ni^

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BULLETINS

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VOL. XXXVI

1955-1956

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i ^

Conrnus of N'oliimc XXXVI

Riilletin No. Plates Pages

l:i5. The (■Mills (^lohotninciiiiii in \ortheaslerii Coloiiihiii Rolanrio Gandolfi 1-10 1-llS

156. The Eocene Fishes of Aliibaina

Enol I. White -11 119-152

157. Xen Fossils from the Cnnadiaii-Chsi/ynii

(()r<lo> ieiaii) Hiatus in 'I'ennessee

Kenneth E. (aster and H. K. Brooks .... 12-23 153-195)

15S. Janiaicun Largrer Foraminffera

W. Storrs Cole '. 24-31 200-233

159. The Genera Miscellanea and Pellatisni-

relLi W. Storrs Cole 32-33 234-254

160. The Foraniinifera of the YorktoAvn Forma-

tion in the York-James Peninsula of Virginia, with notes <»n the Associ- ated .Hollusks James D. McLean, Jr 34-53 255-394

Index 395-414

(0P.ZOOt OCT 19 1356

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BULLETINS

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VOL. XXXVI

NUMBER 155

1955

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PALEONTOLOGIGAL RESEARCH INSTITUTION

1954-55

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BULLETINS

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AMERICAN PALEONTOLOGY

Vol. 36

No. 155

THE GENUS GLOKOTKUXCANA Df NORTHEASTEHX C0L03IBIA

By

Rolando Gandolfi

September 13, 1955

Paleontological Research Institution Ithaca, New York, U.S.A.

Library of Congress Catalog Card Number: GS 55-99

Printed in the United States of America

"mos. comp. zool

LIBRARY

ISEP 2 0 19551

HARVARD

UNIVERSITY

CONTENTS

Page

.\listract , 7

Introduction 7

Acknowledgment 8

(jraphic and stratigraphic occurrences 8

Description of species 13

Globotruncana linnri group 16

Lappaicnti branch 17

Tricarinata branch ^ 20

I'rntrirosa branch 22

Comments on the phylogenetic development of the linnri group 23

Globotruncana bulloidcs group 29

M ar<jinata branch 29

Bulloidcs branch 32

Naussi branch 34

Comments on the phylogenetic development of the bulloidcs group 36

Globotruncana fornicata group 38

Fornicata-plummcrac branches 40,42

Cesar ctisis branch 45

Calicifortnis branch 46

Dijf or mis-inter mcdia-citac branches 48

Contusa branch 53

Comments on the phylogenetic development of the fornicata group 55

Globotruncana thalmanni group 58

Crctacea branch 60

Area branch 62

Stuarti-rosctta branches 64,66

Gansscri-ivirdrnmaycri branches -... 69

Comments on the phylogenetic development of tlie thalmanni group 74

Comments Genetical development of Globotruncana 77

Lines of investigation 77

Origin and early development of the genus 81

Rotalipora subgenus 83

Globotruncana subgenus 84

The "gloliigerinization" of Globotruncana 87

General rules on the development of Globotruncana 89

Ecology and races 93

General conclusions 93

Stratigraphic considerations 95

Key for the determination of Globotruncana ~. 98

Bibliography 108

Plates Ill

Text Figures Page

1. Index map of northeastern Colombia, siiowing location of sections and wells 10

2. Columnar sections with stratigraphic distribution of Globotrun- cana 12

3. Globotruncana lapparetiti longilocula, n. subsp., 60X. showing the rapid increase in size of the chambers. S. 9168. Manaure shale {Marginulina jonesi) 18

4. Comparative view of Globotruncana of the linnet group 19

la-b. Git. imbricata Mornod, 1949 (text fig. 5/1,11), Cenomanian,

Suisses. 2a-b. Git. canaliculata (Reuss, 18 54, pi. 26, fig. 4), Cenomanian ?

Coniacian, Austria. 3a-b. Git. indica Jacob and Sastry, 1950 (fig. 2), Cenomanian, India. 4a-b. Git. linnei (d'Orbigny, 1839, pi. 5, fig. 10-12), age ?, Cuba. 5a-b. Git. linnei Gandolfi, 1942 (text fig. 16 2a-c), equivalent to Git.

lapparenti coronata BoUi, Turonian, south Switzerland. 6a-b. Git. linnei Gandolfi, 1942, (pi. 3, fig. 3)=Glt. lapparenti lap- parenti Bolli, Turonian, south Switzerland. 7a-b. Git. lapparenti lapparenti Cita, 1948 (pi. 4, fig. 2), Turonian-

Maestrichtian, Tignale, north Italy. 8a-b. Git. lapparenti longilocula, n. subsp., Manaure shale {Marginulina

jonesi), Colombia, S. A. 9a-b. Git. canaliculata Cushman, 1946 (not Reuss), pi. 61, fig. 17a-c,

Annona chalk, Texas. lOa-b. Git. mayaroensis Bolli, Colon shale, Pullenia cretacea zone,

Colombia, S.A.

5.

la-c. Git. tricarinata colombiana, showing radial, depressed umbilical sutures in the early chambers of the last volution and slightly inflated roof of chambers. S. 5591. Colon shale, Pullenia cretacea zone; X60 21

2a-c. Git. tricarinata colombiana ?; notice extreme development of last chambers. S. 5606, Colon shale, Pullenia cretacea zone; X60.

