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Cretaceous flowers from Kazakhstan
Review of Palaeobotany and Palynology. 40 (1983): 91--113 Elsevier Science Publishers B V, Amsterdam -- Printed in The Netherlands
91
CRETACEOUS FLOWERS FROM KAZAKHSTAN
V A. KRASSILOV, P V SHILIN and V A. VACHRAMEEV Institute of Bzology and Pedology, Vladwostok, 22 (U S S R.) Instztute of Zoology, Alma-Ata (US S R ) Geologzcal Instztute, Moscow, 109017, Pyzhevsky, 7 (US S R ) (Received and accepted April 29, 1983)
ABSTRACT Krasmlov, V.A., Shdm, P V. and Vachrameev, V.A, 1983. Cretaceous flowers from Kazakhstan. Rev. Palaeobot Palynol., 40: 91--113.
Hyrcantha gen. nov. from the Mxddle Alblan is a pamculate inflorescence. The flowers are bisexual with persistent calyx and apocarpous gynoecium The carpels are ascldlal with broad sessile stigma. The genus is related to the Ranunculaceae and Paeomaceae The Late Cretaceous Sarysua gen. nov has cymold inflorescences of many actmomorphm pentamerous flowers with syncarpous five-lobed ovaries and free styles. A geranialean affinity is suggested. In Taldysaja of the same age much reduced pistillate flowers are born in splkelets or solitary on branches of the fasciculate inflorescence These findings evidence the important role of the ranunculoid--paeoniold complex among ancestral angiosperms and the considerable diversity of the Late Cretaceous flowering structures INTRODUCTION In r e c e n t y e a r s several i m p o r t a n t r e p r o d u c t i v e s t r u c t u r e s of e a r l y a n g l o s p e r m s have c o m e t o l i g h t (Dilche_r, 1 9 7 9 ; V a c h r a m e e v a n d Krassilov, 1 9 7 9 ; Frlls a n d S k a r b y , 1 9 8 1 ; R e t a l l a c k a n d D l l c h e r , 1 9 8 1 ) . A f e w m o r e f i n d s o f t h i s k m d are d e s c r i b e d in t h i s p a p e r . O n e o f t h e m is f r o m t h e M i d d l e A l b l a n o f w e s t e r n K a z a k h s t a n - - t h e s a m e b e d s w h i c h y i e l d e d Caspzocarpus ( V a c h r a m e e v a n d K r a s s i l o v , 1 9 7 9 ) - - w h i l e t w o o t h e r s are f r o m t h e Sant o n i a n - - C a m p a n i a n o f s o u t h - c e n t r a l K a z a k h s t a n . See V a c h r a m e e v ( 1 9 5 2 ) a n d S h i l i n a n d R o m a n o v a ( 1 9 7 8 ) f o r j u s t i f i c a t i o n o f t h e age a s s i g n m e n t s a n d g e n e r a l d e s c r i p t i o n o f t h e fossil floras. I n f l o r e s c e n c e s w e r e m e n t i o n e d in t h e o r i g i n a l d e s c r i p t i o n s as r e p r o d u c t i v e s t r u c t u r e s of u n k n o w n n a t u r e . T h e i r d e t a i l e d s t u d y is h e r e u n d e r t a k e n f o r t h e first t i m e . T h e A l b i a n m f l o r e s c e n c e s o c c u r in l i g h t - c o l o u r e d c l a y as Impressions, gray on dispersed coaly substance. The S a n t o n i a n - - C a m p a n i a n fossils are t h i n i r o n o x i d e i n c r u s t a t i o n s , b r o w n o n h g h t - y e l l o w s i l t s t o n e . No o r g a n i c m a t t e r s u i t a b l e f o r m a c e r a t i o n is p r e s e r v e d b u t at p l a c e s cell o u t l i n e s are visible o n i m p r e s s i o n s a n d i n c r u s t a t i o n s .
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92 SYSTEMATICS Genus Hyrcantha Krassilov et Vachrameev, gen. nov.
Name Hyrcanian is the ancient name of the Caspian Sea. Type species. Hyrcantha karatscheensis (Vachrameev) Krassflov et Vachrameev, comb. nov. Diagnoszs Inflorescence bracteate, paniculate, ultimate branches oneflowered. Flowers terminal, bisexual. Calyx small, persistent, sepals scaly, reflexed. Stamens shorter than carpels. Gynoeclum apocarpous, of three or five ascidial carpels dehiscing along the ventral sutures. Stigma terminal, sessile, rather broad. Hyrcantha karatscheensis (Vachrameev) Krassilov et Vachrameev comb. nov. (Plate I, 1--5; Plate II, 1--7). Bas~onym: Carpotithes karatscheens~s Vachrameev, 1952, Regional Stratigraphy of the USSR, p.274, P1. XLIV, 1--5. H o l o t y p e N 3302/47, Geological Inshtute, Moscow (Vachrameev, 1952, pl. XLIV, 3). Locality Karatsche-Tau Hill, western Kazakhstan. Age. Middle Albian. Description: The best specimen is a part of a paniculate inflorescence (Plate I, 1--3, Fig.l) with a grooved main axis 1.3 mm thick. Minute bracts occur at the nodes and there are also bracteoles on the lateral branches. A lower branch is forking twice in rapid succession, the upper branches are unbranched, one-flowered. They are subopposite, departing at acute angle. The pedicels are thin, about 10--14 mm long. All flowers are evidently at fruiting stage, of equal size, about 13 mm wide. Remains of the calyx are seen in three of them, the better preserved is shown in Plate II, 1, 2. Sepals are scaly, 1.5 mm long, reflexed and more or less appressed to the pedicel. In this specimen there is no unequivocal evidence of androecium. Gynoecla consist of three ascidial carpels, about 7 mm long, 3 mm wide, sessile on a broad receptacle, free to the base, showmg polygonal surface cells and a terminal scar (Plate II, 4--5) or a broad notch (Plate II, 4) probably representing sessile stigma.
PLATE I
Hyrcantha karatscheensis 1, 2 Lateral inflorescence branches, X 3 3. Part of a pamculate inflorescence, × 2. 4.
Lateral inflorescence branch bearing flower. Leaflets of "Legummosztes" karat-
scheensis overlap the axis, × 1.5.
