UPPER JURASSIC PLANTS FROM CABO MONDEGO (PORTUGAL) (1)

BY

JO.Ãü PAIS (2)

RÉSUMÉ

On présente la revlSlon et une étude complémentaire de quelques végétaux du Jurassique supérieur <Lusitanien) de Cabo Mondego, Figueira da Foz. On décrit la morphologie externe et la topographie cuticulaire de 5 especes, dont 3 sont nouvelles: Todites falciformis n. sp., Otozamites m<undae (MORRIS), Pterophyllum mondeguensis n. sp., Brachyphyllum lusitanicum n. sp. et Cupressinocladus micromerum (HEER) n. comb. Ces plantes à caracteres xeromorphiques bien marqués, sont comparées avec d'autres semblab'les, en spécial avec celles du Jurassique supérieur de Y orkshire.

Introduction

'Ilhe material described here was collected at t'he old coaI mine (jf Cabo Mondego in Western Portugal, near Figueira da Foz. This mine is closed and, unfortunately, it is not possible to collect more material. 'Ilhe specimens we studied belong to an old collection, kept in the Geological Museum, «Instituto Superior 'Ilécnico» in Lisbon.

'l1he first important studies on portuguese Jurassic plants, including those of C8!bo Mondego, were made by HEER (1881), and later by SAPORTA (1894). TElXEffiA (1948) studied again all tihe specimens descri!bed by SAPORTA and some new ones. TEIXEffiA'S work is the last one concerning Jurassic plants from

(1) Projecto de InvesDigação LMG 1/2 do Centro de Estudos de Geolo­gia (IAC).

(2) Faculdade de Ciências, Rua Escola Politécnica, Lisboa-2.

20

this locality. This is a revision and a complementary study of some of these plants. Five species are described, three of whiClh are new:

Todites falciformis n. sp. Otozamites mundae (IMORRIS) Pterophyllum mondeguensis n. sp. Brachyphyllum lusitanicum n. sp. Cupressinocladus micromerum (HEER) n. comb.

However, tJhere are many poorly preserved fossils not descri­bed here; among others we could identify Nilssonia sp., Czeka­nowskia sp. and Baiera sp.

AlI the specimens show strong cuticles of strongly xero­morphic charac:ter. ln oue sample o'f rock with Cupressinocladus micromerum) there is also many fragments 01: Dasycladacean algae (Cylindroporella lusitanica RAMALHO, 1971 that is only known at the base of upper Oxfordian [= middle Lusi­tanian of CHOFFAT (MOUTERDE et al.) 1972, p. 93, tab. 3)].

Geology

The plants described here were found in the Iowermost Lusitanian (Oxfordian) CoaI complexo It overlies marine coastal CalIovian with ammonites. The CoaI complex at its base consis'ts of sandsltones and 180ft limes tones, w.hile above there are har'd compact limestones alternating with sandstones bearing Dinosaur lfooltprinJts (RUGET-'PERROT, 1961, p. 44-46 all'<l 49).

This CoaI compIex contains, according to CHOFFAT (in (RUGET-'PERROT, loco cit.) :

Paludina ribeiroi CHOFFAT Planol'bis sp. Corbula sp. Leda sp. Cyprina minor CHOFFAT I socardia striata d'ORB. Cyrena sp.

Perna foliacea CHOFFAT

Mytilus sp. Avicula sp. Ostrea cf. ermontiana THUR

Unio moussoni CHOFFAT

Unio ci. moussoni CHOFFAT

Unio veziani CHOFFAT

Unio mondeguensis CHOFFAT

Unio hermi CHOFFAT

Unio variabilis CHOFFAT

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'Dhis fauna shouId be revised. It may not have been found together. Some forms are quite typicaI of freshwater envi­ronments (riparian or fIuviatile), like Unio and Planorbis. However, other forms cIearIy suggest a Iow-salinity (Cyrena and Mytilus) or even marine environrnerrt (Cyprina and Avi­cula).

. Paleontology

Order ,F:J:LroALES Family Osmundaceae Genus Todites SEW ARD, 1900

Todites falciformis n. sp. (Text-<fig. 1, pI. It fig. 1-4)

? 1.911- Todites williamsoni (BRONG.); SEWARD, p. 667, pI. 2, fig. 27, 27a; pI. 4, fig. 57; pI. 7, fig. 15.

? 1933 - Todites (Cladophlebis) d. whitbiensis (BRONG.); SZE, p. 9, pI. 6, fig. 3-4.

? 1933 - Cladophlebis tingii SZE, p. 11, pI. 6, fig. 1-2.

Holotype: n° 61 (,sterile Ieaf) and n° 20 (tfertile leaf). Stratum typicum: CoaI complex, Oxfordian. Locus typicus: Cabo Mondego. Derivatio nominis: the specific name relates to the shape

of pinnules.

nIiAGNOSIS: leaves, as <far as known, wholly sterile or wolly fertile. Leaf bipilIlnate, witJh estimated width exceeding

22

8 cm, but prOlbrubly not much more. Main rachis smooth in upper part, not ribbed nor ehannelled hut finely striated, without !hairs or se ales ; pinna raehis similar. Pinnae, in upper part of the leruf, arising at an angle of about 60°. Pinna rachis rubout 1 mm broad, not ehannelled. Pinnae af nearly unilform widbh to near the apex, bhen tapering gradually.

