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ELSEVIER Review of Palaeobotany and Palynology 105 (1999) 201–235

Morphology and ultrastructure of elater-bearing pollen fromthe Albian to Cenomanian of Brazil and Ecuador:

implications for botanical affinity

Rodolfo Dino a,b,Ł, David T. Pocknall c, Mary E. Dettmann d

a Petrobras, Cenpes-Divex-Sebipe, Cid. Univ., Ilha do Fundao, 21949-900 Rio de Janeiro, Brazilb UERJ, Univ. do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, Brazil

c Amoco Corporation, Exploration and Production Technology Group, PO Box 3092, Houston, TX 77253, USAd Department of Botany, University of Queensland, Brisbane, Qld. 4072, Australia

Received 27 April 1998; revised version received 28 September 1998; accepted 23 October 1998

Abstract

The morphological range of elaterate pollen grains is reassessed on the basis of detailed light, scanning electron

and transmission electron microscope analyses of representatives from upper Albian–Cenomanian sections in Brazil

and Ecuador. Included in the elaterate complex are Alaticolpites, Elaterocolpites, Elateroplicites, Elateropollenites,

Elaterosporites, Galeacornea, Pentapsis, Regalipollenites, Senegalosporites and Sofrepites. All possess elater-like protu-

berances, but are otherwise morphologically disparate. Ultrastructural analyses of three taxa, Elateroplicites africaensis, Elaterosporites klaszii and Sofrepites legouxiae, reveals granular-alveolate ektexine and wall organization comparable to

that of gnetalean pollen and to fossil Equisetosporites= Ephedripites. A correlation exists between diversity=frequency

levels of Elaterates and successive events in opening of the northern part of the South Atlantic Ocean. This is interpreted

to reflect rapid diversification of the gnetalean sources of elaterate pollen in response to climatic perturbations associated

with opening and enlargement of this ocean. The introduction and diversification of Elaterates coincides with early

phases of angiosperm diversification, whereas extinction of the Elaterates-producing gnetalean group at the close of the

Cenomanian heralded the rise to dominance of angiosperms in low latitudinal areas fringing the northern South Atlantic.

© 1999 Elsevier Science B.V. All rights reserved.

Keywords: pollen; ultrastructure; gnetalean; mid-Cretaceous; Brazil; Ecuador

1. Introduction

The idea that part of northern South Americaand northern Africa supported tropical vegetation inCretaceous times was first postulated in palynologi-

Ł Corresponding author. Fax: C55-21-2803318;

E-mail: [email protected]

cal literature during the late 1960’s by Boltenhagen(1967), Jardiné (1967), and Brenner (1968). In the1970’s new data in support of this, including somefrom several African countries, were provided byJardiné et al. (1972, 1974a,b), Herngreen (1973a,b,

1974, 1975a,b), Brenner (1976), Vakhrameev (1978)and Srivastava (1978, 1981, 1994). Subsequently, inrecognition of the importance of the palynological

0034-6667/99/$ – see front matter © 1999 Elsevier Science B.V. All rights reserved.

P I I : S 0 0 3 4 - 6 6 6 7 ( 9 8 ) 0 0 0 7 6 - 1

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202 R. Dino et al. / Review of Palaeobotany and Palynology 105 (1999) 201–235

data to our understanding of climatic mechanismsthat operated during opening of the South AtlanticOcean, Herngreen and Chlonova (1981) defined theWest Africa–South America (WASA) province for

pre-Albian Cretaceous times and the Africa–SouthAmerica (ASA) province for Albian–Cenomaniantimes. These provinces, now referred to as pre-Albian, Early Cretaceous Dicheiropollis etruscus= Afropollis province, and Albian–Cenomanian Elater-ates province, respectively (Herngreen et al., 1996),occur within a few degrees latitude of the postulatedpalaeoequator, and are recognized in several SouthAmerican countries (Brazil, Colombia, Ecuador,Peru, Surinam, Venezuela), African countries (Alge-ria, Angola, Congo, Egypt, Gabon, Guinea-Bissau,Ivory Coast, Libya, Mali, Morocco, Niger, Nigeria,Senegal, Sudan, Zaire), the Middle East (Israel, Iraq,Kuwait, Saudi Arabia), Bahama Islands, southernAlps, westernmost China and Papua-New Guinea.

The Albian–Cenomanian Elaterates province hasa unique palynoflora, characterized by the occur-rence of many important pollen groups, the mostconspicuous being a group of pollen bearing mor-phological features known as elaters (Stover, 1963).The complex comprises a diverse suite of morpho-logically bizarre forms that are characterized byexinal outgrowths or projections that only superfi-

cially resemble elaters (s. str. as are associated withspores of extant Equisetum). Several genera havebeen defined to encompass these forms, including Alaticolpites Regali, Uesugui et Santos, 1975, Elate-rocolpites Jardiné et Magloire, 1965, ElateroplicitesHerngreen, 1973, Elateropollenites Herngreen, 1973,

Elaterosporites Jardiné, 1967, Galeacornea Stover,1963, Pentapsis Lammons, 1970, RegalipollenitesLima, 1980, Senegalosporites Jardiné et Magloire,1965, and Sofrepites Jardiné, 1967. The projectionsvary enormously in size, shape, and position, and

are either elater-like, horn-like, or resemble smallknobs. Other characters of the fossils are extremelyvariable; they may be ellipsoidal, spherical, hemi-spherical, fusiform, or pentahedral in body shape;and the sculpture ranges from smooth to conspicu-ously ornamented. Their apertural characters are notwell understood or well documented, although mostwere thought to be inaperturate.

The affinity of the elaterate complex has intriguedpalynologists for several decades. There is some un-

certainty as to whether they represent spores of free-sporing plants or pollen of seed plants (Stover, 1963;Elsik, 1974; Srivastava, 1984). Indeed it is unknownwhether they were shed by members of a botani-

cally united group or by plants of diverse botanicalorigins, although Crane (1988, 1996) speculated thatthey may represent specialized forms of gnetaleanpollen adapted to insect pollination. Species of theelaterate complex occur in high abundances only inthe circum-Atlantic basins of northern South Amer-ica and northern Africa, and only during the lateAlbian to Cenomanian (cf. Fig. 1; Crane, 1996), sug-gesting that this area could have been the radiationand diversification centre of the complex.

The purpose of this paper is to provide a reviewof the species assigned to the respective genera of elaterate pollen, examine their varied morphologiesthrough light microscope (LM), scanning electronmicroscope (SEM), and transmission electron mi-croscope (TEM) analyses, with aims of elucidatingwhether or not their morphological and=or structuralattributes indicate a botanical affinity.

2. Material and methods

The specimens studied have been obtained from

strata of late Albian to Cenomanian age in Brazil andEcuador (Fig. 1). Samples containing abundant andwell preserved assemblages of Elaterates are fromBrazilian and Ecuadorian sections as detailed inFig. 2. The majority of the material comes from theCaju Group in the Barreirinhas Basin, northeasternBrazil (Fig. 2a). This is a sequence of interbeddedshale and shallow marine carbonates. Other spec-imens are from outcrop samples of the ItapecuruFormation in the Parnaı́ba Basin, northeastern Brazil.Material from Ecuador is derived from the Napo For-

mation exposed in Rio Misahualli and Rio Chapiza,in the northwest and southern parts of the OrienteBasin, respectively (Fig. 2b). Previous observationshave been made on material from Brazil by Müller(1966), Herngreen (1973a,b, 1974, 1975a,b), andfrom Ecuador by Jaillard et al. (1994).