93
PLATE I
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PLATE II
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Most carpels seem to be dehiscent along the ventral suture letting rock matrix fill the locules. The internal casts show a dorsal suture and anastomosing transverse striation (Plate II, 7). Another specimen (Plate I, 4) is a fragment of the grooved axis 20 mm long, 1.5 m m thick, bearing a single lateral branch terminated by a flower of the same dimensions as in the holotype. This flower is significant in showing, in addition to persistent calyx and tricarpous gynoecium, distinct impressions of stamens (Plate II, 3). The filaments are about 0.5 mm thick, reaching to about mid-length of the carpels. One of them bears a crumpled anther whmh seems bilocular, but its structure cannot be made out with any confidence. While flowers in these inflorescences are trimerous, a specimen figured by Vachrameev (1952) pl. XLIV, 3 shows five carpels (Fig.l). Assocmted leaves (Plate III, 1--5): Inflorescences regularly associate with c o m p o u n d leaves described by Vachrameev (1952) as Legummosltes karatscheensis. In the above described specimen (Plate I, 4) the leaflets overlap main axis slightly above the node. Though t h e y are obvmusly n o t In organic connection, the association seems noteworthy. A few notes can be added to the original description of the leaves. While most fragments of c o m p o u n d leaves are pinnate, some of them (Fig.2 reproduced from pl. XXXIV in Vachrameev, 1952) suggest ternate arrangement of the leaflets. The latter show a midveln which fades out above the middle. Secondary veins are thin, undulate, oblique to the midvein, forking once or twine, their branches running to the margin. Tertiary veins are scalarfform, straight or bowed. Veinlets of higher order form rounded meshes about 0.1 mm wide. Margins seem entire but on closer inspection show scabrations or even minute prickles on the vein ends (Plate III, 4, 5). In SEM the leaf impressions show vague outlines of epidermal cells and fairly distinct stomatal pits which are either e m p t y or filled with the puck-like casts of the guard cells. Rapid decay of the stomata penetrated by lncrustatmg substances could produce this effect. Stomata are scattered withm the vein meshes (Plate III, 1, 2) occasionally occurring over the veinlets (Plate III, 2, upper right corner). They tend to be orientated along the secondary veins. The spacing of the stomata is rather regular, paired stomata seen in Plate III, I are rather u n c o m m o n . The guard cell thickenmgs are elliptmal, 17 pm long, slightly If at all sunken below the leaf surface. There are no indications of specmhzed subsidiary cells. Remarks: What we know about Hyrcanta is hardly suffmient for exact taxonomic assignment. Similar apocarpous gynoecia of three ascidlal follicles
P L A T E II
Hyrcantha karatscheens~s 1, 2 3 4--6. 7.
F l o w e r showing persistent calyx, × 7 and 10 F l o w e r showing stamens, arrow on a c r u m p l e d a n t h e r , × 7 Carpels s h o w i n g t e r m i n a l stigmas, × 7 I n t e r n a l cast o f a carpel showing transverse s t r i a h o n , × 10.
96
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Fig 1 Hyrcantha karatscheenszs, inflorescence and flowers A 5-merous gynoecium (middle right) is reproduced from Vachrameev (1952, pl. XLIV, 3)
97 are known m the Ranunculaceae and especially in the extant Thahctrum subgen. Euthalictrum in which the follicles are usually sessile, about 7--8 mm long. Also in Thalictrum the styles are often reduced and inflorescences can be paniculate, and bracteate, as in T. foetidum L. At the same time, a broad sessile stigma and persistent calyx are characteristic features of Paeonia. Some species of Paeonia (e.g.P. caucasica) have biternate leaves with ovate leaflets and the leaf margins can be scabrate as in "Leguminosites" karatscheensis. Taking allthls into consideration, Hyrcantha can be tentatively placed somewhere in the vicinity of the Ranunculaceae and Paeonlaceae, reinforcing the often debated links between these famlhes. Genus Sarysua Krassilov et Shilin, gen. nov.
Name: After Sarysu River. Type species: Sarysua pomona Krassilov et Shflin, sp. nov. Diagnoszs: Inflorescence cymold, flowers actmomorphm, pedmel shorter than gynoecium, receptacle massive, bearing glands below the whorl of stamens. Calyx persistent, sepals lanceolate, caudate, reflexed. Stamens about ten, in one whorl, some of them reduced to stamlnodia. G y n o e c m m syncarpous with free styles. Ovary five-lobed, pubescent. Locules broad at the base but narrow and presumably sterile above. Styles five, of varying length, glabrous, solid. Stigma terminal, capltate.
Sarysuapomona Krassilov et Shflln, sp. nov. (Plate IV, 1--4; Plate V, 1--7; Plate VI, 1--5; Plate VII, 1--4; Plate VIII, 1--4)
Name: Pomona is the Italian goddess of gardens. Holotype N 284/67, now at repository of the Institute of Biology and Pedology, Vladivostok (Plate IV, 4; Plate V, 1, 7). Locahty: Taldysaj on the Sarysu River, south-central Karakhstan. Age Santonian--Campanmn. Description: Several slltstone slabs contain crowded flowers of one kind. Those in Plate IV, 1 possibly belong in the same mflorescence. No connecting axes are seen, but the flowers seem to be arranged in a regular manner allowing tentative reconstruction of the mflorescence. In this specimen, most of the 32 flowers are assembled within a rectangle three sides of which are formed by rows of parallel flowers pointing outwards or occasionally rewards. Central group comprises flowers with shorter ovaries and slightly longer styles facing each other. The most probable form of inflorescence suggested by this arrangement Is a dlchasial cyme (Fig.3). All the flowers are stalked, with thin pedicels about 3 mm long and relatively massive receptacles 1.5 m m wide. They show a persistent calyx with lanceolate, longly pointed (caudate) reflexed lobes 2 m m long (Plate IV, 3). In most flowers androecium is represented by a few stamens. They are better seen in transfer preparations where the filaments or their stumps often stick up from the cellulose film as hollow cylinders. Plate VI, 1 (see also Fig.3)
98
PLATE III
99
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Fig.2. " L ~ g u m i n o s t t e s " karatscheensis, leaves associating with H y r c a n t h a karatscheensls, reproduced from Vachrameev (1952, pl. XXXIV). A leaf of the extant Paeon~a caucaslca N. Schipez. (bottom left) is shown for comparison s h o w s s t u m p s o f e i g h t f i l a m e n t s in a single w h o r l . J u d g i n g b y t h e i r s p a c i n g , at least two filaments are missing. Hooked appendage on the left side (Plate V I , 4) c o u l d b e a s t a m i n o d e . C l a v a t e b o d y s e e n a t t h e e d g e b e l o w t h e s t a m e n w h o r l is s u p p o s e d l y o f g l a n d u l a r n a t u r e . T h e r e a r e a l s o r o u n d e d s c a r s o n t h e r e c e p t a c l e , p o s s i b l y l e f t b y s i m i l a r g l a n d s ( P l a t e V I , 2). I n S E M t h e f i l a m e n t s a r e r i d g e d , s h o w i n g r o w s o f e l o n g a t e c e l l s ( P l a t e V I I I , 4). PLATE III " L e g u m m o s ~ t e s " karatscheens;s
1. 2. 3 4
SEM of a leaf impression showing stomata, × 180 Stomata scattered m the vein meshes and occasionally over the veinlet, × 350. Stomatal pit with a cast of guard cell thmkenmgs, × 3000. Margin of a leaflet, arrows on scabrahons on the ends of lateral veins, × 10
100 P L A T E IV
