Early Oligocene

Early Oligocene Nothofagus from CRP-3, Antarctica:

Implications for the Vegetation History

D.J. CANTRIE,I,

Geological Sciences. British Antarctic Survey. Natural Environment Research Council. Maclingley Road. High Cross Cainbi'iclge CB3 OET - United Kingdom (djca@pcmail.ncrc-bas.ac.uk)

Received 27 September 2000: accepted in revisedform 3 July 2001

Abstract - A single fossil leaf of Nothqfagiis from CRP-3 drillhole in the Victoria . a n d Basin provides further evidence for woody vegetation in the Tertiary of East Antarctica. The plicate vernation of this small leaf indicates a deciduous habit and suggests a cold climate. Located in the interval between 44.12 to 44.18 nibsf this extends the range of these small-leaved deciduous taxa to the Early Oligocene, and adds to the sparse macrofossil record of the East Antarctic vegetation of this period.

This further reinforces the suggestion that the transition from a diverse and mesic vegetation in the E o c e n e to a depauperate flora in the Early Oligocene w a s a relatively rapid event in East Antarctica. Despite limited Tertiary plant material

from East Antarctica, an emerging picture is one of substantially cooler climates than that seen in West Antarctica at the same time.

INTRODUCTION

Antarctica fossil floras provide unique insights i n t o the vegetation history of this now glaciated l a n d s c a p e . T h e Tertiary record of Antarctica i s particularly interesting as it records biotic changes associated with the final stages of separation of Gondwana fragments. The isolation of Antarctica in a p o l a r position, and subsequent reorganization of oceanic circulation patterns, led to climatic cooling a n d the development of a l a r g e i c e sheet. T h i s resulted in widespread extinction of most of the terrestrial biota from Antarctica, and created disjunct distributions that characterize many S o u t h e r n H e m i s p h e r e groups today. F o r example, New Zealand/Australian genera and species in a number of families ( e . g . Nothofagaceae, Stylidiaceae, Proteaceae) often have their nearest relatives in South America e . g . Manos, 1987; Weston & Crisp, 1987). Antarctic Tertiary floras are critical f o r understanding the h i s t o r y of these S o u t h e r n H e m i s p h e r e g r o u p s . However, although the climatic cooling through the Tertiary was one of the m a j o r m e c h a n i s m s f o r creating such striking biogeographic patterns, it is still unclear how rapidly climate change affected the biota.

Was it one of rapid decline in diversity, or did floral elements progressively drop out over millions of years?

T h e record of Antarctic Tertiary floras is largely confined to the Antarctic Peninsula region. On the west side of the Antarctic Peninsula, floras in the South Shetland Islands (King George Island) range

from Palaeocene to earliest Oligocene in a g e (Zastawniak et al., 1985, and references therein). Rare occurrences of fossil wood are also reported from latest Oligocene marine strata (Destruction Bay Formation, Birkenmajer, 1984; Dingle & Lavelle, 1998). To the east of the Antarctic Peninsula. in the J a m e s Ross Island region, Tertiary floras of Palaeocene to ?earliest Oligocene are known from Seymour Island and include leaf (Dusen. 1908; Case, 1988; Gandolfo et al., 1998~1, 1998b), wood (Gothan, 1908) and spore/pollen (Askin, 1988) assemblages.

Sparse occurrences of Tertiary plant fossils are also present elsewhere throughout the Antarctic Peninsula e . g . Elgar Uplands, Alexander Island; Thomson &

Burn, 1977), but generally these macrofloras a r e poorly age-constrained and have not been fully described.

Despite the relatively greater land area of East Antarctica, there are noticeably fewer Tertiary floras than seen in the Antarctic Peninsula. Erratics of fluvial to shallow marine sandstones f r o m the McMui-do sound (Minna Bluff) region have yielded Eocene to Oligocene plant fossils (Francis, 2000; Pole et al., 2000; Askin, 2000). The flora comprises wood of araucarian and podocarp conifers, and Noflzofag~~s angiosperms (Francis, 2000). Leaf assemblages are numerically dominated by flowering plants, with Notlzofagus as the main component; minor araucarian conifers are a l s o present ( P o l e e t al., 2000).

Palynological assemblages from the eri-atics indicate a greater diversity than that seen in the wood and leaf assemblages, but still support macrofossil evidence for

a vegetation dominated by podocarps and A W ~ o / ^ ' ~ i . s (Askin, 2000). Post-Eocene macrof~loral records f'rom Xiist Antarctica consist of h~othof(igus from the Late O l i g o c e n e of the CIROS- 1 h o l e (Hill. 1 9 8 9 ) and Pliocene Sirius Group deposits (Francis & Hill. 1996:

C a r l q u i s t , 1 9 8 7 ; Hill et a l . , 1 9 9 6 ) . However.

nndescribed isolated seeds and in- growth-position cushion plants and mosses occur in Sirius G r o u p d e p o s i t s ( A s h w o r t h et a l . , 1 9 9 7 ) . T h e s e point to greater diversity than currently recognized. At present, there is a temporal break between the P l i o c e n e / h ~ e O l i g o c e n e floras and t h e m o r e d i v e r s e E o c e n e assemblages. Identifying floras from within this time g q ~ is critical to understanding the rate of florislic c h a n g e s associated w i t h t h e onset of glacial c o n d i t i o n s . T h i s report a d d s a f u r t h e r record of Nothofagus f r o m the E a r l y O l i g o c e n e of E a s t Antarctica.

