New records of fossil flowering plants from Suffolk

NEW RECORDS OF FOSSIL FLOWERING PLANTS

FROM

SUFFOLK H . L . PEARSON

Some 14 species of flowering plants (angiosperms) of pre-Pleistocene age have been described from their fossilised seeds, fruits and wood collected in Suffolk (Pearson, 1987). In addition, the British Museum (Natural History) has in its Palaeontology Department stores more specimens of fossil flowering plants from Suffolk not yet recorded or described. Here I present initial accounts of these additional specimens, which include the first unequivocal record of fossil monocotyledonous plants (viz. Palmoxylon) from Suffolk, plus the first record o f a pre-Pleistocene plant from Felixstowe. i) Palm s t e m s f r o m Waldringfield

Nine fragments of calcified stems from the Red Crag showing vascular structure typical of most monocotylededonous angiosperms were found (see Appendix). However, the size, shape and quality of preservation of these indicate that they probably come from three or four original, intact specimens. As no ground slices are available, their anatomy has been examined using incident light on polished or acid-etched surfaces, and by peel sections (Joy, et al., 1956). The largest specimen is part of a stem at least 130mm in diameter. All of the stems are partially decorticated and each has the peripheral vascular region only. Some of the smaller specimens are either petioles or stems. Fibrovascular bundles are scattered in the parenchymatous ground tissue. In most of these bundles the vascular tissues are completely enclosed by a sheath of fibrous sclerenchyma, which is usually thicker on the abaxial (outer or ventral) surface of the bündle. No entirely fibrous bundles are present. This form of bündle anatomy has also been observed in the Indian palm stem Palmoxylon mahabalei of Eocene age, which Rao and Menon (1967) consider to resemble COCOÄ, the coconut palm.

Fossil palm stems have been reported during the past two centuries showing a worldwide distribution (Mahabale, 1958). Kaul (1960) provided a cosmopolitan review of the earlier records of fossil palm stems with particular reference to specimens in the B.M. (N.H.) collections. As with the fossil woods described above, it has been necessary to assign many of the fossil palm stems to form-genera, principally to Palmoxylon Schenk. Mahabale (1958, 1961) discussed the artificial nature of that form-genus, in part because some of its species are monocotyledonous but not belonging to the Arecaceae (palm family). In contrast, however, certain other Palmoxylon species are more definitely akin to extant palm sub-families or genera. British fossil palm stems have been mentioned by certain authors (Chandler 1964; Brett, 1966), and Edwards (1928) drew attention to such stems from the Red Crag of Suffolk displayed formerly at the B.M. (N.H.).

Recently, Dr. M. E. Collinson has recorded the discovery of many pyritised stumps showing both the root mantle and typical stem anatomy of

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Palmoxylon described above. These were found in the Reading Beds at Felpham, near Bognor Regis, Sussex, and are the only in situ palm stumps yet recorded in Britain (Collinson, 1986). The stems from Waldringfield will be referred to Palmoxylon sp., awaiting further comparison with a more complete ränge of described species.

These palm stems, and the fossil coniferous wood from Suffolk (Pearson.

1988), provide additional evidence for the presence of a group of plants in Palaeogene England which are known more abundantly from fossils of their leaves, pollen, seeds and fruits. Chandler (1964) listed twelve palm genera, belonging both to the Arecaceae and the Nipaceae ('stemless' feather palms), as known from other Organs or cells in the Palaeogene flora of England.

The age of the Waldringfield Palmoxylon sp. specimens is uncertain as for the Red Crag woods from that locality - i.e. probably Palaeogene, with the underlying London Clay suggesting an Eocene age if these fossils have been reworked. ii) Plataninium decipiens from Waldringfield In addition to the pieces of Red Crag wood assigned to this species by Brett (1972), further conspecific specimens from Waldringfield were located at the B.M. (N.H.) - see Appendix. All but one of these slides, (V. 8059), represent isolated fragments of secondary xylem only, although the crushed State of the primary xylem in this one slide severely limits cellular observations. The cut and polished facets of a further 24 hand specimens display sufficient structural detail to permit identification with this species (see Appendix). The main diagnostic character of this wood is the great width of its vascular rays, up to 18 cells wide, with an average width of six cells.