Samples were processed using standard paly-nological preparation methods (Dettmann, 1963;Phipps and Playford, 1984; Wood et al., 1996).The data on age and stratigraphic distribution of

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R. Dino et al. / Review of Palaeobotany and Palynology 105 (1999) 201–235 203

BRAZIL

A T L

A N T I C

O C E A N

P A C I F I C

O C E A N

ECUADOR

81°

0°

2°

77°79°

100 Km

QUITO

COASTALPROVINCE

ORIENTE BASIN

A N D E

S M

O U N T

A I N

S

C O L O M B I A

P E R U

E C U A D O R

E C U A

D O R

500

PARNAÍBA BASIN

BARREIRINHAS BASIN

WELLIN-1

OUTCROPAREA

44° 42°

2°

100 Km500

2 0 0 ́

S O B R AD I N H O P LAT F ORM

RIOMISAHUALLI

RIOCHAPIZA

Fig. 1. Locality map showing the basins in Brazil and Ecuador from where sample material was obtained.

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(a)

(b)

Fig. 2. Montage showing the stratigraphic columns for the Creta-

ceous sections of (a) Brazil and (b) Ecuador.

elater-bearing grains were derived from routine light-microscopic analysis of several well cores and cut-tings samples from wells drilled by Petrobras in allcoastal basins of northeastern Brazil, and outcropsamples collected by Amoco from Ecuador.

For light microscope (LM) analyses, residueswere mounted in Entelan and covered with No. 0

coverslips. Photographs were taken under oil im-mersion using either an Axioplan Zeiss Microscope(Brazilian forms) or a Zeiss Photomicroscope III

(Ecuadorian forms). For scanning electron micro-scope (SEM) analyses, grains were picked fromresidues mixed in alcohol using a micromanipulatorand transferred to a specified section of a ruled alu-

minum square; after drying they were vacuum coatedwith gold-palladium and examined with a Jeol JXA-840A scanning electron microscope. Photographs of whole grains and their specific morphological fea-tures were taken at 15 or 20 kV, respectively.

For transmission electron microscope (TEM)analyses, specimens were picked from residuesmounted in alcohol using a micromanipulator andtransferred to a thermonox coverslip smeared withadhesive. A drop of 1% agar was added and thespecimens stained in osmium tetroxide for 2 hours,followed by uranyl acetate for 1 hour, and thensurface embedded in Spurr’s medium following themethod of Milne and McCaul (see Milne, 1994,1998). Sections were cut with a diamond knife,stained with lead citrate, and examined using a Jeol1010 instrument.

Frequency and diversity levels of Elaterates arebased on a synthesis of palynofloral assemblagesrepresented in late Aptian–Cenomanian sequencesof equatorial and marginal basins of Brazil. Quan-titative analyses were carried out on a range of palyno-assemblages from each of the successive pa-

lynostratigraphic zones delineated for the Albian–Cenomanian of Brazil (Table 2; Fig. 3). Relativeabundance levels of Elaterates are with reference tothe other major groups (spores, polyplicates, Clas-sopollis, angiosperm pollen, and others) representedin the palynofloras. Diversity levels of Elaterates andthe stratigraphic ranges of the individual species rep-resented are detailed for the late Aptian–Turonian of Brazil (Fig. 4).

3. Systematics

Table 1 summarizes the pollen morphological dataand bibliographic references for the pollen discussedin this paper. This includes the characteristics of the body, ornament, and appendages of the elater-ate complex. Data for Galeacornea clavis Stoverare derived from Stover’s (1963) original descrip-tions because we did not observe this species inour studies. For the sake of completeness we con-

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Fig. 3. Relative frequency levels of Elaterates and other spore–pollen groups in assemblages from the upper Aptian–Cenomanian of

Brazil.

sider it important to summarize those data here. A

brief discussion of Alaticolpites Regali, Uesugui etSantos, Elateropollenites Herngreen, Pentapsis Lam-

mons, Regalipollenites Lima, and SenegalosporitesJardiné et Magloire, is given at the end of thissection because these taxa possess elater-like pro-

jections, which, however, are unlike those found inother genera.

Genus Elaterocolpites Jardiné et Magloire, 1965

1965 Elaterocolpites Jardiné et Magloire, p. 206.1967 Elaterocolpites Jardiné et Magloire emend.

Jardiné, p. 247.1984 Elaterocolpites Jardiné et Magloire emend.

Srivastava, p. 232.

Type: Elaterocolpites castelainii Jardiné et Magloire,1965. Monospecific genus consisting of Elaterocol- pites castelainii.

Elaterocolpites castelainii Jardiné et Magloire, 1965(Plate I, 1–5)

1965 Elaterocolpites castelainii Jardiné and Ma-

gloire, p. 206, pl. 4, figs. 6, 7.

Dimensions: (30 specimens) body 35–53 µm (longaxis), appendages 6–10 µm wide and 18–30 µmlong.

Comments: Jardiné (1967) re-examined the type ma-terial of Elaterocolpites castelainii, and subdividedthis species into two subforms. Form ‘A’ has anarrow annular ring surrounding the corpus, whichhe attributed to a young or immature grains. Form‘B’ corresponds to the mature grains and has well

stretched appendages. In the Brazilian material an-other subform named here Form ‘C’ (Plate I, 3) isdistinct from the others in being bigger and havingtwo solid globular expansions at the ends of the longaxis of the corpus. Herngreen (1974, pl. III, fig. 5)illustrated a specimen similar to Form ‘C’, which hecalled Form ‘A’ of Jardiné (1967). All these formsoccur frequently in upper Albian–middle Cenoma-nian strata of the Caju Group in the Barreirinhasbasin.

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Table 1

Pollen morphological data and bibliographic references to species of the elaterate complex

Species Body Ornamentation Appendages

body shape size wall shape number siz

Alaticolpites limai ellipsoidal to subspherical L: 70–72 µm

S : 48–68 µm

1–3 µm smooth flap-shaped 10 W :

L:

Elaterocolpites

castelainii

ellipsoidal to subspherical 40–50 µm smooth to

microgranular

cylindrical 10 W :

L:

Elateroplicites

africaensis

ellipsoidal L: 35–62 µm

S : 25–41 µm

smooth long, slender 2 or 4 W :

L:

Elateropollenites

jardinei

subtriangular 30–45 µm 1–1.5 µm thinly striate short, slender 2 or 3 W :

L:

Elaterosporites

acuminatus

sub-hemispherical L: 38–52 µm

S : 20–35 µm

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Fig. 4. Stratigraphic range and diversity levels of Elaterates during the mid-Cretaceous in Brazil.

Genus Elateroplicites Herngreen, 1973

1973b Elateroplicites Herngreen, p. 550.

Type: Elateroplicites africaensis Herngreen, 1973,by original designation. Monospecific genus consist-ing of Elateroplicites africaensis.

Elateroplicites africaensis Herngreen, 1973 (Plate II,1–5; Plate III, 1–6; Plate IV, 1–6)

1967 Incertae sedis forma A, Jardiné, p. 255, pl.III, figs. K–M.

1973b Elateroplicites africaensis Herngreen, p. 550,pl. 5, figs. 5–7.

