of the FifteenthInternational Botanical Congress (Yokohama,Japan; September 3, 1993); workshop:International Task Force on Mesozoic ConferousWoods, Abstracts, 4. Yokohama: BotanicalCongress.

Vickulin, S. V., S. G. Zhilin & Ya. Yu. Potapova. 1995.Leaf whorls of Cupressaceae in the Maastrichtianof the Central Kazakhstan. Paleontol. Journ.,translation of Russian Paleontol. Zhurn. 29(1A):185-193.

Watson, F. D. 1985. The nomenclature ofpondcypress and baldcypress (Taxodiaceae).Taxon 34(3): 506-509.

Áóäàíöåâ Ë. Þ. Èñòîðèÿ àðêòè÷åñêîé ôëîðûýïîõè ðàííåãî êàéíîôèòà. Ë. 1983. 156 ñ.

Âèêóëèí Ñ. Â. Î ðàííåîëèãîöåíîâîé ôëîðåÏàñåêîâà (þã Ñðåäíåðóññêîé âîçâûøåííîñòè)// Áîò. æóðí. 1987. Ò. 72, ¹ 2, Ñ. 146 – 154.

Âèêóëèí Ñ. Â. Ïåðâàÿ íàõîäêà ðî äàRhodomyrtophyllum (Myrtaceae) â ïàëåîãåíå

Pre-print version.



Âîñòî÷íîé Åâðîïû // Áîò. æóðí. 2002. Ò. 87. ¹9. Ñ. 27 – 37.

Âèêóëèí Ñ. Â., Ãðîìûêî Ä. Â., Ïðîñêóðèí Ê. Ï.Íîâûå äàííûå î ðàííåîëèãîöåíîâîé ôëîðå ñ.Ïàñåêîâî // Òð. 1 ìîëîä. êîíô. áîòàíèêîâ ã.Ëåíèíãðàäà. Ë., 1986. ×.3. Ñ. 159 – 174(ðóêîïèñü äåï. â ÂÈÍÈÒÈ 25.09.1986; ¹ 6847-B).

Äîðîôååâ Ï. È. Î òðåòè÷íîé ôëîðå ã.Ñâåòëîãîðñêà Êàëèíèíãðàäñêîé îáëàñòè //ÄÀÍ ÑÑÑÐ. 1963. Ò. 152, ¹ 4. Ñ. 983 – 984.

Äîðîôååâ Ï. È. Ê ñèñòåìàòèêå íåêîòîðûõTaxodiaceae. // Ïàëåîíòîë. Æóðí. 1975. Ò. 75, ¹1. Ñ. 105 – 116.

Äîðîôååâ Ï. È. Ê ñèñòåìàòèêå òðåòè÷íûõTaxodium // Áîò. æóðí. 1976. Ò. 61. ¹ 10. Ñ.1364 – 1373.

Èëüèíñêàÿ È. À. Íîâûå äàííûå ïî îëèãîöåíîâîéôëîðå ãîðû Àøóòàñ â Êàçàõñòàíå // Áîò. æóðí.1957. Ò. 42. ¹ 3. Ñ. 395 – 413.

Êðèøòîôîâè÷ À. Í., Ïàëèáèí È. Â., ØàïàðåíêîÊ. Ê. è äð. Îëèãîöåíîâàÿ ôëîðà ãîðû Àøóòàñ âÊàçàõñòàíå // Òð. ÁÈÍ ÀÍ ÑÑÑÐ. 1956. Ñåð. 8.¹ 1. Ñ. 1 – 180.

Ïðîñêóðèí Ê. Ï., Âèêóëèí Ñ. Â. Íîâûé âèäEpacridicarpum rossicum (Epacridaceae) èçðàííåîëèãîöåíîâîé ôëîðû ñåëà ÏàñåêîâàÂîðîíåæñêîé îáëàñòè // Áîò. æóðí. 1990. Ò. 75.¹ 2. Ñ. 215 – 220.

Ñâåøíèêîâà È. Í. Ñåìåéñòâî Taxodiaceae Neger,1907. Îñíîâû Ïàëåîíòîëîãèè: ãîëîñåìåííûå èïîêðûòîñåìåííûå. M., 1963a. Ñ. 280 – 290.

Pre-print version.



Ñâåøíèêîâà È. Í. Îïðåäåëèòåëü ñîâðåìåííûõ èèñêîïàåìûõ ïðåäñòàâèòåëåé Sciadopityaceae èTaxodiaceae ïî ýïèäåðìå ëèñòüåâ // Òð. ÁÈÍÀÍ ÑÑÑÐ. 1963b. Ïàëåîáîòàíèêà. Âûï. 4. Ñ. 207– 237.

Ñâåøíèêîâà È. Í. Ïîçäíåìåëîâûå õâîéíûåÑîâåòñêîãî Ñîþçà. I. Èñêîïàåìûå õâîéíûåÂèëþéñêîé ñèíåêëèçû // Òð. ÁÈÍ ÀÍ ÑÑÑÐ.1967. Ïàëåîáîòàíèêà. Âûï. 3. Ñ. 177 – 203.