MATERIALS AND METHODS

C a p e R o b e r t s P r o j e c t d r i l l h o l e C R P - 3 , s i t e d l 1.76 km offshore from Cape Roberts. Antarctica at 77.0106O S and 163.6404O E ( s e e location m a p ) provided the material for this study. Preserved as a compression, the leaf occurs in a muddy medium to fine-grained sandstone at 44.12 to 44.18 mbsf. The f o s s i l leaf w a s revealed by d e g a u g e i n e n t of t h e surrounding matrix, and photographed immersed in a l c o h o l . A c a m e r a l u c i d a d r a w i n g m a d e with a n Olympus stereo dissecting microscope SZHO-10 was u s e d t o h e l p i n t e r p r e t a t i o n of v e n a t i o n p a t t e r n s ( F i g . 1C). T h e leaf is largely s k e l e t o n i z e d , w i t h compressed organic material lying over t h e main secondary and tertiary veins. Attempts were made to prepare cuticular material by dilute chromic acid, Schulze's reagent, and gentle maceration in hydrogen peroxide. However, the leaves were extremely fragile a n d yielded very s m a l l a n d p o o r l y p r e s e r v e d f r a g m e n t s . Descriptive t e r m i n o l o g y f o l l o w s that recommended in the m a n u a l f o r leaf architecture (1999); and Hickey (1988). The material is lodged at the Institute of Geological a n d Nuclear Sciences.

Lower Hutt, New Zealand with accession number B1347.

DESCRIPTION

Leaf with plicate vernation, 18 inn1 long by 1 0 m m w i d e . apex a c u t e , r o u n d e d , m a r g i n l o b e d t o s e r r a t e . Venation p i n n a t e , p r i m a r y vein s t r a i g h t . persisting to the apex with a slight taper. Secondary veins c r a s p e d o d r o n ~ u s . straight o r slightly curved apically, o p p o s i t e , t e r m i n a t i n g at t h e m a r g i n a p p r o x i m a t e l y in t h e c e n t r e of e a c h m a r g i n a l s e r r a t i o n . Tertiary v e i n s p e r c u r r e n t . a l t e r n a t e o r o p p o s i t e , o b t u s e . Q u a t e r n a r y v e i n s a l t e r n a t e

pereurrciit. H i g h c r order veins p r e s e n t Imt

~~i-i-;~i~gcment unclear. aerolation well developrii. No marginal fimbrial vein observed. Leaf margin lol~ed I D

serrated, teeth apparently compound with tin- ina,jor tooth being supplied by a secondary vein. ;nul lower order teeth being supplied b y branches I'~.oin [lie secondaries. Cuticle thin. poorly preserved. n o celliil;ir detail observed.

DISCUSSION

Based on leaf form. shape and venation patlcrn, this small craspeclodronius leaf is best placed i n (lie Southern Hemisphere genus No~I~of([gii.s'. Altlioi1~11 the lack of cuticular details precludes firm icIentil'ic:itio~i, further support for the affinity of the leaf comes from palynological evidence that points to Notho,/?iv,iis being one of the main elements of the v c ~ e t i i t i o i i (Cape Roberts Science Team. 2000; Askin & 1<;1ine, 2000; Raine & Askin, this volume). The distinctive pattern of raised ridges between the secondary veins indicates that the leaf was folded in the bud prior to leaf expansion (plicate vernation) (Fig. 1A). This type of leaf d e v e l o p m e n t in Notho,fagiis i s Found exclusively in the deciduous species (Philipson &

Philipson, 1988) and indicates the fossil material was also deciduous. This perhaps explains t h e deliciite nature of the leaf cuticle, which is generally thinner in deciduous species. However, deciduousness is not a phylogenetically informative character, and so the leaf cannot be placed with any confidence within one of the four extant subgenera of the genus. Placement of fossil Notliofagns leaves into an extant subgenus relies on g o o d p r e s e r v a t i o n of leaf a r c h i t e c t u r a l a n d c~iticular characters (Jordan & Hill, 1999). and the latter is lacking for this material. However. it should be noted that most of the Nothofagiis pollen diversity at this time in the Antarctic is made up of Not17ofagux subgenus Fuscospora (Raine & Askin, this volume).

