Jurassic and Cretaceous trigoniid bivalves from West-Central Argentina 9780877104308, 0877104301

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HARVARD UNIVERSITY -^

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Museum

of

Comparative Zoology

I

Gilbert Dennison Harris

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Bulletins of American Paleontology (1895)

ISBN 0-8771 0-42'

^MSctms of rxcan auontolccisi Begun

OLUME

105,

in

1895

OCTOBER

NUMBER 343

Jurassic

and Cretaceous

Trigoniid Bivalves from

West-Central Argentina

by

Hector A. Leanza

Paleontological Research Institution

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Ithaca,

20,

1993

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^

VOLUME

msqf "'{can rid. Begun 105,

NUMBER 343

in

1895

^^^"^ OCTOBER

Jurassic

and Cretaceous

Trigoniid Bivalves from

West-Central Argentina

by

Hector A. Leanza

Paleontological Research Institution

1259 Trumansburg Road New York, 14850 U.S.A.

Ithaca,

20,

1993

ISSN 0007-5779 ISBN 0-87710-430-1 Library of Congress Card Number: 93-085393

Printed in the United States of America

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CONTENTS Page Abstract

5

Introduction

6

Comments on

the Family Trigoniidae

Geological settmg of the trigoniid bearing strata in west-central Argentina Temporal distribution of trigoniid bivalves in west-centra! Argentina

Lower Jurassic species Middle Jurassic species Upper Jurassic species Lower Cretaceous species Upper Cretaceous species

6 8

9 9 10 11 11

12

Species durations of the Family Trigoniidae in west-central Argentina

12

Acknowledgements

14

Introduction to systematic paleontology

14

Philosophical considerations

14

Terminology Measurements and abbreviations Abbreviations of repository institutions

16 17 18

18

Systematic descriptions

Plates

65 68 74

Index

91

Appendix; Fossil References Cited

localities

of the described taxa and associated fauna

.

LIST

OF ILLUSTRATIONS ^^^^

Text-figure 1

2. 3.

Location of

fossil localities

Schematic stratigraphic section for the Jurassic and Cretaceous of west-central Argentina Morphological terminology used to describe tngoniid bivalves in this paper

LIST

OF TABLES P^ee

Table 1.

2.

and Cretaceous Stratigraphic distribution of Jurassic and Cretaceous

Stratigraphic distribution of Jurassic

9 17

trigoniid bivalves in west-central Argentina, in stratigraphic order

13

trigoniid bivalves in west-central Argentina, in systematic order

15

AND CRETACEOUS TRIGONIID BIVALVES FROM WEST-CENTRAL ARGENTINA

JURASSIC

By

Hector A. Leanza' With

the contribution of Jose

I.

Garate Zubillaga-

ABSTRACT subspecies of precisely dated Trigoniidae from the Lower Jurassic (Liassic) to the This monograph describes 73 species and Upper Cretaceous (Maastnchtian) of western central Argentina. These are classified into 4 subfamilies as follows: Minetngoniinae, Trigoniinae, Neuquenitngoniinae, n. subfam., Frenguelliellinae (emend.), Myophorellinae, Vaugoniinae, Steinmanellinae, An1

1

ditrigoniinae, n. subfam., Megatrigoniinae, Buchotrigoniinae, n. subfam., Pterotrigoniinae, Laevitngoniinae, Austrotrigoniinae

and Nototrigoniinae. The Frenguelliellinae are reinterpreted to range in age from the Triassic to the Middle Jurassic (Bajocian), and include only the genera Frengueltiella and Kumatngoma. Neuquenitngoniinae, n. subfam., include the very specialized Middle Jurassic genus Seuqucnitrigonia. which shows a transversely costate flank and escutcheon, characteristics that are absent in Trigoniinae s.s. Anditrigoniinae, n. subfam., is erected to group the Middle Jurassic to Lower Cretaceous genera and subgenera Eoanditrigonia. n. subgen., Anditrigoma, Parandhngoma, Antulrigoma, Virgolngoma, and Lambertngoma. n. gen., which are characterized by an smooth area in early representatives, or by transverse or radial ornamentation, or a combination of both, and a poor to well developed marginal carina. The Buchotrigoniinae. n. subfam. include the very specialized Lower Cretaceous genera Buchotngonia and Syrotngoma. which are characterized by a tripartite development of oblique, subconcentric and

