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STUDIA GEOLOGI CA POLONICA Vol. 114, Krak6w 1999, pp. 35-75.
Mesozoic stratigraphy of Cuba Edited by A. Pszczolkowski
• 1 ' I Andrzej PSZCZOLKOWSKI & Ryszard MYCZYNSKI
Nannoconid assemblages in Upper Hauterivian-Lower Aptian limestones of Cuba: their correlation with
ammonites and some planktonic foraminifers2
(Figs 1- 13, Tabs 1- 3)
Abstract. The nannoconids are abundant in the Lower Cretaceous pelagic limestones in western and central Cuba. In some lin1estone beds, these nannofossils occur together with ammonites or planktonic foraminifers. Our samples were collected from the Polier, Veloz and Paraiso formations. The Late Hauterivian to Early Aptian age of the studied samples is based mainly on ammonites. The nannoconids identified in these samples are grouped in 4 assemblages: Late Hauter ivian, Early Barremian, Late Barremian and late Early Aptian. In the Early Barremian assemblage, the narrowcanal nannoconids are by far more frequent than the wide-canal ones. Small specimens, classified herein provisionally as N truittii truittii, occur also in this assemblage. On the other hand, the representatives of the Nannoconus steinmannii group are absent in the late Early Aptian assemblage, which includes the wide canal forms only. Nannoconids found in one sample may represent an assemblage of the earliest Aptian age.
Key words: Nannoconid assemblages, ammonites, planktonic foraminifers, Lower Cretaceous, western and central Cuba.
INTRODUCTION
Pelagic limestones are the most important lithologic components of the Cretaceous passive continental margin and basinal successions in Cuba. These finegrained limestones often lack identifiable macrofauna, while stratigraphically useful microfossils are scarce or absent, especially in the Hauterivian to Aptian carbonate rocks. The Lower Cretaceous pelagic limestones of Cuba are strongly lithified and tectonized. Coccoliths are infrequent and/or poorly preserved in these rocks, the dissolution-resistant species being the most common taxa. The nannoconids are
Institute of Geological Sciences, Polish Academy of Sciences, ul. Twarda 51/55, 00-818 Warszawa, Poland.
2 Manuscript accepted for publication September 21, 1999.
36 A. PSZCZOLKOWSKI & R. MYCZYNSKI
usually less affected by carbonate dissolution and diagenesis being the principal source ofbiostratigraphic information for many pelagic limestone beds (nannomicrites ofErba & Quadrio, 1987). Although the coccoliths are frequent in marls and marly limestones (Busson & Noel, 1991), such rocks are uncommon in the Early Cretaceous successions of Cuba.
Systematic affinity ofnannoconids is uncertain. Busson and Noel (1991 ) compared these nannofossils with calcareous dinoflagellates. In Cuba, the Bemasian- Valanginian nannoconid assemblages are dated by calpionellids (Bronnimann, 1955), while the Hauterivian, Barremian and Aptian nannoconid assemblages can be correlated, sometimes, with ammonites. Planktonic foraminifers are scarce in the Valanginian-Barremian limestones (see Pszcz6ikowski, 1999), but do occur in some Lower Aptian limestones.
The main objective of our paper is to date the Late Hauterivian to Early Aptian nannoconid assemblages in Cuba by the ammonites and the p lanktonic foraminifers. A stratigraphic standard of the Late Hauterivian- Early Aptian nannoconid assemblages is proposed, based on this correlation. In the present paper, the calcareous nannofossils (mainly nannoconids) and the planktonic foraminifers have been studied by A. Pszcz6lkowski, and the ammonites have been identified by R. Myczynski.
PREVIOUS WORK
Since the pioneer work by Bronnimann (1955) the stratigraphic distribution of nannoconids in Cuba was not studied in detail. Bronnimann (1955) described several new species of the genus Nannoconus Kamptner, 1931 and tentatively determined the stratigraphic distribution of nannoconids in central Cuba (former Las Villas Province). There, he recognized three typical assemblages ofnannoconids: (1) Nannoconus steinmanni - N. aff. globulus - N colomi, associated with calpionellids; (2) N. steinmanni - N. colomi- N kamptneri - N. bermudezi - N. globulus (with rare "globigerinas" in a single section); and (3) N. truitti - N. minutus - N. elongatus - N bucheri - N. wassalli, associated with Orbitolina sp. The age of the assemblage 1 was determined as the Neocomian, of the assemblage 2 as the Barremian, and of the assemblage 3 as Aptian to Albian (Bronnimann, 1 955).
These tentative age correlations have not been verified or improved until recently (see Pszcz6lkowski, 1999). A single information on the occurrence of Nannoconus cf. truittii Bronnimann and Nannoconus cf. minutus Bronnimann determined by Dr A. de la Torre in the limestones of the Polier Formation at Nottey (Casa Blanca) was presented in Myczynski and Triff (1986).
Outside Cuba, the Early Cretaceous nannoconid stratigraphy was the topic of several studies (e.g., Trejo, 1960; Moshkovitz, 1972; Deres & Acheriteguy, 1980; Erba, 1989). Trejo ( 1960) distinguished six nannoconid zones (A-F) based mainly on data from Nmthem and Eastern Mexico; these zones were correlated with microfossils and ammonites. Deres and Acheriteguy (1980) established 11 nannoconid biozones in the latest Jurassic through Cretaceous (pre-Maastrichtian); in this
NANNOCONID ASSEMBLAGES OF CUBA 37
0 60 KM
' ~ '~ATANZAS CO~
i MARTf •""' 1 6""'• •a ~ 5 ) - ~ ..
J ;VILLA 'AATANZAS C LARA
1f_l!.OV PROVINCE _,..· ' _ _ t·" 1 J
( ( ~
"-. CJE NFUEG OS
'
Fig. l. Location map showing sites sampled in western and central Cuba (see inset for location of the studied area in Cuba). Sampled sites (triangles): 1-Nortey (Casa Blanca); 2a - Lorna Caldoso; 2b - South of Bahia Honda (and Quinones); 3- Mango Bonito hill; 4 - Lomas de Polier; 5- El Sordo Viejo; 6 - Silverio-Cabrera hill ; 7- La Sierra; 8 - South of Playa Gamuza; CORR. - Corralillo
time span, they described and figured thirty seven species and subspecies of the genus Nannoconus,and defined the age of their assemblages by applying the first and the last occurrences of particular species as stage boundaries (see Perch-Nielsen, 1985). Erba (1989) correlated nannoconid events with calcareous nannofossil, calpionellid and planktonic foraminiferal biostratigraphy in Northern and Central Italy.
The Early Cretaceous ammonites were studied in the Pinar del Rio province (Fig. 1) and in the area near the border of the Matanzas and Villa Clara provinces (Myczynski, 1977; Myczyflski & Triff, 1986). The Berriasian- Hauterivian ammonites of Cuba, Mexico and southern United States belong to the same zoogeographic province. On the contrary, the rich Barremian ammonite assemblage of Cuba is similar to the coeval European one (Myczyflski, 1994).
SAMPLES AND METHODS
The samples were collected in 1970- 1990 during our field work ( 1970- 1990) in the Pinar del Rio, Matanzas and Villa Clara provinces of Cuba (Fig. 1 ). The limestone samples in the Pinar del Rio province (Tab. -1) belong mainly to the Polier Formation (Berriasian-Aptian). In central Cuba, three samples were collected from the Veloz Formation (Tithonian- Aptian) and one from the Paraiso Formation (Hauterivian- Aptian?), close to the border between the Matanzas and Villa Clara provinces (Fig. 1; Tab. 1). Fresh cuts of limestone were studied in the SEM. These cuts were taken from 1 1limestone samples containing the ammonites figured in this paper and (in one case) in an earlier publication (Myczynski & Triff, 1986). In one sample, the age of the nannoconid assemblage was established based on planktonic foraminifers identified in thin sections.
38 A. PSZCZOLKOWSKJ & R. MYCZYNSKJ
REGIONAL SETTING OF STUDIED SAMPLES
The limestones of the Polier Formation (Pszcz6lkowski, 1978) were sampled at five sites in the northeastern part of the Pinar del Rio province: Nortey (Casa Blanca); Lorna Caldoso; south of Bahia Honda (and Quinones); Mango Bonito hill; and Lomas de Polier (Fig. 1; Tab. 1 ). Four samples were collected from limestones of the Paraiso and Veloz formations in sites located in the Matanzas and Villa Clara provinces, central Cuba (Fig. 1; Tab. 1).
Table 1
Geographic location of samples used in this study
rc -·- - ·- I- ·- --·--------·----· ·---------· rSa~ _ _ l__ Formatio~-t------- Location_. __ -----:
~M-87/3 ~ ., ' ~-88112- 1 p l' Nortey (CasaBlanca) locality, northeast of San Cristobal, 1
AM-8
S/ l4 --4-__ 0
~r-_linar del Rio province m western Cuba (sit~ Fig.~- 1
~-I 2-H I p !' /Lorna Caldoso, south of Bahia Honda (and Quinones), ~ ~----~ ___
0 Ier __ ~ar del R~rovincc in weste.r_!!_ Cub~~ite E_in ~i& Jj_ -j
·jAM-8512 Polier I ~~ut? of Balna Honda (and Qmil.on~s), Pmar del R10 I ----+-- ____ ~ovmce, western Cu~ stte_1!)_!Q f't!L,l)_ - ··--- ...j
~M-90125 Polier I ~-ango. Bo~ito hill, Pinar del Rio province in western Cuba I
1_:__+------t~ 3m F1g.~) . ·- -:---:-- - · ._J ~6P-598 __ ~--~olie~ _ ~~:;~~l:her, Pmar del Rw provmce, western Cuba (stte I
AM-9411 Veloz I El Sordo Viejo. locality si~atc? southeast of Marti, --j
~·---- ~---·-- ._1 Matan~rovmce ~j_m F.!&, l.l _____ ._ ._
1
/
AM-93/23 Silverio-Cabrera hill located near the border of the -·---~ Veloz jMatanzas and Villa Clara provinces in central Cuba (site 6 I
A M-93/28 in Fig. l)
f3_M __
23:-r--Velo-z- - --, L-a-S~ie"""rra..._l_o_ca-li-~-, -ncar the b.ord-er_o_f the. -M-at-~n-za-. s-an-d- -~
---· ·- _______ Vtlla Cla~rovmces m central ~uba__0Jte 7 m F!&)l.___ [ r . I South of P.laya Gamuza, east of Corralillo, northwestern II
!AM-95_:__j _ _ Para1:__ ~~~;.~~the Villa Clara province in central Cuba (sit~l.:_j
Nortey (CasaBlanca) section
The limestones of the upper part of the Polier Formation, exposed in the Nortey (Casa Blanca) section (Fig. 2: A) located in the eastern part of the Pinar del Rio province, yielded many Early Barremian ammonites (Housa & de Ia Nuez, 1975; Myczyilski, 1977). Later findings of ammonites by Myczynski and Triff (1986) suggested a Barremian- ? Aptian age of these limestones. The limestones in question are about 6 m thick (Fig. 2: A).
