Leclercqia complexa gen. et sp. nov., a new Lycopod from the late middle devonian of eastern New York

Review of Palaeobotany and Palynology Elsevier Publishing Company, Amsterdam - Printed in The Netherlands

LECLERCQIA COMPLEXA GEN. ET SP. NOV., A NEW LYCOPOD FROM THE LATE MIDDLE DEVONIAN OF EASTERN NEW YORK

HARLAN P. BANKS 1 , PATRICIA M. BONAMO 2 and JAMES D. GRIERSON 2

I Division of Biological Sciences, Cornell University, lthaca, N. Y. (U.S.A.) ZDepartment of Biological Sciences, State University of New York, Binghamton, N. Y. (U.S.A.)

ABSTRACT Banks, H. P., Bonamo, P. M. and Grierson, J. D., 1972. Leclercqia complexa gen. et sp. nov., a new lycopod from the late Middle Devonian of eastern New York. Rev. Palaeobot. Palynol., 1 4 : 1 9 - 4 0 .

Leclercqia cornplexa gen. et. sp. nov. is described as a slender, herbaceous lycopod assigned to the family Protolepidodendraceae. Its laminar leaves are divided into an elongate, acuminate, often recurved central division and two opposite, divided, lateral divisions. Leaves are in a low spiral, eight to ten per gyre. Each has a single vein composed of tracheids. Lateral branches from this vein extend only to the base of each lateral division. The main vein extends to tip of leaf. Stomata are slightly sunken and scattered. The xylem strand is a solid rod with fourteen to eighteen protoxylem ridges; maturation is exarch. Protoxylem is composed of annular, spiral, and reticulate elements. Metaxylem is composed of scalariform elements and tracheids with elongate to oval and uni- to multiseriate bordered pits. Leaf traces arise from protoxylem ridges and extend obliquely to bases of leaves. Sporangia are globose to elliptical, attached to sporophylls by a pad of tissue just proximal to the lateral segments and have sporangia on their walls. Dehiscence occurs along the upper margin of the sporangium and is parallel to midline of sporophyll. Groups of sporophylls alternate with vegetative leaves. Spores in situ 60 85 in diameter exclusive of ornamentation, with curvaturae perfectae, spinae 5 - 9 tz long on an equatorial ridge, and biform ornamentation on distal and proximal faces. Plant is eligulate and probably homosporous.

INTRODUCTION C o n s t r u c t i o n o f a n e w p o w e r p r o j e c t along S c h o h a r i e Creek, S c h o h a r i e C o u n t y , New Y o r k has u n c o v e r e d a layer o f richly fossiliferous, fine-grained m u d s t o n e filled w i t h long, leafy axes o f a p r e v i o u s l y u n k n o w n l y c o p o d ( H a t e I, 1). T h e p r o f u s i o n o f t h e s e axes in the m u d s t o n e , t h e u n i f o r m p r e s e n c e o f a t t a c h e d leaves w i t h t h e i r delicate, divided, r e c u r v e d tips, the a b u n d a n c e o f fertile leaves, a n d t h e p r e s e n c e o f spores in sporangia, e v e n in o p e n sporangia, all i n d i c a t e b u r i a l close to t h e i r site o f g r o w t h . MATERIALS AND TECHNIQUES Mr R a y m o n d A. Baschnagel o f Delhi, N e w Y o r k first d i s c o v e r e d a n d s t a r t e d c o l l e c t i n g this material. We n o w have large c o l l e c t i o n s in the Cornell U n i v e r s i t y P a l e o b o t a n i c a l

20

H.P. BANKS, P. M. BONAMO AND J. D. GRIERSON

Collection (CUPC) and the Paleobotanical Collection, State University of New York at Binghamton (PB-SUNY-B). Slabs up to 2 ft. in diameter and 6 inches thick are crowded with what is almost exclusively the remains of this new lycopod. The fossiliferous strata are located in the face of a newly-cut vertical cliff (900--960 f t elevation) in the west flank of Brown Mountain (Gilboa, N.Y. 7.5' Quadrangle map, 1945, at approximately 890,000 ft. N. by 469,000 ft. E.). The cliff was cut to form a platform that will be the site of a new generating plant. The rocks containing the plant remains belong to the upper part of the Panther Mountain Formation (Fisher et al., 1962; Rickard, 1964). The Panther Mountain belongs to the Tioughniogan Stage, of the Erian Series and is approximately equivalent to the Middle Givetian of Europe. The plant remains are preserved both as carbonized compressions and as pyrite petrifactions, necessitating the use of several different techniques to extract the maximum data from the specimens. Petrified axes, either while still included in the rock matrix or after removal from the surface of the rock, were embedded in bioplastic and cut into thin serial slices on a GiUings-Bronwill saw. Occasionally a thicker slice was cut to provide material for longitudinal surfaces. Both surfaces of each slice were polished. Some surfaces were then etched with a 50% HNO3 solution followed by neutralization with NaHCO3. Studies of the compression remains were begun with a modification of the transfer technique described by Grierson and Banks (1963) and Bonamo and Banks (1967). This method involves embedding specimens in bioplastic, grinding away the bioplastic sufficiently to expose the rock on the side opposite the fossil, and placing the block in commercial strength hydrofluoric acid (HF). When the matrix is dissolved away, the side of the fossil previously facing the matrix is exposed. It is situated in a "tray" formed in the remaining plastic by removal of the rock matrix. Both sides of the fossil can then be seen, the original exposed surface through the bioplastic and the newly exposed surface lying in the "tray". Frequently it is advantageous to stop the transfer process before completion (Plate I, '-~) If other axes are present deep in the sediment of the embedded specimen and the removai of sediment by the acid is halted as these deeper axes are uncovered, each, in turn, is revealed. Thus a picture is obtained of the specimens as they were interred, and with it a better understanding of the jumbled remains on the rock surface. Three additional modifications of this basic transfer technique were utilized during the course of the study. The first involved placing the transfers for periods of several minutes to several hours in baths of concentrated hydrochloric acid (HC1) both before and after each treatment with HF. This treatment removed any carbonates as well as flocculents formed by the HF (Leclercq and Bonamo, 1971). Secondly as the transfer process proceeded, the embedded specimens were removed at intervals, treated with HC1, and washed briefly with water. Although still quite acid, the specimens could be examined briefly under a stereobinocular microscope. The depression left by removal of the matrix was kept filled with water while needles were used to carefully remove softened matrix from around the emerging specimens. This technique

