36 



J. WATSON, S.J. LYDON & N.A. HARRISON 



readily distinguishable from all other Czekanowskiales by its gross 

 form, thus differing from the generic proposals of Florin (1936b). 

 Florin ( 1936b: 45) suggested that bundles of leaves agreeing in gross 

 morphology with Heer's (1876) generic diagnosis for Phoenicopsis 

 should be split into four genera: Phoenicopsis for leaves whose 

 cuticular structure was unknown; Stephanophylliim for those with 

 hypostomatic foliage leaves; Culgoweha for amphistomatic leaves 

 with stomata in files; Windwardia for amphistomatic leaves with 

 stomata in bands. In 1972, Samylina again revised the status of the 

 genus Plwenicopsis such that Stephanophylliinu Culgoweria and 

 Windwardia were abandoned as distinct genera but with Culgoweria 

 and Windwardia retained within Phoenicopsis as sub-generic taxa or 

 sections. The genus Phoenicopsis Heer sensu Samylina is recognis- 

 able from gross form alone, whilst the sections or sub-genera are 

 distinguished by differences in stomatal distribution. 



Key for identifying sections within the genus Phoenicopsis: 



1 .a) Leaf hypostomatic. Phoenicopsis (section Phoenicopsis) 



l.b) Leaf amphistomatic. go to 2 



2. a) Stomata in files. Phoenicopsis (section Culgoweria) 



2.b) Stomata in bands. Phoenicopsis (section Windwardia) 



Samylina's work removes the artificial category set up by Florin for 

 leaves whose cuticles are unknown and brings Phoenicopsis into line 

 with other Czekanowskialean genera which were already distin- 

 guished on gross form alone. Thus cuticular features are reserved for 

 distinctions at sub-generic and species level throughout the order. 

 Sun ( 1987) discussed and adopted Samylina's scheme in describing 

 three new species of Phoenicopsis from the Mesozoic of northeast 

 China, all referred to the subgenus Culgoweria. The new species of 

 Phoenicopsis described below is also attributable to the sub-genus 

 Culgoweria as defined above. 



Phoenicopsis rincewindii sp. nov. 



Figs 4-6 



Diagnosis, [based on leaf fragments only] Parallel-sided leaf 2-5 

 mm wide [base and apex unknown]. Veins indistinct, at least 4 per 

 leaf. 



Thicker cuticle (?upper) 5-8 pm thick with stomata arranged in 

 longitudinal files between veins, density about 20 per mm-, longitu- 

 dinally or obliquely orientated. Stomatal apparatus on both surfaces 

 55-90 |jm long x 35-60 pm wide; stomatal pit square or rectangular 

 with 4-6 subsidiary cells in a distinct ring around pit; inner anticlinal 

 walls forming thickened rim to pit; lateral subsidiary cells usually 

 with solid papillae projecting over pit; periclinal walls slightly 

 thicker than on ordinary epidermal cells. Guard cells slightly sunken 

 beneath subsidiary cells; dorsal plates thinly cutinized, axe-head- 

 shaped, faint radiating striae on inside; inner anticlinal walls shallowly 

 cutinized. Encircling cells usually absent. Ordinary epidermal cells 

 arranged in longitudinal files, generally four-sided, elongate 38-1 1 2 



pm long X 10-20 [xm wide, end walls transverse or oblique. Anticli- 

 nal walls narrow, about 1 \xm wide, straight or slightly sinuous and 

 pitted. Longitudinal cutinized ridges present over surface of some 

 cells. Inside surface of periclinal walls finely pitted. Papillae absent 

 from ordinary epidermal cells. Hypodermis absent. Thinner cuticle 

 with stomata arranged in longitudinal files over whole surface, not 

 avoiding veins, density typically 70-76 per mm-, longitudinally or 

 obliquely orientated. Ordinary epidermal cells arranged in longitu- 

 dinal files, generally four-sided; those between stomatal files elongate, 

 typically 50-70 pm long x about 1 \xm wide, end walls transverse or 

 oblique; cells within stomatal files slightly elongate or isodiametric, 

 10-57 pm long x 10-23 |im wide, end walls transverse, rarely 

 oblique. Slight median thickenings or ridges present over surface of 

 most cells. Inside surface of periclinal walls finely pitted. Anticlinal 

 walls narrow, about 1 \xm wide, straight or pitted and appearing 

 slightly sinuous. 