NANNOCOl-110 ASSEMBLAGES OF CUBA 39
Sections:
A - Nortey (Ca•• Blanca)
B -Lema Caldoso
C - Man9o Bonilo
D -Lomas de Polier
A 6 - - - -~AM-SB/14
Chelonie~r.as
(Chefon~eras) sp
- -~~~!~~~ a J5;;l50;;;;;;;;o-_,.. 'Su btimbtia.tum ~
"' w
-' 0 "-
B
c
1-...:
Prote tragon:te-s sp. ~
~~~cf P. erebrisulcatus cr - @> AM-00/25 0
u_
D
Crtoceratitt s (Ern ericicel'3s} cf lh iolliere:i
t::¢;~:>l -':il PulcheWa cf. favret
A . cf diSii nS
m 'r~~~~:~ ~~o~~c~:Ss)~ D sand!.tonK (silcituTbidtes)
rn mafly limeston~ - rcldlolarian cherts and shales:
(j) ammon ltes (nurr~ be,., denote samples studied in SEM tor nannolossis. marnfy n'il nn~nids)
Fig. 2. Sections of the Polier Formation in the Pinar del Rio province (western Cuba); position of samples and/or ammonites indicated (for location of sites see Fig. l and Tab. l )
Three samples were collected for nannoconid study. Sample AM-87/3 comes from the lowermost limestone beds, about 1.3 m above tectonic contact ofthe Polier Formation deposits with serpentinite. The earliest Barremian age of sample AM-87/3 is based on occurrence of Lytoceras subjimbriatum (d'Orbigny) and associated ammonite taxa, such as Phyllopachyceras infundibulum (d 'Orbigny) and Crioceratites sp. (Tab. 2). Other ammonites were found in the middle part of the section (Fig. 2: A): Anahamulina cf. subcincta (Uhlig) (specimen AM-88/9) occurs in the middle part of the Early Barremian (see Tab. 2), in the Nicklesia pulchella Zone sensu Vermeulen (1995, 1996); Hamulinites aff. parvulus (Uhlig) comes from a limestone bed (sample AM-88/ 12) above that with Anahamulina cf. subcincta (Uhlig) (Fig. 2: A). Hamulinites parvulus (Uhlig) is known from Early Barremian (Vasicek, 1972 ), and is also cited from Late Barremian ofi taly ( Cecca & Landra, 1994). Its total range is not clear (see the discussion in description of Hamulinites aff. parvulus (Uhlig) in this paper). In the Nortey (CasaBlanca) section, this ammonite was found together with the Early Barremian ammonites (see below).
Sample AM-88/14 with Cheloniceras (Cheloniceras) sp. (Myczyilski & Triff, 1986, p.l35, lam. II, fig. 1 0) was collected in the uppermost part ofthe Nortey (Casa Blanca) section (Fig. 2: A). This subgenus is lmown from Late Barremian.
Other ammonites collected from the Barremian deposits of the Nortey (Casa
40 A. PSZCZOLKOWSKI & R. MYCZY"NSKI
Table 2
Tentative conelation of the ammonite succession in the Nortey (CasaBlanca) section with the Banemian ammonite biozonation of France and Spain
Company et al., 1995 Vermeulen, 1 99 5, 1996 Nortey (Casa Blanca) - Cuba
SUBSTAGE (Spain) (France) (this paper)
Zones Zones Ammonites
Not figured Gerhardtia Cheloniceras (Che/onic:eras) sp.
UPPER sartousiana Ptychoceras cf. morloti
BARREMIAN Ancyloceras Colchidites cf. colchicus
vandenheckii Heinzia sayni
Mountoniceras mountonianum
Coronites darsi
Kotetishvilia Kotetishvilia Pulche/lia (Nicklesia) sp. cf. compressisima compressisima P dumasiana
Pulchellia (Nicklesia) sp. cf. P. pulchel/a
LOWER Nicklesia pulchella
A.nahamulina cf. subcincta BARREMIAN Kotetishvilia Hamuli no cf. astieriana
nick.lesia Hamulinites aff. parvulus Kotetishvilia nicklesi Eohetemceras norteyi
Psilotissotia Astieridiscus sp. cf. A. mor/eti colombia.na Crioceratites p inarensis
Avramidiscus Psilotissotia Spitidiscus c f. seunesi Crioceratites sp.
hugii mazuca Phyllopachyceras infimdibulum Avramidiscus Moutoniceras cf. anufare
hugii Lytoceras subjimhriatum
Blanca) section include (Myczyilski, 1977; Myczyilski & Triff, 1986): Phyllopachyceras infundibulum (d'Orbigny), ?Karsteniceras sp., Crioceratites pinarensis Myczyilski, C. sp ., Moutoniceras cf. anulare (d'Orbigny), Colchidites cf. colchicum Djanelidze, Hamulina cf. astieriana d 'Orbigny, ?Hamulina sp., Ptychoceras cf. morloti Ooster, Spitidiscus cf. seunesi (Kilian), Pulchellia (Nicklesia) cf. dumasiana (d'Orbigny), P. (Nicklesia) sp. cf. P. (N.) pulchella (d'Orbigny), Eoheteroceras norteyi (Myczynski & Triff), E. cf. norteyi (Myczynski & Triff), Astieridiscus sp. cf. A. morleti (Kilian). The specimen of Ptychoceras cf. morloti Ooster was found in the upper part of the section.
The species Ptychoceras morloti Ooster is known from Late Barremian through Early Aptian of Switzerland, Crimea, and Czech Republic (Vasicek, 1972). The species Colchidites colchicus Djanelidze is known only from the Early Aptian, but genus Colchidites Djanelidze, 1924 occurs also in the Upper Barremian deposits (see Kakabadze & Kotetishvili, 1995). Moutoniceras cf. anulare ( d'Orbigny) is the only taxon that could represent the Hauterivian. Moutoniceras anulare ( d' Orbigny)
NANNOCONID ASSEMBLAGES OF CUBA 41
was originally described from the Upper Hauterivian strata of France (Thomel, 1964). Other species of the genus Moutoniceras are also known from the Barremian, for example M moutonianum (d'Orbigny) (see Company et a!., 1995).
The above ammonite succession (Tab. 2), is mainly of Early Barremian age. The limestones of the uppermost part of the Nortey (Casa Blanca) section belong to the Upper Barremian ( Gerhardtia sartousiana Zone, sensu Vermeulen, 1998), based on the presence of Che/oniceras ( Cheloniceras) sp., Colchidites cf. colchicus Djanelidze and Ptychoceras cf. morloti Ooster.
Lorna Caldoso section
Good outcrops of the Polier Formation deposits existed between 1971 and 1980 south of Quinones, along the road from San Cristobal to Bahia Honda (Fig. 1). Strongly tectonized limestones, sandstones and shales were exposed between Quinones and Lorna Caldoso. The ammonites collected there were identified by Myczyilski ( 1977), who suggested a Barremian- Albian age for the upper part ofthe Potier Formation. SampleP-12-H withAnahamulina cf. subcincta (Uhlig) was collected from a limestone bed about 6 m above the base of the Lorna Caldoso section which includes limestones, sandstones and shales exposed below a local thrust plane (Fig. 2: B). As mentioned above, A. cf. subcincta (Uhlig) is characteristic for the middle part of the Early Barremian.
Section south of Bahia Honda (and Quinones)
Sample AM-85/2 was collected in the same area, south of Bahia Honda (and Quinones), north ofLoma Caldoso (Fig. 1), in another section of the Potier Formation (not shown in Fig. 2). Ammonites Subsaynella sp. cf. S. boyacaensis Haas and ?Paraspiticeras sp., found in this sample, are considered to be of Early Barremian age.
Mango Bonito hill section
Sample AM -90/25 with Protetragonites sp. cf P. crebrisulcatus (Uhlig) comes from an outcrop located at a road cutting on the southwest slope of the Mango Bonito hill (Fig. 1). Jt was collected about 36 m below the top of the Potier Formation (Fig. 2: C). Protetragonites crebrisulcatus (Uhlig) is known from the Banemian- Lower Aptian strata (Vasicek, 1972).
Lomas de Polier section
Sample 6P-598 with Criocemtites (Emericiceras) cf. thiollierei (Astier) was collected in the Lomas de Polier section (Fig. 1 ), about 34m below the top of the Potier Formation, 20m below the base of the Roble Member - the uppermost part of this formation (Fig. 2: D). The Lomas de Polier section was designated as the stratotype ofthe Polier Formation (Pszcz6lkowski, 1978). On the basis of the ammonites collected in this section, Myczyilski (1977) assigned the Polier Formation to the
42
z 0
1-<(
:2 0:: 0 LL
0 (f)
<(
0:: <(
11..
A. PSZCZOLKO\VSKT & R. MYCZYNSKT
B A m
15
m z
12 0 40 ~ 1-
-+@IAIII-93/23 <(
9 :2 Holcodiscus
-+~AM-95/5 0:: 30 aff_ geron ima eformis P seudothurm annia 0 mortilleti oatulloi LL
6 N 20 --~ AM·9~128 0 _j Crioceratites (Crioceraliles) sp. w gr. C. (Cnoceratites) nolani
3 > 10
0 0
~ ~~d~~~~~=~ ~~oa~~c~f~e~jil- [I] sandstones (sili cfturbidites)
ITJ mal1ylimestones -cherts
$ ammonites (numbers denote samples studied in SEM for nannofossils, mainty nannoconids)
Fig. 3. Sections of the Paraiso and Veloz formations in the northwestern part of the Villa Clara province (central Cuba); position of samples and ammonites indicated (for location of sites see Fig. 1 and Tab. 1)
Valanginian-Barremian. The Roble Member of the Polier Formation contains scarce and poorly preserved ammonites only, therefore the age of this unit is not well constrained with macrofauna. The species Crioceratites (Emericiceras) thiollierei (Astier) is known from the Barremian of France (Thomel, 1964), the Hau.teiivian-Barremian ofitaly (Baccelle & Garavello, 1967) and the Early Barremian ofBulgaria (Dimitrova, 1967). In the Lomas de Polier section, Pulchellia cf.favrei (Ooster, 1860) andAnahamulina cf. distans (Hohenegger, 1883) were collected 15 m below beds with Crioceratites (Emericiceras) thiollierei (Astier). The species P. favrei was reported from the Early Barremian of Colombia (Biirgl, 1956). A similar ammonite succession in Spain was determined to be of the middle Early Barremian age (see Company et al., 1995).
Playa Gamuza section
Sa-mple AM-95/6 containing Pseudothurmannia mortilleti catulloi (Parana) was collected from the middle part of the Paraiso Formation, south of Playa Gamuza in central Cuba (Figs. 1, 3: A). This formation was established by Shopov (1982) in the Camajuani succession. He attributed an Upper Hauterivian-Lower Barremian age to the Paraiso Formation, while Myczynski and Triff (1986) preferred a Hauterivian-Barremian age. The species P. mortilleti catulloi (Parona) is
NANNOCONID ASSEMBLAGES OF CUBA 43
known from the Angulicostata auct. Zone, which is the highest Hauterivian ammonite zone (Hoedemaeker et a/., 1993).
Silverio-Cabrera hill section
Sample AM-93/28 with Crioceratites (Crioceratites) sp. gr. C. no/ani (Kilian) was collected from a limestone bed in the middle part of the Veloz Formation, exposed on the Silverio-Cabrera hill (Fig. 3: B) near the border of the Matanzas and Villa Clara provinces in central Cuba (Fig. 1; Myczyilski and Triff, 1986, fig. 1 ). The species C. (Crioceratites) no/ani (Kilian) is known from the Late Hauterivian- ?Early Barremian ofFrance (see Thome!, 1964). Higher up in this section (Fig. 3: B), the species Holcodiscus aff. geronimaeformis Tzankov was collected (sample AM-93/23). This ammonite occurs in the Barremian Nicklesia pulchella Zone. The taxa Pulchellia (Nicklesia) sp. cf. P. (Nicklesia) pulchella (d'Orbigny, 1842) andHamulinites aff.parvulus(Uhlig, 1883) also occur in the assemblage discussed (Myczyilski and Triff, 1986).
El Sordo Viejo section
The ammonite Melchiorites sp. gr. emerici (Raspail) was collected in the Veloz Formation limestone (sample AM-94/1) at El Sardo Viejo locality, about 8 km southeast of Marti in the Matanzas province (Fig. 1). This ammonite occurs in the Upper (possibly the uppermost?) Barremian strata (see systematic description). Other ammonites reported from the El Sordo Viejo area are also Barremian in age (Myczynski & Triff, 1986).