LECLERCQIA COMPLEXA, A NEW LYCOPOD

21

combines some of the advantages of d6gagement (Leclercq, 1960) with those of the transfer technique. In this way leaves were followed all the way to their attachment on the stem and the complex branching pattern of the distal portion of the leaf was determined. A third modification involved removal of very shallow portions of compression specimens that contained almost only the specimen visible on the surface. Material was selected that showed desirable features such as the attachment of a sporangium to a sporophyll or leaves to an axis. These selected portions were lifted from the matrix, embedded in bioplastic, and transferred by the HF-HCI method described above or occasionally were macerated directly. After washing, the plant remains on these thin transfers were cleared in place on the transfer without losing the attachment or connection between parts (Leclercq and Bonamo, 1971). With the present material mild oxidizing agents were inadequate for clearing. Concentrated nitric acid (HNO3) saturated with crystals of potassium chlorate (KC103) was used to clear whole transfers, leaves, sporangia, spores, individual tracheids and whole strands of tracheids. The specimens were then washed in water and sometimes neutralized. The clearing process was carried out in 60 mm petri dishes or in embryological watch glasses while being observed under a stereoscopic binocular microscope. In this way the process was continuously monitored and changes caused by the clearing process observed and controlled. Uncleared specimens were mounted for comparison with cleared ones. Compression materials were affixed to cover glasses with water-soluble Clearcol (Schopf, 1964) and were mounted in Diaphane on microscope slides or between cover glasses. Some slices of the petrified material were mounted on slides using Diaphane, the remainder using Harleco Synthetic Resin. Somewhat over 400 preparations have been made using these several techniques. Scanning electron micrographs were taken with a Polaroid camera and film mounted on an AMR 900 Stereoscan. Spores were coated with gold prior to examination. DESCRIPTION The axes of Leclercqia range from 3.5 to 7.0 mm in diameter and are up to 46 cm in length (Plate I, 1). They show no apical tapering, and bear spirally arranged, divided leaves. The stems branch both dichotomously (Plate I, 3) and pseudomonopodially. The leaves are borne in a low spiral or pseudowhorl (Plate I, 2, 4, 5, 7). Eight to ten leaves are found in one complete gyre. They are attached directly to the stem; nG leaf cushions are present (Hate I, 6). When leaves have been broken off a stem, a typical protolepidodendroid surface pattern is revealed (Hate I, 5, 8; cf., also Kr/iusel and Weyland, 1932, fig.3, 9, 16; Lang, 1926, pl. I, 9, 10, 11; Halle, 1936, pl. II, 7, 13). Stomata with slightly sunken guard cells are present on the stem. Some axes of Leclercqia are petrified by iron pyrite along a part of their length and carbonized elsewhere. The carbonized remains reveal the finer details of stem structure, epidermal pattern, stomata, leaf trace departure and pathway whereas pyrite preservation reveals the three-dimensional aspect of the vascular strand and cortex. During transfer

it. P. BANKS, P, M. BONAMO AND J~ D. GRIERSON

22

PLATE I

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H. P. BANKS, P. M. BONAMO AND J. D~ GRIERSON

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PLATE 1

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26 25

27 (For legend see p. 30.)

28

27

LECLERCQIA COMPLEXA, A NEW LYCOPOD PLATE I

(cont.)

29

30

12

(For legend see pp. 30 and 31.)

28 PLATE 1

tl. P. BANKS, P. M. BONAMO AND J, D. GRIERSON

(cont.)

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LECLERCQIA COMPLEXA, A NEW LYCOPOD

PLATE I

29

(cont.)

44

(For legend see p. 31.)

30

tt. P. BANKS, P. M. BONAMO AND J. D. GRIERSON

PLATE I (pp. 2 2 - 2 9 )

Leclercqia complexa 1. 2, 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

18, 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32.