Description: Ellipsoidal grains comprising a smoothexinal body formed by 3–4 exterior ribs. These ribsor bands are separated by narrow furrows averag-ing 1 µm in width, and exhibit a strong tendency

towards twisting along the long axis of the grain;occasional specimens are not twisted (Plate III, 6).Usually two of the ribs project beyond the body

and form 2, or rarely, 4 long, slender appendages.The appendages are smooth, solid, flexible, of equallength, but slightly thicker at the termination and arealways turned towards one surface of the grain, sug-gesting that the opposite surface may represent theinternal face (proximal) with respect to the tetrad.The ribs surrounding the longitudinal axis convergeand fuse(?) at the end of the axis. SEM photomi-crographs (Plate IV, 5, 6) illustrate the twisting andtapering of the ribs towards one centre of conver-gence where they fuse in a manner similar to the

ribs of polyplicate forms included within Equise-tosporites and Ephedripites. No germinal aperture orcolumellate layer of the exine are discernible underLM. The dimensions of this species (based on 30specimens) are body 35–62 µm (long axis), 25–41

µm (short axis), ribs 3–25 µm wide, 2–3 µm thick,appendages 3–6 µm wide and 20–80 µm long.Ultrastructure: Pollen wall composed of ektexinewhich is differentiated into three zones (Plate IV,2, 3). Innermost zone 0.5 µm thick, homogeneous,

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continuous and of uniform thickness in all regionsof palynomorph; middle zone thin (

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PLATE I

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PLATE II

For description see p. 208.

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PLATE III


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PLATE IV


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PLATE V


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Genus Elaterosporites Jardiné, 1967

1967 Elaterosporites Jardiné, p. 240.

Type: Elaterosporites verrucatus (Jardiné et Ma-

gloire) Jardiné, 1967.

Elaterosporites acuminatus (Stover) Jardiné, 1967(Plate V, 1, 3)

1963 Galeacornea acuminata Stover, p. 89, pl. 2,figs. 8–10, text-fig. 6.

1967 Elaterosporites acuminatus (Stover) Jardiné,p. 246, pl. 3, figs. D, E.

PLATE VI

Specimens from Brazil (1–3, 5) and Ecuador (4, 6).1, 3. SEM of Elaterosporites verrucatus (Jardiné et Magloire) Jardiné, 1967. ð1400.

2. Elaterosporites verrucatus (Jardiné et Magloire) Jardiné, 1967. ð750.

4–6. Elaterosporites klaszii (Jardiné et Magloire) Jardiné, 1967.

4, 6. ð840.

5. ð750.

PLATE VII (see p. 216)

Elaterosporites klaszii (Jardiné et Magloire) Jardiné, 1967. Specimens from Brazil.

1. SEM image showing planar face with very thin exine surrounded by annular ring. ð1700.

2. LM view focused on planar face and annular ring. ð750.

3, 4. SEM images showing convex face. ð1200.

5, 6. Lateral and oblique views. ð750.

PLATE VIII (see p. 217)

Elaterosporites klaszii (Jardiné et Magloire) Jardiné, 1967. Specimens from Brazil.

1, 2. TEM images. Sections cut parallel to equatorial plane.

1. ð1500.

2. ð3000.

3, 4. TEM images. Detail of exine showing thin tectum (T ), granulate to alveolate infratectum (G), and thin foot layer (F ) underlain by

endexine ( En).

3. ð10,000.

4. ð12,000.

5. SEM image showing planar and convex faces. ð1200.

6. LM image. ð750.

PLATE IX (see p. 218)

Specimens from Brazil (2–6) and Ecuador (1). ð750 unless specified otherwise.1–5. Elaterosporites aff. E. klaszii Jardiné, 1967, showing narrow annular ring characteristic of this form.

1. ð840.

6. Elaterosporites protensus (Stover) Jardiné, 1967, showing conspicuous sculpture on convex face.

PLATE X (see p. 219)

Elaterosporites protensus (Stover) Jardiné, 1967. Specimens from Brazil (1, 3–6) and Ecuador (2). ð750 unless specified otherwise.

1–5. LM images of specimens in different orientations.

2. ð840.

4. Note the appendages form a broad circular ring. ð1000.

6. SEM of convex face. ð1000.

Dimensions: (5 specimens): body 42–65 µm (longaxis) and 25–40 µm (short axis); appendages 4–6µm wide and 28–42 µm long.

Discussion: This species is relatively rare in our

material. As already pointed out by Stover (1963), Elaterosporites acuminatus is very similar to E. pro-tensus. The distinction is based mainly in the shapeand size of the body, that is slightly smaller and lessconvex in E. acuminatus; on the ends of the horns,that are slender in E. acuminatus, and rounded in E. protensus; and on the width of the annular ringat the flat face which is narrower in E. acuminatus.

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PLATE VI

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PLATE VII


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PLATE VIII


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PLATE IX


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PLATE X


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In our material only the sharp tipped horns in E.acuminatus can be used to distinguish between thetwo species.

Elaterosporites verrucatus (Jardiné et Magloire)Jardiné, 1967 (Plate V, 2, 4–6; Plate VI, 1–3)

1965 Galeacornea verrucata Jardiné et Magloire, p.204, pl. 3, figs. 28–31.

1967 Elaterosporites verrucatus (Jardiné et Ma-gloire) Jardiné, p. 244, pl. 2, figs. E–G, pl.3, fig. G.

Dimensions: (35 specimens): body 55–75 µm (longaxis) and 35–43 µm (short axis); appendages 4–6µm wide and 30–40 µm long.

Elaterosporites klaszii (Jardiné et Magloire) Jardiné,1967 (Plate VI, 4–6; Plate VII, 1–6; Plate VIII, 1–6)

1963 Galeacornea sp., Stover, p. 89, pl. 2, figs. 16,17.

1965 Galeacornea klaszi Jardiné and Magloire, p.205, pl. 4, figs. 2, 3.

1967 Elaterosporites klaszi (Jardiné and Magloire)Jardiné, p. 246, pl. 3, figs. H–N.

Dimensions: (35 specimens): body 35–52 µm (longaxis), 25–35 µm (short axis); appendages 4–6 µm

wide and 45–60 µm long.Ultrastructure: Exine comprises a thin endexine of uniform electron density and near homogeneous instructure overlain by thicker ektexine composed of a thin homogeneous inner layer (foot layer) beneathan irregularly granulate to alveolate infratectum anda homogeneous tectum. Infratectum and tectum of variable thickness; thickest on ‘horn’ bearing sur-face and beneath cingulum, and thinnest on planarsurface, the central regions of which appear to becomposed solely of foot layer. Infratectum more

loosely structured (i.e., alveolae larger) towards tec-tum interface than at foot layer interface.

Comments: After re-examination of the origi-nal material, Jardiné (1967) created the species Elaterosporites sp. aff. E. klaszii (Plate IX, 1–5) toaccommodate forms, essentially similar to E. klaszii,but having a narrower annular ring. We considerthat is not as distinctive at the specific level. Thisspecies is known as recycled in Cretaceous depositsof Alabama (Gregory and Hart, 1992).

Elaterosporites protensus (Stover) Jardiné, 1967(Plate IX, 6; Plate X, 1–6)

1963 Galeacornea protensa Stover, p. 88, pl. 2, figs.11–15, text-fig. 5.

1967 Elaterosporites protensus (Stover) Jardiné, p.244–245, pl. 3, figs. A–C.

Dimensions: (30 specimens): body 50–73 µm (longaxis) and 30–42 µm (short axis); appendages 4–6

µm wide and 35–42 µm long.

Discussion: Stover (1963, pl. 2, fig. 15) figures an‘unexpanded’ specimen that he argued suggestedformation of the pollen in tetrads with the flat sur-face orientated towards the centre of the tetrad (i.e.,proximal). An alternative interpretation is that inthe young tetrad phase the unexpanded pollen are

aligned with their sculptured, horn-bearing surfacedirected towards the centre of the tetrad. In the ma-

ture tetrad phase expansion may have been confinedto the horn-bearing surface and was perhaps associ-ated with separation of the individuals of the tetrad.Thus, it is feasible that the convex surface may beproximal to the original tetrad.