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Ovaries m most flowers are elongate conical about 7 (6--8) mm long, but the tuner group of flowers in Plate IV, 1, shows much shorter ovaries, less than 2 mm long. At the same time their styles are slightly longer than in the larger gynoecia. Impressions of the ovarms show deep folds, possibly exaggerated by compression (Plate V, 4). These folds conceivably mark boundaries of the connate carpels. Ovaries cleaved through the median plane expose wings of two opposite carpels forming septae and between them a portion of the third carpel showing a longitudinal ridge -- evidently the ventral suture (Plate IV, 2). Different planes of cleavage expose one of the locules which is broadly ovate at the base but narrow and slit-like in the upper half of the carpel (Plate V, 1, 2, 7). These observations suggest that the carpels were closed (ventral suture) and the upper portions of the locules were most probably sterile. A bunch of five free styles crowns the ovary. Usually three or four of them are exposed on the rock surface (Plate V, 1--4) while the rest are broken off, leaving stumps or immersed in the rock but t h e y can be revealed by digging with a needle. Styles are curved, about 0.7--0.9 m m long but in the flowers with shorter ovaries up to 1.1 mm long (Plate V, 5). In transfer preparations styles often stick up from cellulose film in the same manner as stamens. Stigmas are terminal, hemisphaerical or slightly concave, papillate. In SEM the ovaries show coarse pits of the hair bases (Plate VII, 3, 4) while styles are glabrous. Cell outhnes are fax more distinct in styles than in ovaries. It appears that, for some reason, styles were minerahzed to a higher extent than ovaries. It is possible that mineralizing solutions have infiltrated through the transmitting tissue. Epidermal cells of the styles are elongate, forming longitudinal rows. One specimen reveals subepidermal columnar cells of the stylar cortex (Plate VII, 1, 2). There are no traces of vascular bundles which m styles are usually confined to the cortex. Also there are no mdlcatlons of a central hollow, suggesting that the styles were sohd (that is, filled with transmitting tissue). SEM of the longitudinally split styles (Plate VIII, 1--3) show what appears to be transmitting tissue. It consists of narrow longitudinally stretched cells forming undulating rows. R o u n d e d bodies within the transmitting tissue such as seen in Plate VIII, 3 could be either secretory cavities or -- a fascinating possibility which unfortunately cannot be tested at present -- arrested pollen tubes. Remarks: Surveying the extant genera of angiosperms for c o m b m a t m n of such characters as cymold inflorescence, actmomorphm bisexual pedicelled flower of pentamerous structure, persistent calyx, glands in the staminate P L A T E IV
Sarysua pomona 1 F l o w e r s c r o w d e d o n a rock slab, s o m e o f t h e m s h o w i n g regular a r r a n g e m e n t N o t e central g r o u p o f s h o r t e r flowers, × 3. 2 F l o w e r s h o w i n g s t a m e n s and a ridge o n the m e d i a n carpel, arrow, × 10 3 F l o w e r s h o w i n g calyx, × 10. 4 G r o u p o f t h r e e flowers, × 3
102 PLATE V i
4
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103 whorl, s y n c a r p o u s ovaries of five closed carpels w i t h c o n t r a c t e d locules, free styles and capitate stigmas, we smgled o u t Linum, Oxalis and Geramum o f t h e o r d e r Geramales w h i c h share m o s t o f these characters. Linum has a dmhaslal inflorescence, a c t i n o m o r p h m flowers w i t h a persistent calyx, nectaries o n s t a m i n a t e disk, five-lobed o v a r y and m o r e or less free styles. Incid e n t a l l y , in Linum flavum L. styles o f h e t e r o s t y l o u s f o r m s are 6--8 m m and 8--11 m m long, m u c h like in Sarysua. Oxales has t e n stamens in t w o whorls, free styles which are o f t e n glabrous, and capitate stigmas. Geranium is similar m having stamens shghtly if at all c o h e r e n t at t h e base, n e c t a r glands and c o n s p i c u o u s l y five-lobed ovary, o f t e n p u b e s c e n t , with locules a t t e n u a t e d and sterilized m t h e u p p e r half o f t h e carpels ( K a d e n and L a n o v a y a , 1963). In this genus some stamens can b e r e d u c e d t o staminodia. T h e c o h e r e n c e o f stamens and appendiculax central c o l u m n m the o v a r y can b e seen as derived characters n o t t o be e x p e c t e d m early representatives o f t h e order. In p o l y m o r p h i c p o p u l a t i o n s o f h e t e r o s t y l o u s Linum and Oxalis, individuals with longer and s h o r t e r styles c o o p e r a t e in the highly evolved breeding s y s t e m (see Weller, 1 9 7 6 ) . It m a y be possible t h a t t h e association o f longer and shorter flowers with slightly d i f f e r e n t style lengths in Sarysua p o i n t t o incipient h e t e r o s t y l y . G e n u s Taldysa]a Krassilov et Shilin, gen. nov.
Name A f t e r the locality o f Taldysaj m s o u t h - c e n t r a l Kazakhstan. Type species. Taldysaja medusa Krassllov et Shilin sp. nov. Diagnosis I n f l o r e s c e n c e fasciculate o n a long p e d u n c l e bearing a bffid prophyll and i n f l o r e s c e n c e bracts. Branches o f t h e fascicle spiny, distally sterile, beaxmg solitary flowers or in t h e proxLmal part one- or t w o - f l o w e r e d splkelets axlllary t o t h e spmes. Rachillae o f t h e spikelets splnulate s h o w m g long sterile apeces. Flowers with Lmbricate p e n a n t h scales and a flask-shaped g y n o e c i u m .
Taldysa]a medusa Krassllov et Shilin, sp. nov. (Plate IX, 1--7; Plate X, 1--6) Name: Medusa -- a g o r g o n with a head o f snakes (see Plate IX, 1). Holotype: N 2 8 4 / 3 7 5 , n o w at r e p o s i t o r y o f t h e I n s t i t u t e o f Biology and P e d o l o g y , Vladivostok (Plate IX, 1). PLATE V
Sarysua pomona 1_
Flower split through median plane showing side wings of two carpels and a locule
2
o f the third carpel b e t w e e n them, × 10. Top of a gynoecium showing free styles, × 15.
3 Four exposed styles, arrow on a stump of the fifth one, × 15 4 Gynoecmm showing folds b e t w e e n the ovary lobes, × 10 5, 6. Flower with shorter gynoecia, × 10 7 Different focus of 1.
104 P L A T E VI
1
105
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Fig 3. Sarysua pomona, a r r a n g e m e n t o f flowers s u p p o s e d l y r e p r e s e n t i n g a dlchaslal c y m e ( t o p ) and r e c o n s t r u c t i o n o f a flower ( b o t t o m ) , dlagramatic cross-section (left) and tangential s e c t i o n (right) o f a g y n o e c m m .
P L A T E VI
Sarysua pomona 1. 2. 3. 4
Transfer o f a f l o w e r s h o w i n g s t a m e n s , x 20 A r r o w o n a s t a m e n n o t in f o c u s L e f t p o r t i o n o f t h e same transfer, X 100. H o o k e d a p p e n d a g e ( s t a m i n o d e ? ) and a clavate b o d y (gland~), transfer, X 250. Scar o f a gland o n the receptacle, X 400
106
PLATE VII
107
Locahty. Taldysaj on the Sarysu River, south-central Kazakhstan. Age. Santonian--Campanian. Description. Inflorescence is a fascicle of about eight branches, 15--20 mm wide, born on a peduncle more than 45 mm long (base lacking). The peduncle is 2 mm wide, longitudinally striated. Scars of two bracts are seen at the base of a fascicle and 8 mm below them there is a bffid bract slightly wider t h a n the peduncle (Plate IX, 5). The mflorescence branches spread radially and curve upwards, seem fleshy, taper to the apex. They are covered with sprees whmh are born spirally, spreading at acute angle, thickened at decurrent base but thin, recurved and apparently soft above, leaving rounded pits when shed (Plate IX, 6, 7). Distal portions of the branches show nothing but spines and are evidently sterile. Proximally some of them bear rounded scars about 1.2 mm in diameter showmg a central depression and slightly elevated margins (Plate IX, 6). The scars are about 1 mm apart, axillary to the spines. They could be left by abscissed flowers of the type seen in Plate X, 5. Most flowers appear as ovate bodies 4--5 mm long, showing imbricate scales. Occasional planes of cleavage through flowers expose a gynoecium which is flask-shaped, slightly angular, bffid at the apex (Plate X, 1). In Plate X, 2 a longitudinally split gynoecium shows a single seed or internal cast of the locule. At the base of the branches flowers are so crowded that it is difficult to make out individual structures. However some observations suggest that m this region flowers were born in spikelets. Plate X, 4 shows three spirally arranged appendages the upper of which Is a short spinulate branchlet. The lower two are of about the same length but consist of overlapping flowers apparently concealing axis parallel to the upper one. We suggest t h a t two lower appendages are few-flowered spikelets while the upper spinulate branchlet is a rachilla which somehow shed its flowers. In proximal portions of other branches a delicate spinulate axis, 3 mm long -- sterile tips of rachillae -- arises obliquely over densely packed flowers (Plate X, 2, 3). The rachillae look like miniature branches of the first order. Remarks: Despite m a n y uncertainties of the above description, there is little d o u b t t h a t we are dealing with fairly complex inflorescence bearing much reduced pistillate structures -- flowers or, as it may be, florets or antholds (the letter terms are applied to reproductive units of grasses and sedges). In our interpretation, the inflorescence branches are spikes showing proximal-distal gradient of complexity, that is bearing splkelets proximally and solitary flowers distally (Fig.4). PLATE VII Sarysua po mona 1 S E M o f s t y l e s s h o w i n g e p i d e r m a l cells a n d n e a r t h e t o p s o m e o f c o r t e x cells, × 2 0 0 . 2. S t y l a x c o r t e x cells, × 1 5 0 0 . 3 Hair base on the ovary, × 600. 4 Distribution of hairs on the ovary, × 150.