,ln normal sterile leaves, pinnules eommonly arising at rig1ht angles to che raehis, the first alwaysborne on the basis­copie side, near the main raehis. Typieal size of pinnule 4 mm X 3 mm, Ibent forwards. Basal margin usually contraeted at the pinna rachis; upper margin usually slightly expanded. Lateral margins entire or denticulate near apex. Apex aeute. Pinnules usually separated hy gaps of 0,5 mm-1 mm. The shape df pinnules remains nearly uniform over three quarters ai the length of pinna and then C'hanges to a forward pointing aeute angled triangle. Lamina of pinnules cone ave below aml con­vex a:bove. llVIidritb arising very near basiseopie edge, veins inconspieuous; first braneh of veins arising irom base of midrib, forking twiee, next two pairs forked once; veins arising at an angle df about 35°-40°.

Ferlile leaf similar to sterile leaf, but with narrower and rounder pinnae, all pinnules ai very similar size and shape up to near pinna apex. Pinnules smaller than on sterile leaf and separated by wider gaps; shape rounded or oval, apex round; size typiealy 4 mm X 2 mm, placed at right angles to pinna rachis; margins entire, nwer lobed or dentticulate, sharply ref1exed 0,2 mm broad. Veins of fertile pinnules not observed. Sporangia albout 0,8 mm X 0,5 mm wide eovering wholly lower surtfaee. No evidenee Df hairs amang sporangia. Sporangia ovoid wibh thickened eells on topo Spores rounded, mean diameter 42p., range noted in 11 mesur,emenbs 33 p.-48 p.. Wall almos't smoobh but very faintly granular. Triradiate craek nearly as long as spore radius, finely marked without tlhiekened borders. Number of spores per sporangium estimated at 100.

FURJTHER REMARK!S: T. falciformis is represented by 16 sterile fragments and 3 fertile ones. Apart a few representa­tives of the apex ai a pinna :they are all very mueh alike, in the

A E

H

G

Text-fig. 1- Todites falcifo~mis n. sp.

A - Fragment of pinna of sterile leaf (holotype), X2. B-C - Sterile pinnules (holotype), X3. D - Fragment of fertile leaf near the apex (holotype), Xl. E - Detail of D, X3. F - Fertile pinnuies, under &ide, S'howing sporangia and

the margin, X20. G - Sporangia, XI00. H - $pores, X800.

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small size and in the shape of the pinnae and pinnules. The coaI substance o:f sterile pinnules is black, and quite opague in tmnsrers ar when observed under peJtroleum. The veins are only seen as more or less clear ridges. AIl tlhe sterile pinnules have a convex upper sunface, and alI the clearly seen fertille ones have a well marked margino

DJJSCUSSION: T. falciformis resemble the numerous speci­mens of T. williamsoni, T. whitbiensÍ8, T. roesserti and T. goep­pertianus, cited by HARRIS (1961, p. 87-88) in a general way. But most of tlhes-e have larger and often diifferently shaped sterile pinnules, an<} usuaIly larger fertile ones. '!bus only the smallest of some of tlhese resemible our specimens and we con­elude that t'he present material as a whole is distinct. However a few specimens from other lands do resemlble closely the por­tuguese ones bu:t unifortunaJtely they are just a few fragments. These aro T. williamsoni of 'SEWARD (1911, p. 667, pI. 2, fig. 27--27a; pI. 7, fig. 15) of the Kimmeridgian from Sutherland in E. IScotland. These are nhree sterile leaf fragments with smaIl pointed pinnules much like the pres-ent specimens (text-fig. 1, fig. A-C). Other maJterial is from Szechuan, China (SZE, 1933, p. 9-10): two small fertile fragments, one of which figured (pI. 6, fig. 3-4), and there are also similar sterile fragments named Cladophlebis tingii (SZE, 1933, p. 11, pI. 6, fig: 1~2). The fertile pinnules agree wit:h T. falciformis in size and shap€ rund apparently so in having a narrow margin, thOughSzEdoes not refer to this. As far as we know no other Todites of thc williamsoni group has such a margino

. Order BiENiNE'lTI'ITAlLES Family incerta sedis Qenus Otozamites BRAUN, 1842

Otozamites mundae (MORRIS, 1850) (Text-fig. 2-4, pI. II-III, f~g. 5-10)

All the following referenoes concem portuguese specimens:

1850- Zamites gramineus varo mundae MORRIS, p. 199, pI. XXVI, fig. 7a-7b.

D

Text-fig. 2 - Otozamites mundae (MORRIS).

A - Fragment of leaf near the apex, Xl. B - Basal region of pinnae in middle region af leaf showing the auricle and the veins, X4. C - Apex of two continuous pinnae and its veins, X4. D - Basal region of pinnae in upper part of leaf, X5.

E - Terminal pinna, X8.

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1881 - Otozamites ribeiroanus HEER, p. 9, pI. IX, fig. 1-9. 1881 - Otozamites angustifoli:us HEER, p. 9-10, pI. IX, fig. 10-13. 1930 - Otozamites ribeiroanus HEER; THOMAS,p. 398, text-fig. 7. 1948 - Otozamites mundae (MORRIS); TEIXEIRA, p. 23, pI. VIII,

fig. 1-5; pI. IX, fig. 1-7; pI. XI, fig. 5. 1972 - Otozamites natividadei TEIXEIRA, p. 121, pI. I-H. 1972- Otozamites mundae ('MORRIS); TEIXEIRA, p. 122, pI. III.