Ñâåøíèêîâà È. Í. Ìåòîä èçó÷åíèÿ ýïèäåðìëèñòüåâ õâîéíûõ íà ñêàíèðóùåì ýëåêòðîííîììèêðîñêîïå // Áîò. æóðí. 1978. Ò. 63. ¹ 8. Ñ.1168 – 1171.

Ñâåøíèêîâà È. Í., Áóäàíöåâ Ë. Þ. Òðåòè÷íàÿôëîðà Êàëèíèíãðàäñêîãî ïîëóîñòðîâà III //Áîò. æóðí. 1960. Ò. 45, ¹ 6, Ñ. 871 – 875.

Ñåìåíîâ Â. Ï. Ïàëåîãåí Âîðîíåæñêîé àíòåêëèçû.Âîðîíåæ. 1965. 278 ñ.

Ñåìåíîâ Â. Ï. Ïàëåîãåíîâàÿ ñèñòåìà // Ãåîëîãèÿ,Ãèäðîãåîëîãèÿ è æåëåçíûå ðóäû áàññåéíàÊóðñêîé ìàãíèòíîé àíîìàëèè. T. 1. Ãåîëîãèÿ,Êí. 2. Îñàäî÷íûé êîìïëåêñ. Ì., 1972. Ñ. 202 –229.

Pre-print version.



1 This table was not includ ed to the printed version due to the editor

error.

Table 11. Comparative leaf micromorphology ofliving T. mucronatum, T. distichum, T. ascendensand fossil T. balticum.

Species,

locality

Stomat

al size,

length

× width

(:m)

Type of the

stoma tal set

Epider mal ce lls

in stomatal

rows

Epidermal

cells between

stomatal

rows (major

epidermis)

T. balticum

Pasekovo:

Russ ia

35 × 40 Encyclocytic,

stable

Short cells,

with

orthogonal

straight

anticlina l walls

Orthogonal

cells, straight

anticlinal

walls

T. balticum

Haselbach:

German y,

Svetlogorsk:

Russ ia


stable

stomatal type

Short cells,

with

orthogonal

straight

anticlina l walls

Orthogonal

cells, straight

anticlinal

walls

T.

m u cr on a tu m

Mexico,

Gua temala


stable

stomatal type,

with narrow

circle of

subsidiary

cells

Short cells,

with

orthogonal

straight

anticlina l walls

Orthogonal

cells, straight

or slightly-

curved

anticlinal

walls

T. distichum

South-East of

USA

60 × 70 Sub-

encyclocytic,

subsidiary

cells are

similar w ith

major

epidermal

cells

Elong ated ce lls

with rounded

tips, undulated

anticlina l walls

Rounded

cell- tips,

curved or

undulated

anticlinal

walls

T. ascendens

South-East of

USA

60 × 70 Sub-

encyclocytic,

instable

stomatal type

Elongated cells,

with straight

anticlina l walls

and ac ute ce ll-

tips

Elongated

cells w ith

acute cell-

tips

Pre-print version.



Figures 1-5. Leafy shoots of the fossil and living Taxodium . Figs 1-3 : fossil T.

balticum. Fig. 1. Specimen 22 /1392 (Komarov Bot. Inst.). Fragment of shoot

with structurally preserved leaf cuticle. That s hoot re semb les “mo rpholo gical”

species of T. tinajorum. Fig. 2. Specimen 23 /1392 (Komarov Bot. Inst.) . Fig. 3.

Specimen 24 /1392 (Komarov Bot. Inst.). Figs 4-5: modern T. mucronatum

(collected in Guadalajara, Mexico , V. Yu. Shalisko s. n.) Fig. 4. Decidouos

branc hlet. Fig. 5. Shoot sample with smalle r and m ore ap presse d leave s. Sca le

bars = 1 cm.

Pre-print version.



Figures 6-8. Leaf e pidermis micrographs (LM) of fossil and living Taxodium .

Figs 6, 7. T. balticum. Specimen 2 3/1392. Fig. 8. T. mucronatum (collected in

Sierra Madre Or iental, Mexico, C. H. & M. T. Mueller 1303 , L E ) . N ote

a r r a ng e m ent of stomata in rows and orthogonal orientation of the stomatal sets

towards the leaf axis for both living and extant species. Scale bars = 100 µm.

Pre-print version.



Figures 9-22. Comparative SEM leaf surface micro-morphology of fossil and

living species of Taxodium .

Figs 9-12. T. balticum. Scale bars = 10 µm. Figs 9, 11. Clo seup of the sta ble

type of encyclocytic stomata showing regular arrangeme nt of encircling

subsidiary cells, w hich a re differ entiated from r egula r epider mal ce lls (abaxial

leaf surface). Fig. 11. Note thick cuticular ledges of th e stomatal pit and

pronounced T-piece polar lamellae preserved at the upper end of the guard

cells. Figs 10, 12. Inner views of abaxial leaf surface showing general pattern of

stomatal arrangement with prevailing inclined or rectangle orientation towards

the leaf axis and regular epidermal cells with rounded tips and a thick cuticle.

Pre-print version.