La Sierra section
Sample 3M-235-A was collected at La Sierra locality in the Villa Clara province of central Cuba (Fig. 1; Tab. 1 ), from a nannofossil-radiolarian biomicrite of the topmost part of the Veloz Formation, directly below the radiolarian cherts of the Santa Teresa Formation (Pszcz6lkowski, 1986). The sample yielded frequent planktonic foraminifers determined in thin sections: Clavihedbergella semielongata (Longoria), C. cf. eocretacea Neagu, Globigerinelloides cf. maridalensis (Bolli) (Fig. 4: 3), Hedbergella delrioensis (Carsey) (Fig. 4: 1), H. cf. bizonae (Chevalier) (Fig. 4: 4), H. cf kuhryi Longoria, H. cf. longorii (Banner & Desai), H. gr. planispira (Tappan)-delrioensis (Carsey) (Fig. 4: 2), H. sigali Moullade, H. cf. similis Longoria, H. sp. , Leupoldina cf. pustulans (Sigal) and L. sp. This assemblage is of late Early Aptian age (cf Longoria, 1974; Sliter, 1989; Cobianchi et al. 1997).
NANNOFOSSILS RECORDED IN STUDIED SAMPLES
The nannoconid assemblage assigned here to the Late Hauterivian (sample AM-95/6) includes the following taxa (Tab. 3): Nannoconus colomii (Fig. 5: !), N. globulus g lobulus, N. steinmannii minor (Fig. 5: 3) and N. steinmannii steinmannii
44 A. PSZCZ6LKOWSK.I & R. MYCZYNSKI
Fig. 4. Planktonic foraminifers from sample JM-235-A, Veloz Formation, Lower Aptian (thin-section): 1 - Hedhergella delrioensis (Carsey); 2 - Hedhergella gr. planispira (Tappan) -delrioensis (Carsey); 3 - Globigerinelloides cf. maridalensis (Bolli); 4 - Hedbergella cf. bizonae (Chevalier); all figured specimens x 200
(Fig. 5: 2). The specimens of N steinmannii minor and N steinmannii ste inmannii are common in this assemblage, although well-preserved nannoconids are rather infrequent. Coccoliths are relatively frequent, but usually poorly preserved. Only Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968 (Fig. 5: 4), Lithraphidites carniolensis carniolensis Deflandre, 1963 (Fig. 5: 5), and Rotelapillus sp . have been identified.
Only three nannoconid species have been identified in sample AM-93/28 (Tab. 3): N steinmannii minor, N steinmannii steinmannii and N truittii truittii(?). The narrow-canal fonns are the main component of this poor nannoconid assemblage. The presence of N. truittii truittii(?) is interpreted here in favour of an Early Barremian age of this sample. Coccoliths are as frequent as the nannoconids, but poorly preserved. The species Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968, and Rhagodiscus sp. were recognized.
The following nannoconids have been identified in sample AM-87/3 (Tab. 3): Nannoconus s teinmannii minor, N. steinmannii steinmannii and N bucheri. In this sample, the nannoconids are uncommon: Nannoconus steinmannii minor and N. steinmannii steinmannii predominate, whereas N. bucheri is scarce. The coccoliths
NANNOCONID ASSEMBLAGES OF CUBA 45
Table 3
Ammonites and nannoconids identified in the studied samples
~S~mple ~-formation I - Arnm~-s---~ Age I -= Nannoc_o_n_u_s _ _ _ _ l-,
~ I --+' . I' .rv· steinmannh mmor _ I _ L l'loceras suhfimhrwtwn eatliest . . _ AM-87/3 Po her (d . .
0 b' ) · B . N .. 1temmmmu Jlemmannll
t
r tgny arremtan N. buchen
f--------1,---- - --- --- --- - - Barmnian IN. bucheri
AM-88/ 12 1 Potier
1
Hamulmites aff. parvulus (Uhlig) (Earl~ 1 N. steinmannu stemmannu l ~- __ 11_1 - · - - . . I -- -- · I ""-•") I: ::::;=iUU .--- -1 I N. colonm ' I • 1 ; Late N u/ohulus o/obulus
I AM-88/14 Poher Clre/oniceras (Cheloniceras) sp. ., "1 . "'.. . ~· Barremian ,,_ s emmannu stemmannn , : I N cf. /ruittii jrequens
L----L.- - -----·- -----· 1 N. truitLii trui/lii _ _ _ . / - I N. bucheri
·~· Analwmu/ina cf. subcincta Early N cf. minutus = ~: P- 12-H Polier -f. 1 N. sleinmannii minor
~ (Uhlig) . Barremian IN. steinmannii steinm. annii N. truittii truittii
1------1-----+~---- __ __ _,I_N_. -bu- cheri
I' N co/omii (a) Suhsaynel/a sp. cf.. S Early '' k k
Polier I I 1
1>. amptneri amptneri AM-85/2 boyacaensis Haas Barremian N. steimnannii minor
(b) '! Paraspiticera.~ sp. . .. . .. I N. stemmanmr stemmann11
------ I LN. truilfu tnatlii ' ·- .. _ ·-- - p f p --r-B -.---, ,V, stein~annii-steinmannu
I . rotetragomtes sp. c . arremran- . .
AM-9 Poher h . 1 (U'hl' ) , E l A . N. cf. lruttlll jrequem ere n su cafliS 1g I • ar y pnan N .
+'~.----+-·-----------~ .. _ ----~ :~· :~::~~r~rw11_11 __ --- - ·
Polier ! Crioceratites (f!mericicerao) I Early ·
1
; ~~ steinmonnii mmor .. . . . thwllrerer (Asncr) Barremtan . N. stemmannrt sremmannu _ -t- --+- ___ ___ ·- ---' N. 111titlii truirtii ~
I Late ,.N. co/omii Si
6 I Paraiso i Pseudothurmannia mortilleti Hauterivian . N. globulus globulm
:j·atulloi (Parona) ____tAngultcostata lN. steinmannii minor
1 c.mct. Zone) ,-~-/. steinmannii steinmannii • ·----· - ···· ·- --·· --·- - - -.. '' ·- ----· ·- --·- -· ------··---3/~3 1 \ ' 1 Holcodiscus aff. geronimaejimnis , B .. . I." . . . . . .. _j1
, .t. e T k +. arremllln rv. slemmanntt stemmannu zan ov 1----~-- ----- ·--~· . · - -- i --- · --·-~-.. '
Late · I I I
' N. steinmannii minor AM-93128 1
Veloz Crioceratites (Crioceratitesj sp. Hauterivian--? IN. steinmannii steinmannii , gr. Crioceratites no/ani (Kilian)
1 Early
Barremian N. truittii truittii (?)
I
, ---··-- --------·~· --·-----·· -,,. ~ ~~~::;~~e-rt-. k-·a-~~tneri - ~~ AM-94/ l_LI. v~loz 'I c'\-Rfea/scp·haito.,r)iles sp. gr. emeric_i_ Late
w I Barremian 1 N. steinmannii steinmannii
I. f\l. steinrnannii minor 1 N /ruillii truittii __ ______ .. . --- ----'
46 A. PSZCZOLKOWSKl & R. MYCZYNSKI
Table 3, continued
Sampl~-j fonna~~+-----~~~~n_i!:;> _____ L_ A~ __ j__= ~a_;~~;us_=--~ 1 'I I N. elongatus
I 1 t E 1 IN. globulus globulus I I
· 1 a e ·anv 1 JM-235-A Veloz I A . 1 1 N. tmillii rectangulnris j
I I I pttan I N .. . .. 1
. /rui/111 /r ul ffll 1 __._ __ __l_ ________________ l ______ li'{ £L·~'!!.~'E--------'
1 Ammonite figured in: Myczyilski and Triff( I986, 1:\m, II, fig. 10); 2 O n the basis of planktonic foraminifers determination in thin sections (this paper)
are quite frequent, although poorly preserved. The species Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968 (Fig. 9: 1) and Lithraphidites cf. bollii (Thierstein, 1971) (Fig. 9: 4) are the only taxa identified. W. barnesae is common in this sample. The presence of Lithraphidites cf bollii (Tbierstein, 1971) and the absence of Nannoconus truittii truittii suggest a Late Hauterivian-earliest Barremian age of the sample AM -87/3. The earliest Barremian age of this sample is based on ammonites (see chapter: Regional setting of studied samples).
Four nannoconid taxa have been detennined in sample 6P-598 (Tab. 3): N. bucheri (Fig. 6: 4), N ste inmannii minor, N steinmannii steinmannii and N. truitlii truittii (Fig. 6: 6). In this sample, consisting of a highly indurated Lower Barremian nannomicrite, the narrow-canal nannoconid forms predominate. Less frequent coccoliths are represented by Cyclagelosphaera margereliiNoei, 1965 and Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968.
The nannoconid assemblage identified in sample AM-88112, taken from a Barremian (probably Lower Barremian) limestone, comprises (Tab. 3): N. bucheri, N. steinmannii steinmannii and N. truittii truittii (Fig. 8: 2). The narrow-canal nannoconids are more frequent (-70%) than the wide-canal forms (- 30%). This sample, consisting of a slightly marly limestone, contains also poorly preserved coccoliths, such as Lithraphidites carniolensis carniolensis Deflandre, 1963, and coccospheres of Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968 and Cyclagelosphaera margerelii Noel, 1965. Sample P-12-H yielded the following nannoconid taxa (Tab. 3): N. bucheri (Fig. 6: 3), N. cf. minutus (Fig. 6: 2), N. steinmannii minor (Fig. 6: 1), N. ste inmannii steinmannii and N. truittii tntittii (Fig. 6: 5). Coccoliths are scarce; only Haqius sp. was identified in this sample taken from the Lower Barremian limestone.
In sample AM-85/2 the narrow-canal nannoconids (mainly Nannoconus steinmannii steinmannii andN. colomii - Fig. 7: 3) are common, whereas the wide-canal forms (N. bucheri, N. kamptneri kamptneri, N truittii truittii) are less frequent. The subspecies 1Vannoconus steinmannii steinmannii is the most common fonn in this sample. Nannoconids identified as N truittii truittii, although classified here as the wide-canal forms, have a narrower axial canal than the typical representatives of this taxon (see Deres & Acheriteguy, 1980). Such a composition of the nannoconid assemblage is typical for the Lower Barremian limestones in Cuba. The coccoliths
NANNOCONID ASSEMBLAGES OF CUBA 47 ... · · ···~ --- - ------~--- '""':'~-,::v;:;: -:--···---. ,
10tJm
Fig. 5. Nannofossils from sample AM-95/6 (Paraiso Formation, Upper Hauterivian, central Cuba): 1 - lv'annoconus colomii de Lapparcnt, 1931, 2 - Nannoconus steinmannii Kamptner subsp. steinmannii Deres et Acheriteguy, 1980, 3 - Nannoconus steinmannii Kamptner subsp. minor Deres etAcheriteguy, 1980, 4 - Watznaueria barnesae(Biack , 1959) Perch-Nielsen, 1968 (coccosphcre), · 5 - Lithraphidites carniolensis carniolensis Deflandre, 1963 (incomplete specimen)
are frequent but usually poorly preserved. Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968 is frequent, whereas Lithraphidites carniolensis carniolensis Deflandre, 1963 is scarce.
The subspecies Nannoconus ste inmannii steinmannii is the only representative of the genus Nannoconus Kamptner, 1931 identified in sample AM-93/23 taken.