6. Comparative view of Globotruncana of the tricarinata branch 23 la-b. Git. tricarinata Cita, 1948 (pi. 4, fig. 4). Turonian-Maestrichtian,

Tignale Nord, Italy. 2a-b. Git. tricarinata Cushman, 1936, (Pi. 61, fig. IS), St. Johann, Bavaria,

Germany. 3a-h. Git. tricarinata Mornod, 1949 (fig. 12/2a-c) which is probably a

Git. ventricosa ventricosa (White), Santonian, Prealpes Suisses. 4a-b. Git. tricarinata colombiana. Colon shale, Pullenia cretacea zone,

Colombia, S. A.

7. Evolutive line Globotruncana marginata austinensis, n. subsp., (Rugoglobigerina) belJingi belJingi, n. sp., n. subsp. All specimens from the same level. S. 5587, 60X. Colon shale, Pullenia cretacea zone 30

la-c. Git. miiri/iiiattt tiustutrnsis. n. Mih^j). ; notice small >i/e of the specimen which is faintly hut completely keeled.

2a-c. Same as above, however, showing chambers more inflated.

3a-c. (Ruyoi/lohu/frina) hflJiiuii subhrlJuK/i, n. sp., n. subsp., partially keeled in the earlv chambers of the last volution.

4a-c. {Rugoijlohiynina) hclJingi brlJitu/i, n. sp., n. subsp., showinjj only faint rugosity at place where keels disappear.

8. (Rugof/lohu/rrina) prtaloiJrti suhf>rtaloidra, n. sp., n. subsp.; showing faint keel and hantkeninoid spines in the early chambers of the last volution. 8. 5595. Colon shale, Pullcriia cretacea zone; X60 S3

9. Drawings 1-4 show morphological line Git. fornicata manaurensis, n. subsp. Git. caliciformis caluiformis (de Lapparent). All figures X45 57

la-c. Git. fornicata manaurensis, n. subsp. (from PI. 2, fig. 1).

2a-c. Git. fornicata manaurensis, n. subsp. S. 9164. Manaurc shale (Marginulina jonrsi) ; showing intermediate characters.

3a-c. Git. caliciformis caliciformis (de Lapparent). S. 9164. Manaure shale (Marginulina jonrsi); showing beaded sutures in early chambers but still subcircular periphery.

4a-c. Git. caliciformis caliciformis (de Lapparent), from pi. 3, fig. 1, showing well-developed petaloid chambers. Notice nearly straight apertural lips in primitive forms, which become arched in more evolved types.

5a-c. Git. intermedia intermedia (Belli). S. 5881. Bottom of Colon shale (Pullenia cretacea zone) ; showing raised umbilical sutures and intermediate characteristic with Git. fornicata manaurensis and Git. caliciformis caliciformis.

10. Git. rosctta rosetia (Carsey) showing depressed umbilical sutures with "bourrelet sutural" partially disappearing. S. 5602. Colon shale, upper Pullenia cretacea zone; X60 67

11. Comparative view of cleaned umiiilical sides of:

a. Git. rosctta pettcrsi, n. subsp. S. 5587. Colon shale, Pullenia cretai ca zone 69

b. Git. gansseri gansscri (Bolli). S. 5607. Colon shale, Pullenia cretacea zone 69

c. (Rugogl.) rugosa rugosa (Plummer). S. 5607. Colon shale, Pullenia cretacea zone 69

All drawings X60.

12. Theoretic case of a dichotomic evolution. Species A is evolving toward species B and C. Dashed area indicates zone of mixed characteristics between A, B, and C; dark dotted areas, mixed zones between .\, B, and A, C; light dotted area, mixed zone be- tween B and C (no evolution between li and C) 79

IK GKNUS GLOBOTRUNCANA IN NORTHEASTERN COLOMBIA

Rolando Ganoolu*

ABSTRACT

This paper deals with the occurrence, distribution, and development of the genus Glohotnincana in northeastern Colombia.

Thirty-eight species and subspecies of the genus Globutruricana are des- cribed and assigned to the subgenus Glohotruncana. Three species and twenty subspecies of them are new. Tw'enty-two species and subspecies of forms reminiscent of Glohigcrina with partially or not developed keels are described as closely related to Glohotruncana along many phylogenetic lines. Three species and eleven subspecies of them are new. These forms are included under Rugo- globu/rrina Bronnimann, 1952, which is used, however, in a broad sense with a slightly modified definition and considered as a subgenus of Glohotrun- cana, like Ticinclla, Thalmanninclla, and Rotalipora.

INTRODUCTION

This paper deals with the genus Globotruncana in northeastern Colombia, its occurrence, and stratigraphic distribution. The study is of particular interest, primarily since the genus Globotruncana is becoming more and more important due to its wide geographic distribution and its rapid tempo of evolution; secondly, there is a fair opportunity to check, by help of widely distributed pelagic genera, the local stratigraphy of Colombia, the Upper Cretaceous age of which is based on benthonic forms (Cushman and Hedberg, 1941).

Regarding the genus Globotruncayia, there is no previous record of its occurrence in Colombia, with the exception of Git. jornicata Plummer mentioned by Cushman and Hedberg, 1941.