Figures 9-22 (con tinuatio n). Comparative SEM leaf surface micro-

morphology of fossil and living species of Taxodium .

Figs 13-16. T. mucronatum . Scale bars in figs 13, 14, 16 = 100 µm. Scale bar in

fig. 15 = 10 µm. Fig. 13. Outer view of the abaxial leaf surface showing

characteristically oriented stomatal pits with a long axis perpendicular to the

midvein. Note well-developed outer cuticular flanges. Figs 14, 16. Inner views of

abaxial leaf su rface show ing gen eral pa ttern of s toma tal arra ngem ent with

prevailing inclined or rectangle orientation towards the leaf axis and regular

epidermal cells with rounded tips and a thick cuticle. Note shape of

intrastomatal epiderm al cells ( fig. 16) and sligh tly curv ed wa lls of regular

epiderm is (fig. 14). Fig. 15. Closeup of the stable type of encyclocyt i c s t o mata

showing regular arrange m ent of encircling subsidiary cells, which are

differentiated from regular e pidermal cells (abaxial leaf surface). Note thick

cuticular ledges of the stomatal pit, thick cuticle and pronounced T-piece polar

lamellae at both ends of the guard cells.

Pre-print version.



Figures 9-22 (contin uation). Comparative SEM leaf surface micro-

morphology of fossil and living species of Taxodium . F i g s 1 7 - 2 0 . T .

ascendens. Scale bars in f igs 17, 19, 20 = 10 µm, scale bar in f ig. 18 = 100 µmm.

Figs 17, 19. Closeup of the unstable type of sub- encyclocytic stomata showing

irregular arrangement of encircling subsidiary cells, which are w eakly

differentiated from th e regu lar epide rmal c el ls (abaxial leaf surface). Figs 18,

20. Inner views of abaxial leaf surface showing stomata randomly disposed or

oriented more or less parallel to the long-axis of the cupressoid leaf and regular

epidermal cells with acute tips.

Pre-print version.



Figures 9-22 (con tinuatio n). Comparative SEM leaf surface micro-

morphology of fossil and living species of Taxodium .

Figs 21-22. T. distichum. Scale bar in fig. 21 = 10 µm, in fig. 22 = 100 µm. Fig.

21. Closeup of the unstable type of stomata showing irregular arrangement of

several neighboring cells, most ly w eakly differentiated from the regular

epidermal cells (a baxia l leaf surface). Note lacking of any T-piece polar lamellae

at both ends of the guard cells and a thinner cuticle in comparison with T.

mucronatum . Fig. 22. Inner v iew of a baxia l leaf su rface show ing general

pattern of stomatal arrangement with prevailing inclined o r recta ngle

orientation towards the leaf axis and short regula r epider mal ce lls with

rounded tips.

Figures 23-28. Cone scales and se eds of livin g and f ossil Taxodium . Figs 23-

25. T. balticum. The b ore-h ole sam ple from the drill ing hole #7 (depth 10.0-11

m), received from geologist Yu. I. Iosifova (Geol. Service of Central Regions,

Moscow). The bore-hole was drilled in 19 85 at P aseko vo loca lity and fo ssil

seeds/cone-scales from bore-hole sample were deposit ed in Lab of Paleobotany

( B IN RAS) via K. P. Proskurin & P. I. Dorofeev as paleocarpological coll. 462.

Fig. 23. Compound Light Microscope. Fragment of the cone-scale. Note several

distinctive sharp surface dentes and a major bigger spike. Scale bar = 5 mm.

Figs 24, 25. Fossil seeds of Taxodium from P aseko vo (U pper E ocen e? - Ea rly

Oligocene): these elongated seeds are referable to carpological species T. heerii

Dorof. Note esp ecially: w age-li ke seed resembling Upper Cretaceous

morphotype of extinct genus Taxodiastrum Dorof. (fig.24). S cale bars = 2 mm.

Figs 26-28. T. mucronatum (collected in Guadalajara , Mexico, V. Yu. Shalisko

s. n.) Fig. 26. Female cone scale with w ell develo ped sp ine on te rmina l part.

Scale bar = 5 mm. Fig. 27. Seed. Scale bar = 2 mm. Fig. 28. Close up of cone

scale spine. Magnification ×20.

Pre-print version.



Pre-print version.



Figures 29-32. Cones and cone scales of living and Early Tertiary Taxodium .

Figs 29-30. T. balticum. Generalized reconstruction of the cone and the cone

scale summarizing original reconstruction of Sveshnikova & Budantzev (1960),

and modified according to recent findings f r o m Germany (Mai & Walter 1978,

1985) and Ce ntral Ru ssia (V ickulin 1987) . Fig. 29 . Cone recon structio n. Sca le

bar = 1 cm. Fig. 30. Cone scale. Scale bar = 5 m m. Figs. 31-32. T. mucronatum

(collected in Guadalajara, M exico, V. Yu. Shalisko s . n.). Fig. 31. Cone. Scale bar

= 1 cm. Fig 32. Cone scale. Scale bar = 5 mm.

Documents

Palaeogene leaf compressions of Taxodium mucronatum Ten. affinity from Pasekovo, Middle Russian Upland, Southern European Russia