108
PLATE
VIII
Description on p 111.
109 PLATE IX
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Description on p 111.
111 T h e p e d u n c u l a r bracts o f Taldysala are n o t unlike in some p a l m s (Uhl, 1 9 7 2 ) and the raised scars o f flowers on the lateral b r a n c h e s resemble areoles o f r a t t a n s (see, e.g., Dransfield, 1 9 8 2 ) . H o w e v e r , t h e general aspect o f t h e fasciculate inflorescence is r a t h e r sedge-like and t h e flask-shaped bifid pistil also resembles bycarpellate g y n o e c l a o f sedges (generally c o n s i d e r e d as derived f r o m t h e m o r e c o m m o n tricarpellate ones). Also in sedges sterile tips of rechillae o f t e n p r o j e c t b e y o n d antholds. T h e sedge c o m p a r i s o n suggests t h a t t h e spines s u b t e n d i n g spikelets a n d t h e spinules o f t h e rachlllae are glumes ( e m p t y in the distal p o r t i o n s of t h e b r a n c h e s ) and glumellae respectively. DISCUSSION B o t h r e p r o d u c t i v e structures h i t h e r t o k n o w n f r o m t h e middle Alblan o f K a z a k h s t a n - Caspiocarpus ( V a c h r a m e e v a n d Krassilov, 1 9 7 9 ) and Hyrcantha gen. nov. -- are related t o t h e R a n u n c u l a c e a e , suggesting t h a t this g r o u p was p r o m i n e n t a m o n g ancestral angiosperms. Hyrcantha also shows s o m e p a e o m a c e o u s characters. Paeon~a was linked t o t h e R a n u n c u l a c e a e b y classical a u t h o r s , b u t o n t h e evidence o f vascular a n a t o m y it is m o r e similar t o the Magnoliaceae, while certain d e v e l o p m e n t a l features ( t h o u g h d m p u t e d , see Sawada, 1 9 7 1 ) indicate affinities w i t h t h e Dilleniaceae. O u r i n t e r p r e t a t i o n of Hyrcantha seems t o s u p p o r t t h e first view b u t it is also c o m p a t i b l e with an a s s u m p t i o n t h a t Paeonia is a m u c h m o d i f i e d relic of i m p o r t a n t ancestral p l e x u s giving rise t o a n u m b e r o f a n g i o s p e r m lineages. PLATE VIII (p. 108)
Sarysua pomona 1. 2. 3. 4.
SEM of spht styles showing transmitting tissue, × 200 Top of the left style, X 500. Rounded body (arrested pollen tubeg) m the transmitting tissue, x 600. SEM of a stamen, × 300
PLATE IX (p 109)
Taldysala medusa 1--4 5 6. 7 PLATE
Fasciculate mflorescences, × 2 Bifid peduncular bract (prophyll 9) and scars of two bracts above, × 10. Inflorescence branch showing two scars of the flowers, × 10. Distal part of a branch showing spines, × 10. X (p Ii0)
Taldysala medusa 1. Flask-shaped gynoecium blfid at the apex, × 10. 2, 3. Basal portion of a branch bearing spikelets. Note sterile tip of a rachilla (arrow) and a split gynoecium at its base showing seedlike body -- a locule cast or ovule, × 15 and 10 4. Inflorescence branch bearing a rachdla above and two spikelets below, × 10. 5 Inflorescence branch bearing solitary flowers, × 10. 6 Scars of shed flowers on a branch, × 10.
112
1 Fig.4.
Taldysala medusa, r e c o n s t r u c t i o n of an inflorescence b r a n c h .
In the Late Cretaceous diversity of the angiosperm reproductive structures was already considerable. As evidenced b y Taldysaja, they reached a high level of complexity. Sarysua is similar to Hyrcantha in persistent calyx and in the shape and dimensions of the carpels. It is conceivable that these syncarpous reproductive structures have descended from the ancestral ranunculoid--paeonioid complex. On the other hand Taldysa]a represents a separate line of development possibly related to the sedge-like plants from the Lower Cretaceous of the Lake Baikal and Mongolia (Krassilov and Bugdaeva, 1981 ; Krassilov, 1982).
113 REFERENCES Ddcher, D , 1979 Early angiosperm reproduction An introductory report. Rev Palaeobot. Palynol, 27 291--328 Dransfmld, J , 1982 Notes on rattans (Palmae. Lepldocaryldae) occurring in Sabah, Borneo Kew Bull , 36(4) 783--790. Friis, E M_ and Skarby, A , 1981 Structurally preserved angiosperm flowers from the Upper Cretaceous of southern Sweden. Nature, 291(5815): 485--486 Kaden, N N. and Lanovaya. V.P, 1963. Morphology of the gynoeclum and frmt m Geranmm Blol Naukl, 4 104--109 (in Russian)_ Krassilov, V.A., 1982 Early Cretaceous flora of Mongoha Palaeontographica, 181 B 1--43. Krassilov, V A. and Bugdaeva, E V , 1981. Achene-hke fossils from the Lower Cretaceous of the Lake Baikal area Rev. Palaeobot. Palynol, 36 279--295. Retallack, G and Ddcher, D L., 1981. Early angiosperm reproduction Prlsca raynoldsil gen. et sp nov. frora mid-Cretaceous coastal deposits m Kansas, U S.A. Palaeontographma, 179 B: 103--137 Sawada, M , 1971 Floral vascularlzatlon of Paeonta japonica with some conmderatlons on systematic position of the Paeomaceae. Bot. Mag. Tokyo, 84 51--60 Shlhn, P V and Romanova, E.V., 1978. Senoman Floras of Kazakhstan. Nauka Kazakh SSR, Alma-Ata, 176 pp Uhl, N_W, 1972. Inflorescence and flower structure m Nypa fruhcans (Palmae). Am. J Bot_,59(7) 729--743 Vachrameev, V A., 1952 Stratigraphy and fossil flora of the Cretaceous deposits m the western Kazakhstan. In Regional Stratigraphy of the USSR, 1 340 pp. Vachrameev, V A. and Krassilov, V A., 1979. Reproductive structures of angiosperms from the Alblan of Kazakhstan. Palaeontol. J (Moscow), 1' 121--128 (in Russian) Weller, S G., 1976. Breeding system polymorphism in a heterostylous species Evolution, 30(3)- 442--454
91
CRETACEOUS FLOWERS FROM KAZAKHSTAN
V A. KRASSILOV, P V SHILIN and V A. VACHRAMEEV Institute of Bzology and Pedology, Vladwostok, 22 (U S S R.) Instztute of Zoology, Alma-Ata (US S R ) Geologzcal Instztute, Moscow, 109017, Pyzhevsky, 7 (US S R ) (Received and accepted April 29, 1983)
ABSTRACT Krasmlov, V.A., Shdm, P V. and Vachrameev, V.A, 1983. Cretaceous flowers from Kazakhstan. Rev. Palaeobot Palynol., 40: 91--113.