Holotype with an abundance of leafy axes; CUPC 158; X 0.5. Stem; sporophyll at lower arrow; upper arrow indicates leaf showing one intact lateral and one tip of second lateral; distal end of stem with bases o f spirally attached leaves; CUPC 159; X 2 Dichotomizing stem bearing several leaves on which only two of the five tips are visible thus simulating leaves ofProtolepidodendron; CUPC 160; X 1.3. Stem showing at upper end spirally arranged, laminar leaves; arrow indicates enlargement of leaf at j u n c t i o n with stem; CUPC 161 ; X 2. Stem with leaves broken off revealing protolepidodendroid pattern; CUPC 158; × 2, Transfer of stem showing true outer surface; leaves fell away during transfer; CUPC 162; × 3.5 Transfer of stem showing a t t a c h m e n t of laminar leaves in pseudowhorl and fragments of lear s e g m e n t s ; C U P C 163: X 3. Transfer of stem showing protolepidodendroid pattern of resistant cortical tissue impressed ~ outer surface; CUPC 164: X 4. Transfer of stem showing leaf, at arrow, partially uncovered; several other leaves show variou ~ parts of the five tips; CUPC 165; × 3, Macerated tracheids, one at arrow pulled apart showing several wall faces; scalariform pitting evident; CUPC 166; × 500. Macerated tracheid showing double spiral; CUPC 167; X 530. Portion of wall of pyritized tracheid with elongate to oval bordered pits; CUPC 168; X 870. One wall of macerated traeheid with scalariform to oval pits; CUPC 169; × 954. Connected spiral and scalari~brm elements from carbonized strand; CUPC 170; X 490. Pyritized tracheid with scalariform and r o u n d e d bordered pits; c u P C 168; x 870. Transverse section of pyritized stem with p r o t o x y l e m ridges, m e t a x y l e m , outer cortex, zn~d portions of attached leaves; CUPC 171 ; X 27. Transfer preparation that has exposed a radial (diameter) view of a stem; arrows ~ s indicate limits of stem, " x " limits of xylem; vertical strips of carbon are p r o t o x y l e m ridges between which the m e t a x y l e m is still covered by matrix; some leaf traces are still attached to p r o t o x , ¢ k ~ ridges; CUPC 172; X 6. Cleared leaf with stoma (arrow) and tracheids of the vein; CUPC 173; X 128. Enlargement o f a portion of Fig. 17 to show a t t a c h m e n t of leaf traces to p r o t o x y l e m ridge: print reversed; CUPC 172; X I 2. Portion of a carbonized vascular strand with base of a leaf trace still attached; specimen parti:dt~ cleared to show tracheids; CUPC 174: × 25. Whole leaf macerated o u t o f matrix, viewed abaxially; central segment sharply recurved and notched; lateral segments divided; CUPC 175. I; × 9. Attached leaf partially uncovered in a transfer; only lateral segments visible; CUP(? 176; X ~2 Macerated leaf, enlarged base at left; median segment only slightly recurved abaxially; lateral segments in various attitudes; CUPC 175.2; × 10. Leaf macerated out of matrix viewed abaxially; all five tips visible; CUPC 175.3; x 9. Macerated leaf; arrows indicate two tips that would simulate Protolepidodendron if they alone were visible (cf., Fig.3); CUPC 175.4; X 9. Adaxial view o f specimen seen in Fig.24; CUPC 175.3 ; X 9. Macerated leaf viewed adaxially; CUPC 175.5 ; X 9. Macerated leaf viewed adaxiaUy, with short central segment; laminar nature of leaf distinct: PB-SUNY-B 6; X 10. Lateral view of single sporophyll bearing one adaxial sporangium; note similarity of sporophylI to leaves (Fig. 21 - 2 8 ) ; C U P C 176.1; × 8. Portion o f a sporangium showing only the attachment-pad and wall cells radiating away from it: CUPC 1 7 7 . 1 ; × 250. Abaxial view o f single sporophyll and sporangium; CUPC 176.2; X 9. Lateral view of sporangium containing some spores. Attachment-pad and fragments o f sporophyll seen at lower left; PB-SUNY-B 7: × 42.

LECLERCQIA COMPLEXA, A NEW LYCOPOD 33.

34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47.

48.

31

Singlesporangium viewed abaxially showing attachment-pad (arrow, p), wall cells, and some contained spores (arrow, s); arrows "d" indicate the dehiscence which has occurred on the adaxial surface; CUPC 177.2; X 75. Adaxial view of sporangium showing dehiscence, arrow; CUPC 177.3; X 26. Cleared sporangium wall showing spores and one tetrad (arrow); CUPC 177.4; X 100. Enlargment of dehiscing sporangium seen in Fig.34. The horizontal "lines" crossing the split are walls of cells on the abaxial side of the sporangium; CUPC 177.3; × 75. Singlestoma on wall of a cleared sporangium; CUPC 177.5; × 500. Scanning electron micrograph of one spore; arrow "s" indicates dense, long spinae on equatorial ridge; biform ornament on distal surface; PB-SUNY-B 8; × 1000. Proximal view of spore; spinae around equator; CUPC 178.1; × 500. Partial lateral view to show ends of rays joined by curvaturae; CUPC 178.2; × 500. Longest spinae at end of a ray (arrow); PB-SUNY-B 9; × 500. Lateral view showing pointed proximal and convex distal profile; long spinae at ends of two rays; biform ornament on distal surface; CUPC 178.2; × 500. Verrucae of biform ornament on proximal face tend to anastomose; PB-SUNY-B 10; × 500. Young tetrad, ornament developing on distal surfaces; PB-SUNY-B 11; × 500. Partial proximal view, equatorial flange seen as darkened ridge around visible portion of equator; CUPC 178.1; × 500. Older tetrad, scanning electron micrograph; PB-SUNY-B 8; X 500. Scanning electron micrograph showing raised laesurae on proximal face, spinae around equatorial flange; biform ornament on distal surface, ornament on proximal face reduced; PB-SUNY-B 8; X 1000. Scanning electron micrograph; spinae on equatorial ridge, longer and more crowded at end of laesura (arrow "s'); biform ornament on distal surface (arrow "v"); PB-SUNY-B 8; X 2000.