EMENDEID DIAGNOSIS: leaf of unknown length. Width of well developed leaf typically 5 cm in middle but widest 8 cm and narrowest about 2 cm. Wid1Jh in middle region uniform but Ieaf tapering towards apex and base. Pinnae in middle region arising aJt aJIlaJIlgle 0f 70°-80°, bui less towards apex, approa­clhing 90° towards Ieruf base. Pinna typically 30 mm X 4 mm, but narrower as well as shorter near apex; some leaves, or lower parts of some leaves, with pinnae up to 26 mm X 12 mm. ln some leaves, pimlJae in contact or sligthly overlapping but in otlher sepamted by gaJPs of 1-2 mm. Au.ricle modrerately developpeid in :Iillddle region of leaf, rounded enlarging the pinna by 1-2 'mm, oDten over1aJpping mi~ line of raJchis, hut in others leaV'es feebly developped. At apex, some leaves with a broadly wiangular terminal pinna with a rounlded apex, hut other learves with uppeI"Inost pinn8Je narrow.

Normal pinnae straigth to slig1htly {alcate apex rounded or OIbtuse or acute but Ibroadest pinnae of oval shape. Pinna surtface !flat and margin not curved dounwards. Veins arising from proximal ih.alf Df pinna base and radiating into the auricle am.d rest of pinna. VeIDs slender ocurring at a concentration of about 55 per cm in pinnae Df middle of the leaf, and 40 per cm in pinnae near the apex, bramchting al alI leveIs, Margin of pÍmae flaJt 'am.~ u'llspeciJalis€ld, substalIlC'e of lamina thick. Rachis known to exceed 3,5 mm in width in lower paJrt of lamina butbasal part not known. Rachis showing slight longitudinal striae but no wrinkles, wi1Jhout hairs.

Cuticle about 6 p. thick (measured in folds). Upper cuti­cle witihout stomata but, sometimes, with a few trichomes. Epi­dermal cells rectangular, in rows. Walls strongly sinuous, sur­face flaJt, wfthout papiUae. Lower cuticle divid'ed into two regions, the main part and the margino Main part showing

o o A - -õ o -

o n - 00 ~ O O - O

"U O O -o -O O 00 -o

o O-o

Text...<fig. 3 - Otozamites mundae (MORRIS).

A - One square mm of lower epidennis, showing distribution andorientation of sromata (-), and thedistribution of trichome bases (o). B - Stomata view by inside, X800. C - Stomata ano trichome in lower epidennis, X200. D - Tri-

chome base in upper epidennis, X800. E - Upper epidennis cells, X800.

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stomata at aconcentration aí aJbout 65 per SJq. mm. Stomata evenly distributed over Wlhole lower surface of the maiÍl patt in some leaves, and veins indistinguishable, but in other leaves veins marked by one or two rows aí cells witJhout stomata. IDpídermal cells varying in size, more ar less recttamgular with strong rounded silnuous folds, without papiUae.

Text-1iig. 4-0tozamites mundae (MORRIS). Stoma showing mouth of stomatal pit, X800.

Stomata always transversely oriented, aíten irregularly placed in a broaJd band and then not forming definire rows. Stomata and subsidiary cells sunken in a large oval pit roofed by epideTmal celIs. Subsidiary celIs ralther smalI. Guard celIs with welI develIoped crescent shaped thickening not overhung by any papiUa. Sta.maJtal pit coveI"led by about ten epid~,rmal celIs whiClh form a dome-shaped roof wi1Jh a rounded or more or less rectangular hole. Margins of roofing celIs 'at first sinuous, but Ibecoming straighter and thicker near the, hole. Role not situated over the stoma but at end near raC'his, 'while stoma is at distal end.

Trichome bases a;b'llndant OTI lower side of some leaves but tare ou ot!hers. If numerous, distributed everywhere o?- and between veins. Each base usualIy consists of a single, more or

29

less rounded celI with a strongly bhickened sur!face; margins ()f ordinary epidermal celIs running under trichome base. Cen­tral r,egion, where hair is presumed to nave stood, sharply marked run!d only thinly ourtinised. Free part of trichome mis­sing in cuticle prepar8ltions; occ8lsionalIy two trichome bases :occurring in contacto

Marginal region af lower side widely. different from the rest, and very mudh like the upper si de in structure. Stomata a:bsent, celIs almost unirform wibhout papillae, lateral walls strongly marked, showing strong rounded sinuosities.

FURTHER REMAlRKiS: nearly alI specimens look similar ,except at the leaJf apex, ·but ther,e are a ifew smalI leaves, and there are also a few specimens with short broad pinnae; one ,af these, as we regard it, is nhe type of TEIXEIRA'S Otozamites natividadei. This was a single specimen, but there are a few of intermediate in formo Aftter hesitation we identified O. nativi­,dadei wiúh O. mundae hecause: 1) vhe two are associated, 2) the veins look just the sarne, 3) the cuticles are identical, the last being the main reason.

Cuticles are fairly thick and moderately well preserved but often pitted by prints of crystals (pyrite?), specially near :stomata.