Admittedly, the Platanus sp. described by Brett (1972) from the same locality is very similar anatomically, but its vessels are usually in groups and occur about five times as densely as those of Plataninium decipiens. Growth rings are lacking or very weakly developed in these specimens. Brett (1972) commented upon the great similarity between this species and the Oligocene P. europeanum from Czechoslovakia (Prakash et al., 1971), and these may indeed prove synonymous. Similar pyritic wood of Plataninium sp. has been described from the London Clay of the Isle of Sheppey in Kent (Wilkinson, 1984). iii) Other dicotyledonous woods from the Red Crag Two general kinds of dicotyledonous wood, neither very close in structure to any of the described Cainozoic fossil woods known from England, have also been located at the B.M. (N.H.). Both groups of specimens are rustcoloured and the quality of anatomical preservation is much the same as for the woods from the Red Crag at Waldringfield described earlier (Pearson, 1987,1988) (see Appendix).

A ring porous wood which displays distinct growth rings is represented by a Single specimen (V. 8033). These growth rings (annual increments ?) vary between 0.5mm and 3.0mm in approximate width. Only secondary xylem has Trans. Suffolk Nat. Soc. 25

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been preserved and this is traversed by vascular rays between two and five cells wide. T h e vessels are crowded, but mostly solitary, and have an average diameter of about 65nm. Cellular details of the tracheids, fibres and ray cells have not been preserved with clarity.

The remaining 47 microscope slide preparations of dicotyledonous wood from the Red Crag of Waldringfield are diffuse porous (see Appendix). In addition, a total of 80 hand specimens of Red Crag woods were located and examined at the B.M. ( N . H . ) . Many of these have not beensectioned, and so their taxonomic affinities remain obscure. It is noteworthy, however, that at least one of these specimens, (V. 3118), was collected from the Red Crag at Felixstowe.

Conclusion The review (Pearson, 1987) and accompanying new records of structurallypreserved stems and woods (Pearson, 1988) show that the fossil flora of Suffolk, particularly in its megafossils, is more diverse than hitherto generally reported in geological literature. The preliminary report given here has not only brought to light new finds of taxa rarely recorded in the Cainozoic of Britain, but has also indicated the greater abundance, in both absolute and relative terms, of certain woods previously described - e.g. Plataninium decipiens. T h e greater abundance of microscopic and/or Pleistocene fossils will probably perpetuate the bias in the palaeobotanic literature on Suffolk.

Nevertheless, the data presented here, obtained from somewhat limited collections of megafossil plants, indicate the value of further investigation of localities already known to be fossiliferous, as well as searching for new sites.

Regarding Assington, Collinson (1983, p. 13) writes '. . . the locality would clearly repay f u r t h e r study if its exact whereabouts could be established.' Much the same might be said for sites of origin of many of the Red Crag woods and stems.

Appendix The fossils recorded above are lodged at the Palaeontology Department of the British Museum (Natural History), Cromwell Road, London, SW7 5BD. The specimens have been registered in the Plants Section there with ' V ' numbers as follows: Palmoxylon sp.; Blocks only - V.2457, V.4626, V.45461, V.52375, V.52808, V.52959a & b, V.53393. In addition. I have prepared, and mounted on slides, peels of block V.45459.

Plataninium decipiens Brett; Microscope slide preparations - V.7815, V.8009, V.8011, V.8018, V.8031, V.8043, V.8054-8055, V.8069, V.52696a-c, V.7832 (from block V.57155), V.8035 (from block V.57156), and V.8059 (from block V.3130). Hand specimens or blocks - V.2459, V.4989, V.4996, V.4998, V.5018, V.5020, V.5028, V.5253, V.5263, V.5640, V. 13256, V.27527, V.48765, V.52690, V.52733, V.57419 and V.57157-57164. (The holotype specimen is from the London Clay of Sheppey.)