Hyrcantha gen. nov. from the Mxddle Alblan is a pamculate inflorescence. The flowers are bisexual with persistent calyx and apocarpous gynoecium The carpels are ascldlal with broad sessile stigma. The genus is related to the Ranunculaceae and Paeomaceae The Late Cretaceous Sarysua gen. nov has cymold inflorescences of many actmomorphm pentamerous flowers with syncarpous five-lobed ovaries and free styles. A geranialean affinity is suggested. In Taldysaja of the same age much reduced pistillate flowers are born in splkelets or solitary on branches of the fasciculate inflorescence These findings evidence the important role of the ranunculoid--paeoniold complex among ancestral angiosperms and the considerable diversity of the Late Cretaceous flowering structures INTRODUCTION In r e c e n t y e a r s several i m p o r t a n t r e p r o d u c t i v e s t r u c t u r e s of e a r l y a n g l o s p e r m s have c o m e t o l i g h t (Dilche_r, 1 9 7 9 ; V a c h r a m e e v a n d Krassilov, 1 9 7 9 ; Frlls a n d S k a r b y , 1 9 8 1 ; R e t a l l a c k a n d D l l c h e r , 1 9 8 1 ) . A f e w m o r e f i n d s o f t h i s k m d are d e s c r i b e d in t h i s p a p e r . O n e o f t h e m is f r o m t h e M i d d l e A l b l a n o f w e s t e r n K a z a k h s t a n - - t h e s a m e b e d s w h i c h y i e l d e d Caspzocarpus ( V a c h r a m e e v a n d K r a s s i l o v , 1 9 7 9 ) - - w h i l e t w o o t h e r s are f r o m t h e Sant o n i a n - - C a m p a n i a n o f s o u t h - c e n t r a l K a z a k h s t a n . See V a c h r a m e e v ( 1 9 5 2 ) a n d S h i l i n a n d R o m a n o v a ( 1 9 7 8 ) f o r j u s t i f i c a t i o n o f t h e age a s s i g n m e n t s a n d g e n e r a l d e s c r i p t i o n o f t h e fossil floras. I n f l o r e s c e n c e s w e r e m e n t i o n e d in t h e o r i g i n a l d e s c r i p t i o n s as r e p r o d u c t i v e s t r u c t u r e s of u n k n o w n n a t u r e . T h e i r d e t a i l e d s t u d y is h e r e u n d e r t a k e n f o r t h e first t i m e . T h e A l b i a n m f l o r e s c e n c e s o c c u r in l i g h t - c o l o u r e d c l a y as Impressions, gray on dispersed coaly substance. The S a n t o n i a n - - C a m p a n i a n fossils are t h i n i r o n o x i d e i n c r u s t a t i o n s , b r o w n o n h g h t - y e l l o w s i l t s t o n e . No o r g a n i c m a t t e r s u i t a b l e f o r m a c e r a t i o n is p r e s e r v e d b u t at p l a c e s cell o u t l i n e s are visible o n i m p r e s s i o n s a n d i n c r u s t a t i o n s .
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© 1983 Elsevmr Sc;ence Pubhshers B.V
92 SYSTEMATICS Genus Hyrcantha Krassilov et Vachrameev, gen. nov.
Name Hyrcanian is the ancient name of the Caspian Sea. Type species. Hyrcantha karatscheensis (Vachrameev) Krassflov et Vachrameev, comb. nov. Diagnoszs Inflorescence bracteate, paniculate, ultimate branches oneflowered. Flowers terminal, bisexual. Calyx small, persistent, sepals scaly, reflexed. Stamens shorter than carpels. Gynoeclum apocarpous, of three or five ascidial carpels dehiscing along the ventral sutures. Stigma terminal, sessile, rather broad. Hyrcantha karatscheensis (Vachrameev) Krassilov et Vachrameev comb. nov. (Plate I, 1--5; Plate II, 1--7). Bas~onym: Carpotithes karatscheens~s Vachrameev, 1952, Regional Stratigraphy of the USSR, p.274, P1. XLIV, 1--5. H o l o t y p e N 3302/47, Geological Inshtute, Moscow (Vachrameev, 1952, pl. XLIV, 3). Locality Karatsche-Tau Hill, western Kazakhstan. Age. Middle Albian. Description: The best specimen is a part of a paniculate inflorescence (Plate I, 1--3, Fig.l) with a grooved main axis 1.3 mm thick. Minute bracts occur at the nodes and there are also bracteoles on the lateral branches. A lower branch is forking twice in rapid succession, the upper branches are unbranched, one-flowered. They are subopposite, departing at acute angle. The pedicels are thin, about 10--14 mm long. All flowers are evidently at fruiting stage, of equal size, about 13 mm wide. Remains of the calyx are seen in three of them, the better preserved is shown in Plate II, 1, 2. Sepals are scaly, 1.5 mm long, reflexed and more or less appressed to the pedicel. In this specimen there is no unequivocal evidence of androecium. Gynoecla consist of three ascidial carpels, about 7 mm long, 3 mm wide, sessile on a broad receptacle, free to the base, showmg polygonal surface cells and a terminal scar (Plate II, 4--5) or a broad notch (Plate II, 4) probably representing sessile stigma.
PLATE I
Hyrcantha karatscheensis 1, 2 Lateral inflorescence branches, X 3 3. Part of a pamculate inflorescence, × 2. 4.
Lateral inflorescence branch bearing flower. Leaflets of "Legummosztes" karat-
scheensis overlap the axis, × 1.5.
93
PLATE I
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94
PLATE II
95
Most carpels seem to be dehiscent along the ventral suture letting rock matrix fill the locules. The internal casts show a dorsal suture and anastomosing transverse striation (Plate II, 7). Another specimen (Plate I, 4) is a fragment of the grooved axis 20 mm long, 1.5 m m thick, bearing a single lateral branch terminated by a flower of the same dimensions as in the holotype. This flower is significant in showing, in addition to persistent calyx and tricarpous gynoecium, distinct impressions of stamens (Plate II, 3). The filaments are about 0.5 mm thick, reaching to about mid-length of the carpels. One of them bears a crumpled anther whmh seems bilocular, but its structure cannot be made out with any confidence. While flowers in these inflorescences are trimerous, a specimen figured by Vachrameev (1952) pl. XLIV, 3 shows five carpels (Fig.l). Assocmted leaves (Plate III, 1--5): Inflorescences regularly associate with c o m p o u n d leaves described by Vachrameev (1952) as Legummosltes karatscheensis. In the above described specimen (Plate I, 4) the leaflets overlap main axis slightly above the node. Though t h e y are obvmusly n o t In organic connection, the association seems noteworthy. A few notes can be added to the original description of the leaves. While most fragments of c o m p o u n d leaves are pinnate, some of them (Fig.2 reproduced from pl. XXXIV in Vachrameev, 1952) suggest ternate arrangement of the leaflets. The latter show a midveln which fades out above the middle. Secondary veins are thin, undulate, oblique to the midvein, forking once or twine, their branches running to the margin. Tertiary veins are scalarfform, straight or bowed. Veinlets of higher order form rounded meshes about 0.1 mm wide. Margins seem entire but on closer inspection show scabrations or even minute prickles on the vein ends (Plate III, 4, 5). In SEM the leaf impressions show vague outlines of epidermal cells and fairly distinct stomatal pits which are either e m p t y or filled with the puck-like casts of the guard cells. Rapid decay of the stomata penetrated by lncrustatmg substances could produce this effect. Stomata are scattered withm the vein meshes (Plate III, 1, 2) occasionally occurring over the veinlets (Plate III, 2, upper right corner). They tend to be orientated along the secondary veins. The spacing of the stomata is rather regular, paired stomata seen in Plate III, I are rather u n c o m m o n . The guard cell thickenmgs are elliptmal, 17 pm long, slightly If at all sunken below the leaf surface. There are no indications of specmhzed subsidiary cells. Remarks: What we know about Hyrcanta is hardly suffmient for exact taxonomic assignment. Similar apocarpous gynoecia of three ascidlal follicles
P L A T E II
Hyrcantha karatscheens~s 1, 2 3 4--6. 7.