preparations the cuticular sac and carbonized remains of the epidermis and cortex were slit open and the remainder of the vascular strand of the stem removed and studied (Plate 1,20). The center of the stem is occupied by a solid, cylindrical, exarch xylem strand composed entirely of tracheids (Plate I, 16). Protoxylem forms fourteen to eighteen longitudinal ridges on the periphery of the strand (Plate I, 16, 17, 19). The tips of the ridges are composed of annular, connected annular, or spiral elements (Plate I, 11, 14). Transition elements near the base of the ridge adjacent to the metaxylem show more vertical thickening in the form of indirectly connected spiral and reticulate patterns (Plate I, 14). Metaxylem consists of tracheids with scalariform to oval-bordered pits, the borders barely visible on some and prominent on others (Plate I, 12, 13, 15). As in modern plants, tracheid walls are irregularly flattened or faceted by the walls of adjacent tracheids (Plate I, 10). Some walls bear scalariform pits, others on the same tracheid uni- to multiseriate oval pits, or both types are mixed on a single wall. Tissues immediately outside the vascular strand are usually poorly preserved but when present (Plate I, 16) consist chiefly of parenchyma. Groups of thicker-walled cells (? sclerenchyma) are found adjacent to the leaf base just within the epidermis. These cells form a three-dimensional reticulum that is responsible for the protolepidodendroid pattern seen in Plate I, 5 and 8. The leaf trace accompanied by parenchyma passes through the openings in this sclerenchyma into the leaf. Epidermal cells are tabular. Stem cuticles show that epidermal cells are elongate and

32

It. P. BANKS, P. M. BONAMO AND J. D. GRIERSON

polyhedral in surface view, occasionally interrupted by stomata and slightly sunken guard cells. Transfer preparations taken out of the acid when removal of the matrix had reached level that might be called a "radial section" (see material and techniques) dentonstrate leaf traces. These traces clearly arise from protoxylem ridges (Plate I, 17, 19t and exteno obliquely into the base of the leaves. A portion of a stern vascular strand and the base oi a departing leaf trace are illustrated in Plate I, 20. Tracheids are visible in both strands. The definitive character of Leclercqia is the complex morphology of its leaves. They are slender, 0.5 mm wide, laminar structures that bear at one-half to two-thirds their length a pair of lateral divisions (Plate I, 21- 28). The robust median portion of the lamina, 2.5-~3.0 mm in length, tapers gradually to its apex and recurves abaxially (Plate ! 2 1 , 2 3 - 2 8 ) . It is occasionally notched at its apex (Plate I, 21 ). The full length of the leaf is 4 . 0 - 6 . 5 mm. The lateral segments divide almost immediately into two short acuminate tips (Plate I. 21, 22, 24, 26) each about 1.0-2.0 mm in length. The divisions occur in the plane of the leaf but the resulting slender tips are often variously spread (Fig. 1). Leaves still enclosed in the sediment, viewed adaxially, often show only two apparent dichotomies (Plate I, 22). However, maceration of these leaves demonstrates conclusively the presence, in addition, of the sharply recurved median segment (cf.. Pla~c 1, 26 adaxial, and 24 abaxial views of the same macerated leaf). Other leaves still in the sediment, viewed laterally, often reveal only two tips (Plate 1, 3). Nevertheless maceratior~s of such leaves show that the other three segments were buried in the sediment (Plate 1. 125) The recurvation of the main lamina and its lateral divisions, the presence of five slender tips on each leaf, and the close proximity of leaves in a gyre, resulted in a stem surrounded by a crowded and often confusing mass of leaf parts.

Fig.1. Leclercqiacomplexa, Reconstruction of one leaf; adaxial view showing all five segments; magnifi cation ca. × 10.

LECLERCQIA COMPLEXA, A NEW LYCOPOD

33

The base of the leaf is slightly enlarged but there is no evidence of a leaf cushion nor of a ligule (Plate I, 4, 5, 6 attached leaves; Plate I, 23 macerated leaf). Cleared leaves show a pattern of polygonal epidermal cells on the cuticle; elongate on the lamina and spiny tips, more isodiametric on the base of the leaf and lateral appendages. Stomata are scattered on the blade (Plate I, 18) and on all five tips, and are especially numerous on the enlarged leaf base. A single vascular strand traverses the leaf(Plate I, 18). A branch vein extends to the base of each lateral division but does not enter. Annular, spiral, reticulate and pitted tracheids are found in the strand. In order to establish the identity of stems, leaves, sporophylls, sporangia, and spores, we began by isolating, treating, and studying only organs that were physically attached to clearly identifiable specimens of Leclercqia. Once the major characteristics of these organs were established, it was then possible to recognize isolated organs that occasionally yielded evidence to supplement that obtained from attached parts. Sporophylls occur in zones presumably intercalated between zones of vegetative leaves, as in Lycopodium lucidulum. Sporangia are adaxial on leaves otherwise identical to vegetative leaves (Plate I, 29, 31). They are elliptical when seen laterally (Plate I, 2, 29, 31, 32), almost circular in ad- or abaxial view (Plate I, 34), and 1 - 2 mm in diameter. Sporangia are attached just proximal to the lateral segments of the sporophyll by a circular pad of tissue (Plate I, 30, 33). The attachment-pad is located near one end of the sporangium, the end nearer the leaf tip (Plate I, 32, 33). The body of the sporangium rests on the surface of the sporophyll. The cuticle of cleared sporangia reflects an epidermal pattern of elongate cells (Plate I, 33, 35), interrupted occasionally by slightly sunken guard cells whose walls are noticeably thickened adjacent to the stoma (Plate I, 37). The elongate cells radiate out from the circular pad (Plate I, 30, 33) and around the sporangial wall so that when an entire sporangium is fully cleared those on one surface appear to cross over those of another surface lower on the slide (Plate I, 34, 36). The cells of the attachment-pad are essentially isodiametric (Plate I, 30, 33). Detachment of a sporangium from a sporophyll occurs through the pad in such a way that a portion of it remains on the sporangium (Plate I, 33) and another remains on the sporophyll. This makes it possible to distinguish between cleared sporophylls whose sporangia have become detached and cleared vegetative leaves. Sporangia are overwhelmingly abundant in our material. Many are attached, many are detached, some are full of spores either in tetrads or in various stages of post-tetrad maturation. Some contain a few spores (Plate I, 32-35), some are empty. Some have not dehisced, some have. The sporangium splits into two equal lateral halves, dehiscing parallel and perpendicular to the midline of the sporophyll (Plate I, 34). Detached halves of sporangia are abundant in the matrix. The long axis of the cells adjacent to the line of dehiscence is parallel to it (Plate I, 36). The data on spores come from spores that were in situ in attached sporangia. Mature, well-preserved spores are trilete (Plate I, 39, 43) and range from 6 0 - 8 5 / a in diameter exclusive of their ornamentation. Fifty spores were measured. In order to obtain the true