• We still need to learn about nhe length of a normal leaf .and about the petiole. I

nISCUS'SIOiN: figures resembling. O. mundae in gene­ral form are numerous, and he spedmens range from lower Liassic to lower Crebaceous. '.Dhey have been described under lhe names O. becheiJ O. graphicusJ O. brevifoliusJ O. gra­mineus including O. goldiaeiJ O. sewardi and O. pterophylloides) O. linearis and O. bucklandi. The cuticle of mos't of these is unknown but it has been described in O. graphicus and O. gra­mineus from Yorkshire, O. pterophylloides from Bornholm and O. bechei from the Lower Liassic of England. The best known {)f 1!hese are O. graphicus and O. gramineus from Yorkshire. The smallest forms of O. graphicus (IlARRIS, 1969, text-fig. 6, fig. C-E) have pinnae of very similar size and shape. However

30

the cuticle is v'ery different. The stomata are similar but: 1) fuey are in weIl defined rows, 2) the veins are very easy to see, 3) the epidermal cells have papillae, 4) there is no t:d~ chome bases. O. gramineus nave also pinnae ofsimilar size and shape, but 1) the veins are not so numerous, 2) cuticles are very thin (1 fL), 3) stomata are in narrow bands separated by slightly wider ibands along the veins, 4) the epidermal cells have' papillae. O. pterophylloides have pinnae of very simi­lar size and shape. The stomata are very similar in shape, but this is the only information we have a:bout the cuticle (FLORIN, 1931, p. 510, 't.af. 56, fig. 2).

Genus Pterophyllum BRONGNIART, 1828

pterophyJlum mondeguensis n. sp . . (Text-fig. 5-6, pI. IV-V, fig. 11-12)

Holotype: n° 45. Btratum typicum: Coalcomplex, OXlfordian. Locus typicus: Cabo Mondego. Derivatio nominis: the speciific name relates to t,he type

locality.

iD'IAGNOSIS: form and size of leaf unlmown. Rachis up to 3 mm broad in middle region of leaf. Lamina about 12 cm broad. Pinnae arising ifrom lateral margins of rachis, at an angle af rubout 80°, separated by gaps of 2-3 mm broad. Pinnae 2-4mm wi~e at base and 2-3,5 mm broad in mi!ddle region and 6 cm in length. Apex acute. Base of pitIl1lJae decurrent. Edge of pinnae parallel with a well developped margin abotlt 0,2-0,3 mm broad. Surface flat. Veins typicaIly 6 per pinna, paraIlel, very rarely ibranched.

Upper cuticle without stomata but with rare trichome bases, composed of polygonal ceIls arranged in longitudinal rows. VeÍlIls not dis'tinct. WaIls of epideI'lffial ceIls finely sinuous, not conspicuously marked. No prupillae presenlt.

Lower cuticQe di.vided into two distinct portions: marginal regions,about 0,3 mm broad, similar to upper cuti:cle and main

E

: : ~

Text-fig. 5 -Pterophyllum mondeguensis n. 1Sp.

A-B - Basal region of pinna in middle region of leaf(B-holotype), X2. C - Apex of pinna showing the margin and the veins (holotype), X2. D - Upper epidermis, X200. E - Distribution 'arrd orientation of stomata, of trichomebases and showing the margin, X30. F - Upper epidermal eells, X800. G - Lower epi'<iermi~ showing stomata, triohome bases and epidermaI ceHs with 'papi1lae, X200.

32

parit with stomata. Stomatal regúon 'showing untformiy distri­buted stomata. Veins not distinct. Epidermal 'Cena polygonal or rectangular, with sinuous walls like those of upper cuticle, but some sihowing a well defined solid papiHa. Stomata not nume­rous, irregularly sca:btered and ndt in longitudinal rows. Aper­ture variably oriented, transverse, ablique but moSt often lon­gitudinal. SU1bsidiary cells smaller than guard cells. Stomatal ap~rture somewhat sunken. Guard cell thickenings well deve­lopped. Trichome bases consisting of one, or two or, of four epidermaJ cells usually showing a large thinly cutinised round area occupying most of the surface and considered to be the the base of a singlel'tubular hafr. Free part not observed.

FURTHER REIMARKS: P. mondeguensis is represented by 3 similar ifragments of leaves in the sarne sla!b of rock. 'l'hey are;very typical with their long and narrow pinnae, with decur­rent base. The margin is very easy to see, and the apex is acute.

i Thecuticle is not very well preserved, and the lower one was, for some reason, often missing from preparations that gave fairly goad Uipper cutides. However every pinna does show its marginal zone clearly, whether the lower cuticle is presBr­ve:i or noto

1)ISCUSSION: there are many upper Triassic and Liassic leaves rather like P. mondeguensis in appearance but the thicke­ned margin is unusual.

By middle Jurassic, Pterophyllum leaves become scarce. The most sÍlmilar is P. fossum from Yorkshire, that agrees in general appearance and in its thickened margins. However in P. fossumrachis is covered with hairs, but none were seen in P. mondeguensis. The stomata are similar hut not mostly lon­gitudinal, and it has unicellular hair bases whereas P. mon­deguensis has 1, 2 or 4 basal censo P. fossum has much less sinuous walls, indeed they are almost straight on the upper side. The other Yorkshire species are less similar and lack the thick margino

.~.~

B

Text-fig. 6 - Pterophyllum mondeguensis n. sp.

A - Trichome ba'S'e with two ceUs, and épilderma.I ee1Is in Iower epi'Clermis, X800. B - Stoma in Iower epi­

dermis, ~800.