Name. After Rincewind, ineffective wizard of the Unseen Univer- 

 sity in the Disc world novels of Terry Pratchett. 



HOLOTYPE and type LOCALITY. V.64527, a portion of leaf from 

 Fairlight, near Hastings. East Sussex. Figs 4B, D, E, H, I. J; 6B. D, E. 

 Ashdown Beds Formation, Berriasian. 



Material and occurrence. Phoenicopsis rincewindii sp. nov. 

 is known only from dispersed material from Fairlight, near Hastings, 

 East Sussex. Ashdown Beds Formation, Berriasian. 



Description. The remains of the largest leaf fragments of 

 Phoenicopsis rincewindii recognised so far are shown in Fig. 4A, B 

 with the latter opened up to show both leaf surfaces. Both are 

 photographed after the removal of part of their length for SEM 

 cuticle preparations. The rather thinner cuticle on the left of Fig. 4B 

 is presumed to be from the lower surface of the leaf. Apart from its 

 thickness, this cuticle (Figs 6A-E) only differs from that of the other 

 surface (Figs 4C-I) in having more stomata per mm^ and having 

 somewhat less elongate epidermal cells. Otherwise most features are 

 more or less similar on both cuticles. Fig. 4E, I, J shows the 

 longitudinal cuticular ridges over the epidermal cells of the upper 

 surface, some restricted to one cell but often extending along a file of 

 cells. Figs 5C and 6B show the lower surface of the leaf which is less 

 strongly ridged and thus thinner overall. The arrangement of the 

 stomata in files on the lower surface can be seen in Figs 4B (left) and 

 6A. It is less apparent for the upper surface with sparser stomata (Fig. 

 4C) but this is partly because of the strong longitudinal wrinkling 

 (Fig. 4B, right) which is a preservational feature, probably associ- 

 ated with a tendency for the leaf surface to become furrowed between 

 the veins (Fig. 4E). 



A high frequency of paired stomata is noted with two stomata 

 either sharing one polar subsidiary cell, or with their polar subsidiary 

 cells sharing an end wall as in the pair of stomata shown in Figs 5C 



Fig. 4 A-J Phoenicopsis rincewindii sp. nov. A, B, D, both leaf surfaces; C, E-J, thicker ( ? upper) leaf cuticle. A, longest fragment of leaf showing whole 

 width, V.64526, LM. x 15; B, holotype, leaf fragment opened up to show both surfaces, thicker cuticle on right, V.64527, LM. x 25: C, sparse stomata 

 avoiding vein tracts; ordinary epidermal cells elongate, arranged in well-defmed longitudinal files, V.64526, LM, x 125; D, holotype, inside view of 

 opened up leaf with elongate cells of leaf margin in centre (arrow), thicker cuticle on left with stomata between vein tracts, thinner cuticle with higher 

 stomatal density on right, V.64527, SEM, x 125; E, holotype, outer surface showing strong longitudinal wrinkling and lateral compression, probably with 

 veins forming the ridges, V.64527, SEM, x 125; F, stoma showing subsidiary cells with more thickly cutinized periclinal walls than surrounding cells and 

 pit overhung by papillae of subsidiary cells, V.64526, LM, x 500; G, cuticle viewed from the inside showing pitted anticlinal walls to ordinary epidermal 

 cells and stoma with two lateral and two polar subsidiary cells, V.64527, SEM, x 500; H, inside view of a stoma showing axe-head-shaped dorsal plates to 

 guard cells with fine radiating striae, V.64527, SEM, x 1000; I, J, holotype, cuticle viewed from the outside showing ordinary epidermal cells with 

 longitudinal ridges; ridges in Fig. I ending abruptly adjacent to stoma with smooth subsidiary cell surface and papillae overhanging pit, V.64527, SEM, x 

 500. 