F l o w e r showing persistent calyx, × 7 and 10 F l o w e r showing stamens, arrow on a c r u m p l e d a n t h e r , × 7 Carpels s h o w i n g t e r m i n a l stigmas, × 7 I n t e r n a l cast o f a carpel showing transverse s t r i a h o n , × 10.
96
t7; " 7i" /
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Fig 1 Hyrcantha karatscheenszs, inflorescence and flowers A 5-merous gynoecium (middle right) is reproduced from Vachrameev (1952, pl. XLIV, 3)
97 are known m the Ranunculaceae and especially in the extant Thahctrum subgen. Euthalictrum in which the follicles are usually sessile, about 7--8 mm long. Also in Thalictrum the styles are often reduced and inflorescences can be paniculate, and bracteate, as in T. foetidum L. At the same time, a broad sessile stigma and persistent calyx are characteristic features of Paeonia. Some species of Paeonia (e.g.P. caucasica) have biternate leaves with ovate leaflets and the leaf margins can be scabrate as in "Leguminosites" karatscheensis. Taking allthls into consideration, Hyrcantha can be tentatively placed somewhere in the vicinity of the Ranunculaceae and Paeonlaceae, reinforcing the often debated links between these famlhes. Genus Sarysua Krassilov et Shilin, gen. nov.
Name: After Sarysu River. Type species: Sarysua pomona Krassilov et Shflin, sp. nov. Diagnoszs: Inflorescence cymold, flowers actmomorphm, pedmel shorter than gynoecium, receptacle massive, bearing glands below the whorl of stamens. Calyx persistent, sepals lanceolate, caudate, reflexed. Stamens about ten, in one whorl, some of them reduced to stamlnodia. G y n o e c m m syncarpous with free styles. Ovary five-lobed, pubescent. Locules broad at the base but narrow and presumably sterile above. Styles five, of varying length, glabrous, solid. Stigma terminal, capltate.
Sarysuapomona Krassilov et Shflln, sp. nov. (Plate IV, 1--4; Plate V, 1--7; Plate VI, 1--5; Plate VII, 1--4; Plate VIII, 1--4)
Name: Pomona is the Italian goddess of gardens. Holotype N 284/67, now at repository of the Institute of Biology and Pedology, Vladivostok (Plate IV, 4; Plate V, 1, 7). Locahty: Taldysaj on the Sarysu River, south-central Karakhstan. Age Santonian--Campanmn. Description: Several slltstone slabs contain crowded flowers of one kind. Those in Plate IV, 1 possibly belong in the same mflorescence. No connecting axes are seen, but the flowers seem to be arranged in a regular manner allowing tentative reconstruction of the mflorescence. In this specimen, most of the 32 flowers are assembled within a rectangle three sides of which are formed by rows of parallel flowers pointing outwards or occasionally rewards. Central group comprises flowers with shorter ovaries and slightly longer styles facing each other. The most probable form of inflorescence suggested by this arrangement Is a dlchasial cyme (Fig.3). All the flowers are stalked, with thin pedicels about 3 mm long and relatively massive receptacles 1.5 m m wide. They show a persistent calyx with lanceolate, longly pointed (caudate) reflexed lobes 2 m m long (Plate IV, 3). In most flowers androecium is represented by a few stamens. They are better seen in transfer preparations where the filaments or their stumps often stick up from the cellulose film as hollow cylinders. Plate VI, 1 (see also Fig.3)
98
PLATE III
99
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Fig.2. " L ~ g u m i n o s t t e s " karatscheensis, leaves associating with H y r c a n t h a karatscheensls, reproduced from Vachrameev (1952, pl. XXXIV). A leaf of the extant Paeon~a caucaslca N. Schipez. (bottom left) is shown for comparison s h o w s s t u m p s o f e i g h t f i l a m e n t s in a single w h o r l . J u d g i n g b y t h e i r s p a c i n g , at least two filaments are missing. Hooked appendage on the left side (Plate V I , 4) c o u l d b e a s t a m i n o d e . C l a v a t e b o d y s e e n a t t h e e d g e b e l o w t h e s t a m e n w h o r l is s u p p o s e d l y o f g l a n d u l a r n a t u r e . T h e r e a r e a l s o r o u n d e d s c a r s o n t h e r e c e p t a c l e , p o s s i b l y l e f t b y s i m i l a r g l a n d s ( P l a t e V I , 2). I n S E M t h e f i l a m e n t s a r e r i d g e d , s h o w i n g r o w s o f e l o n g a t e c e l l s ( P l a t e V I I I , 4). PLATE III " L e g u m m o s ~ t e s " karatscheens;s
1. 2. 3 4
SEM of a leaf impression showing stomata, × 180 Stomata scattered m the vein meshes and occasionally over the veinlet, × 350. Stomatal pit with a cast of guard cell thmkenmgs, × 3000. Margin of a leaflet, arrows on scabrahons on the ends of lateral veins, × 10
100 P L A T E IV
¢
m
I01
Ovaries m most flowers are elongate conical about 7 (6--8) mm long, but the tuner group of flowers in Plate IV, 1, shows much shorter ovaries, less than 2 mm long. At the same time their styles are slightly longer than in the larger gynoecia. Impressions of the ovarms show deep folds, possibly exaggerated by compression (Plate V, 4). These folds conceivably mark boundaries of the connate carpels. Ovaries cleaved through the median plane expose wings of two opposite carpels forming septae and between them a portion of the third carpel showing a longitudinal ridge -- evidently the ventral suture (Plate IV, 2). Different planes of cleavage expose one of the locules which is broadly ovate at the base but narrow and slit-like in the upper half of the carpel (Plate V, 1, 2, 7). These observations suggest that the carpels were closed (ventral suture) and the upper portions of the locules were most probably sterile. A bunch of five free styles crowns the ovary. Usually three or four of them are exposed on the rock surface (Plate V, 1--4) while the rest are broken off, leaving stumps or immersed in the rock but t h e y can be revealed by digging with a needle. Styles are curved, about 0.7--0.9 m m long but in the flowers with shorter ovaries up to 1.1 mm long (Plate V, 5). In transfer preparations styles often stick up from cellulose film in the same manner as stamens. Stigmas are terminal, hemisphaerical or slightly concave, papillate. In SEM the ovaries show coarse pits of the hair bases (Plate VII, 3, 4) while styles are glabrous. Cell outhnes are fax more distinct in styles than in ovaries. It appears that, for some reason, styles were minerahzed to a higher extent than ovaries. It is possible that mineralizing solutions have infiltrated through the transmitting tissue. Epidermal cells of the styles are elongate, forming longitudinal rows. One specimen reveals subepidermal columnar cells of the stylar cortex (Plate VII, 1, 2). There are no traces of vascular bundles which m styles are usually confined to the cortex. Also there are no mdlcatlons of a central hollow, suggesting that the styles were sohd (that is, filled with transmitting tissue). SEM of the longitudinally split styles (Plate VIII, 1--3) show what appears to be transmitting tissue. It consists of narrow longitudinally stretched cells forming undulating rows. R o u n d e d bodies within the transmitting tissue such as seen in Plate VIII, 3 could be either secretory cavities or -- a fascinating possibility which unfortunately cannot be tested at present -- arrested pollen tubes. Remarks: Surveying the extant genera of angiosperms for c o m b m a t m n of such characters as cymold inflorescence, actmomorphm bisexual pedicelled flower of pentamerous structure, persistent calyx, glands in the staminate P L A T E IV