A l a r g e n u m b e r of f o s s i l s p e c i e s h a v e b e e n ascribed to Notl~ofc~gzis in the Southern Hemisphere (Roniero & Dibbern, 1985; Tanai, 1986: Hill. 1989;

Scriven et al.. 1995; Hill et al. 1996), but few have features diagnostic of deciduous taxa (i.e. plicate vernation). Amongst the deciduous taxa, those from East Antarctica include Nothofagz~s beardmorensis from the Pliocene Sirius Group (Hill et a l . , 1996).

Although N. beardmorensis can be more than twice as l o n g a s the leaf described here, it shares a number of i m p o r t a n t s i m i l a r i t i e s . F o r e x a m p l e , in b o t h t h e secondary veins are straight and they also terminate the marginal lobeslserrations. In this respect, the leaf described here is also like the extant h? a l e s s a ~ ~ c l r i (Fziscospora) and N. obliqua (Lophozonia).

Other deciduous taxa include a single leaf from the Late Oligocene of the CIROS-1 hole (Hill, 1989).

This leaf differs. as the secondary veins terminate in the sinus of the lobes where they branch to form a

Fig. I - h l o t l i o f t ~ g ~ i s leaf. A. whole specimen illustrating the plicate morphology and crenate margin terminated by straight secondary veins.

B. leaf immersed in ethyl alcohol to enhance venation detail. C. interpretive drawing of leaf venation pattern. D. details of the higher-order venation revealed by immersion in ethyl alcohol. A-C. scale bar = 5 mm. D. scale bar = 1 mm.

niargiinil vein, much like thc extant A'. gannii (Hill, 1989. fig. 3 ) . Elscwherc in East Antarctica poorly preserved Eocene No111ofo~~i1.s leaves occur in the McMurdo Sound region (Pole et al.. 2000). These leaves are sn-iall (10-20 mm Ion". plicate, and have a c r e n a t e leaf m a r g i n , but d e t a i l s o f tlic vein architecture are not well preserved, Pole et ill. (2000) compared this material to ^A'. gunnii, N. piimirilio and thc Oligocene fossil from CIROS-1 mentioned iibovc.

Tile lack of details of higlher order venation pauerns prccii.ides meaningful comparison with the materiiil described here.

in the Anttirctic I'eninsula region, leaves rcfcrrcd to Noiho,f(~gii'i o c c u r in Paliieoccne to POIigoccne strata on Seymour Island (Dusc~i. 1908: Case. 1988:

Ganclolfo et ; > I . , 1998a) and in the South Shetland Islands (Zastawniak et al., 1985). Amongst these leaves considerable diversity exists in leaf s i x class, niargin type. and venation arcliitecturc. Tlwse few with plicate vernalion are largcly confined to the latest Eocene to earliest Oligoccne ( R . Hunt. pers.

c o m m , ) . All t h e s e leaves a r c still poorly circi~ii~scribecI, making comparison with the material described above difficuh.

AGE

Biostri.~ligraphy of thc upper 200 ¹¹¹ of the CRP-3 core is based on cliatoms (Cuvifuiii.s joii,sec~izii.v) and c a l c a r e o u s n a n n o f o s s i l s ( T r a n s v e r . s o p o n i i , ~ pii1cheroide.s) and is supported by ~i~agnctosti'c~tigrapl~y (Cape Roberts Science Team. 2000). Thc combined data i n d i c a t e d e p o s i t i o n in the mid-part of inagnetocliron C i 2 r of Early Oligoccne age,

VEGETATION

Terrestrial palynofloras i n C R P - 3 are o f a low diversity, and largely doiiiinated by A'oihofuvuiiivs and Po(loc(irpi(}l!e.'>. Thcse a~iemopliilous (wincl-pollinated) a x a produce a large amount of pollen, and s o i t is perhaps not surprising that they are most Sreque~itly encountered in residues. However, palynoniorph yiekl in CRP-3 is low: this could be due to either a high flux o f seclimem, or sparseness of vegeti~tion in the source area (Cape Roberts Science Team, 2000). The p a l y n o f l o r a i n c l u d e s rare g r a i n s of b r y o p h y t e s (Coplo'lporci). lycopliyles ( I ~ y c o p o f l i ~ i n i . Â ¥ i p o r i i e ' s ) ptcridopliytes (C?aihid'nes. l~aevi,qcito.sporiic"', and Rugiiltinsporii(~s). conifers (l'odocarpicfi~es sp) and angiiosperms ( " . C y y l ~ e r ( ~ c e n ( ~ l ) o l l i . s . T r i c o l l ~ i i m . Triporo/~olle~iiie.s. '?ProiecicHiiies, Atyr;cipife.s I~ctrrLsii, S r e l / ( ~ r i a - t y ~ ~ e , d i e n o p o d i p o l l ; . ~ ) ( C a p e R o b e r t s S c i e n c e T e a m , 2 0 0 0 ) . T h e s e all point to a low diversity vegetation with broad similarities to present day magellanic o r alpine vegetation (Askin & Raine.