In Europe the genus was thoroughly investigated during recent years with the aim of obtaining finer stratigraphic subdivisions and recognizing, as far as possible, the morphologic and genetic rela- tionship between the steadily increasing number of new species. Brotzen, 1942, and Sigal, 1948, named respectively the genera Rotal- ipora and Thalmanninella. These were considered by Reichel, 1949, as subgenera of Globotruncana along with the new subgenus Tici- nella which he erected. The importance of Globotruncana, s.l. as a time marker and its interest as paleontologic evidence for evolution has been recognized over the world.

♦Formerly with International Petroleum (Colombia) Ltd., Bogota, Colom- bia, S.A. At present consulting geologist in Italy.

Bulletin 155

In America the most notable advance in the study of distribu- tion and development of Glohotruncana is seen in the recent paper issued by Bolli, 1951, based on the Glohotruncana fauna of Trinidad.

Thirty-eight species and subspecies of the genus Glohotruncana, twenty-three of which are new, are described in the paper and assigned to the subgenus Globotruncatia. Twenty-two species and subspecies of forms reminiscent of Globigerina, with partially or no developed keels, have also been described as closely related to Glohotruncana along many phylogenetic lines. Of these, three species and eleven subspecies are new. These forms are included under Rugoglohigerina Bronnimann, 1952, which, however, is used in a broad sense with a slightly modified defmition and considered as a subgenus of Glohotruncana, as are Thalmanninella, Ticinella, and Rotalipora. No complete systematic study of the abundant "Glohi- gerinai" population has been carried out, since it was thought to be beyond the scope of the paper. Therefore, the possibility exists that other similar forms may still be present in our material.

These 38 forms were first arranged in groups based on certain morphological similarities. Each of them is believed to represent a unit with a common genetic development.

The groups were in turn subdivided into branches, whenever branches were recognized or postulated. Each of the branches has, or is believed to have, generally the value of a direct line. Ob- viously, the scientific value of such subdivisions will be, for each case, carefully discussed and their paleontologic evidence verified.

No attempt is made here to place a systematic value on the group or its branches; these divisions only represent forms which ap- pear to be related based on the study to date.

The classification and delimitation of species and subspecies in the present material is felt to be more artificial than usual since frequently one form grades into another without any apparent sharp break in the morphologic line. Consequently, nomenclatural units were created only when a sufficient number of specimens with common characteristics allowed fixing, even if artificially, some limits of variability between the single species and/or subspecies.

Globotruncana in Coi-omiua: (Ianuoi.m

The study has been carried out withui the hunts of detail allowed by the routine work of practical paleontology. A systematic study of the apertures was, therefore, not attempted, although it would have been advisable in many cases. Nevertheless, the fair preservation of the material and the possibility of occasionally cleaning the imibilical cavity in some specimens provided for a fair amount of information. The holotypes of the new species and new subspecies described hereui have been deposited m the Paleonto- logical Research Institution cf Ithaca, New York; topotypes at the Museo Geologico of Bogota. Specmiens of species not described as new in the text are deposited with the collection of the Micropal- eontological Laboratory of the International Petroleum (Colombia), Limited.

ACKNOWLEDGMENT

Acknowledgment is given to the directors of International Petroleum (Colombia), Ltd., who kindly authorized the publica- tion of the paper and gave financial help toward the cost of the plates. The writer feels greatly indebted to his friend, V. Petters, head of the Intercol's Paleontological Laboratory, for his interest and readiness to discuss some of the more important arguments of the study. Thanks are due also to Mr. H. BoUi, Paleontologist of Trinidad Leaseholds, Limited, for topotypc material of Trinidad; Mr. B. F. Ellis, head of the Micropaleontological Department of the American Museum of Natural History; Professor M. Reichel, head of the Paleontological Department of the Geological Institute of Basel, Switzerland; Professor A. Desio, head of the Geological In- stitute of Milan, Italy; Messrs. C. P^miliani of the Walker Museum of Chicago, and A. R. Loeblich, Jr., of the United States National Museum of Washington, D. C, who contributed comparative ma- terial to the writer.

GEOGRAPHIC AND STRATIGRAPHIC OCCURRENCES

I he material was derived entirely from the northeastern part of Colombia, where marine Upper Cretaceous sediments are well developed in open sea facies: the Rancheria and Cesar Valleys.

10

Bulletin 155

INDEX MAP OF NORTHEASTERN COLOMBIA

SHOWING LOCATION OF SECTIONS AND WELLS FIG. I

Fig. 1. Index map of northeastern Colombia, showing location of sections and

wells.

Three surface sections and two wells have supplied the greatest quantity of the material. The sections are:

1. Manaure Section: Cesar Valley, Rio Manaurc, 10() km. east- southeast of the town of La Paz: 60 m. of thin-hedded brown shale weathering gray (Manaure shale, occurrence of Marginulina jonesi).

Globotruncana in Colombia: Gandolfi 11

2. Molino Section: Cesar Valley, Rio Molino, 20() km. noitii- cast of the town of Villaiuieva; 70 m. of Manaure shale uiulerlyin^ 5(X) m. of soft green silty shale (Colon formation: PuUenia cretacea and Siphogcncrinoides bramlettei zones).