Genus Galeacornea (Stover) Jardiné, 1967

1963 Galeacornea Stover, p. 86.1967 Galeacornea Stover emend. Jardiné, pp. 237–

240.

Type: Galeacornea clavis Stover, 1963.

Comments: The genus Galeacornea was describedby Stover (1963) and included four elater-bearingpollen. Two of these species, G. causea and G. clavisremain in the genus, the other two, G. acumina-tus and G. protensus, were transferred to the genus Elaterosporites by Jardiné (1967). Subsequent stud-ies by Zhang and Zhan (1986) resulted in the descrip-tion of Galeacornea tarimensis, a species so far not

PLATE XI

Galeacornea causea Stover, 1963. Specimens from Brazil (1–4,

6) and Ecuador (5).

1, 3. Form ‘A’ of Jardiné (1967), possibly representing im-

mature grains. ð1400.

2, 4–6. Form ‘B’ of Jardiné (1967), the most common form of

the species, in a range of orientations.

2, 4, 6. ð1400.

5. ð840.

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PLATE XI

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PLATE XII

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recorded from Ecuador or Brazil. G. clavis, whichhas hitherto been known only from West Africa, hasrecently been found (E.H. Roesner, Petrobras, pers.commun.) in the Ceará Basin, northeastern Brazil.

Galeacornea causea Stover, 1963 (Plate XI, 1–6;Plate XII, 1–3)

1963 Galeacornea causea Stover, p. 87, pl. 1, figs.16, 17; pl. 2, figs. 1–7, text-fig. 4.

Dimensions: (20 specimens): body 30–57 µm (longaxis) and 23–42 µm (short axis); flaps 27–38 µmwide and 10–15 µm high.Comments: Jardiné and Magloire (1965) did not con-sider Galeacornea causea and G. clavis as two usefulspecies because of the general similarities of their

morphology, co-occurrence, identical stratigraphicrange, and the scarcity of Galeacornea causea like

specimens. They concluded that G. causea was a vari-ant of G. clavis. Later, Jardiné (1967) re-examined theoriginal material and agreed with the maintenance of the two species, and distinguished two varieties of G.causea, naming them Form ‘A’ and Form ‘B’. Accord-ing to Jardiné (1967), Form ‘A’ includes immaturespecimens and Form ‘B’, which has a lobed appear-ance, contains mature ones. In our Brazilian samples

Form ‘A’ is very rare and Form ‘B’ is Abundant.

Genus Sofrepites Jardiné, 1967

1967 Sofrepites Jardiné, p. 248.1981 Sofrepites Jardiné emend. Jingxian, p. 98.1982 Sofrepites Jardiné emend. Boltenhagen, p. 150.

Type: Sofrepites legouxiae Jardiné emend. Jingxian,

1981.

Comments: Jingxian (1981) emended the descriptionof Sofrepites based on the unequal length of theprojections. The quality of the illustrations make it

PLATE XII

Specimens from Brazil.

1–2. Galeacornea causea Stover, 1963, SEM images of planar

face of grain.

1. ð1700.

2. ð2000.

3. Galeacornea causea Stover, 1963, LM view. ð1400.

4–6. Sofrepites legouxiae Jardiné, 1967, LM views. ð1400.

difficult to ratify this emended description. The illus-trations seem to be of a polyplicate pollen grain sim-ilar to pollen belonging to the genus RegalipollenitesLima, 1980 and thus there is doubt as to whether

the Jingxian (1981) specimens belong in Sofrepites.Boltenhagen (1982) also emended the generic de-scription but this was not accepted by Jansonius andHills (1976–1996, card 4164) as the type of thegenus was excluded. Jansonius and Hills proposedthe new name Sofrepites boltenhagenii for the taxondescribed by Boltenhagen (1982) in accordance withthe ICBN (1994).

Horowitz (1970) described Sofrepites michalifrom southern Israel, however, the illustration (pl.III, fig. 8) appears to show a fragment of a speciesof Elaterosporites. The fragmentary nature of thespecimen and doubts surrounding its inferred age(Late Jurassic) renders this record highly suspect(see Herngreen, 1974, p. 520). As such this speciesis considered invalid as it is based on a fragment.

Sofrepites legouxiae Jardiné, 1967 (Plate XII, 4–6;Plate XIII, 1–6; Plate XIV, 1–5)

1967 Sofrepites legouxae, Jardiné, p. 255, pl. 3, Figs.H, J; text-fig. 5.

Description: Subspherical to ellipsoidal body with a

subcircular, elliptical or convexly subtriangular out-line where 2 or 3 smooth, solid appendages of equallength project. Monocolpate; colpus parallel to longaxis of grain, extends almost to the border whereits extremities are spatulate. In some specimens theaperture is clearly visible but in others is coveredby a very thin exinal layer. Exine smooth to infra-granulate, approximately 1 µm thick. Dimensions(50 specimens): body 20–45 µm (long axis), 20–42µm (short axis); colpus 22–42 µm long and 2–5 µmwide; appendages 3–6 µm wide and 7–21 µm long.

Ultrastructure: Exine with ektexine comprising outerhomogeneous zone (tectum) of uniform electrondensity and of variable width, a middle zone (in-fratectum) that is granulate–alveolate in structureand up to 3 µm in thickness, and a thin inner zone(foot layer). A very thin layer (endexine) with faintlylamellate structure is discernible (Plate XIII, 3, 4) insome sections. The tectum and infratectum are thick-est in the interapertural areas of the grain and on theappendages, and are very thin or absent at the mar-

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gins of the colpus; infratectum with larger alveolaeat tectum interface adjacent to the foot layer. Discussion: Scanning electron microscopic analysesconfirm the pollen is monocolpate (Plate XIII, 6;

Plate XIV, 5) and that the exine is tectate granulate.

Genus Elateropollenites Herngreen, 1973 (PlateXIV, 6; Plate XV, 1–4)

1965 Incertae sedis CI. 50 Jardiné et Magloire, p.207.

1973b Elateropollenites Herngreen, p. 549.

Type: Elateropollenites jardinei Herngreen, 1973.

Comments: Herngreen (1973b) created this genusto accommodate pollen with elater-like appendages.The type species Elateropollenites jardinei possessesa swollen body and 3 appendages thickened at theirextremities (Herngreen, 1973b, p. 531, pl. IV, figs. 5–8). Herngreen differentiated Elateropollenites from

PLATE XIII

Sofrepites legouxiae Jardiné, 1967. Specimens from Brazil.

1, 2. TEM images. Sections cut perpendicular to equatorial plane through appendages.

1. ð2500.

2. ð1500.

3, 4. TEM images. Detail of exine showing homogeneous tectum (T ), granular layer (G), thin foot layer (F ) and endexine ( En).3. ð6000.

4. ð8000.

5, 6. SEM images.

5. ð1100.

6. Note monocolpate aperture. ð1900.

PLATE XIV (see p. 226)

Specimens from Brazil (1, 2, 4–6) and Ecuador (3).

1, 3. Dyads of Sofrepites legouxiae Jardiné, 1967.

1. ð1400.

3. ð840.

2. Sofrepites legouxiae Jardiné, 1967, showing the monocolpate aperture and (in this case) only two short appendages. ð1400.

4, 5. SEM images of Sofrepites legouxiae Jardiné, 1967 showing the monocolpate aperture. ð2000.6. Elateropollenites jardinei Herngreen, 1973, focused on striations of the corpus. ð1400.

PLATE XV (see p. 227)


1, 3. SEM images of Elateropollenites jardinei Herngreen 1973.

1. Showing three appendages. ð2200.

3. ð2600.