48
1
4
A. PSZCZ6LKOWSK1 & R. MYCZYNSKI
5
' "" .. . .......,... ---·i .-: .. ......... ~-
• -··""" \( #
\'
Fig. 6. Nannoconids from samples P-12-H, 6P-598, AM-88-14 and AM-90/25 (Polier Formation, Sierra del Rosario, western Cuba): 1 - Nannoconus steinmannii Kamptner subsp. minor Deres et Acheriteguy, 1980, sample P-12-H (Lower Barremian); 2 - Nannoconus cf. minutus Brtinnimann, 1955, sample P-12-H (Lower Barremian), 3, 4, 8 - Nannoconus bucheri Bronnimann, 1955, (3 -oblique section, sample P-1 2-H; 4 - tangential section, sample 6P-598, Lower Barremian; 8-subaxial section, sample AM-88/14, Upper Barremian); 5- 7- Nannoconus truittii Bronnimann subsp. truittii Deres et Acheriteguy, 1980 (5- tangential section, sample P-12-H; 6 - sample 6P-598; 7 - sample AM-90/25, Barremian- Lower Aptian), 9 - Nannoconus cf truittii Bronnimann subsp.frequens Deres et Acheriteguy, 1980 (sample AM-88/1 4)
NANNOCONID ASSEMBLAGES OF CUBA 49
Fig. 7. Nannoconids from samples AM-88-14, AM-85-2 and 3M-235-A: I , 2- Nannoconus truittii Bronnimann subsp. truittii Deres et Acheriteguy, 1980 (1 - sample AM-88-14, Potier Formation, Upper Barremian?- Lower Aptian; 2 - axial section, sample 3M-235-A, Veloz Formation, Lower Aptian); 3- Nannoconus co/omii de Lapparent, 1931 (axial section, sample AM-85/2, Potier Formation, Upper Barremian- lowermost Aptian), 4 - Nannoconus globulus Bronnimann, 1955 subsp. g/obulus Bra1ower et Thierstein, 1989 (sample 3M-235-A, Veloz Fonnation, Lower Aptian)
from a Barremian limestone. This nannoconid species occurs together with poorly preserved coccoliths, mainly Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968.
The nannoconid assemblage found in limestone sample AM -9411 of Late Barremian age contains: Nannoconus bucheri(?), N cf. kamptneri kamptneri, N. steinmannii steinmannii, N. steinmannii minor and N. truittii truittii (Fig. 8: 1). The narrow-canal nannoconids slightly predominate over the wide-canal forms. The coccoliths are uncommon: Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968 and Lithraphidites carniolensis carniolensis Deflandre, 1963 are the main taxa present.
50 A. PSZCZ6LKOWSKJ & R. MYCZYNSKI
1
(
3 4
6
• Fig. 8. Nannoconids from samplesAM-88/ \2,AM-88/l4,AM-94/J and JM-235-A: 1-3 - Nannoconus truitlii Bronnimann subsp. truittii Deres et Acheriteguy, 1980 ( l - sample AM-94/1, Veloz Formation, Upper Barremian; 2 - sample AM-88/ 12, Polier Formation, Lower Barremian, 3- sample 3M-235-A, Veloz Formation, Lower Aptian), 4 -Nannoconus truittii Bronnimann subsp. rectangu/aris Deres et Acheriteguy, 1980 (sample 3M-235-A, Veloz Formation, Lower Aptian); 5 - Nannoconus steinmannii Kamptner subsp. steinmannii Dercs et Achcriteguy, 1980 (sample AM-88/14, Polier Formation, Upper Barremian?-Lower Aptian); 6 - Nannoconus elongatus Bronnimann, 1955 (sample 3M-235-A, Veloz Fonnation, Lower Aptian)
NANNOCONID ASSEMBLAGES OF CUBA 51
Fig. 9. Nannofossils from samples AM-87/3 and AM-90/25: 1 - Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968, sample AM-87/3, Lower Barremian; 2- Microstaums cf chiastius (Worsley, 197 J) Grtin in GrUn and Allemann, 1975, emend. Bra lower and Thierstein in Bra lower et a/. ( 1989), sample AM-90/25, Barremian- Lower Aptian; 3 - Retecapsa angustiforala Black, 1971, sample AM-90/25; 4 - Lithraphidites cf. bollii (Thierstein, 1971 ), incomplete specimen, sample AM-8713
Nannoconids found in limestone sample AM-88/14 of Upper Barremian age include the following taxa (Tab. 3): Nannoconus bucheri (Fig. 6: 8), N. colomii, N. globulus globulus, N. steinmannii steinmannii (Fig. 8: 5), N. cf truittiifrequens (Fig. 6: 9) and N. tnlittii truittii (Fig. 7: /).The coccoliths are as frequent than nannoconids, but poorly preserved: Haqius? sp. and coccospheres of Watznaueria harnesae (Black, 1959) Perch-Nielsen, 1968, have been observed.
The subspecies Nannoconus steinmannii steinmannii, N cf truittiifrequens and N truittii truittii (Fig. 6: 7) were identified in sample AM-90/25 (Tab. 3). In this sample, the wide-canal nannoconids predominate over the narrow-canal ones. A minor share of the latter forms is characteristic for the Early Aptian nannoconid assemblages (see Erba, l 994). Coccoliths are present, with Watznaueria barnesae
52 A. PSZCZ6t.KOWSKI & R. MYCZYNSKI
(Black, 1959) Perch-Nielsen, 1968 as a common species; scarce Microstaurus cf. chiastius (Worsley, 1971) Griin and Allemann, 1975, emend. Bralowcr and Thierstein, 1989 (Fig. 9: 2), and Retecapsa angustiforata Black, 1971 (Fig. 9: 3) can also be observed.
Sample 3M-235-A contains a well-preserved wide-canal nannoconid assemblage oflate Early Aptian age (Tab. 3): N elongatus (Fig. 8: 6), N globulus globulus (Fig. 7: 4), N. truittii rectangularis (Fig. 8: 4), N. truittii truittii (Figs 7: 2, 8: 3) and N. cf. wassallii. Coccoliths are very scarce and poorly preserved: the longranging Microstaurus cf. chiastius (Worsley, 1971) Grtin and Allemann, 1975, emend. Bralower and Thierstein, 1989 (Upper Jurassic-Cenomanian according to Perch-Nielsen, 1985) is the only identified one.
NANNOCONID ASSEMBLAGES
Vertical distribution of Nannoconus taxa identified in the studied Lower Hauterivian to upper Lower Aptian limestone samples is shown in Fig. I 0 (at right), together with stratigraphic distribution of the Nannoconus species after Bronnimann (1955) - Fig. 10, at left Nannoconids identified in our samples are grouped in 4 assemblages, denoted A l, A2( a), A2(b) and A3 in order to link them to Bronnimann' s (1955) standard.
Late Hauterivian nannoconid assemblage
The Late Hauterivian assemblage (AI in Fig. 10) is based on sample AM-95/6 (Paraiso Formation, central Cuba). This assemblage includes: Nannoconus steinmannii steinmannii, N steinmannii minor, N colomii and N. globulus globulus. The subspecies Nannoconus steinmannii steinmannii and N. steinmannii minor are the most common components of this assemblage. Its stratigraphic position corresponds to Pseudothurmannia angulicostata auct. Zone; this is based on Pseudothurmannia mortilleti catulloi (Parana) found in sample AM-95/6 (Tab. 3). Our assemblage A1 corresponds to the assemblage 1 ofBronnimann (1955), which is characterized by the occurrence of N steinmannii - N aff. globulus - N colomii.
Nannoconids identified in sample AM-87/3 may occupy an intermediate stratigraphic position between the Late Hauterivian (A I) and the Early Barremian A2(a) assemblages. Lack of specimens assigned to N. truittii truittii in samples AM-95/6 and AM-87/3 is in agreement with the post-Hauterivian appearance of this taxon.
Early Barremian nannoconid assemblage
The Early Ban emian assemblage A2(a) (Fig. I 0) is based on Nannoconus taxa identified in samples: AM-93/28, 6P-598, P-1 2-H and AM-88112. This assemblage includes the following taxa: Nannoconus steinmannii steinmannii, N. steinmannii minor, N. bucheri, N. cf. minutus, N truittii truittii, and N. truittii truittii(?). Nannoconids identified in sample AM-93/23, as Nannoconus steinmannii steinmannii
NANNOCONID ASSEMBLAGES OF CUBA
BRONNIMANN (1955) THIS PAPER
STAGES NANNOCONUS ASSEMBLAGES
ALBIAN !
~ Upper
J} b:: 1---L-o;-ve-r ---11(A3] ""~ ·· .. ~.,.,,.,., ,=· ....... ·:""••'"'':"'"·;·.-.. --.~.-.;"";ill-,··=·-· ~'.'"'•-:•.-,11 ~+-~o-~~~~~~-LJ-~,r~~----~'rx'l~--~~~ --... -. ~--~-~.: ,~,. -'"'"· ~
z ... : :~: . .. --'~· : ·( ;
~ Upper ~b~ •·• •· • • •-• -~ r---~;~l:l~··,;~X:~;· .··~·~,:~~; ~· ·~~J~- c·~2~-~-- =; =.~=;~~ <( , !D ·. Lower
p.; ~-.::~~~-.-~- -- ._ , . . .. .
(a-, ·• .fL • . ·~ c · ~ ·· :· "· • . · .. ·: .
3 f-' + H-,Lo .. c:!~l,-__ ~-------11--t-------l}=<Ji='"=: .. :::;:=;~:C=~::=::::t~=====:';':::~ 1 1 ~~ Upper A1 ~ <• -•c. t~·
~ ~ 1---------j ICJ' Lower
VP.LANGII'JIAN
BERRIASIAN
<-·
I • occurr<1nce ct taxon
1 I I I I I
I I I _l I I
: I I I
:
53
Fig. 10. Upper Hauterivian-Lower Aptian Nannoconus assemblages in Cuba (this paper); Lower Cretaceous Nannoconus Assemblages ofBronnimann (1 955) are shown for comparison
(the only taxon found) may also represent this assemblage. In the discussed assemblage, the narrow-canal forms, especially those of N steinmannii group, are much more frequent than the wide-canal ones. Among true wide-canal forms (N bucheri), small specimens (as wide as long) classified herein as N. truittii truittii, often show axial canal narrower than wall thickness. The nannoconid assemblage A2(a) has no exact equivalent in Bronnimann's (1955) standard: its Early Barremian age links it with his Assemblage 2, tentatively assigned by him to the Barremtan.
Late Barremian nannoconid assemblage
The Late Barremian nannoconid assemblage A2(b) is distinguished (Fig. 1 0) on the basis ofnannoconids found in samples AM-94/1 and AM-88/ 14 (Tab. 3). It in-
54 A. PSZCZ6LKOWSKI & R. MYCZYNSKI
eludes the fol1owing taxa (Fig. l 0): Nannoconus steinmannii steinmannii, N. steinmannii minor, N. colomii, N. cf. kamptneri kamptneri, N. globulus globulus, N. bucheri, N. truittii truittii and N. cf truittii frequens. The narrow-canal nannoconids slightly predominate over the wide-canal ones. Among the Late Barremian representatives of N. truittii truittii there occur specimens with the axial canal as wide as the thickness of their walls (Fig. 8: 1). Our nannoconid assemblage A2(b) has no equivalent in Bronnimann's (1955) standard (see Fig. 10).
Late Early Aptian nannoconid assemblage
The late Early Aptian assemblage A3 (Fig. 10) was recognized in sample 3M-235-A. This assemblage contains the followingnannoconids (Tab. 3): Nannoconus elongatus, N. g/obulus globulus, N. truittii rectangularis, N. truittii truittii and N. cf. wassallii. The specimens of Nannoconus belonging to thesteinmannii group are absent in this assemblage which includes the wide-canal fonns, only. Our nannoconid assemblage A3 correlates with Assemblage 3 ofBronnimann ( 1955). Probably, the Aptian- Albian nannoconid Assemblage 3 of this author may be subdivided into 2 or 3 (sub )assemblages, as suggested by the changes in the Nannoconus taxa occurrence during Aptian time, recorded worldwide by Erba ( 1994).
In sample AM-90/25, the wide-canal nannoconids predominate over the narrow-canal ones. Moreover, in specimens assigned to N. truittii truittii the width of axial canal is often comparable with the wall thickness (Fig. 6: 7). This may support the Lower Aptian rather than Barremian age of the limestone with Protetragonites sp. cf. P. crebrisulcatus (Uhlig). According to Erba ( 1994), the major change in the Nannoconus assemblages composition occurred close to the Barremian/ Aptian boundary. In the latest Barremian, abundance of narrow-canal nannoconids decreased, and in the Early Aptian assemblages the wide-canal forms were dominant (Erba, 1994). Therefore, the nannoconids identified in sample AM-90/25 may represent an assemblage intermediate between the A2(b) and the A3 ones (Fig. 1 0), of the earliest Aptian age.