3. Km. 92 Section: Rancheria Valley, Fonseca Rio Hacha road, 400 km. northeast of the town of Fonseca; a few meters of calcareous, siliceous shale (Manaure ?) underlymg 175 m. of Colon formation.

The wells are:

1. Papayal ^pl^ ^^^ ^^'TI- north-northeast Fonseca.

2. Cerrejon #1, 200 km. east of Papayal 4^1.

The best and most fossdiferous material was obtained from the Km. 92 section (Colon shale) and Papayal :^1 (Colon shale). In general, the occurrence of Globotruncana is more frequent to the north, and locally (wells Cerrejon ^1 and Papayal #1) from east to west in accordance with the facies change toward more open sea conditions. This is especially true of, and is limited to, the lower Colon shale {Ptdlenia cretacea zone), where the frequence of Globo- truncana follows and marks the ingression of the sea from the north. In the upper Colon shale, the population of Globotruncana decreases rapidly and disappears completely, corresponding to the progressive development of more brackish conditions at the end of the Creta- ceous.

In the Manaure shale, the Globotruncana population is scarce and poorly preserved. In the underlying beds a uniform Globigerina- Guembelina-^?iA\o\-a.v\d assemblage is usually all that is present in Colombia.

The study is confined, therefore, to the lower part of the Colon formation (PuUenia cretacea zone) and only a few observations were possible for the upper portion (Siplwgenerinoides bramlettei zone) for the underlying Manaure shale.

The stratigraphic results are consequently considered as indi- cative. Regarding the local stratigraphic subdivision, it is to be noted that respectively the Manaure shale, the PuUenia cretacea zone, the Siphogenerinoides bramlettei zone are considered Conia- cian, Campanian, and Maestrichtian in age (Santonian has not been

12

Bulletin 155

12158 12157

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COLUMNAR SECTIONS

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ITH STRATI6RAPHICAL DISTRIBUTION OF GLOBOTRUNCANA |

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Fig. 2. Columnar sections with stratigraphic distribution of Glohotruncana.

Gl.(1BOTRUNCANA IN COLOMBIA: CjANDOI.II

13

recognized locally). Stratigraphic boundaries cannot be definitely correlated, bowever, witb European time divisions; and overlaps

probably exist, as will bo brougbt out when discussing tbe distri- bution of Globntruncana.

DESCRIPTION OF SPECIES

Genus GLOIJOTHrNCAJfA Cushman, 1927 Type species. By original designation, Pulvinulina area Cush- man, 1926, Cont. Cushman Lab Foram. Res., vol. 2, p. 23, pi. 3, fig. 1. Mendez shale, Upper Cretaceous, Mexico.

The following species and subspecies are described in the paper:

Plate Figure

Globotruncana lapparenti longilocula, n.subsp. 1 1

Globotruncana mayaroensis Bolli 1 2

Globotruncana tricarinata colombiana, n.subsp. 1 3-4

Globotruncana tricarinata desioi, n.subsp. pp. 27, 103

Globotruncana ventricosa ventricosa (White) 1 5

Globotruncana marginata austinensis, n.subsp. 1 6

( Rugoglobigerina) beldingi beldingi, n.sp., n.subsp. 1 8

( Rugoglobigerina) beldingi subbeldingi, n.subsp. 1 7

Globotruncana bulloides bulloides (Vogler) 1 9

Globotruncana bulloides globigerinoides (Brotzen) 1 10

(Rugoglobigerina) hexacamerata hexacamerata

(Bronnimann) 1 12 (Rugoglobigerina) hexacamerata subhexacamerata,

n. subsp. 1 11

Globotruncana bulloides naussi, n. sp., n. subsp. 1 13 Globotruncana mariai, n.n. pp. 33, 106

(Rugoglobigerina) loetterli subloetterii, n. subsp. 1 14

Globotruncana fornicata fornicata (Plummer) 2 2

Globotruncana fornicata manaurensis, n. subsp. 2 1

Globotruncana fornicata plummerae, n. subsp. 2 3-4

Globotruncana fornicata ackermanni, n. subsp. 2 5-7 (Rugoglobigerina) circumnodifer circumnodifer

(Finlav) 2 9

14 Bulletin 155

Plate Figure

(Rugoglobigerina) circumnodifer subcircumnodifer,

n. subsp. Globotruncana fornicata cesarensis, n. subsp. (Rugoglobigerina) macrocephala macrocephala

(Bronnimann) (Rugoglobigerina) macrocephala submacrocephala

n. subsp. Globotruncana caliciformis caliciformis (de Lapparent) 3 Globotruncana caliciformis tnnidadensis, n. subsp. Globotruncana caliciformis sarmientoi, n. subsp. Globotruncana intermedia difformis, n. subsp. (Rugoglobigerina) ornata ornata (Bronnimann) (Rugoglobigerina) ornata subornata, n. subsp. Globotruncana intermedia intermedia

(Rugoglobigerina) glaessneri glassneri, n. sp., n. subsp. 3 (Rugoglobigerina) glaessneri subglaessnen, n. sp., n.