2, 4. Elateropollenites jardinei Herngreen, 1973 showing central sulcus (doubtful aperture) and striations. ð1400.

5–6. Regalipollenites amphoriformis (Regali et al.) Lima, 1980.

5. With a ?monocolpate aperture. ð750.

Elaterocolpites, Elaterosporites, and Sofrepites, onthe basis of number of appendages, the shape of appendages, and the size of the body, but suggestedthat the appendages in E. jardinei were similar to

those of Elaterocolpites castelainii. We have notstudied this species even though it is recorded inlower Albian sediments in Brazil.

Regali (1989), and Regali (in Regali and Viana,1989) described three species, E. bicornis, E. dis-similis, and E. praecursor , and differentiated themon the basis of elater length. Further, Regali (1989)emended the genus Elateropollenites Herngreen toinclude forms with large variations in size of theelaters, but such variation was accounted for in theoriginal generic description.

Genus Regalipollenites Lima, 1980 (Plate XV, 5, 6)

1975 Steevesipollenites amphoriformis Regali, Ue-sugui et Santos, p. 271.

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PLATE XIII

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PLATE XIV


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PLATE XV


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PLATE XVI

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1980 Regalipollenites Lima, p. 45.

Type: Regalipollenites amphoriformis (Regali et al.)Lima, 1980. Monospecific genus consisting of Re-galipollenites amphoriformis.

Comments: Lima (1980) created this genus to ac-commodate polyplicate pollen grains of unequal ex-ine thickness=extension at opposing ends of the longaxis of the grain. The type species Regalipollenitesamphoriformis is polyplicate with a long appendageat one end and a small knob on the other end of

the ellipsoidal to fusiform grain. Lima (1980) placed Regalipollenites in the polyplicate group includingSteevesipollenites amphoriformis (described by Re-gali et al., 1975a); but is similar also to the elateratesin possession of long elater-like appendages. Fur-thermore, R. amphoriformis, shows some similarityto Elateroplicites africaensis and to Ephedriptes= Eq-uisetosporites in its possession of longitudinal ribs.

Genus Pentapsis Lammons, 1970 (Plate XVI, 2, 4)

1970 Pentapsis Lammons, p. 175.

Type: Pentapsis valdiviae Lammons, 1970. Mono-specific genus consisting of Pentapsis valdiviae.

Comments: Of all the genera discussed in this paper

Pentapsis is the most disparate morphologically and

may be unrelated to the other elater-bearing genera.Lammons (1970) erected Pentapsis to accommodatepollen grains that contain buttress-like structures thatare terminally attached at more-or-less equal anglesaround the periphery of each of two parallel pentag-onal polar plates, and therefore connecting the twoplates. The buttress morphology gives an appearanceof elater-like projections, with slight resemblanceto Sofrepites legouxiae or Elaterocolpites castelainii.

PLATE XVI


1. Senegalosporites costatus Jardiné et Magloire, 1965. ð1400.

2. Pentapsis valdiviae Lammons, 1970. Equatorial view.

ð1400.

3. Senegalosporites petrobrasi Herngreen, 1974. Note the par-

allel ridges. ð1400.

4. Pentapsis valdiviae Lammons, 1970. Polar view. ð1400.

5. Alaticolpites limai Regali, Uesugui et Santos, 1975. ð1400.

6. SEM image of Alaticolpites limai Regali, Uesugui et Santos,

1975. ð1400.

This species is restricted in Brazil to sediments of early Albian age.

Genus Senegalosporites Jardiné et Magloire, 1965

(Plate XVI, 1, 3)

1965 Senegalosporites Jardiné et Magloire, p. 208.1974 Senegalosporites Jardiné et Magloire emend.

Herngreen, p. 548.

Type: Senegalosporites costatus Jardiné et Magloire,1965, by original designation.

Comments: The genus Senegalosporites Jardiné etMagloire, 1965, is represented by a cylindrical tofusiform grain with twisted or straight ridges re-sembling the general organization of the polyplicate

pollen group. The ridges, along the long axis of thegrain, usually fuse at the ends and form a conspic-uous protrusion similar to an elater-like appendage.The type species is characterized by twisted ridges.Herngreen (1974) broadened the generic diagnosesof Senegalosporites to include pollen grains withstraight ridges and erected the species S. petrobrasi.Regali et al. (1975b, p. 271, pl. VI, fig. 1), misin-terpreted the morphology of the ‘polar’ appendages

and placed S. petrobrasi into Steevesipollenites, andcreated S. duplibaculum. Re-examination of the orig-

inal material of Steevesisporites duplibaculum re-veals a striking similarity to S. petrobrasi Hern-green. Additionally, the elater-like appendages beara slight resemblance to those of Sofrepites legouxiae.Jingxian’s (1981) species, Senegalosporites minor and S. mirifus, are here interpreted as polyplicate

grains conformable with Steevesipollenites. Senega-losporites is rare in Brazil and is restricted to lateAlbian to Cenomanian aged deposits.

Genus Alaticolpites Regali, Uesugui et Santos, 1975(Plate XVI, 5, 6)

1975 Alaticolpites Regali, Uesugui et Santos, p. 288.

Type: Alaticolpites limai Regali, Uesugui et Santos,1975. Monospecific genus consisting of Alaticolpites

limai.

Comments: Alaticolpites accommodates colpatepollen of ellipsoidal to subspherical shape andwith 10 handle-shaped or leaf-like appendages. Thepollen is similar in some respects (general outline

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and form of the flaps) to species of Galeacornea, dif-fering in the form and number of appendages. Spec-imens attributed to Galeacornea causea by Brenner(1968, pp. 353–354, pl. III, figs. 4–5), and Schrank

and Ibrahim (1995, p. 12, pl. 2, figs. 9–10) fromthe Albian–Cenomanian of Peru and Egypt are con-formable with Alaticolpites. In Brazil the genus isrestricted to strata of Albian age.

4. Botanical affinities

Affinities of elaterate pollen have remained ob-scure as they bear little morphological resemblanceto spores and pollen of extant taxa, and thus farare unknown in situ from fossil plants. Stover(1963) suggested that the presence of a sulcus- orcolpus-like germinal apparatus in some taxa im-plied an angiospermous or gymnospermous affinity.Moreover, the nature of unexpanded examples of Elaterosporites protensus, implied to Stover (1963)that the individuals of the species probably formed ina tetrad configuration. However, he found it difficultto reconcile that the horn-bearing surface representedthe proximal face, and concluded that the taxon ac-commodates spores with the horns borne on thedistal surface. The possibility that some elaterate

pollen were borne in dyads is hinted at by specimensattributed by Srivastava (1984) to Elaterocolpites pentarhethus. Srivastava’s figured specimens mayrepresent obligate dyads of Sofrepites, and moreover,with sporopolleninous (?tapetal) material uniting theproximal faces of the individuals. The ‘colpi’ de-scribed by Srivastava may represent uneven breaksbetween the individuals of the dyad, rather thansignifying an angiospermous origin of the grains.