REMARKSONOCCURRENCEOFSOMENANNOCONUSTAXAIN THE UPPER HAUTERIVIAN TO LOWER APTIAN LIMESTONES OF
WESTERN AND CENTRAL CUBA
The assemblages distinguished in the present paper may not include all the taxa which occur in the Upper Hauterivian to Lower Aptian pelagic limestones in Cuba. Thus, a Late Hauterivian assemblage should also contain Nannoconus bucheri which is reported in European sections since the Early Hauterivian (Channell et al., 1995) up to Late Aptian (Erba, 1989). Considering the studied Cuban samples only, N. bucheri first appears in the Early Barremian assemb !age A2( a) (Fig. 1 0). Bronnimann ( 1955) did not report this species from his Assemblages 1 and 2 , of preAptian age. Possibly, N. bucheri is scarce in the Hauterivian limestones in Cuba.
The subspecies Nannoconus kamptneri kamptneri is another taxon poorly represented in our samples. Specimens belonging to this subspecies have been identified
NANNOCONID ASSEMBLAGES OF CUBA 55
in one sample only (AM-85/2), while N. cf. kamptneri kamptneri was identified in sample AM-94/1. In Cuba, N. kamptneri kamptneri does occur in some Valanginian to Lower Aptian limestones (Bronnimann, 1955; Pszcz6lkowski, 1999), but seems to be scarce to very scarce. Sometimes, this species may be difficult to notice, especially in the limestones strongly altered by diagenetic changes and tectonic deformation.
The same remarks apply to the occurrence of N. wassallii, which has not been found in our samples of pre-Aptian age (Fig. 1 0). This is in agreement with Bronnimann' s ( 1955) observations from central Cuba, but is contrary to informations published by Deres and Acheriteguy (1 980), and Erba and Quadrio ( 1987) from Europe. We have not observed typical specimens of N minutus in our samples. N. elongatus was found in an upper Lower Aptian sample only (Tab. 3; Fig. 1 0); this is in agreement with the presence of this species in the Aptian to Albian assemblage 3 of Bronnimann (1 955) in central Cuba.
Our observations concerning the probable disappearance of Nannoconus colomii and N steinmannii in the Early Aptian are concordant with data from Italy (see Erba, 1989, and Cobianchi et a!. , 1997). Nevertheless, the Cuban Aptian- Albian nannoconid assemblages still need a further study, in order to record some events recognized outside Cuba. According to Erba ( 1994), the Early Aptian "nannoconid crisis" has a global causes. This nannofossil event is recorded within the C. litterarius (nannofossil) and G. blowi (foraminiferal) zones (op. cit. ). Cobianchi et a/. (1997) placed this "nannoconid crisis" in the upper part of the C. litterarius Zone, and at the G. blowi/L. cabri zones boundary. The "nannoconid crisis" preceded deposition of organic carbon-rich sediments (the OAE l a, Selli level or equivalent intervals) p laced in the uppermost G. blowi and in the L. cabri zones, respectively (Erba, 1994).
In central Cuba, Bronni mann ( 19 55) suspected a break between his assemblages 2 (Barremian) and 3 (Aptian to Albian). However, later geological studies proved a stratigraphic continuity between the Aptian- Albian and underlying Lower Cretaceous depsosits in central Cuba (Kantchev et al., 1978; Pszcz6lkowski, 1986). During the Aptian, a major change occurred in the deep-water successions of western and central Cuba: the radiolarian cherts and shales succeeded the nannofossilradiolarian limestones. An upper Lower Aptian age of sample 3M-235-A is thus significant, because it documents a major sedimentary change from pelagic limestones (Veloz Formation) to radiolarian cherts and shales (Santa Teresa Formation) in central Cuba.
In western Cuba (Northern Rosario belt), lithologic boundary between limestones and turbiditic sandstones (Po!ier Formation) and radiolarian cherts and shales (Santa Teresa Formation) probably also correlates with Early Aptian (Pszcz6lkowski, 1999). However, in the Lomas de Poli er section, this boundary may be slightly older, preceding both the "nannoconid crisis" and the last occurrence (LO) of N. steinmannii steinmannii in the late Early Aptian (reported from the Italian sections - see Cobianchi et a!., 1997). In the nannoplankton-radiolarian biomicritic interbeds occurring in cherts and shales of the Santa Teresa Formation
56 A. PSZCZOLKOWSKI & R. MYCZYNSKI
(Pszczolkowski, 1982) nannoconids are present, but were not yet studied. In the light of the above observations, in the Cuban sections, evidences for the "nannoconid crisis" (Erba, 1994) should be looked for in the Lower Aptian cherts and shales of the Santa Teresa Formation and their stratigraphic equivalents.
SYSTEMATIC DESCRIPTIONS
lncertae sedis Family Nannoconidae Deflandre, 1959
Genus Nannoconus Kamptner, 193 1 Species belonging to this genus have been described in details by Bronnimann
(1955), Trejo (1960), Moshkovitz (1972), Deres and Acberiteguy ( 1980), and Bralower et al. (1989) . In this paper, only brief descriptions of the taxa important for the studied Cuban nannoconid assemblages are given.
Nannoconus bucheri Bronnimann, 1955 (Fig. 6: 3, 4, 8)
1955 Nannoconus bucheri Bronnimann; p. 39, pl. 1, figs 1-3,5-7; text-fig. 2k-n 1960 Nannoconus bucheri Bronnimann; Trejo, p. 297-298, lam. I, 9; figs I 0-11 1972 Nannoconus bucheri Bronn imann; Moshkovitz, p. 16-1 7, pl. III, figs 4-6 1980 Nannoconus bucheri Bronnimann; Deres & Acheriteguy, p. 20, pl. 3, fig. 6
Description: Test subovoid with broad and flat basal part. Length oftest larger than width. Axial canal diameter exceeds wall thickness.
Dimensions: The figured specimens are oblique sections. For this reason their length is about the same as width. Wall thickness is 2.4-2.8 !liD, diameter of the axial canal is about 3 llffi (Fig. 6 : 4, 8) and 4 .6 !liD (Fig. 6: 3).
Stratigraphic position: Originally reported from Aptian- Albian (Bronnimann, 1955); in this study: Early Barremian (Fig. 6: 3, 4) and Late Barremian (Fig. 6: 8) to earliest Aptian (sample AM-85/2). Outside Cuba, known from Hauterivian to Late Aptian (Deres & Acheriteguy, 1980; Erba, 1989). According to Channell et al. (1995) and Bralower et al. ( 1995), N. bucheri appears in the Early Hauterivian.
Nannoconus colomii (de Lapparent, 1931) (Figs 5: 1, 7: 3)
1931 Lagena colomi; de Lapparent, p. 222 (partim) 1955 Nannoconus colomi (de Lapparent); Bronnimann, p. 35-36, pl. 2, figs 9, 17; text- fig. 3n-r 1960 Nannoconus colomi (de Lapparent); Trejo, p. 289, fig. 6 a-f 1980 Nannoconus colomi Lapparent, 1931; Deres et Acheriteguy, p. 17, pl. 2, fig. 4 et 9; pl. 3,
fig. 1 1987 Nannoconus colomii (De Lapparent, 1931) Kamptner, 1938; Erba & Quadrio, p . 66, tav. 6,
figs 4, 7.
Description: Cone-shaped test with convex sides and rounded, sometimes flat base. Characteristic bulbous cavity is present near the base; this cavity extends into thin axial canal forming a minute apical aperture.
--- -- ----- --- - - - --- - - -
NANNOCONID ASSEMBLAGES OF CUBA 57
Dimensions: Length of the test 12- 15 f..LID, width 7-8 f..LID in the figured Cuban specimens (Figs 5: 1, 7: 3).
Stratigraphic range: Late Tithonian to Early Aptian (Erba & Quadric, 1987; Erba, 1989). The age of our figured specimens is Late Hauterivian (Fig. 5: 1) and Late Barremian to earliest Aptian (Fig. 7: 3), respectively.
Nannoconus elongatus Bronnimann, 1955 (Fig. 8: 6)
1955 Nannoconus elongatus Bronnimann; p. 38-39, pl. 1, figs 10-14; text-figure 2v-y 1980 Nannoconus elongatus Bronnimann; Deres & Acheriteguy, p. 23-24, pl. 4, fig. 6
Description: U-shaped test length exeeds its width. Diameter of canal axial (or cavity) is nearly equal to, or slightly smaller than wall thickness (cf. Bronnimann,
1955). Dimensions: Length 10- 16)lm, width 6- llf..Lm (Deres & Acheriteguy, 1980). The dimensions of our Cuban specimen are: length 13 f..LID, width 7.5 f..LID .
Stratigraphic range: Barremian to Early Campanian (Deres & Acheriteguy, 1980). Bronnimann (1955) reported this species from the Aptian to Albian assem
blage in central Cuba. Remarks: N. elongatus was found in sample 3M-235-A of upper Lower Aptian
age, only.
Nannoconus globulus Bronnimann, 1955 subsp. globulus Bralower et Thierstein, 1989
(Fig. 7: 4)
1955 Nannoconus globulus Bronnimann; p. 37-38, pl. 2, fig. 13 1980 Nannoconus globulus Bronnimann; Deres & Acheriteguy, p. 16-17, pl. 2, figs. 5, 15; pl. 3,
tig. 7 1989 Nannoconus globulus Bronnimann subsp. globulus Bralower et Thierstein; Bralower eta!.,
p. 23 1, pl. Vlll, fig. 24
Description: The specimen' s description is conformable with that ofBronnimann (1955); see also Bralower et al. (1989). Test is low barrel-shaped to globular. Usually, width oftest exceeds its height. Test walls enclose a subcircular cavity, at least two times as large as wall thickness.
Dimensions: Width 8- 14 )lm, height 6- 12 )lm (Bralower et al. , 1989). The figured Cuban specimen is 8.8 )liD wide and 7.6 )liD high; walls are 2 flm thick.
Stratigraphic range: Berriasian to Aptian (Bralower et al, 1989). The illustrated Cuban specimen (Fig. 7: 4) was found in the Lower Aptian limestone of the Veloz Formation (sample 3M-235-A).
58 A. PSZCZOLKOWSKI & R. MYCZYNSK!
Nannoconus kamptneri Bronnimann, 1955 subsp. kamptneri emend. Bralower et Thierstein, 1989
• 1989 lv'annoconus kamptneri Bronnimann subsp. kamptneri emend. Bralowcr et Tbicrstcin;
Bralower et al. , p. 230-231, pl. VIII, figs 32, 33
Description: The species description is conformable with that of Nannoconus kamptneri Bronnimann, 1955. N kamptneri differs from other cone-shaped forms by its basal cavity, wide axial canal and large terminal aperture (see Bronnimann, 1955). In the subspecies N kamptneri kamptneri Bralower et al. (1989) included specimens with length exceeding 10 ~m.
Dimensions: Length exceeding 10 ~m, width 5-8 f.lill (see Bralower et al., 1989).
Remarks: Deres and Acheriteguy (1980) reported greater width (9-14 ~m) of N. kamptneri as compared with this species definition given by Bronnimann (1955). This author noted that (1) N. kamptneri is related toN. colomii, and (2) at sections perpendicular to the axis, N kamptneri, N colomii and N. globulus not always can be distinguished from each other (Bronnimann, 1955).
Stratigraphic range: Early Berriasian to Early Aptian (Deres & Acheriteguy, 1980; Bralower eta!., 1989; Cobianchi et al. , 1997).
Nannoconus cf minutus Bronnimann, 1955 (Fig. 6: 2)
1955 Nannoconus minutus Bronnimann, p. 38, pl. 2, tigs. 4, 6, 8, 12; text-fig. 2t-u
Description: Minute Nannoconus specimen with almost square outline. The Cuban fonn has a narrow axial canal, unlike specimens of N. minutus figured by Bronnimann (1955). One Cuban specimen is thus provisionally determinedNannoconus cf minutus, mainly because of its very small dimensions and narrower axial canal.