34

H.P. BANKS, P. M. BONAMO AND J. D. GRIERSON

diameter at the equator, we measured only spores undeformed by compression that showed the proximal surface delimited by curvaturae. Approximately two hundred spore~ were examined in order to obtain the fifty valid measurements. In proximal view the equatorial outline (amb) is circular to slightly triangular (Plate I, 43, 39). In equatorial view the proximal profile is pointed while the distal profile is convex (Plate It 42, 38). -t~t-t~ rays of the trilete mark (laesurae) are 23 40/a long and l--3 ~t high (Plate I, 47) and extend to the equator (Plate I~ 39, 47). The contact areas are delimited distally by distinct curvaturae perfectae which coincide with the equator (Plate I, 40). The contact areas constitute the proximal surface. The curvaturae delimit the inner margin o~ an equatorial flange formed by a ridge bearing crowded spinae 5 - 9 / ~ long (Plate 1, 39, 47, 48). The spinae taper from a base that is approximately 2/~ in diameter to an extremely delicate apiculate tip (Plate I, 39, 45, 48). Occasionally the tip is hooked. Spinae completely encircle the equator but are denser and longer in the radial areas (Plate I, 48, 4 1 , 3 8 at arrow"s'). The proximal and distal surfaces of the spores are covered with a crowded, biform ornament. The ornamentation is similar on both surfaces but is somewhat reduced on the proximal surface (Plate I, 48). Each element is composed of a basal enlargmem (verruca) at least twice as wide as it is high (usually 2 × 1 /1). The rounded apex bears :~ tiny, non-tapering projection (Plate I, 48 at a r r o w " v ' ) up to 3 ~t in length, that is some times hooked. The verrucae are so crowded that their bases often anastomose, simulatiae, irregular ridges (Plate I, 43). Young (newly formed) tetrads are approximately 70/~ in diameter (Plate i. 44). Therefore each spore at this stage is only approximately one quarter the diameter of its mature size. Its ornament is crowded on the distal surface but has reached neither its mature configuration nor size. Spores in older tetrads (Plate I, 46) are more like marine spores in size but are not fully ornamented. Spore structure and ornament are modified by fossilization and by acid and oxidatior~ treatments as well as by maturation. When a compressed spore is viewed proximally (Plate I, 39), the curvaturae are not obvious and the ornament seems to consist only oJ spinae. Partial lateral views, however, reveal both curvaturae and the equatorial flange which are especially obvious in scanning electron micrographs (Plate I, 40, 47). Differential compression may accentuate the equatorial flange making it appear as a thick, dar~ line (Hate I, 43, 45). These more lateral views show the distribution of ornamentation: spinae restricted to the flange, biform elements prominent distally, reduced proximally (Plate I, 40, 47, 48). Fossilization and oxidation treatments may considerably alter the size and appearance of the ornamentation. During the course of this investigation the clearing of sporangia and spores was followed at magnifications up to 70 X and the effects of the oxidation observed. Uncleared material was mounted for comparison with the cleared and mounted specimens. The smaller proximal ornament is especially susceptible to erosion, the fine projections on the biform elements being easily reduced or lost.

LECLERCQIACOMPLEXA,A NEW LYCOPOD

35

The universal occurrence in sporangia of a single kind of spore throughout many attached sporangia supports the premise that the plant was homosporous.

Leclercqia gen. nov. Diagnosis. Slender, leafy, lycopodiaceous plant with leaves arranged in a tight spiral. Leaves divided near their mid-point into one elongate, central and two divided, lateral segments. Central segment usually sharply recurved abaxially. Vascular tissue a solid strand of primary xylem with longitudinal ridges of protoxylem on its periphery. Leaf traces oblique and continued in the leaf as a single vein. Sporangia adaxial, attached just proximal to the divisions of the sporophyll. Spores with curvaturae perfectae, elongate spinae on a complete equatorial flange, biform ornamentation on proximal and distal surfaces. Plant probably homosporous.

Leclercqia complexa sp. nov. (Hate I) Diagnosis. Stems branching dichotomously and pseudomonopodially, 3.5-7.0 mm in diameter, bearing laminar leaves, up to 6.5 mm long, eight to ten per gyre. Leaves with a single vein extending to the tip, divided near the midpoint into a central segment that is approximately 2.5-3.0 mm in length sometimes notched and usually recurred abaxially below the proximal segment, and with two opposite, lateral segments divided near their base; tips variously spread. Stomata scattered on leaves. Xylem a solid strand with 14-18 ridges of protoxylem. Metaxylem scalariform and uni- to triseriate bordered pitted. Leaf traces originate on protoxylem ridges and extend obliquely to leaf bases. Sporophylls similar to vegetative leaves, probably grouped among vegetative leaves along the axis. Sporangia globose to ellipsoidal, attached by a circular pad of tissue to sporophyll just proximal to division of leaf lamina. Stomata on sporangia. Dehiscence is parallel to the midline of the sporophyll. Spores 60-85/~ in diameter exclusive of ornamentation, trilete rays 23-40/1 long, 1-3/a high, connected by curvaturae perfectae which coincide with equator. Equatorial flange bearing spinae 5-9/a long, longest in the radial areas. Biform ornament on proximal and distal surfaces, reduced on proximal. Ornament with basal enlargement (verruca) twice as wide as high, with a tiny projection up to 3/a long and sometimes hooked.