Morphological relationships between elaters, au-riculae, sacci, and thickenings found on gnetalean

and some angiospermous pollen were considered atlength by Elsik (1974) who concluded that a rangeof morphologically disparate palynomorph taxa(Galeacornea, Elateroplicites, Auriculiidites, Pedi-culisporis and others) represented ephedroid grains,some perhaps shed from an “intermediate gnetalean-monocotyledonoid offshoot (?early Araceae) whichis now extinct or may in fact be representative of early angiosperms” (Elsik, 1974, p. 529). Trevisan(1980) explored possible relationships between fos-

sil Ephedripites sp. from the Cretaceous of Italy andpollen of extant Gnetales ( Ephedra, Welwitschia) andthe monocotyledon Spathiphyllum (Araceae). Fromcomparative morphological and ultrastructural stud-

ies, she demonstrated that Ephedripites grains weremore similar to those of Ephedra and Welwitschiathan to those of Spathiphyllum. The exine of pollenof the last mentioned genus possesses an infratectallayer that is columellate in organization by con-trast to the loosely granular infratectum of pollen of extant gnetaleans (Kurman and Zavada, 1994; Row-ley, 1996) and the compact granular infratectum of the Italian Ephedripites. It should be noted, how-ever, that collumellae-like rods have been reportedin fresh fixed grains of Ephedra foliata Bois et K.ex C.A. Mey, but dried grains of the same specieshave a granular infratectum (El-Ghazaly and Rowley,1997).

Cretaceous ‘ephedroid’ pollen assigned to Equise-tosporites from Brazil are similar in exine ultrastruc-ture and stratification to the elaterate pollen studiedby us and Ephedripites studied by Trevisan (1980)and others (Lima, 1978, 1980; Osborn et al., 1993,p. 171). The latter authors demonstrated a lamel-lated endexine overlain by ektexine characterized bya granulate infratectum that is capped by a homo-geneous tectum. Ektexine of the furrows separating

the ridges thins to “a single homogeneous layer(D tectum) that forms a folded, hinge-like structuredirectly over the furrow”; these furrows were in-terpreted to serve as potential apertures (Osborn etal., 1993, p. 179, pl. 2, figs. 4–6). Regions of thinexine that occur in the three elater taxa sectionedby us (Plate IV, 2, 3; Plate VIII, 3, 4; Plate XIII,3, 4) are probably analogous, but we interpret thatexine thinning involves the infratectum and tectum,whereas the foot layer persists and thins little, if any. A comparable persistence of the foot layer and

marked thinning of the tectum and infratectum hasbeen demonstrated for the furrow regions in pollenof Ephedra (Van Campo and Lugardon, 1973, pl. 1,fig. 4; Kurman and Zavada, 1994, fig. 32; Rowley,1996, pl. 8, fig. 2).

Taking into account wall stratification and ultra-structural compatibility of Sofrepites, Elateroplicitesand Elaterosporites with that of Ephedripites andother Cretaceous polyplicate pollen it is suggestedthat elaterates and polyplicate pollen are botanically

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related. Furthermore, based on ektexinous ultrastruc-tural similarity to pollen of Ephedra and Welwitschiarelationships are suggested to be gnetalean and sup-port earlier speculations by Crane (1988, 1996), who

suggested that Elaterates may represent a specializedgroup of ephedroids adapted to insect pollination.

Although initially thought to be gnetalean, Tri-assic pollen assigned to Equisetosporites chinleanaDaugherty and Cornetipollis reticulata Pocock etVasanthy, both have an infratectum that is distinctlycolumellate, and the Triassic pollen are thought tobe angiospermous (Zavada, 1984, 1990; Pocock andVasanthy, 1988).

5. Palaeoecological and palaeoclimaticinterpretations

An appreciation of elaterate-producing plants maybe gained from knowledge of associated vegetationand the types of environments they inhabited. As-sociated plant fossils provide a perspective of thevegetation and the enclosing sediments reflect theinteraction of physiographic=biotic processes in theregion.

The Cretaceous was a period of continentalbreakup and drift and the initiation of new oceans

worldwide. In the northern Gondwana region theSouth Atlantic Ocean was initiated with the sep-aration of South America from Africa. Sequencesdeveloped in the marginal basins of Brazil and west-ern areas of northern Africa reflect the environmentsduring the initial phases of rifting, marine incursion,and open marine conditions, as the northern part of the South Atlantic Ocean opened.

The rift phase is marked by a thick sequenceof lacustrine deposits of Neocomian age. The con-tained palynofloras are dominated by Classopollis

Table 2

Relative frequencies (%) of major groups represented in spore–pollen assemblages from Albian and Cenomanian sediments of Brazil

Age Spores Polyplicates Classopollis Elaterates Angiosperms Others

Latest Cenomanian 5 5 3 2 60 25

Late Cenomanian 5 15 20 10 40 10

Early Cenomanian 5 30 25 20 15 5

Late Albian 5 35 30 20 8 2

Early Albian 15 30 40 3 10 4

and associated with diverse cryptogam spores com-prising lycophytes, ferns and bryophytes. Palaeoen-vironments are interpreted to have alternated be-tween humid and drier phases. Marine incursions

occurred during the latest Aptian and a thick se-quence of evaporites accumulated in what is inter-preted to have been a hypersaline lacustrine setting.Palynofloras in these sediments are characterizedby abundant Classopollis and an increase in poly-plicate pollen whereas bisaccate pollen and cryp-togam spores occur in low abundances. Angiospermpollen are present but restricted to monosulcate(Clavatipollenites, Dichastopollenites, Stellatopollis,Transitoripollis), zonosulcate ( Afropollis), and smalltricolpate forms (most presumed to be of hamameli-did affinity).

A transgressive event in the latest Aptian heraldedthe onset of marine conditions with deposition of siliclastics interbedded with shallow platform car-bonates and marls in the early Albian. Palynoflorasfrom these sediments are the oldest known elateratepollen ( Elateropollenites jardinei) together with in-creased frequencies of angiosperms and increasinglydiverse dinocysts (Table 2; Fig. 3).

Diversity and frequency levels of the elateratesclimaxed during late Albian–Cenomanian times (Ta-ble 2; Figs. 3 and 4). Other features of the Brazil-

ian and Ecuadorian late Albian–Cenomanian paly-nofloras are high frequencies of Classopollis, scarcebisaccate pollen, and low diversity cryptogam assem-blages. As such the palynofloras conform with thosethat characterize the ASA phytogeographic provinceof Herngreen and Chlonova (1981). The vegetationof this low latitude region (Fig. 5) is considered tohave comprised dry-zone and=or mangrove commu-nities of Cheirolepidaceae, perhaps with savannahof gnetalean associations; climates are considered tohave been warm although the equator to pole temper-

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Fig. 5. Known palaeogeographic distribution of Elaterates assemblages in mid-Cretaceous strata. Plotted on a mid-Cretaceous (100 M

graphic map (after Barron et al., 1981). The mid-Cretaceous Elaterates province extended from the low latitude region surroundingAtlantic Ocean to southeastern Asia. Oldest reported members of the complex are Elateropollenites jardinei and Pentapsis valdiviae,

Albian sediments. The former species is known in low frequencies in palynofloras of South America (Venezuela, Peru, Brazil) and Af

from South America. Early diversification of the complex occurred soon after (late early Albian) with appearances of Elaterosporit

Thereafter diversity and frequency levels increased to an acme at the Albian=Cenomanian boundary, and in Brazil the complex extend

Janeiro State. Last appearances of the elaterate complex are in upper Cenomanian sediments. Amongst taxa represented in the Ceno

(reported here for the first time from Brazil) and S. petrobrasi, which, on present records, are restricted to the Barreirinhas and Arari

Africa.

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ature gradient may have been less than today (Barronand Washington, 1982). By the close of the Cenoma-nian temperatures are thought to have lessened withthe onset of deeper and more open marine conditions

as the South Atlantic Ocean widened; at this timeelaterate pollen disappear from the record whereasangiosperm pollen display rapid diversification (Ta-ble 2; Fig. 3).

Relationships between the decline in frequencyand diversity of the ephedroid elaterates andcheirolepidacean pollen and increased diversity of the angiosperms have been noted (Brenner, 1963;Hughes, 1976; Doyle et al., 1977; Doyle et al., 1982;Crane, 1987; Crane et al., 1995) as indicating pro-found vegetational changes that heralded the rise todominance of the angiosperms in the terrestrial veg-etation of low latitudinal regions early in the LateCretaceous.