Dimensions: Length 3.5 f.lill, width 3.6 ~m, wall thickness 1.5 ~m.
Stratigraphic range: The figured specimen (Fig. 6: 2) is of Early Barremian age. Nannoconus minutus Bronnimann, 1955, was originally described as an AptianAlbian species from central Cuba. Deres and Acheriteguy ( 1980) considered this species to range from Hauterivian to Cenomanian.
Nannoconus steinmannii Kamptner, 1931 subsp. steinmannii Deres et Acheriteguy, 1980
(Figs 5: 2, 8: 5)
1931 Nannoconus steinmanni Kamptner; p. 288-297, figs 2-3 1955 Nannoconus sleinmanni Kamptner; Bronnimann, p. 36, pl. I, fig. 16; pl. 2, tigs 10, 15 1972 Nannoconus sleinmanni Kamptner; Moshkovitz, p. 11- 12, pl. I, figs 1-6 1980 Nannoconus steinmanni steimnanni Kamptner; Deres & Acheriteguy, pp. 15-16, pl. 2, figs
2, 8; pl. 3, fig. 3; pl. 4, fig. 2
Description: The specimens figured are confonnable with definition given by
NANNOCONID ASSEMBLAGES OF CUBA 59
Deres and Acheriteguy ( 1980) and partly, with that of N. steinmanni ofBronnimann (1955) . Cone-shaped test shows a very narrow central canal. Base of test flat or rounded.
Dimensions: Test length 10- 20 f.liD, width 7-12 ~tm (Deres & Acheriteguy, 1980). The figured Cuban specimens (Figs 5: 2, 8: 5) fall within these values.
Stratigraphic range: Late Tithonian to (Late?) Aptian (Erba, 1989).
Remarks: N. steinmannii steinmannii was not observed in the upper Lower Aptian limestone ofthe Veloz Formation (sample 3M-235-A).
Nannoconus steinmannii Kamptner, 1931 subsp. minor Deres et Acheriteguy, 1980
(Figs 5: 3, 6: 1)
1980 Nannoconus steinmannii minor Deres et Acheriteguy, p. 16, pl. 1, fig. 7; pl. 2, figs 3, 14
Description: According to Deres and Acheriteguy (1980), cone-shaped test small, with flat base; length slightly exceeds its maximum width.
Dimensions: length 8- 10 ).lrn, width 7-9 11m (Deres & Acheriteguy, 1980). The figured Cuban specimens are smaller (length 5.7 )..lm and 7. 1 )..lm; width 5.5 11m and 6.7 ).liD, respectively).
Stratigraphic range: Late Tithonian to Barremian-Early Aptian(?)
Remarks: According to Deres and Acheriteguy (1980), subspecies is restricted to Late Tithonian- Valanginian. Cobianchi eta!. (1 997) noted N. steinmannii minor also in the Hauterivian- Barremian strata. In our samples from Cuba, this taxon occurs in the Upper Hauterivian to Upper Banemian limestones, but is also reported from deposits of the Berriasian, Valanginian and probable Early Aptian age (Pszcz6lkowski, 1999).
Nannoconus truittii Bronnimann, 1955 subsp. rectangularis Deres et Acheriteguy, 1980
(Fig. 8: 4)
1980 Nannoconus truitti rectangularis Dcres & Acheriteguy, p. 25, pl. 1, fig. 1 l
Description: Small Nannoconus with rectangular slightly convex test. Width of test exceeds its length. In axial sections, wall thickness is usually equal to the diameter of axial canal.
Dimensions: Test length 6- 8 ).LID, test width 9- 11 ).liD (Deres & Acheriteguy, 1980). Our figured specimen (Fig. 8: 4) is about 8 )..lm long and 11 11m wide. Maximum diameter of axial canal is 3.5 ).lm; wall thickness is slightly larger (3.7 ).lffi) than axial canal diameter.
Stratigraphic range: Albian- Cenomanian. The figured specimen from central Cuba is Early Aptian in age.
Remarks: The figured specimen is a tangential section.
60 A. PSZCZOLKOWSKI & R. MYCZYNSKI
Nannoconus cf truittii Bronnimann, 1955 subsp . .frequens Deres et Acheriteguy, 1980
(Fig. 6: 9)
1980 Nannoconus truitti f requens Deres et Acheriteguy, p. 24-25, pl. 1, fig. 10
Description: Test similar to that of N. truittii truittii, but its length exceeds the width. Size of axial cavity equal to wall thickness.
Dimensions: Test length is 8.4 !-1-m, test width 7.4 !-1-m. These dimensions are smaller than those reported for N. truittii frequens (length 11- 13 f..UTI; width 8- 10 !-LID) by Deres and Acheriteguy (1980). Wall thickness about 2.4 f.lm.
Stratigraphic range: According to Deres and Acheriteguy (1980), N truittii .frequens is known from Lower Aptian to Turonian strata. The figured Cuban specimen (Fig. 6: 9) is Late Barremian in age.
Remarks: N. cf. truittiifrequens is a tangential (subaxial) section (Fig. 6 : 9).
Nannoconus truittii Bronnimann, 1955 subsp. truittii Deres et Acheriteguy, 1980 (Figs 6: 5-7; 7: 1-2; 8: 1-3)
1955 Nannoconus tntitti Briinnimann, p. 38, pl. 2, figs. 2-5, 7 1960 Nannoconus truilti Bronnimann; Trejo, p. 298-300, pl. II, figs 6-9 1980 Nannoconus truitti truitti Deres & A cheriteguy, p. 24, pl. 5 , fig. 10
Description: Test small, subcircular to almost square in axial section. Usually, length oftest same as its width; the walls are convex. Basal part of the U-shaped test rounded, its top flat. Axial canal elongate, its diameter often equal to wall thickness. Basal aperture slightly smaller than apical one. Walls rather thick: 2.5- 3 f.liD in case of specimens from central Cuba (Bronnimann, 1955), 2.5-4 !-LID for N. truittii from Mexico (Trejo, 1960).
Dimensions: 6-12 !-1-ffi (Deres & Acheriteguy, 1980). Dimensions of figured Cuban specimens are smaller: 5.2- 10.5 f.lill.
Stratigraphic range: According to De res and Acheriteguy (1980), this subspecies occurs from Early Aptian to Early Campanian. In Mexico, Trejo ( 1960) reported N. truittii Bronnimann, 1955, from the top of the Hauterivian to top of the Albian strata. Bralower ( 1987) reported N truittii from the Barremian (in some Italian sections): in the Gorgo a Cebara section, N. truittii occurs together with the last representatives of Lithaphidites bollii Thierstein in the Lower Barremian strata (Bralower, 1987). In Italy, Erba (1989) noted the first occurrence of N. truittii in the Late Aptian. Later, Erba ( 1994) reported the presence of this species from the Late Barremian. Recently, a Late Barremian occurrence of N. truittii was also reported by Cobianchi eta/. (1997) . On a contrary, Thierstein (1973) defined the range ofN. truittii as Early Berriasian- Cenomanian, while Bra lower et al. ( 1989) identified (but not figured) this species in the Berriasian deposits at the DSDP Sites 391 C and 534A, and in two Italian sections (Foza and Fiume Bosso).
Remarks: Some Early Barremian specimens assigned in this paper toN. truittii
--- - ---·-- ---· --
NANNOCONID ASSEMBLAGES OF CUBA 61
truittii (especially Figs 6: 5; 7: I and 8: 2) display features characteristic for this subspecies, except that their axial canal diameter is narrower ( 1- 2 11m) than wall thickness (3-3.5 Jlill). This feature is not compatible with the definition of the subspeciesN. truittii truittii and of the species N. truittiiBronnimann, 1955, as well; sometimes these differences may be a result of tangential sections of the studied specimens. The Early Barremian and Late Barremian to earliest Aptian specimens, herein assigned provisionally to N. truittii truittii, might represent a new subspecies of N. truittii, or even a new species (?). Solving this problem needs an additional study of those Barremian specimens which are characterized by an axial canal narrower than usual. The (late) Early Aptian specimens of N. truittii truittii (Figs. 7: 2; 8: 3) have a wide axial canal, its dimension comparable to the wall thickness.
SYSTEMATIC DESCRIPTION OF THE AMMONITES
All specimens described here are housed in the Institute of Geological Sciences, Polish Academy of Sciences; 00-818 Warsaw, Twarda 51/55, Poland. In descriptions of the ammonites, it was adopted classification of the Cretaceous Ammonoidea as proposed by Wright ( 1981). The following abbreviations have been used: D - maximum diameter; H - whorl height; 0 - umbilical width; HID - whorl height/shell diameter; 0/D - umbilical diameter/shell diameter.
Following the suggestion made by Cecca and Landra (1994), the term "shaft" is used for narrower arm and the term "hook" - for wider arm of uncoiled ammonite shell.
Order Ammonoidea Zittel, 1884 Suborder Lytoceratina Hyatt, 1889
Superfamily Lytocerataceae Neumayr, 1875 Family Lytoceratidae Neumayr, 1875
Subfamily Lytoceratinae Neumayr, J 875 Genus Lytoceras Suess, 1865
Type-species: Lytoceras postjimbriatum Prinz, 1904 (=Ammonites.fimbriatus in d 'Orbigny, 1845)
Lytoceras subjimbriatum (d'Orbigny, 1841) (Fig. II: 1)
1964 Lytoceras subfimbriatum (d'Orbigny, 1841); Fiilop, pl. 27, fig. 2 1967 Eulytoceras subflmhriatum (d'Orbigny); Dimitrova, p. 27, pl. 10, fig. 1967 Lytoceras su~fimbriatum (d'Orbigny, 1841); Baccelle & Garavello, p. 130, pl. I, fig. 8; pl.
11, fig. I 1972 Lytoceras aff. sub_fimbriatum (d'Orbigny); Vasicek, p. 34, pl. l , fig. 7 1987 Lytoceras aff. suf?fimbriatum (d 'Orbigny); Immel, p. 6 1, pl. 2, fig. l 1998 Lytoceras subfimbriatum (d 'Orbigny); Cecca et at., p. 68, pl. 1, fig. 1 6; tab. 4
Material: One specimen, AM-87/3.
Dimensions: D - 41 .5 mm; H - 16.5 mm; 0 - 17 mm; HID - 39%; OlD - 40%.
Description: Shell evolute, with elliptical cross-section and convex sides. Umbili-
. - -- - - ---- - - -· - ·- - - - - .•. - - - - ------
62 A. PSZCZ6t.KOWSKI & R. MYCZYNSKI
cus wide and shallow, with steep walls. Ornamentation consisting of numerous simple thin ribs curved prosiradiately at the umbilicus; they are more loosely spaced at inner whorls. On the last whorl, ribs are more closely spaced, situated between collars of the lytoceratide type. Suture line poorly preserved.
Occurrence: Limestone of Polier Formation at Nortey (CasaBlanca) locality, Sierra del Rosario, Pinar del Rio province, western Cuba. The species Lytoceras subfimbriatum (d'Orbigny) is known from Hauterivian and Barremian of southeastern France, Switzerland, Austria, Italy, Hungary, Romania, Yugoslavia and Caucasus (Va~icek, 1972) and from latest Hauterivian (P. angulicostata Zone) of Umbria-Marche Apennines, Central Italy (Cecca et al. , 1998).
Superfamily Tetragonitaceae Hyatt, 1900 Family Protetragonitidae Spath, 1927
Genus Protetragonites Hyatt, 1900
Type-species: Ammonites quadrisulcatus d'Orbigny, 1840
Protetragonites sp . cf. Protetragonites crebrisulcatus (Uhlig, 1883) (Fig. 11: 3)
Material: One flattened specimen, AM-90/25
Dimensions: D - 132 mrn; H - 52 mm; 0 - 53 mm; HID - 39%; OlD - 40%.