2000).

T h e reliitivcly depaiiperale Hdrly O l i g o c c n c palyiioflora (C.$. Cape Robcrls Science Team. 2000:

Molir, 1 9 9 0 ) , w h e n c o m p a r e d to o l d e r E o c e n e

asseinblages (c.,q. Askin, 2000; Mohr, 1990), su-.-. ~ ~ ~ , c s t s a major changc i n the vegetation. This interpretation is supported by llie ~i~acrofossil record: Eocene floras in East Antarctica include Ardiic(ir;(i, A~oihofo,~iis (both deciduous and evergreen), and at least three other angiosperm types (Pole et a l . , 2 0 0 0 ) . These E o c e n e !caves range from n o t o p h y l l o u s to micropliylions in size. ^ti c o n t r a s t f r o m t h e microp11ylIoi.i~ foliage of the Oligocene. Such ²¹ shift in leaf s i z e class is to be cxpcctecl a s c l i m a t i c conditions cooled. The pattern seen i n the fossil leaf 111atcri;il is also supporteci by paiynology. Eocene slri.iui contiiin consic.lcrable more diversity. piutic~ilarly in podocarp conifers and angiosperms (Proteaceae and otl-icrs). than seen i n Early Oligocene strata (Askin, 2000: Askin & Raine. 2000; Raine & Askin, this volume).

CLIMATE

The marked change i n composition and abundance of pi~lynofloi'cil residues bctwecn the Eocene and the Early Oligoccnc (Askin, 2000; Askin & Raine. 2000:

Ruinc & Askin. this voktmei suggests a major change in v e g e t a t i o n . T h i s lias p o t e m i a l l y i m p o r t a n t i ~ i ~ p l i c i i t i o n s . a s u c h a n g e f r o m forest to tu11~1ra vegetation would result in increiised albeclo, ^i11iO lead to positive feedback loop that reinforces the climatic cooling seen in this pan of thc stratigraphic column.

Indeed recent modeling experiments suggest ^tihiit high l a t i t u d e vegetation pltiyed 2111 in1))ortant role i n medialingthe climate of these regions (Otto-13iiesner

& Upcluirch. 1997). Although a single leaf is not

r c p r c s e n t a t i v e o f the vegetation a s a w h o l e , the affinity of the leiif can be used to infer past climate conditions. This is largely due to more wide-ranging studies on extant (c," Hill & Truswcll. 1993; Hill &

J o r d a n , 1 9 9 6 ) a n d fossil ( F r a n c i s & H i l l , 1 9 9 6 ) N~ihofcign',' assemblages that provide physiological limits 10 growtli in this taxon. Hill & Tniswell (1993) e s t i m a t e d f r o s t tolcrancc linlit of d e c i d i ~ o u s N ~ i h o f a g n x s p e c i e s tit -22° but t h i s m a y be conservative, pi~'ticuIar1)~ for ground Inigging forms ( H i l l & J o r d a n , 1996). As plant growth relies o n liquid water at least part of the year must have been above freezing. Hill & Jordan (1996) suggested tllat in summer months "tcrnperattire must have been at least 5° f o r several weeks" f o r Noi110,fo~qii.s hi~d/'dmoi~eii.vi.s to survive. The highly seitso11i.11 nature of polar e ~ i v i r o n ~ ~ i e n t s is often not considered when using nearest living relative approaches to estinitite c l i m a t i c conclitions from fossil A~~1f1ioj'tigii.s (<,,g.

Mercer, 1986. 1987). However. Francis & Hill (1996) biisetl their cstimates of mean annual temperature for Nofhofii,fii.s bearc1111ore11.si.s o n c o m p i i r i s o ~ ~ s to Northern Hemisphere iingiosperms (Salix) growing i n

ii similar cnvironincnt 1'11ic1 with ;I si~nihir li;ihit. Tliis suggests thiU the growing season was short and ~ t i r i n ( u p to 5 Â ° C but the winter season down to -.l5 to -22 "C, possibly with a mean ttnnual temperature of

- 1 2 "C ( F r a n c i s & Hill 1 9 9 6 ) . T h e s e e s t i m a t e s a r c probiibly ei.ii.iaIly a p p l i c a b l e t o t h e l e a f d e s c r i b e d i n t h i s s l u d y .