The

subvertical costae on the flank.

treated genera are twenty one, including: Groeberella, n. gen. (type species:

Myophoha

neuquensis Groeber, 1924), Tngonia. FrenguelUella. Jaworskiella. Myophorella. Scaphotngonia, Scaphorella. Neuquemtngonia, Vaugoma, Andimugoma, n. gen. (type species: Tngonia radixscnpla Lambert, 1944), Sleinmanella, Virgotrigonia, Lambertrigonia, n. gen. (type species Tngonia pichimoncolensis Lambert, 1944), Anditrigonia, Antulngonia, Rutitngonia, Syrotngoma, Pterotngonia. Quoiecchia. Auslrotngonia. and Pacitngonia. stricto,

The genus Myophorella

Promyophorella. and Haidaia. The genus Sleinmanella

is

divided into the subgenera Myophorella sensu

represented by the subgenera Transitngonia, Macrotngonia,

is

and Splendilngonia, n. subgen. (type species: Tngonia splendida A. F. Leanza, 94 ). Anditrigonia is represented by Anditrigonia stricto, and by an early representative, Eoanditrigonia. n. subgen. (type species: Trigonia keideli Weaver, 1931). The Upper Jurassic and Cretaceous genus Pterotrigonia is divided into the subgenera Pterotngonia sensu stricto, Scabrotrigonia, Rinetrigonia, and Notoscabrotngonia. Ten new species and one new subspecies are established, as follows: FrenguelUella pouhoni (Liassic)i Trigonia losadai, Trigonia leyyi, FrenguelUella perezreyesi. and Scaphorella camachoi (Middle Jurassic); Myophorella (Myophorella) schulzi. Myophorella (Haidaia) elgiietai. Pterotngonia (Notoscabrotngonia) coheni. and Anditrigonia (A.) eximia tesselicaudata (Upper Jurassic); Rutitngonia kaiiffniani and Syrotngoma brocardoi (Lower Cretaceous). Comments on the Family Trigoniidae, as well as taxonomic considerations, stratigraphic occurrence, and facies relationships of the described species are presented. With the new taxonomy proposed here, the trigoniids have a much greater temporal 1

1

sensu

resolution than previously thought, especially at the species level.

RESUMEN En la presente monografia se describen 73 especies y una subespecie de Trigoniidae precisamente datadas del Jurasico inferior (Liasico) al Cretacico superior (Maastnchtiano) del oeste central de la Argentina. Estas se clasifican en 14 subfamilias a saber: Minetrigoniinae, Trigoniinae, Neuquenitrigoniinae, manellinae, Anditrigoniinae,

n.

trotrigoniinae y Nototrigoniinae. el

Jurasico

incluye

al

Medio

muy

caracteristica

que

subfam., Frenguelliellinae (emend.), Myophorellinae, Vaugoniinae, Stein-

La subfamilia Frenguelliellinae

n.

esta ausente en Trigoniinae

el

Jurasico

.Antutngonia, \'irgotngonia.

s.s.

subfam., Pterotrigoniinae, Laevitrigoniinae, Ausedad desde el Triasico hasta

se reinterpreta extiendiendose en

(Bajociano), e incluye solamente los generos FrenguelUella y

especializado genero del Jurasico

extienden desde

n.

subfam., Megatrigoniinae, Buchotrigoniinae,

Kumatngonia. Neuquenitrigoniinae,

Medio Neuquemtngonia. que muestra Anditrigoniinae,

n. subfam.. se erije

n.

subfam.