33

P. mondeguensis is also v:ery similar in size and shape of pinnae to P. augustum, butthe cuticle of this species is not well known and it is of Liassic age.

34

Order C01\WER.A!LffiS Family Araucariaceae Form-genus Brachyphyllum LIND. & HUT., 1936

BrachyphyJlum Jusitanicum n. sp. (Text-fig. 7-8, pI. V, fig. 13-14)

H olotype: n° 23 A. Stratum typicum. CoaI complex, Oxfordian. Locus typicus: Cabo Mondego. Derivatio nominis: the specific name relates to 'Ilhe origi­

nal name o~ Portugal.

DiAGNOSIS: main axis not knoWlIl. Bvanches straigh't, ari­si,ng at ang}es of aboUlt 10°. Leaves arranged in aspiraI of pro­bably two-fjlfths phyllotaxis. Leaves 81bout 2 mm long and 2 mm broad on small branches. Apex of leaJf always overlapping the top of its own leaIÍ base cushion. Leaf ma:rgins entire forming a sharp edge. Apex round or slightly obtuse. No midrib. Leaves pressed closely one another and to the stern.

Cuticle thick, 12 p. in the abaxial cutic1e but IDuch less in adaxial one. Stomata on lower surface tending to form longi-tud:'nal rows, but often widely spaoed in their rows with sto­mata out of line. Stomatal orientation not known. Stomatal pit deep, round or polygonal in surface view. Subsidiary cells for­ming a round group of 4-6 cells but mostly 5 cells. Each subsi­diary cell w,ith a solid papilla oveI1hanging the bottom of sto­mataI pit. Encircling cells forming a complete ring but quite unspecialized. Epidermal cells polygonal, arranged in longitu­dinal rows without àny papiUae. Walls of epidermal cells not sinuous, strongly cutinized. Trichom€s absent. Leaf margin scarious with elongated cells.

Upper cubicle not well known. Much thinner t<han lower one, but apparently similar.

FURTHER REMARKS: Brachyphyllum lusitanicum IS

represented by two small fragments. The preservation is good, and preparation Df lower cuticle were excellent, however the upper cutic1e is"rather dif;ficult to obtain.

35

nISOUHSION: Brachyphyllum lusitanicum is very similar in general view with B. crucis and Pagiophyllum connivens KENDALL [= P. kurrii (SCHIMPER), after oral information of T. HARRIS].

B. crucis differs from B. lusitanicum as follows: the phyl­lotaxis is 3/8, against 2/5 in B. lusitanicum; leaves in B. crucis are more elongate; the cuticle is thicker in B. lusitanicum (12 fl against 6 p. ); the stomata are less numerous in B. crucis and

. . . • • e ••••

• . . ... • : . · .. • · . · ..

c

Text-fig. 7 - Brachyphyllum lusitanicum n. sp.

A - Fragment of shoot showing the 'position of leaves, X3. B - Abaxial cuticle with sC3!rious margin of le3!f (holotype); X200. C - Distribution of

stomata, X30. D -Abaxial cuticle (holotype), X200.

do not form so pertfeçt longitudinal rows as in B. lusitanicum J'

the papillae of su'bsidiary cells in B. crucis never overhang the bottom of stomatal pit and in B. lusitanicum the papillae some­times almost roof all the pito

Pagiophyllum connivens KENDALL has shoots that look quite different as its leaves are longer and diverge from the stern, trupering to sharp points. But their cutilCles are similar in their longitudinal rows of stomata and in their papillae con­verging over the stomatal pito ln P. connivens the adaxial cuticle is exposed and thick like the abaX!ial one.

/

Test-fig. 8 - Brachyphyllum lusitanicum n. sp.

Abaxi'aI cutioIe with stoma, ,epidermaI edIs, encircli'1lg cetl~, subsidiary eells a'1ld 'Papillae, X800.

3T

Family Cupressaceae Form-genus Cupressinocladus SEWARD) 1919

Cupressinocladus micromerum (HEER, 1881) (Text-fig. 9-10, pI. VI, fig. 15)

All the following references concern portuguese specimens:

1881-Blfachyphyllum micromerum HBER, p. 10, pI. X, fig. 1-3, 1b. 1894 - Palaeocyparis lusitanica '8APORTA, p. 54, 'pI. V, fig. 1-3; est. VIII,

fig. 12; est. IX, fig. 1-3. 1894-Brachyphyllum microcladum SAPORTA, p. 51, pl. IV, fig. 16a;

pI. V, fig. 6-8, 9c, 11. . 1894 - Brachyphyllum majusculum SAPORTA, p. 51, pt XII, fig. 4-5. 1894- Thuyites pulchelliformis SAPORTA, p. 55, pl. II, fig. 7; pl. IV,

fig. 21; pI. V, fig. 17-22; pI. IX, fig. 5, 6b; pl. XII, fig. 6. 1894- Thuyites leptocladus SAPORTA, p. 55, pI. V, fig. 12-16. 1894 - Widdringtonites debilis SAPORTA, p. 54, pI. V, fig. la, 9d. 1894 - Sphenolepidium choffati SAPORTA, p. 53, pI. V, fig. 5, 10. 1948 - Cyparissidium micromérum (HEER); TEIXEIRA, P. 24, 31, pl. X,

fig. 4-5; pI. X'I, fig. 1-3; pI. X'llI, fig. 7-22.