subsp. Globotruncana citae Bolli

( Rugoglobigerina ) petaloidea petaloidea, n. sp., n. subsp (Rugoglobigerina) petaloidea subpetaloidea, n. sp.,

n. subsp. Globotruncana contusa contusa (Cushman) Globotruncana contusa scutilla, n. subsp. Globotruncana contusa patelliformis, n. subsp. Globotruncana thalmanni thalmanni, n.sp., n. subsp. Globotruncana thalmanni flexuosa (van der Sluis) Globotruncana aff. cretacea Cushman Globotruncana bollii, n. sp. Globotruncana area area Cushman Globotruncana area caribica, n. subsp. Globotruncana stuarti stuarti (de Lapparent) Globotruncana stuarti parva, n. subsp. Globotruncana stuarti conica (White) Globotruncana rosetta rosetta (Carsey) Globotruncana rosetta insignis, n. subsp. Globotruncana rosetta pettersi, n. subsp. Globotruncana gansseri gansseri Bolli

2

8

2

10

2

12

2

11

3

1

3

2

3

3

3

4-5

3

7

3

6

3

8

3

11

3

10

3

12

3

14

3

13

4

3

4

1

4

2

4

4-5

4

6

4

7

5

1

5

2-4

5

5

5

6

5

7

5

8

6

1

6

2

6

3-4

6

5-6-8

Plate

Figure

6

7

7

2

7

1

Cl.OBOTRUNCANA IN Ccn.OMBIA: GaNDOLFI 15

Globotruncana gansseri subgansscn, ii. suhsp. ( Rugoglobigerina) rotundata rotundata (Bronnimann ( Rugoglobigerina ) rotundata subrotundata, n. subsp. Globotruncana wiedenmayeri wiedenmayeri, n. sp.

n. subsp. 7 4

Globotruncana wiedenmayeri magdalenaensis, n.sp.,

n. subsp. 7 3

(Rugoglobigerina) rugosa rugosa (Plummer) 7 6

( Rugoglobigerina ) rugosa subrugosa, n. subsp. 7 5

(Rugoglobigerina) pennyi pennyi (Bronnimann) 7 8

(Rugoglobigerina) pennyi subpennyi, n. subsp. 7 7

All species listed above are described as belonging to the genus Globotruncana with the exception of the forms which are geneti- cally related to Globotruncana but morphologically reminiscent of Globigerina. These last forms were included under Rugoglobigerina Bronnimann, 1952, under the following description, which is slightly modified from the original description of Bronnimann:

Subgenus Rugoglobigerina Bronnimann, 1952. Type by original designation: Rugoglobigerina rugosa rugosa (Plummer 1926). Test Globigerina-Wkt, almost planispiral to trochoidal. Chambers of Globigerina type, rounded peripherally, truncated toward the umbilicus. Umbilical cavity generally large with umbilical apertures, protected bj' liplike projections. Test smooth, with partially de- veloped keels or rough with rich ornamentation, rugosities of various types, irregularly distributed or arranged in rows radiating from a central point of the surface towards the aperture (meridian pattern). The chambers may be occasionally pro\ided with hantkeninoid points, especially in the first stages of the last whorl.

This subgenus fits into the Globotruncana genus according to the definition which was given by Reichel, 1949, (p. 600), as Thalmanninella, Ticinella, Rotalipora, and Globotruncana, s. str.

In the description of the following species, several morphological terms are used. A few of them perhaps need some kind of explana- tion:

"Bourrelet sutural" (from French authors): Raised sutures; continuous (pi. 1, fig. lb) or beaded (pi. 1, fig. 2b).

"Bourrelet umbilical" (from French authors): Sutural thicken- ing limited to the area around the umbilicus (pi. 6, fig. 2b).

Lapparenti type of ventral sutures: Sigmoidal and plunging back into the umbilicus (pi. 1, fig. lb).

16 Bulletin 155

Rosetta type of ventral sutures: Raised, curved, and generally attached to suture of previous chambers (pi. 6, fig. lb).

Peripheral band: The portion of the test which is embraced by the keels of double-keeled forms (pi. 1, fig. Ic).

Umbilical lips: Slightly arched (pi. 1, fig. lb), strongly arched with central projections (pi. 5, fig. 6b), nearly straight (pi. 4, fig. 4b, 6b).

Ventral side and dorsal side: In agreement with Reichel, 1949 (p. 602, footnote 7) respectively umbilical and spiral side.

GLOBOTRUNCANA LINNEI GROUP

Description. Flat or slightly convex forms, double-keeled, two being equally developed, peripheral band at right angle to the coil- ing plane, and symmetrical in the middle of the chamber; chambers generally flat with occasional protruding or inflated ventral side, elongated or short; thick, continuously raised or finely beaded sutures, margmal elevations partially disappearing when the sutures are radial and depressed in the umbilical side.

The group, as will be discussed later, is in a broad sense intended to include primitive double-keeled species with short chambers and radial sutures {Git. imbricata Mornod, Git. inflata Bolli, Git. indica Jacob and Sastry, Git. canaliculata Reuss); Git. lapparenti forms with elongated chambers and curved sutures on the umbilical side; later evolved species with chambers becoming sec- ondarily short and sutures radial in the same umbilical side {Git. canaliculata Cushman, Git. mayaroensis) and finally forms with protruding, truncated umbilical side {Git. tricarijiata, Git. colom- biana, n. sp.. Git. ventricosa). Three main branches are here con- sidered:

Lapparenti branch: Flat double-keeled forms.