costulacion transversal en area y flanco,

para agrupar generos y subgeneros que se

Medio al Cretacico Inferior, tales como Eoanditrigonia. n. subgen.. .Anditrigonia. Paranditrigonia. and Lambertngoma. n. gen., que se caracterizan por areas lisas en representantes tempranos, o por

o una combinacion de ambas. y una debil a bien desarrollada carena marginal. Buchespecializados generos del Cretacico Inferior Buchotngonia y Syrotrigonia que se caracterizan por un desarrollo tripartito de costillas obliquas. subconcentricas y subverticales sobre los flancos. Los generos tratados son veintiuno, incluyendo: Groeberella. n. gen. (especie tipo; Myophoria neuquensis Groeber, 1924), Trigonia, Fren-

una omamentacion transversal o

radial,

otrigoniinae, n. subfam., incluye los

Secretaria de Mineria.

Museo Juan

Member

muy

of the National Research Council (CONICET). Av. Julio A. Rosa 651. 1067 Buenos Aires. Argentina.

Olsacher. Direccion General de Mineria. Olascoaga 421. 8340 Zapala. Neuquen. Argentina.

Bulletin 343

Myophorella. Scaphotrigonia, Scaphorella. Neuquenithgonia. Vaugonia, Andivaugonia, n. gen. (especie radixscnpla Lambert, 1944), Sleinmanella. Virgotrigonia, Lambertrigonia, n. gen. (especie tipo: Trigonia pichimoncolensis Lambert, 1944), Andithgonia, Antutngonia. Rutitrigonia, Syrotrigonia, Pterothgonia, Quoiecchia, Austrolrigonia, and Pacirrigonia. El genero Myophorella se divide en los subgeneros Myophorella sensu stricto, Promyophorella, y Haidaia. El genero Sleinmanella esta representado por los subgeneros Transitrigonia, Macrotrigonia, y Splenditrigonia. n. subgen. (especie guelliella, Jaworskiella.

tipo: Trtgonia

Tngonia splendida A. F. Leanza, 1941). Anditngonia esta representado por los %\x\>%ineTos Anditrigonia sensu stricto, y por un representante temprano, Eoandilrigonia. n. subgen. (especie tipo: Trigonia keideli Weaver, 1931). El genero Pterotrigonia

tipo:

caracteristico del Jurasico Superior y Cretacico se divide en los subgeneros Pterotrigonia sensu stricto, Scabrotrigonia, Rinetrigonia,

and Notoscabrotrigonia. Se establecen diez nuevas especies y una nueva subespecie a saber: Frenguelliella poulloni (Liassico); Trigonia losadai, Trigonia levyi, Frenguelliella perezreyesi, y Scaphorella camachoi (Jurasico Medio); Myophorella (Myophorella) schuhi, Myophorella (Haidaia) elguetai, Pterotrigonia (Noloscabrotrigonia)coheni y Anditngonia (A.) eximia tesselicaiidata. n. ssp. (Jurasico Superior); Rutitrigonia kaujfmani y Syrotrigonia brocardoi (Cretacico Inferior). Se efectuan comentarios sobre la Familia Trigoniidae, asi como consideraciones taxonomicas, distribucion estratigrafica, y relaciones de facies de las especies descriptas. Segun la nueva taxonomia propuesta, los trigonidos muestran una resolucion temporal de la que se creia previamente, especialmente al nivel de especie.

INTRODUCTION

20 years from 41 different

This revision of the Trigoniidae from west-central Argentina was necessary in order to update the taxonomic knowledge of this interesting group of bivalves, and to improve the Jurassic and Cretaceous biostratigraphy and paleontology of the southern Andes. The first description of trigoniids in west-central Argentina was

made by Gottsche

(1878), based

on

fossils

from Espinacito Pass in the High Cordillera of San Juan Province. The knowledge of the family in this region was later improved by Behrendsen ( 89 1-1 892), Tomquist (1898), Burckhardt (1900a, 1900b, 1901, 1 903). Haupt ( 1 907), Douville (1910), Jaworski (1916, 1925, 1926), Groeber (1924), Weaver (1931) and A. 1

F.