Description and remarks: Coiling evolute, with flat rounded and smooth lateral side. Umbilicus wide and shallow. Constrictions slighty curved and not pronounced. The character of constrictions, dimensions and style of coiling seem similar to those typical of the genus Protetragonites Hyatt, 1900 ( cf. Dimitrova, 1967). Our specimen appears similar to P. crebrisulcatus (Uhlig), described and figured by Arkell eta!. (1957, p. L200, fig. 229, 3a-c) and Vasicek (1972, p. 40, pl. Ill, fig. 5; pl. XV, figs 1, 2- re-figured holotype of Uhlig), but poor preservation precludes its specific identification.
Occurrence: Limestone of Potier Formation, Mango Bonito hill, Sierra del Rosario, Pinar del Rio province, western Cuba (specimen AM-90/25).
The species P. crebrisulcatus (Uhlig), comparable with our specimen, is known from Barremian and Early Aptian of Algeria, Mallorca, Austria, Romania, Yugoslavia and, probably, Crimea and Caucasus (Vasicek, 1972) .
Fig. 11. I - Ly toceras subfimbriatum (d 'Orbigny), specimen AM-87/3, Nortey (CasaBlanca) locality, Sierra del Rosario, western Cuba, Polier Formation, Lower Barremian, x 2; 2 - A nahamulina cf. subcincta (Uhlig), specimen P-12-H, Loma Caldoso, south ofBahia Honda (and Quinones), Sierra del Rosario, Polier Formation, Lower Barremian, x 2; 3 - Protetragonites sp. cf. Protetragonites crebrisulcatus (Uhlig), specimen AM-90/25, Mango Bonito hill, Sierra del Rosario, Potier Formation, Barremian-Lower Aptian, x I ; 4 - ?Parasp iticeras sp., specimen AM-85/2(b), south of Bahia H onda (and Quinones), Sierra del Rosario, Potier Formation, Lower Barremian, x 2
--- - - ---- - -------
"NA"NNOCON!D ASSEMBLAGES OF CUBA 63
-~ · '
~ ..
.. .. . .:., • '· .. ~ t ·.' • ~ ' :·~ ~·
64 A. PSZCZOLKOWSKI & R. MYCZYNSKI
Superfamily Perisphinctaceae Steinmann, 1890 Family Holcodiscidae Spath, 1923
Genus Holcodiscus Uhlig, 1882
Type-species: Ammonites Caillaudianus d'Orbigny, 1850
Holcodiscus aff. geronimaeformis Tzankov, 1935 (Fig. 12: 3)
aff 1967 Holcodiscus geronimaeformis Tzankov; Dimitrova, p. 157, pl. LXXIX, figs 9, 10 aff. 1986 Holcodiscus sp. cf. Holcodiscus geronimaejormis Tzankov; Myczyiiski & Triff, p.
132, pl. III, fig. 2 aff. 1995 Holcodiscus geronimaeformis Tzankov; Avram, p. 20, pl. 4, fig. 13
Material: One specimen, AM-93/23.
Dimensions: D -17.5 mm; H -7.5 mm; 0-2.7 mm; H/D- 42%; OlD -15%.
Description: Coiling involute, with weakly convex sides. Umbilicus narrow and deep with skew wall. The sculpture is characterized by strong ribs, slightly prosoclinal in the dorsal margin, curved back and divided near the middle part of a whorl. Inter-rib spaces wider than ribs. Some ribs are more robust, and having a large elongated, club-shaped bula on ventral margin. Constrictions and suture line not visible.
Remarks: The specimen resembles well Holcodiscus geronimaeformis Tzankov as described and illustrated by Dimitrova (1967), but differs by a slightly wider umbilicus. It also resembles the specimen described and figured as Holcodiscus caseyi Manolov (see Manolov, 1962; p. 53 7, pl. 76, figs 2-5) but differs by shorter club-shaped hula.
Occurrence: Limestone of the Veloz Formation exposed at Silverio-Cabrera hill, near the border of the Matanzas and Villa Clara provinces, central Cuba. The species H geronimaeformis Tzankov is known from the Barremian of Bulgaria (Dimitrova, 1967; Avram, 1995).
Fig. 12. 1 - Subsaynella sp. cf. Subsaynella boyacaensis Haas, specimen AM-85/2(a), south of Bahia Honda (and Quinones locality), Sierra del Rosario, Polier Formation, Lower Barremian, x 2; 2-Anahamulina cf. subcincta (Uhlig), specimen AM-88/9, Nortey (CasaBlanca) locality, Sierra del Rosario, western Cuba, Polier Formation, Lower Barremian, x 2; 3 - Holcodiscus aff. geronimaeformis Tzankov, specimen AM-93/23, Silverio-Cabrera, border of the Matanzas and Villa Clara provinces, central Cuba, Veloz Formation, Barremian, x 2; 4- Crioceratites (Emericiceras) thiollierei (Astier), specimen 6P-598, Lomas de Polier, Sierra del Rosario, western Cuba, Polier Formation, Upper Hauterivian?-Lower Barremian, x 1,5; 5- Hamulinites afT. parvulus (Uhlig), specimen AM-88112, Nortey (CasaBlanca) locality, Potier Formation, Barremian, x 2; 6 .. Pseudothurmannia mortilleti catulloi (Parona), specimen AM-95/6, south of Playa Gamuza locality, northwestern part of the Villa Clara province in central Cuba, Paraiso Formation, Upper Hauterivian, X 1
NANNOCONID ASSEMBLAGES OF CUBA 65
66 A. PSZCZOLKOWSKI & R. MYCZYNSKI
Superfamily Desmocerataceae Zittel, 1895 Family Desmoceratidae Zittel, 1895
Subfamily Eodesmoceratinae Wright, 1955 Genus Subsaynella Spath, 1923
T ypc species: "Desmoceras" sayni Paquier, 1900
Subsaynella cf. Subsaynella boyacaensis Haas, 1960 (Fig. 12: I)
Material: One specimen, AM-85/2(a).
Dimensions: D- about 26 mm; H - about 11 mm; 0 - 8mm; HID - about 42 %: OlD- about 30%.
Description and remarks: Weakly involute shell, tectonically flattened, sides probably originally slightly convex. Ventral part of shell not preserved. Umbilicus wide, not deep, umbilical margin rounded, umbilical wall vertical. Omamentation consists of fine sinuous ribs arising on umbilical edge, and of irregular shallow constrictions. Last part of shell almost smooth: this feature is characteristic for the genusSubsaynella Spath, 1923 (see Arkell eta!., 1957 p. L362; Dimitrova, 1967, p. 136). Our specimen is close to the species S. boyacaensis Haas, 1960, described from the Hauterivian of Colombia (see Haas, 1960, p. 51 , figs 123-127); it differs in somewhat wider umbilicus, only. Our specimen resembles also the species Zurcherella zurcheri (Jakob, 1906), as figured by Thome! (1980, p. 124, fig. 246), but differs in more flattened flanks and shallower umbilicus. From the genus Pseudosaynella Spath, 1923, the Cuban specimen differs by more evolute shell coiling, fine ribs and wider umbilicus.
Occurrence: The secimen AM -85/2( a) was found in a limestone layer of the Polier Formation, together with ? Paraspiticeras sp. (Fig. 11: 4), south of Bahia Honda (and Quinones locality), in Sierra del Rosario. The species Subsaynella boyacaensis Haas, 1960, with which our specimen is compared, occurs in the Hauterivian of Colombia (see Haas, 1960). The genus Subsaynella Spath, 1923, is known from Late Hauterivian and Barremian of England, France, Bulgaria, North Africa and Madagascar (Arkell et al. , 1957; Dimitrova, 1967).
Genus Melchiorites Spath, 1923
Melchiorites sp. gr. Melchiorites emerici (Raspail, 183 1) (Fig. 13: f a)
Material: One specimen, AM-94/ l (a)
Dimensions: D- 19 mm; H - 8.0 mm; 0- 6.0 mm; HID - 42%; OlD - 31%.
Description and remarks: Shell (mould) weakly involute, with flattened sides and short, vertical umbilical wall. Umbilicus wide, shallow. Ornamentation very much obliterated, consisting on the last whorl of slightly pronounced, widely spaced, thin
NANNOCON!D ASSEMBLAGES OF CUBA 67
ribs. Ornamentation on initial whorls invisible. Some deep constrictions are present on the last whorl. Suture line not preserved. The shape, mode of coiling, dimensions and ornamentation of this specimen appear close to the genus Melchiorites Spath, 1923, particularly to the specimen described and figured as Melchiorites emerici (Raspail) by Arkell et al. (1956, p. 1364-365, fig. 4 76, 4a-b ). Our specimen is also similar toM cf. melchioris (Tietze), described and illustrated by Vasicek (1972, p. 74, pl. XII, fig. 5). Poor preservation and obliterated ornamentation of our specimen impeded specific identification. Flattened sides and the presence of deep constrictions suggest, however, its affiliation with the species Melchiorites emerici (Raspail).
Occurrence: This specimen here described was found together with a small fragment of ]vfacroscaphites sp. in limestones of the Veloz Formation at El Sordo Viejo locality (southeast of Marti, Matanzas province). The species Melchiorites emerici (Raspail), is known from Late Aptian (Arkell et al., 1957). According to Vasicek and Rakus (1995), typical representatives of this species are mainly reported from Early Aptian of France, Spain, Sardinia and Balearic Islands. A similar specimen described by Vasicek (1972) as Melchiorites cf. melchioris (Tietze) was found in the Lower Barremian strata of the Beskydes Mts (Czech Republic). The presence of Macroscaphites sp. (Fig. 13: 1 b), probably gr. M yvani (Puzos), together with the discussed specimen, suggests that limestone in which it was found is not older than Upper Barremian. According to Vermeulen (1998, p. 624), the species Macroscaphites yvani (Puzos) is characteristic for the Gerhardtia sartousiana Zone (Vermeulen, 1995), of the latest Barremian. Lack of typical Aptian ammonites in the El Sardo Viejo locality, suggests that the limestone with Melchiorites sp. gr. Melchiorites emerici (Raspail, 1831) is of Upper Barremian age.
Suborder Ancyloceratina Wiedmann, 1960 Superfamily Ancylocerataceae Gill, 1871
Family Ancyloceratidae Gill, 1871 Subfamily Crioceratitidae Gil, 1871
Genus Pseudothurmannia Spath, 1923
Type-species: "Parahoplites" (Thurmannites?) angulicostatus (d'Orbigny) in Pictet = Pseudothurmannia picteti Sarkar, 1955
Pseudothurmannia mortilleti catulloi (Parana, 1898) (Fig. 12: 6)
1967 Crioceratites (Pseudothurmannia) mortilleti catulloi Parana; Baccelle & Garavella, p. 137, pl. III, fig. 4
1994 Crioceratites (Pseudothurmannia) mortilleti catulloi (Parana); Cecca et al., p. 560, fig. 5c 1995 Crioceratites (Pseudothurmannia) mortilleti catulloi (Parana); Cecca et al., p. 207, pl. 1,
figs 3, 4
Material: One specimen, AM-95/6.
68 A. PSZCZOLKOWSKT & R. MYCZYNSKT
Fig. 13. Ia - Melchiorites sp. gr. M emerici (Raspail, 1831), specimen AM-94/ la, x 2; lb Macroscaphites sp. , specimen AM-94/lb, El Sordo Viejo locality, Matanzas province, Veloz Formation, Upper Barremian, x 2; 2 - Crioceralites (Crioceratites) sp. gr. C. no/ani (Kilian, 1907), specimen AM-93/28, Silverio-Cabrera hill, central Cuba, Veloz Formation, Upper Hauterivian?Lower Barremian, x 2
NANNOCONID ASSEMBLAGES OF CUBA 69
Dimensions: D - 34 mm; H - 14 mm; 0 - 13 mm; HID - 41 %; OlD - 38%.