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Dicotyledons f r o m Waldringfield; O n e slide only, V.8033, of ring porous wood. Diffuse porous woods - V . 7 8 1 6 - 7 8 1 7 , V.8010, V.8012-8014, V.8016, V.8019, V.8021-8029, V.8032, V.8034, V.8039-8042, V.8044-8047, V.8049-8050, V.8052-8053, V.8056-8058, V.8060, V.8062-8067, V.8070.

N o blocks have yet been associated with these specimens. M a n y of these slides bear the name A . Bell, the date 1875, and some have been labelled ' R e d Crag, Waldringford, (sie) near W o o d b r i d g e ' , suggesting their provenance to be Waldringfield.

Dicotyledon f r o m Feixistowe; V.3118. (A diffuse porous wood. No precise details of locality available.)

Acknowledgements I thank the Staff and Trustees of the British Museum (Natural History) for permission to examine fossils in the national collections.

References Brett, D . W. (1966). Fossil wood of Anacardiaceae from the British Eocene.

Palaeontology, 9, 360.

Brett, D . W. (1972). Fossil wood of Platanus from the British Eocene.

Palaeontology, 15, 496.

C h a n d l e r , M. E . J. (1964). The Lower Tertiary floras of Southern England.

IV. A summary and survey of findings in the light of recent botanical observations. British Museum (Natural History) London.

Collinson, M. E . (1983). Fossil plants of the London Clay. Field Guides to fossils, No. 1. Palaeontological Association, L o n d o n .

Collinson, M. E . (1986). The Felpham flora: a preliminary report. pp.

2 9 - 3 2 , in B o n e , D . A . The Stratigraphy of the Reading Beds (Palaeocene), at Felpham, West Sussex. Tert. Res., Leiden, 8, 17.

E d w a r d s , W. N. (1928). Some British Tertiary floras. Proc. Geol.

Assoc., London, 39, 238.

Joy, K. W . , Willis, A . J. & Lacey, W . S. (1956). A rapid cellulose peel technique in palaeobotany. Ann. Bot., N. Ser., 20, 635.

Kaul, K. N. (1960). The anatomy of the stem of palms and the problem of the artificial genus Palmoxylon Schenk. Rull. Nat. Botanic Gdns., Lucknow, No. 51.

M a h a b a l e , T . S. (1958). Resolution of the artificial palm genus, Palmoxylon-, a new approach. Palaeobotanist, Lucknow, 7, 76.

M a h a b a l e , T. S. (1961). Water ferns, palms and other monocots from the Deccan I n t e r t r a p p e a n Series, India, and their resolution into natural c o m p o n e n t s . Recent Adv. Bot. (lectures), Toronto, 10, 953.

Pearson, H . L. (1987). Megafossil plants f r o m Suffolk: a review of the pre-Pleistocene records. Trans. Suffolk Nat. Soc., 23, 56.

Pearson, H . L. (1988). New records of fossil conifers f r o m Suffolk. Trans.

Suffolk Nat. Soc., 24, 84.

Prakash, U . , Brezinova, D . & BĂźzek, C. (1971). Fossil woods from the

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Doupovske hory and Ceske stredohon Mountains of Northern Bohemia.

Palaeontographica, Stuttgart, (B) 133,103.

Rao, A. R. & Menon, V. K. (1967). Palmoxylon mahabalei, a new petrified palm from Mohgaon Kalan, India. J. geol. Soc. India, Bangalore, 8, 51.

Wilkinson, H. P. (1984). Pyritised twigs from Sheppey. Tert. Res., Leiden, 5,189.

Hugh L. Pearson, Claydon High School, Church Lane, Claydon, Ipswich, IP6 OEG

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