Derivation of the name. The genus is named in honor of Professor Suzanne Leclercq. The species epithet refers to the complex structure of the leaf.

Holotype CUPC 158. Paratypes. CUPC 159-178; PB-SUNY-B 6-11. Type locality. Along Schoharie Creek at foot of Brown Mt., Schoharie County, New York.

36

[1. P. BANKS, P. M. BONAMO AND J D. GRIERSON

Horizon. Panther Mt. Formation, Tioughniogan Stage, Erian Series (= Middle Givetian

oi

Europe). DISCUSSION

Leclercqia is unquestionably a lycopod even by criteria applied to extant members: single-veined, microphyllous leaves are arranged in a tight spiral; single sporangia are adaxial on sporophylls; and leaf traces depart from a solid, exarch xylem strand withou~ leaf gaps. The excellence of its preservation is unique among pre-Carboniferous lycopods. The details of its anatomy, morphology and reproduction make it the most completely understood Devonian lycopod. The distinctive feature of Leclercqia, and the least lycopodiaceous by present-day standards, is its divided, laminar leaves and sporophylls. The spine-like tips of its lateraJ segments and their divergent attitude plus the abaxial recurring of the long median segment obscure the planate nature of the leaf and sporophyll. Yet both are dorsiventrat structures in their attachment, in the consistent orientation of the recurred median segment, and in the attachment of sporangia, Neither leaves nor sporophylls show traces of a ligule. The quality of preservation and the number of appendages observed throughout their length, both carbonized and cleare~ indicates that this is a positive character of Leclercqia, not simply a failure to observe ~ structure. For other Devonian lycopods the eligulate character has been based oll supposition rather than good evidence The stem of Leclercqia shows an even greater range of primary xylem elements than that of living lycopods. It has annular, spiral, reticulate, scalariform, variously pitted elements, and some intermediate between these categories. The leaf trace originating o~~, ,~ protoxylem ridge is single and is continued to the tip of the median segment of" the lea~. This is the first demonstration of tracheids in the leaf traces and veins of a Devonian lycopod. Two small lateral veins running only to the base of lateral segments are unknow~ in living lycopods although branched traces and veins are known in Selaginella (Rosello, 1966). In fossils, Halle (1936) reported two leaf traces in Protolepidodendron and tw~ veins are known in Sigillariopsis. Slightly sunken stomata are present on stem, leaf, sporophyll and, somewhat unexpec~ edly, on sporangia of Leclercqia. There is no evidence that stomata occurred in grooves as in lepidodendrids. Dehiscence of sporangia of Leclercqia is parallel to the axis of the sporophyll along the adaxial side of the sporangium, in Lycopodium and Selaginella it is at a right angle to the axis of the sporophyll. Leclercqia could not be confused with any other lycopod if its leaves were visible three-dimensionally in the matrix. Since what is visible can be misleading, we compare Leclercqia briefly with several other Devonian genera. Those with forked leaves are Prot~: tepidodendron (Kr~iusel and Weyland, 1932), Colpodexylon Banks (1944), and Sugambrophyton Schmidt (1954). Leclercqia recalls Protolepidodendron immediately. Its habit

LECLERCQIACOMPLEXA,A NEW LYCOPOD

37

size, leaf size and arrangement, sporangial position and, in the case ofP. gilboense Grierson and Banks (1963), its xylem strand, are almost identical. Even the markings on the stem (Plate I, 6, 8) that outline the position of leaves are alike. However, the genus Protolepidodendron is defined on the basis of its bifid leaf. Further there is a question as to the anatomy of the type species ofProtolepidodendron, P. scharianum. Kr~iusel and Weyland (1932) described it as a triangular strand with mesarch protoxylem near the points of the triangle. However, Grierson and Banks (1963) described a new species of Protolepidodendron, P. gilboense, identical to P. scharianum except for its possession of a terete, solid strand of xylem surrounded by ridges of protoxylem. Its maturation was exarch. A careful study of material from the type locality is required to confirm or deny the triangular strand reported for P. scharianum because the specimens were lost during World War II. Thus although the xylem of Leclercqia agrees with that of Protolepidodendron gilboense it differs markedly from that described for P. scharianum. In certain other details Leclercqia differs from Protolepidodendron. The veins reported for Protolepidodendron by Kr~iusel and Weyland (1932), on the basis of carbonized lines on the carbonized leaf, fork and then extend into the two leaf tips. In Leclercqia one main vein extends to the tip of the central division but the two, opposite laterals end at the base of each lateral division. Halle (1936) reported two apparent leaf traces in the base of some leaves of Protolepidodendron scharianum from China. Only in Leclercqia have tracheids been demonstrated in the leaf traces and veins. The attachment of sporangia and the spores are known for Leclercqia, not for Protolepidodendron. Stomates are known on leaves, sporophylls, and sporangia only in Leclercqia. Both plants are considered eligulate but only in Leclercqia there is strong evidence for this character. The similarity of the stele of Leclercqia to that ofProtolepidodendron gilboense caused us to re-examine the type of the latter. We could find no evidence whatsoever of more than one division in its leaf. Also one of us (H.P.B.) examined well-preserved specimens ofP. wahnbachense collected by Stockmans and deposited in the Royal Museum of Natural History at Brussels. These too show no evidence of additional division of the leaves. At present therefore Leclercqia is sharply distinct from Protolepidodendron in leaf characters. Leaves of Colpodexylon Banks (1944), are divided into one slender, attenuated, central division and two opposite, delicate divisions but the latter are never subdivided. The dividing of the lateral segments and the recurved median segment distinguished Leclercqia. Leaves of Leclercqia are 6.5 mm in length whereas those of Colpodexylon are 2 0 - 3 0 mm long. Stems of Colpodexylon are 25 mm in diameter and bear sixteen to twenty leaves per gyre whereas those of Leclercqia are 3 - 5 mm in diameter and bear eight to ten leaves per gyre. Finally, the vascular strand of Leclercqia differs markedly from the lobed protostele of Colpodexylon (Banks, 1944; Grierson and Banks, 1963). Leclercqia resembles Sugambrophyton only in possessing divided leaves. The habit and gross morphology of Sugambrophyton resemble Drepanophycus spinaeformis to which it is probably most closely related. It bears unforked thorn-like, once-forked, twice- or even three-forked leaves, and finally simple, Thursophyton-like leaves. Its anatomy and