Leanza (1941, 1942).

published the

first

It

was Lambert (1944) who

paper exclusively dedicated to

tri-

Neuquen Province, describing a total of 24 species. Levy (1966, 1967a, 1967b, 1967c. 1969, 1985) published a number of papers devoted to the

goniids from

taxonomic revision of the Argentine trigoniids, and Marifielarena (1959) described an Upper Jurassic species from Neuquen. Camacho (1967. 1968) described Upper Cretaceous trigoniids, and Camacho and Riccardi (1978) published a list of fossil invertebrates from Neuquen including an updated list of trigoniid bivalves. In recent years, Camacho and Olivero (1985), Leanza(1981, 1985), Leanza and Garate(1983a, 1983b, 1985, 1986, 1987), Leanza, Perez and Reyes (1987), Manceiiido and Damborenea (1984), Farinatti, Quattrocchio and Labudia (1987), and Leanza and Casadio (1991) described several species mainly from the Jurassic and Cretaceous of the Neuquen Basin. The present monograph includes the description and taxonomic revision of 73 species and one subspecies of trigoniid bivalves. Of these, 7 1 species have been collected in Neuquen Province, one species is common both in Neuquen and La Pampa Provinces, and the remaining two taxa were found in La Pampa Province. The studied material has been collected over the past

mucho mayor

fossil localities (Text-figure

In the systematic descriptions, a concise diagnosis

1).

provided for each genus and/or subgenus, and a is added in the case where new morphologic information or new taxa are described. New concepts of trigoniid morphology and descriptive features, which are valuable in differentiating taxa, are included in the is

discussion

systematic descriptions, such as the dorsoposterior and ventroposterior angles or junctions (Kauffman et al. in preparation); these parameters better define the shell

shape of each species than those previously used. Charornamentation of the area (see Terminology, p. 16) were especially taken into account when distinguishing species or even genera and subgenera acters of the

(Perez and Reyes,

1987).

Many

previous trigoniid

workers (e.g.. Cox, 1952, 1969; Nakano, 1960) have been conservative in their approach to higher taxonomic division of the Trigoniaceae, but more detailed morphologic analysis in this study has allowed new revisions at the subfamily level. Taking as a point of departure the interpretations of the family by van Hoe-

pen (1929), Kobayashi (1954), and Saveliev (1958), 13 subfamilies, two of them new, are herein distinguished. Species duration may be as little as one million years for

27%

of the described trigoniid species; the average is 3.8 million years.

species duration

COMMENTS ON THE FAMILY TRIGONIIDAE Trigoniidae, generally the group Lamarck (1819), had a cosmoof of "les trigonees" the Mesozoic. During throughout politan distribution diversity of form immense developed they this time

The bivalve family

and external

sculpture,

which

is

reflected in a large

number of genera and species described from every continent. The family is characterized by a peculiar paleoheterodont dentition and by varied, highly ornate, thick shells of trigonal shape. The superfamily Trigoniaceae, which includes both

Trigoniid Bivalves of Argentina: Leanza

1

Bulletin 343

The pallial line is complete, and the ostracum As far as known, the original constitution of the shell was wholly aragonitic, and commonly prismato-nacreous. The shell microstructure of Neotrigonia was studied in detail by Taylor, Kennedy and Hall

few trigoniaceans survived in temperate waters of the continental shelf of the Austral Province, where they were represented by Eotrigonia. now extinct, and the only living genus Neotrigonia. Paleozoic and Mesozoic trigoniaceans inhabited diverse environments within epeiric seas. They were physiologically adapted to or tolerant of a wide range

teeth.

of salinities (poikilohaline) as indicated by the common occurrence of their shells with stenohaline forms, such as ammonoids, and in dolomites, in association with evaporites and red beds. In the southern Neuquen

trigonia

Basin, Argentina, the Piedra Pintada Formation yields

typical

Liassic trigoniids in association with

muddy tuffaceous

sandstones that also contain abundant remains of land plants.