EMEiNiDillID DIAGNOSIS: large lateral branch systems shed intacto Main axis often 6 mm thick but lateral ones down to 3 mm thick. Shoots richly branched. Primary branches more or less alternate, forming angles of 60°.80°. Secondary branches alternating mostly at 40°-50°. Leaves persistent, on smalllest branClhes strictly in decussate pairs. ln larger branches leaves in alternating whorls of three. ln ultima te branches leaves short Ibut in main branches leaves with long decurrent bases. Leaves in all branches projecting evenly around the stern. Leaf margins entire, apex round or obtuse. No midrib visible. Leaves overlapping one another, those aí the main axis in particular.

Aibaxial cuticle very1:!hick (more or less 9 ri ), but adaxial cuticle much less. Stomata of abaxial suI'IÍace in longitudinal rows of one stoma wide. Stomatal pit deep, rounded or poly­gonal. Subsidiary cells forming a rounded group of 4-6, some­times of different shrupe rold size. Some subsildiary cells bea­ring a solid papilla overhanging the bottom of the stomatal pit

38

•• • • . . . .. . • •

c Text-d'ig. 9 - Cupressinocladus micromerum (HEER).

A - Main axilS with a branclland decussate leaves, X3. B - Termina!! region of a shoot, showing the branching and decussate leaves, X3. C - Distribution of stomam, X30. D - Fragment of abaxiaI cuticle with stomata antd ep1dermal

cells with papinae, X200.

but other subsidiary cells wilbh no papillae. Papillae arising inside the stomatal pit, well below its top, sometimes pointing upward and reaching epidermal surface. Subsidiary cells outer

39

cuticle sloping downwards the pit, outer part thick, inner part usually tJhinner than any other part of the cutide, pit round, with a very conspicuous ring of cuticle. Guard cells very thinly outinised rund rarely visible. Encirding cells unspecialized and never fo:rm.ing a complete ring.

Epide:rm.al cells polygonal with rou'I}ld~d cOmers someti­me3 tending to form obscure longitudinal rows. Some epider­mal cells with a solid papilla. Anrtidinal walls of epi!dermal cells bo1Jh bro~d an'd prominel!l;t, not sinuo'll's. mnermost edge often slightly expanded. Hypodermis not observed, if present not strongly ,cutinised. Trichome bases absent.

Upper cuticle not well preserved, muchthinner than lower one, hut apparently similar to abaxial cuticle. Stomata present.

Leaf margins forming a sharp edge but not scarious.

FURTHER RlEiMARKS: Gupressinocladus micromerum is a frequent spedes in Oxfordian beds of C~bo Mondego, and also i:n Forte Constantino, Dois Portos, Cabanas de Torres, Vale de Gato and Pederneira.

The specimen figured here and one figured by TEIXEIRA

(1948, pI. XI, fig. 1) are magnificent and clearly where shed intacto

TEIXEIRA made no statement about the phyllotaxis and his figures certainly do _ not shaw it clearly. However transfers make it plain beyond doubt, ànd even the exposed su:r'lface is convincing when carefully examined. TEIXEIRA figured asso­c:ated cones from Pederneira (Nazaré). They are on shoots with leaves like G. micromerum. Cones are oval in shape and about 15 mm X 9 mm. The scales seem to be simple and poin­ted and, iram the inclination of the rows to the rig.ht and left, they suggest alternating whorls of four. 'l'hese cones are consis­tent with classification in the Gupressaceae) but the scales also might be the persistent scales of a conirfer like Hirme­riella; thi:s can only -be settled by further studies.

The cuticle was diJfficult to 'Prepare, perhaps because it is very thick. Many l'eaves required 4-5 days in stTong nitric acid + potassium clorate for oxidation, and then cuticles more

Text-Ifig. 10- Cupressinocladus micromerum (íHEER).

A - Stoma in abaxial cuticle, showing subsidiary ceUs divided in two regions and tJhe papHlae, X800. B - Transversal section (imaginary) through the black line ln the stoma of fig. A, X800. C - Stoma in abaxia,l cutic1e, X800.

41

or less showed its epidermal cells and stomata. However satis­factory prepara:tions were finally obtained.

'Dhe interpretation of the structure of stomata is difficult. It seems that each subsidiary cell had a thin inner region shar­ply marked from a thick outer one (text-fig. 10, fig. A-B). An alternative interpretation is that there are two separated cells, ihe thin iIllIler one being subsidiary, the thick outer one, encircling.

D]SCUS'SION; C. micromerum was compared by TEIXEIRA

(1948, p. 32) to Cyparissidium gracile but, in general, HEER'S figures suggest spiralIy arranged leaves. C. micromerum is more like C. ramonensis from the Jurassic of Makhtesh Ramon in southern Israel (CHALONER & LoRCH, 1960).

Ultimate shoots of C. ramonensis di~fer from those of C. micromerum in their longer and more pointed leaves. Larger stems are unknown. The cuticle of C. ramonensis shows thinner and less prominent walled celIs in muoh more conspicuous lon­gitudinal rows. The stomata seem r81t;her similar; oue of the figures (pI. 36, fig. 7) shows subsidiary celIs with a thin inner region and a thick outer one. The pit has similar papillae. However C. ramonensis has a welI marked scarious leaf mar­gin, never seen in C. micromerum.