38

H.P. BANKS, P. M. BONAMO AND .I.D. GRIERSON

histology are unknown. Sporangia are reported to be adaxial on the twice-forked leaves.

Leclercqia is a slender plant with long, non-tapering stems, quite different from Sugambrophyton whose lower axes measure 2.5 cm in diameter and then taper markedly upward.

Leclercqia has more general features in common with two species whose leaves are unforked. One is Drepanophycus colophyUus Grierson and Banks (1963). The leaves o~ the latter are falcate, a character diagnostic of Drepanophycus. The two taxa are sharply distinct on the basis of leaves but in size of stem and number of leaves per gyre they arc similar. In size and habit Leclercqia also resembles Eleutherophyllum waldenburgense. Carboniferous plant that has been restudied by Remy and Remy (1960). Both bear one sporangium adaxially on each sporophyll and in both the attachment is at the outer er~d of the sporangium. In Eleutherophyllurn attachment is by a short stalk as in some sporangia ofDrepanophycus spinaeformis (Kr/iusel and Weyland 1935, cf. fig.6a, c;pf. 4i. 8, 9). In Leclercqia attachment is by a flat pad of tissue so that the sporangium lies against the sporophyll rather than standing free as in Eleutherophyllum (Remy and Remy, 1960, fig.l). The ornamented spores of Leclercqia are markedly different from tI~: "smooth to infragranulate '~ spores of Eleutherophyllum. The spores of Leclercqia demonstrate some of the variation which can occur within z~ single fossil species. The spores come from attached sporangia, therefore the variation see~ is due to maturation, fossilization, chemical treatment or a combination of these, ~oi ~,. different biological origins, if found as Sporae Dispersae such spores could only be assigned to the same genus with great difficulty. Thus the paleobotanist describing spore~: in situ and the palynologist classifying a spore assemblage of unknown botanical origins are starting from a different premise and could validly arrive at different results. This may be part of the reason that named species of Sporae Dispersae in Devonian strata n o ~ exceed in number the named species of macrofossils. Though Leclercqia spores are unlike any known taxon of the Sporae Dispersae, they share some features with several genera discussed below. Spores of Leclercqia resemble Retusotriletes sensu Richardson 1965 in shape, presence of curvaturae perfectae and a wedge-shaped thickening of the curvaturae when laterally compressed. Richardson (1965, p. 564) considers that curvaturae perfectae are a constant character only of smooth-walled spores. Thus Leclercqia is markedly different in its possession of ornament. Yet its curvaturae are always present even though sometimes obscured in proximal view by superposition of the flange and spinae. Leclercqia resembles somewhat Apiculiretusispora Streel (1964) a spore shaped like Retusotriletes but with ornament. The two are alike in contour, curvaturae perfectae, and reduction of ornament on the proximal face. But Leclercqia differs because its rays go all the way to the equator, its ornament is much longer, and it has an equatorial flange. Leclercqia and Aneurospora Streel (1964) are similar in shape and both have curvaturae and rays that extend to the equator. Aneurospora does not have biform ornament and does have a zona which lacks ornament. Leclercqia has an equatorial flange with spinae, as well as biform ornament. Even if its equatorial flange were interpreted as a zona, its spinae