Sarysua pomona 1 F l o w e r s c r o w d e d o n a rock slab, s o m e o f t h e m s h o w i n g regular a r r a n g e m e n t N o t e central g r o u p o f s h o r t e r flowers, × 3. 2 F l o w e r s h o w i n g s t a m e n s and a ridge o n the m e d i a n carpel, arrow, × 10 3 F l o w e r s h o w i n g calyx, × 10. 4 G r o u p o f t h r e e flowers, × 3
102 PLATE V i
4
P
103 whorl, s y n c a r p o u s ovaries of five closed carpels w i t h c o n t r a c t e d locules, free styles and capitate stigmas, we smgled o u t Linum, Oxalis and Geramum o f t h e o r d e r Geramales w h i c h share m o s t o f these characters. Linum has a dmhaslal inflorescence, a c t i n o m o r p h m flowers w i t h a persistent calyx, nectaries o n s t a m i n a t e disk, five-lobed o v a r y and m o r e or less free styles. Incid e n t a l l y , in Linum flavum L. styles o f h e t e r o s t y l o u s f o r m s are 6--8 m m and 8--11 m m long, m u c h like in Sarysua. Oxales has t e n stamens in t w o whorls, free styles which are o f t e n glabrous, and capitate stigmas. Geranium is similar m having stamens shghtly if at all c o h e r e n t at t h e base, n e c t a r glands and c o n s p i c u o u s l y five-lobed ovary, o f t e n p u b e s c e n t , with locules a t t e n u a t e d and sterilized m t h e u p p e r half o f t h e carpels ( K a d e n and L a n o v a y a , 1963). In this genus some stamens can b e r e d u c e d t o staminodia. T h e c o h e r e n c e o f stamens and appendiculax central c o l u m n m the o v a r y can b e seen as derived characters n o t t o be e x p e c t e d m early representatives o f t h e order. In p o l y m o r p h i c p o p u l a t i o n s o f h e t e r o s t y l o u s Linum and Oxalis, individuals with longer and s h o r t e r styles c o o p e r a t e in the highly evolved breeding s y s t e m (see Weller, 1 9 7 6 ) . It m a y be possible t h a t t h e association o f longer and shorter flowers with slightly d i f f e r e n t style lengths in Sarysua p o i n t t o incipient h e t e r o s t y l y . G e n u s Taldysa]a Krassilov et Shilin, gen. nov.
Name A f t e r the locality o f Taldysaj m s o u t h - c e n t r a l Kazakhstan. Type species. Taldysaja medusa Krassllov et Shilin sp. nov. Diagnosis I n f l o r e s c e n c e fasciculate o n a long p e d u n c l e bearing a bffid prophyll and i n f l o r e s c e n c e bracts. Branches o f t h e fascicle spiny, distally sterile, beaxmg solitary flowers or in t h e proxLmal part one- or t w o - f l o w e r e d splkelets axlllary t o t h e spmes. Rachillae o f t h e spikelets splnulate s h o w m g long sterile apeces. Flowers with Lmbricate p e n a n t h scales and a flask-shaped g y n o e c i u m .
Taldysa]a medusa Krassllov et Shilin, sp. nov. (Plate IX, 1--7; Plate X, 1--6) Name: Medusa -- a g o r g o n with a head o f snakes (see Plate IX, 1). Holotype: N 2 8 4 / 3 7 5 , n o w at r e p o s i t o r y o f t h e I n s t i t u t e o f Biology and P e d o l o g y , Vladivostok (Plate IX, 1). PLATE V
Sarysua pomona 1_
Flower split through median plane showing side wings of two carpels and a locule
2
o f the third carpel b e t w e e n them, × 10. Top of a gynoecium showing free styles, × 15.
3 Four exposed styles, arrow on a stump of the fifth one, × 15 4 Gynoecmm showing folds b e t w e e n the ovary lobes, × 10 5, 6. Flower with shorter gynoecia, × 10 7 Different focus of 1.
104 P L A T E VI
1
105
U
Fig 3. Sarysua pomona, a r r a n g e m e n t o f flowers s u p p o s e d l y r e p r e s e n t i n g a dlchaslal c y m e ( t o p ) and r e c o n s t r u c t i o n o f a flower ( b o t t o m ) , dlagramatic cross-section (left) and tangential s e c t i o n (right) o f a g y n o e c m m .
P L A T E VI
Sarysua pomona 1. 2. 3. 4
Transfer o f a f l o w e r s h o w i n g s t a m e n s , x 20 A r r o w o n a s t a m e n n o t in f o c u s L e f t p o r t i o n o f t h e same transfer, X 100. H o o k e d a p p e n d a g e ( s t a m i n o d e ? ) and a clavate b o d y (gland~), transfer, X 250. Scar o f a gland o n the receptacle, X 400
106
PLATE VII
107
Locahty. Taldysaj on the Sarysu River, south-central Kazakhstan. Age. Santonian--Campanian. Description. Inflorescence is a fascicle of about eight branches, 15--20 mm wide, born on a peduncle more than 45 mm long (base lacking). The peduncle is 2 mm wide, longitudinally striated. Scars of two bracts are seen at the base of a fascicle and 8 mm below them there is a bffid bract slightly wider t h a n the peduncle (Plate IX, 5). The mflorescence branches spread radially and curve upwards, seem fleshy, taper to the apex. They are covered with sprees whmh are born spirally, spreading at acute angle, thickened at decurrent base but thin, recurved and apparently soft above, leaving rounded pits when shed (Plate IX, 6, 7). Distal portions of the branches show nothing but spines and are evidently sterile. Proximally some of them bear rounded scars about 1.2 mm in diameter showmg a central depression and slightly elevated margins (Plate IX, 6). The scars are about 1 mm apart, axillary to the spines. They could be left by abscissed flowers of the type seen in Plate X, 5. Most flowers appear as ovate bodies 4--5 mm long, showing imbricate scales. Occasional planes of cleavage through flowers expose a gynoecium which is flask-shaped, slightly angular, bffid at the apex (Plate X, 1). In Plate X, 2 a longitudinally split gynoecium shows a single seed or internal cast of the locule. At the base of the branches flowers are so crowded that it is difficult to make out individual structures. However some observations suggest that m this region flowers were born in spikelets. Plate X, 4 shows three spirally arranged appendages the upper of which Is a short spinulate branchlet. The lower two are of about the same length but consist of overlapping flowers apparently concealing axis parallel to the upper one. We suggest t h a t two lower appendages are few-flowered spikelets while the upper spinulate branchlet is a rachilla which somehow shed its flowers. In proximal portions of other branches a delicate spinulate axis, 3 mm long -- sterile tips of rachillae -- arises obliquely over densely packed flowers (Plate X, 2, 3). The rachillae look like miniature branches of the first order. Remarks: Despite m a n y uncertainties of the above description, there is little d o u b t t h a t we are dealing with fairly complex inflorescence bearing much reduced pistillate structures -- flowers or, as it may be, florets or antholds (the letter terms are applied to reproductive units of grasses and sedges). In our interpretation, the inflorescence branches are spikes showing proximal-distal gradient of complexity, that is bearing splkelets proximally and solitary flowers distally (Fig.4). PLATE VII Sarysua po mona 1 S E M o f s t y l e s s h o w i n g e p i d e r m a l cells a n d n e a r t h e t o p s o m e o f c o r t e x cells, × 2 0 0 . 2. S t y l a x c o r t e x cells, × 1 5 0 0 . 3 Hair base on the ovary, × 600. 4 Distribution of hairs on the ovary, × 150.