Description: Coiling involute, with fl attened sides. Umbilicus wide and shallow with steep walls. Ornamentation consisting of numerous, thin or thick, slightly prosoclinal S-shaped ribs, which bifurcate in the middle part of side. Usually, each 5th or 6th rib is stronger. Some ribs have small tubercles on umbilical margin. Suture line not preserved.
Remarks: The specimen corresponds to descriptions and illustrations of Pseudothurmannia mortilleti catulloi (Paron a), referred to in the synonymy. It is also very similar to a species described as Balearites pseudothurmanni n. sp. by Dimitrova (1967, p. 77, pl. XXXVI, fig. 3); the latter differs from our specimen in having more straight ribs. Our specimen is also similar to the species Pseudothurmannia angulicostata (d'Orbigny) as figured by Ceccaet a/. (1995 , p. 207, pl. l , fig. 2), but differs in having thicker ribs and smaller diameter.
Occurrence: Limestone of the Paraiso Fonnation, south ofPlaya Gamuzalocality, Villa Clara province (central Cuba). Our specimen was folmd together with Phyllopachyceras sp. (P. injimdibulum group), Euphy /loceras cf. ponticuli (Rousseau) and Eodesmoceras (Afiodesmoceras) sp. In Italy, Pseudothurmannia mortilleti catulloi (Parona) is known from the Angulicostata auct. Zone, Catulloi Subzone of the Late Hauterivian (Cecca eta!., 1995).
Subfamily Leptoceratoidinae Thieuloy, 1966 Genus Hamulinites Paquier, 1900
Type-spec ies: Hamulina munieri Nikles, 1894
Hamulinites aff. parvulus (Uhlig, 1883) (Fig. 12: 5)
aff. 1962 Eoleptoceras (Wrightites) parvulum (Uhlig); Manolov, p. 532, 534, pl. 75, figs 3, ll -12.
Material: One specimen, AM-88/ 12.
Description: Small (D =about 21 mm), ancylocone with arched, slowly increasing shaft. Shell initialy smooth, then ornamented by single sharp, non-tubercled ribs. Ribs on the hook and older shaft are more spaced. Suture line and heteroceratid torsion of initial coil not preserved.
Remarks: The specimen resembles Hamulinites parvulus (Uhlig, 1883) determined by Manolov (1962, p. 532, 534, pl. 75, figs 3, 11-12) as Eoleptoceras (Wrightites) parvulum (Uhlig), by Dimitrova ( 1967, p. 36; pl. XVII, fig. 7) as E. (Eoleptoceras)parvulum (Uhlig, 1883), and by Vasicek and Wiedmann (1994, p. 221, pl. 3, figs 5-1 2; text-fig. SA; see for an extended synonymy list) asHamulinites parvulus (Uhlig, 1883). Similar forms from Cuba, described by Myczyilski and Triff (1 986, p. 126, pl. II, figs l , 9, 15) as Hamulinites aff. parvulus (UhHg, 1883), have been referred by Vasicek and Wiedmann (1994, p. 221) to ?Hamulinites
- - - - ·- · -· - -- - - ---· - · -- - ~-- - - ----· - - -
70 A. PSZCZOLKOWSKI & R. MYCZvNSKl
parvulus (Uhlig, 1883). Lack of suture line and heteroceratid torsion of initial coil make it difficult to determine the species of our specimen. Occurrence: Limestone of the Polier Formation at Nortey (CasaBlanca) locality, Sierra del Rosario, western Cuba. The species Hamulinites parvulus (Uhlig) is cited from Early Barremian of Bulgaria (Dimitrova, 1967) and from Barremian of Silesia (Vasicek, 1972). According to Cecca and Landra ( 1994), this species occurs in the Lombardy Basin, Northern Italy (at the LG 39level), together with E. norteyi (Myczynski and Triff), E. silesiacum Vasicek and Wiedmann and a Late Barremian form Silesites seranonis (d' Orbigny). This means that this fauna is younger than Early Barremian (possibly latest Barremian- ?earliest Aptian). According to Bartolocci et al. (1992) the species S. seranonis (d'Orbigny) appears in the Heinzia sartousi Zone of Late Barremian age (in zonal scheme of Hoedemaeker at al., 1993). According to Venneulen (1998), this species occurs in the Gerhardtia provincialis Horizon of the Gerhardtia sartousiana Zone, also of Late Barremian age. In conclusion, the age of Hamulinites parvulus (Uhlig) and other similar uncoiled ammonites, such as Eoheteroceras norteyi (Myczynski and TritT) and E. silesiacum Vasicek and Wiedmann, probably corresponds to Early- Late Barremian. In Cuba, ammonite zonation for Barremian has hitherto not been elaborated.
Family Ancyloceratidae Gill, 1871 Subfamily Cdoceratitidae Gill, 187 1
Genus Crioceratites Leville, 1837
Type-species: Crioceratites duvali Levi lie, 1837
Subgenus Crioceratites Leville, 1837
Crioceratites ( Crioceratites) sp. gr. Crioceratites no/ani (Kilian, 1907) (Fig. 13: 2)
Material: One incomplete specimen, AM-93/28. Dimensions: Maximum width of shaft 12 mm, maximum diameter - 56 mm.
Description and remarks: Specimen (AM-93/28) is a large form with slightly convex sides of shaft. Shaft ornamented with numerous, moderately strong ribs, slightly curved backward. Inter-rib spaces wider than ribs . Few small tubercles visible on last part of shelL Suture line not preserved. Obliterated ornamentation and unsatisfactory preservation, make it difficult specific attribution of this specimen. However, moderately strong, backward curved ribs, and wide inter-rib spaces, suggest that it is close to the Crioceratiles (Crioceratites) no/ani (Kilian, 1907) group (see Thome), 1964, p. 15, pl. 2, fig. 1; text-fig. 1).
Occurrence: The specimen AM-93/28 was found in limestones of the Veloz Fonnation on the Silverio-Cabrera hill, near the border of the Matanzas and Villa Clara provinces in central Cuba. The species Crioceratites ( Crioceratites) nolani (Kilian, 1907), is known from the Late Hauterivian and probably Early Barremian
NANNOCONID ASSEMBLAGES OF CUBA
offrance (see Thomel, 1964, p. 17).
Subgenus Emericiceras Sarkar, 1954
Type-species: .Emericiceras thiol/ierei (Astier, I 851)
Crioceratites (Emericiceras) thiollierei (Astier, I 85 1) (Fig. 12: 4)
71
1964 Crioceratites (Emericiceras) thio/lierei (Astier); Thome!, p. 34, pl. V, fig. I; pl. XU, fig. 6;
text-fig. 4 1964 Crioceratites thiollierei (Astier); Breskovski , p. 77, pl. li, fig. 2 1967 Crioceratites (Crioceratites) thiollierei Aslier; Baccelle & Garavello, p. 135, pl. lll, Fig. 2 1967 Crioceratites lhiollierei (Astier); Dimitrova, p. 46, pl. IV, figs 2, 2a; pl. XV, fig. 2. 1998 Emericiceras thiol/ierei (Aslier); Arnaud eta!., p. 15; fig. 38: pl. 2, fig. 2 199X Crioceratites (Emericic:eras) thioflierei (Asticr); Cecca, Faraoni & Marini p. 90, pl. 3, fig.
23
Material: One specimen, 6P-598.
Dimensions: D - 39 mm; H - 9 mm; 0- 25 mm; HID- 23%; 0 /D - 64%.
Description: Specimen moderate in size, loosely and spirally coiled. Whorls sides convex, whorls thickest in mid-height. Ornamentation consists of strong, straight ribs and two rows of tubercles (on ventral and dorsal zones). Occasionally, ventro-lateral tubercles have long spines. Some ribs are strong and tubercled.
Suture line not preserved.
Remarks: This specimen is closest to Crioceratites (Crioceratites) thiollierei (Astier) as described and illustrated by the authors cited in the synonymy.
Occurrence: Limestone ofPolier Formation, Lomas de Polier, Sierra del Rosario, Pinar del Rio province, western Cuba. The species Crioceratites (Emericiceras) thiollierei (Astier) is known from Barremian of France (Thomel, 1964); Late Hauterivian of Central Apennines, Italy (Faraoni et al., 1995); Hauterivian and Barremian ofltaly (Baccell e & Garavello, 1967) and Early Barremian of Bulgaria
(Dimitrova, 1967).
Family Ptychoceratidae Gill, 187 1 Subfamily Ptychoceratinae Meek, 1876
Genus Anahamulina Hyatt, 1900
Type-species: Hamulina subcylindrica d'Orbigny, 1850
Anahamulina cf. subcincta (Uhlig, 1883) (Figs II : 2; 12: 2)
Material: Two incomplete specimens, shafts only (P-12-H and AM-88/9).
Dimensions (maximum): P- 12-H - shaft width 7 mm, shaft length 67 mm; AM-88/9 - shaft width 7 mm, shaft length 94 mm.
. --· ---- -- · ·- - - -- - - - -- · ·-·
72 A. PSZCZOLKOWSKJ & R. MYCZYNSKI
Description and remarks: The specimen AM-88/9 represents a large form. Both specimens have shaft sides slightly convex. Shaft ornamented with numerous, moderately strong, markedly flattened blunt ribs somewhat oblique to shell axis. Inter-rib spaces and ribs equal in width. The specimens are closest to Anahamulina subcincta (Uhlig, 1883) as described by Sarasin and Schondelmayer (190 1, p. 170, pl. 24, fig. 2) and Thomel (1964, p. 66, pl. 10, fig. 3) but they somewhat differ in ornamentation. These features, and incomplete preservation of the specimens, do
not permit specific determination. Occurrence: Limestones of the Potier Formation. Specimen AM-88/9 was found at Nortey (CasaBlanca) locality; specimen P-12-H- at Lorna Caldoso, south of Bahia Honda (and Quinones), Sierra del Rosario, western Cuba. The species Anahamulina subcincta (Uhlig) occurs in middle part of Early Barremian (Nicklesia pulchella Zone, see Vermeulen, 1995, 1996, 1998).
Family Douvilleiceratidae Parona et Bonarelli, 1897 Subfamily Cheloniceratinae Spath, 1923
Genus Paraspiticeras Kilian, 1910
Type species: Ammonites percevali Uhlig, 1883
? Paraspiticeras sp. (Fig. Il: 4)
Material: One specimen, AM-85/2(b). Description and remarks: Small whorl fragment 10 mm wide, with moderate convex venter. Ornamentation consisting of robust, straight major and 2-3 weak secondary ribs and prominent ventrolateral tubercles; constrictions present. Identification of this specimen is uncertain, mainly because of the lack of data on whorl-section, suture line and number of tubercle rows. The presence of straight major and secondary ribs and ventrolateral or ?lateral tubercles permit to assign (with reservation) this specimen to the genus Paraspiticeras Kilian, 1910 (see Arkell eta/., 1957). By details of ornamentation (for example ribs in form of tears), our specimen is similar to Paraspiticeras cf. guerini (d'Orbigny) of Arnaud et al.
(1998, pl. 2, fig. 4). Occurrence: The specimen AM-85/2(b) was found together with Subsaynella cf. boyacaensis Haas in a limestone of the Polier Formation, south of Bahia Honda (and Quinones locality), Sierra del Rosario. The genus Paraspiticeras Kilian, 1910, is known from Barremian of Bulgaria, Silesia and France (see Dimitrova, 1967). The specimen of Paraspiticeras cf. guerini ( d'Orbigny) of Arnaud eta!. (1 998) was found in Lower Barremian strata of France.
Acknowledgments
We thank Prof Andrzej Wierzbowski and the Chief Editor of Studia Geologica Polonica Prof Krzysztof Birkenmajer for critically reviewing the manuscript. The assistance of Dr. Ryszard
NANNOCONID ASSEMBLAGES OF CUBA 73
Orlowski (Laboratory of Scanning Microscopy, Institute of Geological Sciences, Polish Academy of Sciences) during preparation of scanning micrographs is appreciated with gratitude.
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