Tricarinata branch : Flat dorsal side, protruding truncated umbilical side.

Ventricosa branch: Flat dorsal side, protruding umbilical side, chambers inflated on this side.

Apertural system. All Git. linnet types, regardless of belonging to the linnet, tricarinata, and ventricosa branches, are characterized by an umbilical cavity with the apertures of the chambers pro- tected by liplike borders which are tiiin init developed as a contin-

Gldbotruncana in C\)H)mi!Ia: (Jandolu 17

uous thin plate in the more primitive forms (Alornod, 1949, p. 581, fig. 2c, 3c), more strongly developed and split into single arched lips in the last chambers (Reichel, 1949, pi. 16, fig. 9) in Git. lapparenti. \\'ith more evolved species as Git. colomhiana (fair observa- tions were possible in the Colombian material. Pi. 1, fig. 3, 4), Git. ventricosa (PI. 1, fig. 5), the cover plates keep their arched shape, but they reduce agam to fine lips which tend to blend together as a continuous thin plate all around the umbilicus.

The observations on Git. mayaroensis were poor, but apparently apertural cover plates still exist.

LAPPARENTI BR.\NCH

Globotrniioaiiii lai»]>iireiiti l<>Il^-iI<)oul;l, n. subsp.

PI. 1, fig. 1, Text figs. 3,4 (8a-b)

Description. Flat or only slightl}' convex on both sides, peri- pheral band wide and perpendicular to the coiling plane, double- keeled; chambers short, slightly over-lapping each other in the early stages, becoming later in the adult stage (four-five in the last whorl) long, arched and strongly overlapping: (fornicata type); sutures con- tinuously raised, sigmoidal on the ventral side, running and plunging back into the umbilicus {lapparenti type). Test smooth, dextrally coiling in all counted specimens, umbilical apertures with slightly arched, moderately developed cover plates.

Dimensions of holotype. Width, 0.40 x 0.36 mm.; thickness, 0.12 mm.

Holotype. No. 20826, Paleontological Research Institution.

Occurrence. Rare in the Manaure shale, Manaure and Km. 92 sections. Holotype (PI. 1, fig. la-c) from the Manaure shale, Manaure section, S. 9168.

Remarks. It is the usual flat double-keeled form of the lap- parenti type. The chambers, however, are more elongated and arched, the sutures more finely raised than in Git. lapparenti lap- parenti.

As can be seen in text figures 3 and 4, the tests of the Breggia material (south Switzerland) have chambers (five-six) in the last whorl which, however, overlap less on each other and increase less rapidly in size as added. In text figure 4 Git. lapparenti Cita appears

18 Bulletin 155

to be similar with chambers somewhat elongated. The few speci- mens of the present material show more pronounced elongated chambers. Git. tricarinata colombiana seems to bear an analogous relationship to Git. tricarinata tricarinata.

Git. canaliculata Cushman (not Reuss) of the Annona chalk is a different, more evolved species, showing more oblique sutures on the dorsal side, which are clearly beaded and, on the ventral side, simply curved without any sigmoidal development; the test, especi- ally in the early chambers, is abundantly spinose.

Fig. 3. Gldhotruncaua lapparcnt'i longilocula, n. subsp., 60 X, showing the rapid increase in size of the chambers. S. 9168. Manaure shale {Maryinulina jonrsi).

Crlobotrimcana mayaroensis Bolli PL 1, fig. 2a-c, Text fig. 4(10a-b)

Globotruncana mayaroensis Bolli, 1951, p. 198, pi. 35, figs. 10-12.

Description. Besides the double-keeled peripheral band, typi- cal characteristics are, according to Bolli, the oblique arrangement of the chambers with respect to each other and the radial sutures on the umbilical side.

A close examination of our material, as well as of topotype material of Trinidad, shows further that the keels are not parallel or converging in the direction of the coiling, as generally occurs in Upper Cretaceous species, but are diverging, sometimes strongly and in such a way that the last chambers have a considerably wider peripheral band than the early ones. On the umbilical side the sutures are generally radial, but isolated specimens show the last chambers with curved, finely beaded sutures. The lines of beads are, in part, fringing the chambers and, in part, disappearing in the sutural depressions, while the sutures of the early chambers remain radial and depressed.

CiI.dROTRlNCANA IN Coi-OMBIA: (lANDOI.FI

19

Occurrence. Colon shale. Km. 92 section and Papayal ^\cll, appearing somewhat in the midtlle of the Pullenia cretacea zone. Rare.