CONCLUSIONS

T h e T e r l i i i r y l i i s i o r y o f A n l i ~ r c l i c v e g e t i i t i o ~ i is s t i l l r e l a t i v e l y p o o r l y k n o w n a n d n n u c h w o r k r e m a i n s t o be d o n e , b o t h i n t e r m s o f f u l l y d e s c r i b i n g k n o w n d e p o s i t s . iinci d i s c o v e r i n g n e w d e p o s i t s f r o m c r i l i c i i l l i m e p e r i ( ~ l s , D e s p i t e t h i s , t i n c i n e r g i n g p a l t e r n suggests t h a t c i i i i i i i t i c c o o l i n g p r o f o u n d l y i n l ' i i ~ e ~ i c e d t h e v e g e t a t i o n h i s t o r y . T h e p r e s e n c e o f s m a l l d e c i d u o u s N i 1 f / i i [ f i i g ~ s l e a v e s in t h e E t i r l y O l i g o c e n e s u b s t a n t i a l l y n a r r o w s t h e l i m e g a p b e t w e e n d c p i ~ i p e r ~ ~ t e " g l i ~ c i i i l " f l o r a s a n d t h e m o r e d i v e r s e m e s i c f l o r a s o f t h e E o c e n e . i t a p p e i i r s t h a t t h e N a n s i t i o n f r o m c o o l l c ~ ~ ~ ~ ~ e r a t e and r e l a t i v e l y d i v e r s e v e g e t a t i o n in t h e mid- t o L a t e E o c e n e t o l u n i - l r a - t y p e v e g e t a t i o n s e e n i n t h e P l i o c e n e m a y l i i i v e o c c u r r e d r e l a t i v e l y r a p i d l y (i.e. I ~ e i w c e ~ i t l I.:itest ~ E o c c n e i l i i c l t h e c t ~ r l i e s t O l i g o c c n e ) . E s t a b l i s h i n g 111c e x a c i n a t u r e i i n d t i m i n g o f v c ~ c t d t i o n a l c h a n g e s will b e i m p o r l a n t w h e n e x i i m i n i n g p o t e ~ i l i t i l p o s i t i v e f e e d b a c k s 1 0 c l i i i ~ i ~ t i c c o o l i n g .

C o m p a r i s o n o f t h e A n t i i r c i i c P e n i n s u l a f l o r a s (i.?.

P L l k i c o c e n e l o O l i g o c e n c ) w i t h t l i o s c o f t h e R o s s S e a r e g i o n s u g g e s t s t h a t A m a r c t i c v e g e t a t i o n w a s r e g i o n a l l y h e t e r o g e n e o u s . A l t h o u g h E o c e n e f l o r a s f r o m t h e R o s s S e a r e g i o n a r c p o o r l y p r e s e r v e d . a n d i 1 1 1 i t c d m a t e r i a l i s a v a i l a b l e . t h e f l o r a i s r e l t t t i v e l y s m a l l e r - l e a v e d c o m p a r e d l o c o e v a l f l o r a s hi t h e A n t a r c t i c P e ~ i i n s u l a . F u r l l i e r ~ i ~ o r e . E x t A n t i i r c t i c f l o m s a r e of l o w e r d i v e r s i t y ( t h i s 11it1)' b e a rel'lectio11 of t h e l i m i t e d s a m p l e s i z e ) a n d c o n t a i n m o r e d e c i d u o u s t a x a t h a n E o c e n e f l o r a s in t h e A m a r c t i c P e n i n s u l a . T h i s p o i n t s t o c! c o o l e r E a s t A n t a r c t i c a coii1p;ireii t o t h e m o r e ~ i i ~ l r i l i ~ i l c A n U n - d i e I ' e n i n s u l i ~ . H o w e v e r . i m p o r l a n t l ) ~ t h e A n t a r c t i c P e n i n s u l a f l o r a s s h o w an i n c r e a s e i n d i v e r s i t y o f d e c i d u o u s t i i x a t o w i i r d s t h e E o c c n e - O l i g o c e n e b o u n d a r y , s u p p o r t i n g a c o o l i n g t r e n d i n t h i s r e g i o n a l s o .

l3irke1majer K . , l98..1. Geology o f IIIC C q x h ~ l ~ l ~ i l l c ,\rca. K i n g Geoqc lsI;~,,<l ISOLII~ SIKII~III~ l s l ~ ~ ~ ~ c l s , Anl;irclica): ~ ~ r c - l ' l i ~ ~ c c n t g l ; t c i < ~ ~ ? , i t r i ~ ~ c ~ I e { x ~ s i l s ;VII<I ll>cir s t ~ l ~ s l ~ ~ l ~ ~ t ~ ~ . .S!wdi<! <;~'o/osiv,t

I'nlimir,,, 79. ?..X5

C:;twl<j~~isl S.. 1987. l ' l i , ~ c c ~ ~ c 1\J0t/><,/<,gtt.r \wcxl f r o m :hc 'TS;~~IS:~~II:~WCI~C ~ ~ ~ I ~ I I I ; C ~ I , S , ,t/>i<,, 11, 571-5%

I l o b e n s Science T c i i m , 2000 5 - I ' a l a o i n n ~ l ~ ~ g y . 'fi,rrct ,\iiiililini. 7. 133-170.