LECLERCQIA COMPLEXA,A NEW LYCOPOD

39

would differentiate Leclercqia. Richardson (1969, p. 215) considers that Aneurospora goensis, the type species, may belong to Geminospora. Leclercqia has nothing in common with other species of that genus. Leclercqia in some views, modes of preservation, and compression planes (e.g., Plate I, 45, proximal) resembles Naumova's original broad concept of Acanthotriletes, many of whose species have been transferred to newer genera. One example is Dibolisporites Richardson which has variable, biform ornament (grana, coni and spinae on one spore), curvaturae imperfectae or sometimes perfectae, and large spores. D. cf. correctus Richardson (1965) is smaller but its exine is thin, usually with taper-pointed folds and no equatorial flange. The equatorial flange, non-folded exine and constant curvaturae perfectae separate Leclercqia from D. correctus. We sent samples of our matrix to Dr M. Streel, Li6ge, for an analysis of the dispersed spores and for comment on their stratigraphic meaning. His results are found in a later paper in this volume. Leclercqia contributes significantly to knowledge of Devonian lycopods by reason of its good preservation and the extensive use of techniques to obtain evidence. Details previously unknown for lycopods of this age are: (1) Stomata slightly sunken on leaves, sporophylls, sporangia and stems; stomata on leaves scattered, not in grooves as in lepidodendrids; (2) leaf traces composed of tracheids; (3) veins composed of tracheids; in earlier described Devonian lycopods the evidence of traces and veins consisted only of carbonized "lines"; (4) positive evidence that the plant was eligulate; (5) evidence of dehiscence parallel to the midline of the sporophyll; (6) spores with marked differences in morphological appearance extracted from different attached sporangia; these differences are caused by the stage of maturation of the spores, oxidation during fossilization, and/or oxidation during preparation. Together with other Devonian genera with divided leaves Leclercqia suggests that by late Middle Devonian the lycopods showed a wide diversity in leaf form that has since been lost.

ACKNOWLEDGMENTS The order of authors is purely alphabetical. The three of us are equally responsible for this paper. We acknowledge gratefully the assistance of Federal Hatch Funds (H.P.B.), N.S.F. Grant GB 8282x (H.P.B.), N.S.F. Grant GB 13098 (J.D.G., P.M.B.) in the conduct of this research. We thank Prof. M. S. Parthasarathy, Biological Sciences, Cornell, for the SEM photographs, Mr Edward Zyskowski for technical assistance and Mrs Jane Blanchard for photographic assistance. We also thank Mr Richard Sousa and his staff of Uhl, Hall, and Rich, Engineers, and Mr Edward Burke of the Power Authority of the State of New York for their assistance at the Blenheim-Gilboa site.

40

H.P. BANKS, P. M. BONAMO A N D J. D. GR1ERSON

REFERENCES Allen, K. C., 1965. Lower and Middle Devonian spores of North and Central Vestspitsbergen Palaeontology, 8 : 6 8 7 748. Banks, H. P., t944. A new Devonian lycopod genus from southeastern New York. Am. J Bot, 3~ 650-659~ Bonamo, P. M. and Banks, I-t. P., 1967. Tetraxylopteris schmidtii: its fertile parts and its relationship~ within the Aneurophytales. Am. Z Bot., 54:755--768. Fisher, D. W., lsachsen, Y. W., Rickard, L. V., Broughton, J. G. and Offield, T. W., 1962. Geologic m~i; of New York, State Museum and Science Service. Geol. Surv. Albany. Map, Chart Ser., 5. Grierson, J. D. and Banks, H. P., 1963. Lycopods of the Devonian of New York State. Palaeontogr Am., IV (31): 220-295. Halle, T. G., 1936. On Drepanophycus. Protolepidodendron and Protopteridiurn, with holes orl tile Palaeozoic flora of Yunnan. Palaeontok Sin., Ser. A, 1(4): l - 2 8 . Kr/iusel, R. and Weyland, t1, 1932. Pflanzenreste aus dem Devon, 4. Protolepidodendrorl Krejci. Senckenbergiana Lethaea, 14:391 4 0 3 . Kr//usel, R. and Weyland, H., 1935. Neue Pflanzenlunde im Rheinischen Unterdevon. P~zlaeontograp~;~. B, 80: 17l 190. Lang, W. H., 1926. Contributions to the study of the Old Red Sandstone flora of Scotland, 4. ()f~ ~. specimen of Protolepidodendron from the Middle Old Red Sandstone of Caithness. Trans. t¢ ~,,~ Edinb., 54: 790-792. Leclercq, S., 1960. Refendage d'une roche fossilif~re et d~gagement de ses fossiles sous binoculam' Senckenbergiana Lethaea. 41:483 487. Leclercq, S. and Bonamo, P. M., 19'71. A study of the fructification ofMilleria (Protopteridium) tho~s~,,Jn~ Lang from the Middle Devonian of Belgium. Palaeontographica, B 136:83--114. Remy, W. and Remy, R., 1960. Eleutherophyllum waldenburgense (Stur) Zimmermann. Monatsber. Deut. Akad. Wiss. Berlin, 2:54 62. Richardson, J. B., 1965. Middle Old Red Sandstone spore assemblages from the Orcadmn basin northea..! Scotland. Palaeontology 7:559 605. Richardson, J. B., 1969. Devonian Spores. In: R. H. Tschudy and R. A. Scott (gditorsl. ~Ispects ot Palynology. Wiley-Interscicnce, New York, N.Y., pp, 193- 222. Rickard, L. V., 1964. Correlation of the Devonian Rocks in New York State. New York Slate Muse~J~ and Science Service. Geol. Surv., Albany, Map, Chart Ser., 4. Rosello, S., 1966. L'anatomic de Selaginella willdenowii Baker et la notion de polyst6lie %z,' MonspeliensiaBot., 17 189 207. Schmidt, Wo., 1954. Pflanzenreste aus der Tonschieter-Gruppe lUntercs Siegen) des Siegerlandes. i Sugambrophyton pilgeri n. gen., n. spec., eine Protolepidodendracee aus den Hanrberg Schichten. Palaeontographica, B, 97:1 22. Schopf, J. M., 1964. Practical problems and principles in study of plant microfossils. In: A '][. Cross (Editor), Palynology in Oil Exploration. Soc. k'con. Paleontologists Mineralogists Spe~ Pap. i ] 29-57. Streel, M., 1964. Une association de spores du Giv~tien inf~rieur de la Vesdre, ~ Go~ (BelgiqueL ,-~lptr: Soc. Gbol. Belg., 87:2 3!t.