Fig. 4. Comparative view of Globotruncana of the linnci group, la-b. Git. tm- bricata Mornod, 1949 (Text fig. 5/1,2), Cenomanian, Prealpes Suisses. 2a-b. Git. canaluulata (Reiiss, 18 54, pi. 26, fig. 4), Cenomanian ?-Coniacian, .Austria. 3a-b. Git. inJica Jacob and Sastrv, 1950 (fig. 2), Cenomanian, India. 4a-b. Git. linnrl (d'Orbign)', 1839, pi. 5, fig. 10-12), age ? Cuba. 5a-b. Git. lirtnri Gan- dolfi, 1942 (Text fig. 16, 2a-c), equivalent to Git. l/ippannti coronata Belli, Turonian, south Switzerland. 6a-b. Git. linriri CJandolfi, 1942 (pi. 3, fig. 3) = Git. lappunrtli lappurrriti Holli, Turonian, south Switzerland. 7a-b. Git. lappar- ent'i lappurrnti Cita, 1948 (pi. 4, fig. 2), Turonian-Maestrichtian, Tignale, north Italy. 8a-b. Git. lapparcnti longilocula, n.subsp., Manaure shale {.Mdrf/iriulina joncsi), Colombia, S. A. 9a-b. Git. canaliculata Cushman, 1946 (not Reuss), pi. 61, fig. 17a-c, Annona chalk, Texas. lOa-b. Git. mayarornsis Bolli, Colon shale, Pullenia cretacea zone, Colombia, S. A.

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Remarks. No intermediate forms were found with Git. inter- media intermedia as Bolli points out. From fig. 3, Git. m-ayaroensis occupies a singular position among all Globotruncana of the linnei group, bemg quite different from all Git. canaliculata, Git. linnei, and Git. lapparenti forms. A certain smiilarity is shown only with Git. canaliculata Cushman of the Annona chalk because of the arrangement and shape of chambers and the straight, oblique sut- ures.

The position of Git. mayaroensis is, therefore, still uncertam. A genetic as well as a morphologic relationship with Git. intermedia is still possible as Bolli suggests and may be postulated by a slight dorsal convexity, which is occasionally shown in some specimens and by the slightly elongated chambers. It was, however, placed in the linnei group because of the wide, double-keeled peripheral band, which is perpendicular to the plane of coiling; the generally flat form with equally flat chambers, which are considered as common char- acters of the linnei group, and because of the similarity to Git. can- aliculata Cushman.

TRICARIXATA BRANCH

Globotriuitaiia tricariiiata colombiana, n. subsp.

PI. 1, fig. 3a-c, 4a-c, Text figs. 5(la-c), 5(2a-c), 6(4a-b)

Description. The form is flat dorsally with protruding umbili- cal side, sidewall making a large angle with the roof of the chambers, as in Git. tricarinata tricarinata (Quereau, 1893) and Git. stuarti. The peripheral band is wide, perpendicular to the plane of coiling, with two well-developed, parallel keels. The chambers are generally arched, considerably overlapping, and rapidly increasing in size as added. The sutures are curved, generally thick, and continuously raised; on the ventral side the sutural elevations are running sig- moidal around the umbilicus (lapparenti type) thickening consid- erably around the same umbilicus ("bourrelet umbilical," Mornod, 1949) which appears in side view or axial section as a third well- developed keel. The umbilicus is large and open.

In some specimens (PI. 1, fig. 4, Text fig. 5 ( la-c) the early chambers ot the last coil are slightly inflated, gradually becoming flat in the more adult stage; the keels are finely beaded becoming

Gl.(1B(1TRlNCANA IN CoiOMHIA: (lANDOI.I'I

21

increasingly raised in the adult stage; the test is spmose; on the umbilical side, the sutures are radial and depressed, -the chambers slightly inflated. Ihe forms arc quite similar to CIt. ventricosa (\\'hite), as described in detail by Mornod, 1949. The only remain- ing distinctive characteristic: the strongly developed umbilical thick- enmg. Git. ventricosa of Mornod (op. cit . fig. 85/3a-c) may belong to this type of transitional form, but due to the strong umbilical thickening should still belong to the Git. tricarinata type.

Dimensions of holotype. Width 0.44 x 0.32 mm.; thickness, 0.16 mm.

Holotype. No. 20827, Paleontological Research Institution.

Occurrence. Manaure shale; frequent at the bottom of Colon shale {PuJlenia cretacea zone). Holotype (PI. 1, fig. 3a-c) from the Colon shale, Pullenia cretacea zone, Molmo section, S. 12141.

Remarks. The form shows a side view which is identical to Git. tricarinata ( (Juereau 1893, pi. 5, fig. 3). As is known, this form is named only from thin section. Later the authors made pictures of Git. tricarinata which show all the same typical axial sections, but the number, shape, and arrangement of chambers ( fig. 6) differ considerably. Therefore, the problem arises which of those forms, including ours, is to be identified with the original of Quereau. Since, however, it is here believed that many forms of "tricarinata type" are perhaps present m the original material, and since there is no possibilit\" for the writer to check it, the forms figured by Cushman.

Fig. 5. la-c. Gil. trhaririatd culomhiana showing radial, depressed umliilical sutures in the early chambers of the last volution and slightly inflated roof of chambers. S. 5591. Colon shale, Pullmia crctacra zone, 2a-c. GU. tr'nurinatci colomhiana f; notice extreme development of last chambers. S. 5606. Colon shale, Pullmia crctacra zone. 60 X.

22 Bulletin 155

1936 (pi. 61, fig. 18a-c) are considered as holotype of Git. tricarinata tricarinata in spite of some apparently evolved characteristics.