C i w J.,\., 1988. l ' ~ ~ l ~ ~ c ~ g c n ~ I'Iorah fhn, SC~IIK>LI~ Isl;\n<l, As!li~rclic l ~ c ~ ~ i ~ ~ s ~ ~ l ~ t . i;~w/o,yi~oI ,So<i<,;y ar,l!~,<>rir<, , i ~ ~ ~ ~ ~ z , ~ i r , 169, 523- 530.

i g k ' R.V. & L i u c l l c M,. 1998. Aiilarclic l'cninsul:~ crymsphcrc:

l<mly Oligcxcnc l<. 30 h4a) i ~ ~ i l i a l i w ? :!nd it sc\'iscd gIaci:%l c l ~ r ~ ~ n o l o g ! , J < ~ , r m t / 01' !/W (;?o/q~ic,d/ .Soci<'Iy, /.0!8donl. 155.

433-437.

1Dt~sc11 l'., I9OX. l.lt>cr clit 'T'cr~iiirc i I w ; t < I t r S c y ~ n o u r In s c l .

t t ~ i . s . s ~ ~ ~ ~ . s c / ~ ~ ~ / t I i ~ / ~ ~ ~ /:rg/>~!i.s.s~, cler . S c / ? ~ r ~ ~ ~ / i . s ~ ' / z ~ ~ ! t .S/~<l/>o/<tr- /:,/mli,/,iil / W / - / W . 3, l - l ? ? .

Ffi!~~cis l,l;,, 2 0 ~ ~ 0 , 1=<1~siI ncx~cl ~ V W I , I E ~ ~ c c ~ ~ c lhigl~ l: t I i l ~ ~ d c ic>rcsls

\ ~ I c h f ~ ~ ~ r d o S < ~ I K I , , \ ~ ~ l ~ t r c l i c ~ ~ . 11,: S l i l n e l l J.11. & l - ~ e l ~ l l 1 l ~ l l ~ ~ ~ [<.h{. (ccIsI. l P ~ , l ~ l ~ < ~ l ~ i ~ > l , > g y :,,,<l l';,l~,c<,c,,v,r,,,,,,,c,,l~ <>l' l:<>cc,lc

f ~ ~ s s i l i 1 ' c s ~ ~ ~ 1 s err131ics. i ~ T c h ~ l ~ > r d c S o i > ! ? ~ l , I,::!sl , \ $ ~ l i ! r c l i c z ~ . ,1~,!0!r!i,, / l ~ ~ , ~ ~ ~ ~ , r c / # .Seri~~.s. 7 6 , 253-260.

I.'x:%ncis S.I.1. & l i i l l l?..'., 1996. l:obsil ~>I:~III\ f r o ~ n t l ~ c l ' l i < ~ c t ~ ~ c Siritus <;r<~hl>, 'T'fi!~~s:o~l:~rclic h'l,>ttnIz$i$?s: c ~ ' i d m ~ c i w c l i ~ l ~ ~ l l c from proiv~l~ rings and I'nsiil leaves. Piiliiiiis. 11, 389-390.

G : i i ~ l o l l o M A . . M;n-ei!ssi S.A. & S;imiil;in;i S.N.. i998;i. I-'lo!-.! y

~pitIae~~cli~~,a cl? l:> I-'o~I,;K~~~I l.;$ h'lcsel:~ (I~OCC~IC iVIc~lio). 1sli1

34;1ra11,11io (SC~II,<>LI~). ,\x,lAs~i~l;t. ,t.soci<witj!r / ' ~ t / o e ~ ~ 8 ~ l ~ ~ / ~ i , s i c ~ ! ,lt:q~,miiui I'uldiciirit'ni l:.spvri:il. 5. 155.162.

G.mclolio .M,,\,. Hoc l'.. SaiiiiI1an:i S.%, A M2iirnssi S.A.. I'iOXb, G,,$, I ' I O ~ f h i ~ I I I ~ ~ ~ ~ , I I ~ > I ~ ~ ~ C Z ~ I I I ~ , , I C >tii,, ;I izts Cir<>s>t~l:tric\cc;~e i<,r<lc,l I<<>s~,~cs] '!C l;, lF,>r,,,:,ci6,, 1.2, hlcscl:, [I<<>C~,I<> h'I~<li<>l

lsl;t h4aran1hio. ,\nlc!~~cli<l;~, /I,$<,cioci6,> / ~ ~ ~ / ~ , ~ ~ , ~ , , ; ~ ~ / ~ j ~ i c ~ ~ Ar,q<,nri~,o / ' ~ ~ / ~ / i c ~ w i 4 ~ , /~.~p~mi,d S, lJ7-153.