Climatic implications of, the Cabo Mondego Flora

The five species, of which just two (Otozamites mundae and Cupressinocladus micromerum) are abundant in the CoaI complex df Cabo Mondego, are too poor1y represented to allow any definite concIusion. Nevertheless it is tempting to establish some comparisons wi\th the most similar middle Jurassic (Bajocian and lower Bathonian) species of Yorkshire.

We can ascertain that the xeromorphic charact,ers in all portuguese species are much more clear1y marked.

Todites falciformis has smaller pinnules than T. william­soni. The lamina is very thick, its under surface holIow and the fertile pinnules have a thickened margino

Otozamites mundae, t:hough it looks like O. graphicus and

Text-:fig. 10- Cupressinocladus micromerum (iHEER).

A - Stoma in abaxial cutide, showing subsidiary ee1Is divided in two regions and t1he papiMae, X800. B - Transversal section (irnaginary) through the black line ln the storna af fig. A, X800. C - Storna in abaxial cuticle, X800.

41

or less Slhowed its epidermal cells and stomata. However satis­factory prepara:tions were finally obtained.

'Dhe interpretation of the structure of stomata is difficult. It seems that each subsidiary cell had a thin inner region shar­ply marked from a thick outer one (text-fig. 10, fig. A-B). An alternative interpretation is that there are two separated cells, the thin iTIlller one 'being subsidiary, lhe thick outer one, encircling.

D]SCUS'SION: C. micromerum was compared by TElXEffiA

(1948, p. 32) to Cyparissidium gracile but, in general, HEER'S figures suggest spirally arranged leaves. C. micromerum is more like C. ramonensis from the Jurassic of Makhtesh Ramon in southern Israel (GHALONER & LoRCH, 1960).

Ultimate shoots of C. ramonensis di:IJfer from those of C. micromerum in their longer and more pointed leaves. Larger stems are unknown. The cuticle of C. ramonensis shows thinner and less prominent walled cells in much more conspicuous lon­gitudinal rows. 'The stomata seem r8Jeher similar; one of the figures ('PI. 36, fig. 7) shows subsidiary cells with a thin inner region and a thick outer one. The pit has similar papillae. However C. ramonensis has a well marked scarious leaf mar­gin, never seen in C. micromerum.

\

Climatic implications of the Cabo Mond'ego Flora

The five species, of which just two (Otozamites mundae· and Cupressinocladus micromerum) are abundant in the CoaI complex df Cabo Mondego, are too poorly represented to allow any definite conclusion. Nevertheless it is tempting to establish some comparisons with the most similar middle J urassic (Bajocian and lower Bathonian) species of Yorkshire.

We can ascertain that the xeromorphic characters in alI portuguese species are much more clearly marked.

Todites falciformis has smaller pinnules than T. william­soni. The lamina is very thick, its under surface hollow and the fertile pinnules have a thickened margino

Otozamites mundae) though it looks like O. graphicus and

42

O. gramineus~ has a far thicker cuticle and very hearvily pro­tected stomata.

Pterophyllum mondeguensis has a lamina thick enough for the stomata to be evenly distributed and not avoiding the veins, am.d it has a marginal region on the lower side without stomata. It is rather like P. fos8Um~ the most xeromorphic of the Yorkshire species.

Brachyphyllum lusitanicum has very closely appressed lea­ve3. The exposed cuticle is 12 p. thick, twice as thicker as in the most similar Yorkshire species, B. crucis.

There is no Cupressinocladus in Yorkshire but, after T. HARRIS, there is no Yorkshire conifer with such a thick cu ti­cle or one so resistant to maceration.

Acknowledgements

This work has been suggested by Prof. C. TEIXEIRA (Facul­dade de Ciências, Universidade de Lisboa). The specimens stu­died here, kept in the geological Museum of the «Instituto Superior Técnico», were kindly loaned by Prof. D. THADEU.

We have studied the specimens with very kind help of Prof. T. HARRIS and also of Dr. P. BARNARD (Reading Univesity).

Manuscript has been critically read :by Prof. M. T. ANTUNES (Universidade Nova de Lisboa).

The Dasicladacean alga, Cylindroporella lusitanica~ has been identified by Dr. M. RAMALHO (Serviços Geológicos).

'To all, our best thanks.

43

Bibliography

CHALONER, W. G. & LORCH, J. (1960) - An opposite-Ieaved Conifer from the Jurassic of Israel. Palaeont., VoI. 2, parto 2, p. 236-242, 1 pI. London.

FLORIN, R. (1931) - Untersuchungen zur staumergeschichte der Coni­ferales und CQrdaitales. Kung. Sv. Veto Hand. Bd. 10, n° 1, p. 3-588. Stocholm.

- (1958) - On jurassic lTaxads and Conifers from Norrh-western Europe and Eastern Greenland. Aeta H arti Ber giani, bd. 17, n° 10, p. 257-402, 56 pI. Uppsala.

FRENGUELLI, J. (1947) - E1 genero CIadaphlebis e sus representantes en la Argentina. An. Mus. La PIata, (n. s.) Paleont. (B) n° 2, P. 1-74, 12 pI. La Plata.

HARRIS, T. M. (1961) - The Yorkshire Jurassic Flora, I, Thallaphyta­-Pteridaphyta. Brit. Mus. (Nat. Rist.), 212 p. London.