It is of particular phylogenetic interest to describe in detail a single specimen which was found high and isolated in the section and is shown in fig. 4 (2a-c). The side view shows the identical profile which is common to all tricarinata forms with the third keel well developed. Peculiar, however, is the extreme development of the last chamber, the spinose test, the radially depressed umbilical sutures in the early stages and the slight inflation of the chambers. In accord- ance with our procedure of not creating any new nomenclatural units without having a sufficient number of specimens, this specimen has been considered as a Git. tricarinata colombiana and was conse- quently not named. It is believed, however, that it may represent a stage of a well-defined line of. evolution and, accordingly, a new species or subspecies for the following reasons:

1. It cannot be interpreted as an immature form of Git. colom- biana because of the extremely peculiar development of the last chambers.

2. It was found isolated and high in the section where no Git. colombiana was found.

A similar tendency toward such forms with few chambers in the last whorl is shown in other groups ( cf . Git. cesarensis, PI. 2, fig. lOa-c).

VEXTRICOSA BRANCH

(.lilobotruncaiia ventrlcosa veiitricosa (White) PI. 1, fig. 5a-c

Git. vcntr'icosa White, Cushman 1946, p. 150, pi. 62, fig. 3a-c; Mornod. 1949, p. 590, fig. 121a-c; Cita 1948, p. 20, pi. 4, fig. 9.

Description. The early chambers tend to become short with radial sutures (general genetic development). The sutures are finely beaded. Four or five chambers are present in the last whorl with a more pronounced increase in size as in the references. In some speci- mens the first chambers of the last whorl show a slight inflation on the dorsal side ( cf. Git. tricarinata colo?nbiana, PI. 1, fig. 4a-c, Text fig. 5 (la-c).

Higher in the section (Git. gansseri zone) the keels are slightly converging so that in the last chambers they are almost joined.

Occurrence. Colon shale. Rare.

Globotruncana in Colombia: Ganuolii

23

Remarks. By conipanng the tigurcs of Cushnian ( Cusliman, 1936, pi. 62, fig. 3a-c), Cita (Cita, 1948, pi. 4, fig. 9a-c) and Mornod (Mornod, 1949, text fig. 12/la-c), there are practically no appreci- able differences. However, it can be seen that the specimen shown by Cita is slightly flatter than the other one; the specimen of Mor- nod has a more pronounced petaloid periphery. Our Colombian ma- terial, however, has increasingly larger chambers.

Bolli suggests for this species a genetic derivation from Git. tricarinata which appears probable to the writer (see descriptif)n of Git. tricarinata colontbiana). It is noteworthy that the American records of the species do not agree, having different stratigraphic ranges in Texas, Mexico, and Trinidad.

O^

Fig. 6. Comparative view of Globotruncana of the tricarinata branch, la-li. Git. tricarinata Cita, 1948 (pi. 4, fig. 4) Turonian-Maestrichtian, Tignale Nord Italy 2a-b. Git. tricarinata Ciishman, 1936 (pi. 61, fig. 18), St. Johann, Bavaria, Germany. 3a-b. Gtt. tricarinata Mornod, 1949 (fig. 12/2a-c) which is probably a Git. ^'cntricosa vcntricosa (White), Santonian, Prealpes, Suisses. 4a-b Git. tricarinata colombiana, Colon shale, Pullrnia crrtacra zone, Colombia, S. A.

COM.MENTS OX THE PHVLfXiKNKTIf DI-A r.I.OI'MKNT OF THE LINNEI GROUP

Although the Colombian material is poor in linnei forms and consequently is not favorable for phylogenetic investigation, some general considerations will be tentativch- discussed.

24 Bulletin 155

From the bibliographic references, it appears that all flat, double-keeled forms have been called Git. linnet in Europe and Git. canaliculata in America. The writer believes that there are many different species of flat two-keeled forms within what has been called Git. linnei in Europe and Git. canaliculata in America. The reason for this is that in many cases only thin sections were available (Renz, 1936).

Brotzen (1936) recognized that the forms described by De Lap- parent as linnei were not identical to Git. linnei (d'Orb). Accord- ingly, the flat forms with elongated sigmoidal raised sutures on the umbilical side were later separated {Git. lapparenti Brotzen) from other forms which show depressed, radial sutures {Git. linnei, Git. canaliculata). Figure 4 shows a comparative view of some of the main flat, double-keeled forms.

Flat forms with a sharp three-keeled profile were called Git. tricarinata from Git. tricarinata (Quereau) which is known only from thin sections. Git. tricarinata was often included in Git. can- aliculata (Cushman, 1936) or considered as a subspecies of Git. lap- parenti by other authors (Vogler, Cita, Bolh). Figure 6 shows a comparative view of "tricarinata" forms.

Flat double-keeled forms with chambers more or less inflated on the ventral side were called Git. ventricosa (White). This species was first described as a "variety" of Git. canaliculata and later as a separate species closely related to Git. tricarinata (Mornod, 1949, BolH, 1951).

From the above short review it appears that lin?iei (lapparen- ti), tricarinata, and ventricosa tests are considered genetically re- lated. The writer does not object to this view. The respective mor- phological relationship was pointed out also in the species descrip- tions and appears unquestionable. The only problem is to define when the splitting of the three main phylogenetic developments oc- curred. From our material it appears that the ventricosa branch diverged from the tricarinata branch last (Santonian ?), since forms which can be interpreted as transitional ones between ventricosa and tricarinata are still to be observed in Campanian (PI. 1, fig. 4a-c,