C;OIII:~II \4'.. 1908. I l i c iossilcn l ~ l t i l ~ c r V ~clcr S c y $ ~ ~ o k ~ r I $tocl S ~ n v

l . l i l l - l x ~ ~ c l , I l ~ i . ~ . v ~ ~ r ~ . ~ ~ / ~ ~ ~ / ~ / i ~ / ~ ~ ~ fi.'r~~~/~,,i.s.r~~ </<,r . Y c l ~ ~ ~ ' ~ ' ~ / i . s ~ / ? ~ ' ~ ! , S i i ~ i p ~ ~ l n r - / i . c / , ~ ~ ~ / i u i w !W/-!W13. X81, 1-33.

l-lickcy l,.)., l ~ J S 8 . l < c v i s c ~ l c l ~ ~ s i f i c ~ i ~ i o ~ ~ o f l l x ~ ~ v c l ~ i l c c l u r c o f

'I~C~,I~IC~I~,I,,,L,S ICIVCS. I,,: h ' 1 ~ t ~ : t l i ~ r . ~ i . & C:IICII~ I.. (C(ISL

,%~I;NWII~ o i IIIC I ~ ~ c ~ ~ I ~ ~ c ~ I ~ ~ ~ ~ s , \ / ~ I L I I ~ ~ l. S y s l c ~ ~ ~ ; > l i c ~ I I ~ : ~ I ~ ~ I I ~ ~ 01' IIIC lcitf ~ I I I ~ SICIII, 211d l < < I i l i < ~ % ~ . C.'l;~rcnd~~n I'rcsh, O x 1 ' w d

25-39.

I.I~II !<,S,, 1989, l:<xsil IC;,~. ,\III;~WCI~C C c ~ m ~ o i c l ~ i s i o r y I'ron, IIW CIROS-l Drillhole, MeMiirilo Sound, ;\'<-I? '/.rulom! 11mai-linnil

<f.?<U~ni(/ir c i ~ i t i /ndii.rli-iol /li'.wnr/i /Sul/<,lni. 245, 143-144.

H i l l l?.'., 1l:irwixid D . M . & Wcbl). !'-N., 1996. N i i ~ l r l i . / ' ~ ~ s u s / ~ ~ ~ ~ , r ~ / ~ ~ ~ ~ ~ r ~ ~ ~ r . ~ / . s I N ~ ~ l I ~ ~ ~ f i ~ g i ~ c ~ : ~ ~ ) , :I 11cn spccics l>;lscd lcwcs

I'rm, IIW l ' l i w c t ~ c Sirius G r w p ' T r ~ i ~ ? s m ? l ~ ~ r c l i c ~ I ~ ~ t ~ I l ~ ~ i ~ ~ s . t~,,l~~rclic>,, /<<Ti<,,,. 01' /~<,/<,<,,,/><>,~,,,y <,,,</ l'<</y,!,>/<>~y. 94, l 1 - 3

H i l l R.S. & 'T'niswcll B.M.. 1993, h'oihofd,qtt.s Idivcs i n llsc Sirius

<;hm(>. 'T'~~nsi$nl;trcIic 34wx,I2il,s: I c w c s ; t l d ) p ~ l i i c t ~ m d I k i r c l i ~ x ~ ~ i c i ~ n p i c ; t ~ i w s . , l m ~ ~ r c ~ i c / t c , s ~ ~ ~ t r c / , .Swi<,.s, 60, 67-73.

H i l l R.S. !lI o n i a n G.S., 1996. Macrofossils as indicalurs o i l'lio- l ~ l c i s ~ ~ ~ c ~ n c clit~,;ws it, Tivbnaniit ~ I C I Anl:trclici!. /~<qwr.s ,utd /'roceeding.s or ^;/M, l<<>y,d .?o<ie!y Xt.sut<o,i<~. 1311, 9- 15.

Sc>r<lzw (;.S. & l i i l l IZ.'., l W 9 . 'l'l,c ~ ~ l , y l ~ ~ g ~ ~ ~ c l i c ; a f f i ~ ~ i l i e s c>(

(\1,,;/~4i$g!!.s ~ N ~ ~ l l ~ ~ ~ i : ~ g ~ ~ c c ~ t e ) leaf i ~ ~ s s i l s lx~se<l c l ~ ~ i i l ) i n c d

~moIect>li,c :and ~ ~ , < > s ~ ~ l ~ ~ > l < > g i c : ~ l d a l a / ~ ~ ~ e r m t t i m w / . / o u r m ~ / 0 1

l'/cua . S ' i  ¥ à ‡ ~ à § , ~ 160. 1 177-1 188,

h ' l m 1 ~ 1 o f I w f : ~ r c l ~ i l c c l ~ ~ r c 1 9 W h ~ l ~ ~ r ~ ~ l ~ , ~ l ~ ~ g ~ c : ~ l c l c s c r i ~ ~ l i m :811cl c : ~ ~ c g o s i , . ; ~ ~ i ~ ~ ~ , 01' ~ l i c ~ ~ l y l e ~ l , ~ ~ ~ ~ ~ t ~ h :t>1<1 , > c l ~ e i l l c d