- (1964) - The YorkShire Jurassic Flora, II, Caytaniales, Cycadales Pteridasperms. Brit. Mus. (Nat. Rist.), 191 p., 1 pI. London.

- (1968) -The Yorkshire Jurassic Flora, III, Bennettitales. Brit. Mus. (Nat. Rist.), 186 p. 7 pI. LondoIl.

- (1969) - Naming a fossil Conifer. J. SEN Mem. Cammittee and 13]t. Saco Bengal. p. 243-252. Cacutta.

REER, O. (1881) - Contributions a la Flore fossile du Portugal. Sel. Trav. GeoI. Part. p. 'l-51, pI. A-XXVII'!. Lisboa.

KENDALL, M. W. (1947) - On five species aI Braehyphyllum from the Jurassic of Yorks'hire and Wilts'hire. Ann. Mag. Nat. Hist. ser. 11, n° 14, p. 225-251. London. \ .

- (1948) -On six species af Pagiophyllum from the Jurassic of Yorkshire and Southern England. Ann. Mag. Nat. Hist., ser. 12, n° 1, p. 73-108. London.

- (1952) - Some Conifers from the Jurassic of England. Ann Mag. Nat. Hist. ser. 12, n° 5, p. 583-593. London.

MORRIS, J. (1850) - Remarks on Zamites gramineus. Quart. Jaurn. GeaI. Soe. Londan, nO 6, p. 199, 1 pI. London.

MOUTERDE, R. et aI. (1972) - Le Jurassique du Portugal. Esquisse stratigraphique et zonale. BoI. Soco GeaI. Part., voI. XVIII, fasc. I, p. 73-104, 3 tab. Lisboa.

RACIBORSKI, M. (1894) - Flora kopalna ogniotrwa1ych glinek kra­kows'kich. Czesc L Rodnimvce (Archaegoniatae). Pam Matprzyr. Akad. Um., 18, p. 143-243, pI. 6-27. Krak(jw.

RAMALHO,M. M. (1971) - Cylindroporella lusitanica n. sp., une nou­velle Dasyc1adacée du Jurassique supérieur portugais. BoI. Saco GeaI. Part., voI. XVIII, fase. II-lN, p. 123-127, 2 PI. Lisboa.

44

RUGET-PERROT, C. (1961) - Études stratigraphiques sur le Dogger et le MaIm inférieur du Portugal au Nord du Tage. Mem. Servo GeaI. Port., (n. s.) n° 7, p. 13-197, pI. I-XI. Lisboa.

SAPORTA, M. de (1894) - Flore fossile du Portugal. Nouvelles contribu­tions à la Flore Mesozoique. Dir. Trav. Géol. Porto 280 p., 40 pI. 'Lisboa.

SCHIMPER, W. P. (1869-74) -Traité de Paléontologie végétale, ou la flore du monde primitif dans ses rapports avec formations géologi­ques et la flore du monde actueI. 4 voI., Atlas 53 pI. Paris.

SEWARD, A. C. (1911) - The Jurassic flora of Sutherland. Trans. Roy. Soe. Edirrb. voI. 47,p. 643-709, pI. 1-10. Edill'burg.

- (1919) - Fossil plaÍlts. 4 voI. Cambridge. , SZE, H. C. (1933) - Fossiles pflanzen ausShensi, Szechuan .und Kuci­

chC1w. Palaeont. Sinica, 1-3, p. 1-33, pI. 1-6. Peking. TEIXEffiA, C. (1948) ---, Flora Mesozoica portuguesa, I. Mem. Serv.

GeaI. Porto P. 7-118, pI. I-XIJI. Lisboa. - (1972) - Otozamites du Lusitanien du Cap Mondego au Portugal.

BoI. Soe. GeaI. Port., voI. XVIII, p. 121-122, pI. I-III. Lisboa. THOMAS, H. (1930) - Further observations on rhe cuticle structure of

Mesozolc cycadean fronds. louro Linn. Soe. Lond., Botany, voL XLVI'lI, n° 323, p. 389-415, 2 pI. London .

. " ".

I

ExpIanation of pIares

Plate 'I - Todites falciformis n. sp.

1 - S terile pinnules, X2,5. 2 - Sterile pinmiles, holotype, X2,5. 3 - Fragment of fertile leaf, holotype, X1,2. 4 - Sterile pinnules, X3.

Plate II - Otozamites.·mundae (MORRIS) IR

5, 6; 7 - Fragmentsof leaves. 5, X2. 6, Xl. 7, XO, 8.

PIa te III - Otozamites mundae (MORRIS)

45

8 - Slab of rock with numerous fragments of leaves, XO,5. 9 - Type specimen of TEIXEIRA's Otozamites natividadei, XO,8.

10 - Pinnae with acute apex and auric1e well developped, Xl.

Plate IV - Pterophyllum. mondeguensis n. sp.

11 - Slab of rock with fmgments of 3 leaves. H - Holotype. XO,8.

Plate V - Pterophyllum mondeguensis n. sp. and Brachyphyllum lusita­nicum n. sp.

12 - Pterophyllum mondeguensis n. sp., holotype. See the decurent base, the veins and the margin of pinnae, X1,5.

13 - 14 - Brachyphyllum lusitanicum n. sp. 13 - Holotype, X1,5. 14, X2.

PIate VI - Cupressinocladus mzcromerum (HEER), XO,8.

PI. I

PI. II

PI. III

PI. V

PI. VI