Moreover, the trigger for the rapid spread of angiosperms may well have resulted from ecologicalinstability associated with opening of oceans andfluctuating climates.

Acknowledgements

We thank the Management of Petrobras Research

Center for permission to publish this paper andWendy Armstrong, Department of Botany, Univer-sity of Queensland for expert ultrasectioning andassistance with Transmission Electron Microscopy.Helpful reviews from Dr. G.F.W. Herngreen and Dr.S.K. Srivastava are acknowledged. Support from theAustralian Research Council during the tenure of aSenior Research Fellowship by MED is gratefullyacknowledged. Mark Schendel (Amoco, Houston)drafted Figs. 1 and 2.

References

Barron, E.J., Washington, W.M., 1982. Cretaceous climate: a

comparison of atmospheric simulations with the geologic

record. Palaeogeogr., Palaeoclimatol., Palaeoecol. 40, 103–133.

Barron, E.J., Harrison, C.G.A., Sloan, J.L., Hay, W.W., 1981.

Paleogeography, 180 m.y. to the present. Eclogae Geol. Helv.

74, 443–470.

Boltenhagen, E., 1967. Spores et pollen du Crétacé supérieur du

Gabon. Pollen Spores 9, 335–355.

Boltenhagen, E., 1982. Amendement de Sofrepites legouxae Jard.

1967 Pollen Albien du Gabon. Rev. Micropaléontol. 25, 150–

153.

Brenner, G.J., 1963. The spores and pollen of the Potomac Group

of Maryland. Md. Dep. Geol. Mines Water Resour. Bull. 27,

1–215.Brenner, G.J., 1968. Middle Cretaceous spores and pollen from

northeastern Peru. Pollen Spores 10, 341–383.

Brenner, G.J., 1976. Middle Cretaceous floral provinces and

early migrations of Angiosperms. In: Beck, C.B. (Ed.), Origin

and Early Evolution of Angiosperms. Columbia Univ. Press,

New York, NY, pp. 23–47.

Crane, P.R., 1987. Vegetational consequences of the angiosperm

diversification. In: Friis, E.M., Chaloner, W.G., Crane, P.R.

(Eds.), The Origins of Angiosperms and their Biological Con-

sequences. Cambridge Univ. Press, pp. 107–144.

Crane, P.R., 1988. Major clades and relationships in the ‘higher’

gymnosperms. In: Beck, C.B. (Ed.), Origin and Evolution of

Gymnosperms. Columbia Univ. Press, New York, NY, pp.218–272.

Crane, P.R., 1996. The fossil history of the Gnetales. Int. J. Plant

Sci. 157 (6 Suppl.), S50–S57.

Crane, P.R., Friis, E.M., Pedersen, K.R., 1995. The origin and

early diversification of angiosperms. Nature 374, 27–33.

Dettmann, M.E., 1963. Upper Mesozoic microfloras from south-

eastern Australia. Proc. R. Soc. Victoria 77, 1–148.

Doyle, J.A., Biens, P., Doerenkamp, A., Jardiné, S., 1977.

Angiosperm pollen from the pre-Albian Lower Cretaceous

of Equatorial Africa. Bull. Cent. Rech. Explor.-Prod. Elf-

Aquitaine 1, 451–473.

Doyle, J.A., Jardiné, S., Doerenkamp, A., 1982. Afropollis, a

new genus of early angiosperm pollen, with notes on the Cre-

taceous palynostratigraphy and paleoenvironments of northernGondwana. Bull. Cent. Rech. Explor.-Prod. Elf-Aquitaine 6,

39–117.

El-Ghazaly, G., Rowley, J.R., 1997. Pollen wall of Ephedra

foliata. Palynology 21, 7–18.

Elsik, W.C., 1974. Fossil auriculate pollen. Pollen Spores 16,

507–534.

Gregory, W.A., Hart, G.F., 1992. Towards a predictive model for

the palynologic response to sea-level changes. Palaios 7, 3–33.

Herngreen, G.F.W., 1973a. Palynomorphes du Crétacé moyen du

Nord-Est du Brésil. Résultats de l’analyse palynologique de

quelques sondages et comparaisons avec l’Afrique. Sympo-

sium Palynologie et Dérive des Continents, Association des

Palynologues de Langue Française, Strasbourg, October 1973,

pp. 13–14 (abstract).

Herngreen, G.F.W., 1973b. Palynology of Albian–Cenomanian

strata of borehole 1-QS-1-MA, State of Maranhão, Brazil.

Pollen Spores 15, 515–555.

Herngreen, G.F.W., 1974. Middle Cretaceous palynomorphs from

northeastern Brazil. Results of a palynological study of some

boreholes and comparison with Africa and the Middle East.

Sci. Géol. Bull. 27, 101–116.

Herngreen, G.F.W., 1975a. An Upper Senonian pollen assem-

blage of borehole 3-PIA-10-Al, State of Alagoas, Brazil.


8/17/2019 Dino et al., 1999

34/35


Herngreen, G.F.W., 1975b. Palynology of Middle and Upper

Cretaceous strata in Brazil. Meded. Rijks Geol. Dienst N. S.

26, 39–91.

Herngreen, G.F.W., Chlonova, A.F., 1981. Cretaceous microfloral

provinces. Pollen Spores 23, 441–555.

Herngreen, G.F.W., Kedves, M., Rovina, L.V., Smirnova, S.B.,

1996. Cretaceous floral provinces: a review. In: Jansonius, J.,

McGregor D.C. (Eds.), Palynology: Principles and Applica-

tions. Am. Assoc. Stratigr. Palynol. Found. 3, 1157–1188.

Horowitz, A., 1970. Jurassic microflora from the northern Negev,

Israel. Isr. J. Earth Sci. 19, 153–182.

Hughes, N.F., 1976. Palaeobiology of Angiosperm Origins, Prob-

lems of Mesozoic Seed-plant Evolution. (Cambridge Earth

Science Series.) Cambridge Univ. Press, 242 pp.

ICBN (International Code of Botanical Nomenclature), 1994.

Tokyo Code. In: Greuter, W., Chaloner, W.G., Demoulin, V.,

Grolle, R., Hawksworth, D.L., Nicolson, D.H., Silva, P.C.,

Stafleu, F.A., Voss, E.G. (Eds.), Adopted by the Fifteenth

International Botanical Congress; Regnum Vegetabile, 131,International Association of Plant Taxonomy. Koeltz, König-

stein, 389 pp.

Jaillard, E., Ordoñez, M., Huaman, C., Jimenez, N., Rivadeneira,

M., Zambrano, I., 1994. Sintesis estratigrafica del Cretaceo

y Paleogeno de la Cuenca Oriental del Ecuador. Informe del

Convenio ORSTOM-Petroproducción, Deciembre 1994, 136

pp.

Jansonius, J., Hills, L.V., 1976–1996. Genera File of Fossil

Spores and Pollen. Dep. Geol., Univ. Calgary, Spec. Publ.

Jardiné, S., 1967. Spores à expansions en forme d’élatères du

Crétacé moyen d’Afrique occidentale. Rev. Palaeobot. Palynol.

1, 235–258.

Jardiné, S., Magloire, L., 1965. Palynologie et stratigraphie duCrétacé des bassins du Sénégal et de Côte d’Ivoire. In: Col-

loque de Micropaléontologie, Dakar, 1963. Mém. Bur. Rech.

Géol. Min. 32, 187–245.