~ ~ ~ ~ ~ ~ ~ , ~ c ~ I I ~ I c ~ I ~ ~ I I ~ ~ ~ I s gnt>giospcsn~s thy 1.cxf ,\rcl,iwct~~re Whrki%>g Group. Smi~!i;,oi~i;in Insiiliiiion. Wiishiiig~on, 1-65,

Manos l'..',, $TO?, Syslcmalics o f M u ; / i v / ~ u s INoiliol'.igacc;ic) txtsc<l m r D N \ slx>ter s c q t ~ $ ~ c c s (1.1-S): 1 : t x ~ ~ ~ m n ~ c c,n,gr~?mx will^ ~ n m ~ ~ ~ l w l ~ ~ g y lpI$tslid s q t w ~ c e s . A m w i c : ~ r SOI~I>;II o f Boiany. 84. I 137-1 155.

h4crces d.11.. 19x0. S o ~ r l I ~ c r n C l ~ i l c : ;I ~n>o<Icm $nn;~Iog llx s m ~ l ~ e s n sl,orcs of ~IIC l t m s I ! ~ ~ ~ l x ~ y m c n l d u i ~ , g l' l i w c w U W Y

i n ~ c r m l s , A ~ m r c ~ i c S ~ ~ w ~ ~ ~ ~ l o i IIW Uniicd SI:IICS. 21. 103-105.

h,lcsccr S.14.. 1987. 'I'ltc ~ \ 1 1 1 ~ ~ w c l i c icc SINXI d ~ t r i n g ll,c 1,nIc

Neugene. 11): COCILW J;T, lc<l,), ~ ' ~ ~ I ~ C ~ ~ C C O I O ~ ~ o f Africz and ll,~ s,,sr<,t,,,ding idt,,l<k. ,\,,\. 13aIkma l<,>ll~s<k~l,,. 21-23,

Mohr B . A . R . . 1 9 9 0 . Eocene and O l k o c c n c sporoniorphs a n d dinoflagellate cycsts from Icg 1 1 3 ilrillsilcs. Wcddcll Sea.

A n t a r c t i c a . Proeredine.\

of

Otto-Bliesner B.L. & Upchurch G . R . , 1997. Vegetation-induced warming of high-latitude regions during the Late Cretaceous period. Nature. 385, 804-807.

Philipson W.R. & Philipson M.N.. 1988. A classil'ica~ion of the genus Nofhofasus (Fagaccae). Botanical Jol~rnal o f the Linncan Society. 98, 27-36.

Pole M,. Hill R.S. & Harwood D.. 2000. Eocene plant macrofossils from erratics. McMurdo Sound. Antarctica. I n : Stilwcll J.D. &

Feldmann R.M. (eds). Palaeobiology and I'alaeocnvii-onments of E o c c n c f o s s i l i f e r o u s c r r a t i c s . M c M u r d o S o u n d , E a s t Antarctica. Antarctic Research Series. 7 6 . 243-25 1 .

Raine J.I. & Askin R . A . . 2001. Terrestrial palynology of C a p e Roberts Drillhole CRP-3, Victoria Land Basin. Antarctica. This volume.

Romero E . J . & D i b b e r n M . C . . 1985. A review of the s p e c i e s d e s c r i b e d a s F a g u s a n d Notl~o,fa,qus by D u s e n .

P d l ( ~ c o n t o , y ~ ~ a ~ ~ h i c n Aht. IS. 107. 123- 137.

Striven I,..).. McLouglilin S. <t Hill R.S.. 1995. Notl~i?fli,q~~\ / i / i r d f n (Nothol'agaccac). ;I new ileciduoi~s Kocene ~iiacrofossil ¥-ln'cic\

from soutl~crn continental Australia. Re\'iew of P a l a c o b o t m ~ ~ (iiul 1'~tl~iioIo~qj~. 86. 199-206,

-,-.

Journal o f the l-'(icnlty of' Science Hokkaido Univer.si/y ,S~,rii,\

IV. 21. 505-582.

Thomson M.R.A. & Burn R . W . . 1977. Angiospcrm f o s s i l s l'rom atituclc 7 0 5 . Nature. 269. 139- 141.

Weston P.H. & Crisp M.D.. 1987. Evoliuion and biogcogr;ipliy of the waratillis. In: Armslrong J.A. (eel.). Waratcihs, t11oir /~ioli>w cultivation a n d conservatioii. Occasional Publication No. 0 Australian National Botanic Gardens. Canberra. 17-34.

Zastawniak E.. Wrona R.. G a ~ d z i c k A. & Birkenmajer K . , 108.5.

Plant remains from the top of the Point H e n n e q u i n ( i r o u p (Upper Oligocene) King George Island (South Shetland Isl:i~ids, Antarctica). Stiulia Geolo,yira Polonica, 81. 143-164.