108
PLATE
VIII
Description on p 111.
109 PLATE IX
D e s c r i p t i o n o n p_ 1 1 1
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Description on p 111.
111 T h e p e d u n c u l a r bracts o f Taldysala are n o t unlike in some p a l m s (Uhl, 1 9 7 2 ) and the raised scars o f flowers on the lateral b r a n c h e s resemble areoles o f r a t t a n s (see, e.g., Dransfield, 1 9 8 2 ) . H o w e v e r , t h e general aspect o f t h e fasciculate inflorescence is r a t h e r sedge-like and t h e flask-shaped bifid pistil also resembles bycarpellate g y n o e c l a o f sedges (generally c o n s i d e r e d as derived f r o m t h e m o r e c o m m o n tricarpellate ones). Also in sedges sterile tips of rechillae o f t e n p r o j e c t b e y o n d antholds. T h e sedge c o m p a r i s o n suggests t h a t t h e spines s u b t e n d i n g spikelets a n d t h e spinules o f t h e rachlllae are glumes ( e m p t y in the distal p o r t i o n s of t h e b r a n c h e s ) and glumellae respectively. DISCUSSION B o t h r e p r o d u c t i v e structures h i t h e r t o k n o w n f r o m t h e middle Alblan o f K a z a k h s t a n - Caspiocarpus ( V a c h r a m e e v a n d Krassilov, 1 9 7 9 ) and Hyrcantha gen. nov. -- are related t o t h e R a n u n c u l a c e a e , suggesting t h a t this g r o u p was p r o m i n e n t a m o n g ancestral angiosperms. Hyrcantha also shows s o m e p a e o m a c e o u s characters. Paeon~a was linked t o t h e R a n u n c u l a c e a e b y classical a u t h o r s , b u t o n t h e evidence o f vascular a n a t o m y it is m o r e similar t o the Magnoliaceae, while certain d e v e l o p m e n t a l features ( t h o u g h d m p u t e d , see Sawada, 1 9 7 1 ) indicate affinities w i t h t h e Dilleniaceae. O u r i n t e r p r e t a t i o n of Hyrcantha seems t o s u p p o r t t h e first view b u t it is also c o m p a t i b l e with an a s s u m p t i o n t h a t Paeonia is a m u c h m o d i f i e d relic of i m p o r t a n t ancestral p l e x u s giving rise t o a n u m b e r o f a n g i o s p e r m lineages. PLATE VIII (p. 108)
Sarysua pomona 1. 2. 3. 4.
SEM of spht styles showing transmitting tissue, × 200 Top of the left style, X 500. Rounded body (arrested pollen tubeg) m the transmitting tissue, x 600. SEM of a stamen, × 300
PLATE IX (p 109)
Taldysala medusa 1--4 5 6. 7 PLATE
Fasciculate mflorescences, × 2 Bifid peduncular bract (prophyll 9) and scars of two bracts above, × 10. Inflorescence branch showing two scars of the flowers, × 10. Distal part of a branch showing spines, × 10. X (p Ii0)
Taldysala medusa 1. Flask-shaped gynoecium blfid at the apex, × 10. 2, 3. Basal portion of a branch bearing spikelets. Note sterile tip of a rachilla (arrow) and a split gynoecium at its base showing seedlike body -- a locule cast or ovule, × 15 and 10 4. Inflorescence branch bearing a rachdla above and two spikelets below, × 10. 5 Inflorescence branch bearing solitary flowers, × 10. 6 Scars of shed flowers on a branch, × 10.
112
1 Fig.4.
Taldysala medusa, r e c o n s t r u c t i o n of an inflorescence b r a n c h .
In the Late Cretaceous diversity of the angiosperm reproductive structures was already considerable. As evidenced b y Taldysaja, they reached a high level of complexity. Sarysua is similar to Hyrcantha in persistent calyx and in the shape and dimensions of the carpels. It is conceivable that these syncarpous reproductive structures have descended from the ancestral ranunculoid--paeonioid complex. On the other hand Taldysa]a represents a separate line of development possibly related to the sedge-like plants from the Lower Cretaceous of the Lake Baikal and Mongolia (Krassilov and Bugdaeva, 1981 ; Krassilov, 1982).
113 REFERENCES Ddcher, D , 1979 Early angiosperm reproduction An introductory report. Rev Palaeobot. Palynol, 27 291--328 Dransfmld, J , 1982 Notes on rattans (Palmae. Lepldocaryldae) occurring in Sabah, Borneo Kew Bull , 36(4) 783--790. Friis, E M_ and Skarby, A , 1981 Structurally preserved angiosperm flowers from the Upper Cretaceous of southern Sweden. Nature, 291(5815): 485--486 Kaden, N N. and Lanovaya. V.P, 1963. Morphology of the gynoeclum and frmt m Geranmm Blol Naukl, 4 104--109 (in Russian)_ Krassilov, V.A., 1982 Early Cretaceous flora of Mongoha Palaeontographica, 181 B 1--43. Krassilov, V A. and Bugdaeva, E V , 1981. Achene-hke fossils from the Lower Cretaceous of the Lake Baikal area Rev. Palaeobot. Palynol, 36 279--295. Retallack, G and Ddcher, D L., 1981. Early angiosperm reproduction Prlsca raynoldsil gen. et sp nov. frora mid-Cretaceous coastal deposits m Kansas, U S.A. Palaeontographma, 179 B: 103--137 Sawada, M , 1971 Floral vascularlzatlon of Paeonta japonica with some conmderatlons on systematic position of the Paeomaceae. Bot. Mag. Tokyo, 84 51--60 Shlhn, P V and Romanova, E.V., 1978. Senoman Floras of Kazakhstan. Nauka Kazakh SSR, Alma-Ata, 176 pp Uhl, N_W, 1972. Inflorescence and flower structure m Nypa fruhcans (Palmae). Am. J Bot_,59(7) 729--743 Vachrameev, V A., 1952 Stratigraphy and fossil flora of the Cretaceous deposits m the western Kazakhstan. In Regional Stratigraphy of the USSR, 1 340 pp. Vachrameev, V A. and Krassilov, V A., 1979. Reproductive structures of angiosperms from the Alblan of Kazakhstan. Palaeontol. J (Moscow), 1' 121--128 (in Russian) Weller, S G., 1976. Breeding system polymorphism in a heterostylous species Evolution, 30(3)- 442--454