Jardiné, S., Doerenkamp, A., Legoux, O., 1972. Le genre Hexa-

porotricolpites Boltenhagen 1967: morphologie, systématique,

stratigraphie et extension géographique. In: Proceedings Col-

loque African Micropaléontologie Abdjan, 1970, 4, 175–191.

Jardiné, S., Biens, P., Doerenkamp, A., 1974a. Dicheiropol-

lis etruscus, un pollen caractéristique du Crétacé inférieur

afro-sudaméricain. Conséquences pour l’évaluation des unités

climatiques et implications dans la dérive des continents. In:

Palynologie et Dérive des Continents. Sci. Géol. Bull. Stras-

bourg 27, 87–100.

Jardiné, S., Kieser, G., Reyre, Y., 1974. L’individualisation pro-gressive du continent africain vue à travers les données paly-

nologiques de l’Ere Secondaire. In: Palynologie et Dérive des

Continents. Sci. Géol. Bull. Strasbourg 27, 69–85.

Jingxian, Y., 1981. Late Cretaceous sporo-pollen assemblages of

Shache District, Xinjiang. Acta Geol. Sin. 2, 93–104.

Kurman, M.H., Zavada, M.S., 1994. Pollen morphological di-

versity in extant and fossil gymnosperms. In: Kurman, M.H.,

Doyle, J.A. (Eds.), Ultrastructure of Fossil Spores and Pollen.

Royal Botanic Gardens, Kew, pp. 123–137.

Lammons, J.M., 1970. Pentapsis, a new palynomorph genus

from the Cretaceous (Aptian) of Peru. Micropaleontology 16,

175–178.

Lima, M.R., 1978. Palynological characteristics of the Albian

in Brazil. Advances in Palaeobotany and Allied Sciences in

Brazil. Bol. Inst. Geocienc. Univ. São Paulo 9, 140–143.

Lima, M.R., 1980. Palinologia da Formação Santana (Cretáceo

do Nordeste do Brasil). III Descrição sistemática dos polens

da Turma Plicates (Subturma Costates). Ameghiniana 17, 14–

47.

Milne, L.A., 1994. Relationship between Propylipollis annularis

(Tertiary dispersed pollen) and extant Xylomelum (Proteaceae).

In: Kurmann, M.H., Doyle, J.A. (Eds.), Ultrastructure of Fossil

Spores and Pollen. Royal Botanic Gardens, Kew, pp. 193–213.

Milne, L.A., 1998. Surface embedding of fossil pollen for time-

and cost-effective ultramicrotomy (TEM) and microscopy

(LM, SEM, TEM) of single grains. In: Bryant Jr., V.M.,

Wrenn, J.H. (Eds.), New Developments in Palynomorph Sam-

pling, Extraction, and Analysis. Am. Assoc. Stratigr. Palynol

Contrib. Ser. 33, 95–105.Müller, H., 1966. Palynological investigations of Cretaceous sed-

iments in northeastern Brazil. In: Van Hinte, J.E. (Ed.), Proc.

2nd. W. Afr. Micropaleontol., Colloq., Ibadan, 1965, 2: 123-

136.

Osborn, J.M., Taylor, T.N., Lima, M.R., 1993. The ultrastructure

of fossil ephedroid pollen with gnetalean affinities from the

Lower Cretaceous of Brazil. Rev. Palaeobot. Palynol. 77, 171–

184.

Phipps, D., Playford, G., 1984. Laboratory techniques for extrac-

tion of palynomorphs from sediments. Pap. Dep. Geol. Univ.

Queensl. 11, 1–23.

Pocock, S.A.J., Vasanthy, G., 1988. Cornetipollis reticulata, a

new pollen with angiospermid features from Upper Triassic(Carnian) sediments of Arizona (U.S.A.), with notes on Equi-

setosporites. Rev. Palaeobot. Palynol. 55, 337–356.

Regali, M.S.P., 1989. Sistemática, bioestratigrafia e paleo-

geografia do gênero Elateropollenites Herngreen 1973, na

margem equatorial brasileira. Bol. Inst. Geocienc.-USP São

Paulo Publ. Espec. 7, 45–153.

Regali, M.S.P., Viana, C.F., 1989. Late Jurassic–Early Creta-

ceous in Brazilian Sedimentary Basins: Correlation with the

Internacional Standard Scale. PETROBRAS=SEDES, Rio de

Janeiro, pp. 47–95.

Regali, M.S.P., Uesugui, N., Santos, A.S., 1975a. Palinologia dos

sedimentos meso-cenozóicos do Brazil (I). Bol. Téc. Petrobrás

17, 177–191.

Regali, M.S.P., Uesugui, N., Santos, A.S., 1975b. Palinologiados sedimentos meso-cenozóicos do Brazil (II). Bol. Téc.

Petrobrás 17, 263– 301.

Rowley, J.R., 1996. Exine origin, development and structure in

pteridophytes, gymnosperms and angiosperms. In: Jansonius,

J., McGregor, D.C. (Eds.), Palynology: Principles and Appli-

cations. Am. Assoc. Stratigr. Palynol. Found. 1, 443–462.

Schrank, E., Ibrahim, M.I.A., 1995. Cretaceous (Aptian–

Maastrichtian) palynology of foraminifera-dated wells

(KRM-1, AG-18) in northwestern Egypt. Berl. Geowiss. Abh.

Reihe A 177, 1–44.

8/17/2019 Dino et al., 1999

35/35


Srivastava, S.K., 1978. Cretaceous spore-pollen floras. Biol.

Mem. Palaeopalynol. Ser. 53, 1–130.

Srivastava, S.K., 1981. Evolution of Upper Cretaceous phyto-

geographic provinces and their pollen flora. Rev. Palaeobot.

Palynol. 35, 155–173.

Srivastava, S.K., 1984. A new elater-bearing Late Albian pollenspecies from offshore eastern Saudi Arabia. Bot. J. Linn. Soc.

89, 231–238.

Srivastava, S.K., 1994. Evolution of Cretaceous phytogeo-

provinces, continents and climates. Rev. Palaeobot. Palynol.

82, 197–224.

Stover, L.E., 1963. Some Middle Cretaceous palynomorphs from

West Africa. Micropaleontology 9, 85–94.

Trevisan, L., 1980. Ultrastructural notes and considerations on

Ephedripites, Eucommiidites and Monosulcites pollen grains

from Lower Cretaceous sediments of southern Tuscany (Italy).


Vakhrameev, V.A., 1978. The climates of the northern hemi-

sphere in the Cretaceous in the light of palaeobotanical data.

Paleontol. J. 2, 3–17.

Van Campo, M., Lugardon, B., 1973. Structure grenue infratec-

tale de l’ectexine des pollens de quelques Gymnospermes et

Angiospermes. Pollen Spores 15, 171–188.

Wood, G.D., Gabriel, A.M., Lawson, J.C., 1996. Palynologicaltechniques — processing and microscopy. In: Jansonius, J.,

McGregor, D.C. (Eds.), Palynology: Principles and Applica-

tions. Am. Assoc. Stratigr. Palynol. Found. 1, 29–50.

Zavada, M.S., 1984. Angiosperm origins and evolution based on

dispersed fossil pollen ultrastructure. Ann. Mo. Bot. Gard. 71,

444–463.

Zavada, M.S., 1990. The ultrastructure of three monosulcate

pollen grains from the Triassic Chinle Formation, western

United States. Palynology 14, 41–51.

Zhang, Y., Zhan, J., 1986. Evolution of angiosperm pollen of

the early Late Cretaceous in the Western Tarim Basin, south

Xinjiang. Acta Palaeobot. Palynol. Sin. 1, 47–63.

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