The

trigoniids

commonly are found

in a variety

of sedimentary rocks such as bituminous shales and many kinds of calcarenites, but they are by far most common in fine- to medium grained arenitic sandstones.

The combination of sedimentological evidence and paleoecological analysis indicates that a large majority

of Mesozoic trigoniids inhabited areas of the seafloor no deeper than perhaps 10 or 1 5 meters (Stanley, 1977). Living populations of Neotrigonia live primarily in

deeper waters (150 m) in terrigenous muddy sands, so that the occurrence of the genus in this environment is

quite atypical for the family,

and may represent

a

refugium.

The

trigoniids are considered suspension feeders,

nacreous.

(1969).

One

of the most important features of living Neofoot,

which gives

species within this genus the ability to

jump when

is

its

large

and muscular

threatened (Ansell, 1969; Stanley, 1977, p. 870, his pi. 116, fig. 6-9), showing a strong resemblance to the

muscular foot of the Cardiidae. The foot and

visceral

mass

are closely appressed to the anterior ad-

ductor muscle. Posteriorly, the foot attaches to the shell above the adductor by an elongate and discrete pedal muscle (Tevesz, 1975, p. 333). Though not itself fos-

unusual muscular foot can be traced back through trigoniid phylogeny by indirect means because of its coadaptative relationship to certain skeletal feasilized, the

tures (Stanley, 1970, 1977).

969) stated that the Trigoniidae were non-byssate, contrary to the view of Lycett (1870), a study by Gould (1969) on the non-functional byssal apparatus oi Neotrigonia margaritacea (Lamarck) con-

Although Cox

( 1

cluded that this system functions in juveniles only. Gould therefore dismissed previous arguments that this is a vestigial organ reduced from an hypothetical byssate adult ancestor. Supporting Gould's assertion, in the collection of Trigoniidae from Argentina there are possible byssal

possibly supplementing their diet of living plankton

some examples of trigoniids with

and bacteria with organic detritus (Purchon, 1957). Hinge teeth of the Trigoniidae are large and distinctive, radiating from the beaks far into the interior of

e.g., T. carinata (see Weaver, 1931), T. aliexpandita Leanza and Garate (1983) and some species of Steinmanella (see Leanza and Garate, 1987). Judging by their functional morphologies (Kauffman et al., in press), these species are presumed to have possessed

the shell.

The

dentition consists typically in the

left

valve of a strong median tooth and a weaker one on each side, and in the right valve of two main teeth

an active bysal apparatus,

dividing deep sockets which receive the teeth of the valve; additional, smaller teeth

the early Mesozoic trigoniids to the living Neotrigonia.

The ligament

is external, paravincular and opisshowing remarkable conservatism during evolution (Newell and Boyd, 1975). The insertion areas of the anterior and posterior adductor muscles are generally small, and are placed very close to the hinge

thodetic,

at least as juveniles.

GEOLOGICAL SETTING OF THE TRIGONIID-BEARING STRATA IN

may

be present. The articulating surface of the teeth typically bear very well developed transverse ridges which are interpreted to have a crucial role in the alignment of the valves (Stanley, 1977). Fossil evidence documents the origin of this kind of dentition early in the Mesozoic. Newell and Boyd (1975) suggested that dentition evolved in parallel in several lineages that are recognized by their external morphology. In coincidence with Poulton's (1979) opinion, however, this view is not tenable, as once established, this specialized dentition remained a conservative and stable feature, changing little from left

slits,

WEST-CENTRAL ARGENTINA The Neuquen Basin of west central Argentina is famous for its well exposed Mesozoic sediments; in this

m of marine and continental deposits accumulated in a typical back-arc setting. The basin expands toward the eastern foreland forming a large embayment in which different sedimentary cycles of lowermost Jurassic to uppermost Cretaceous age can

area up to 6000

be recognized. Text-figure 2 shows, in simplified form, the stratigraphic terms used in this paper from the Hettangian to the Maastrichtian in the Neuquen Basin, including the trigoniid-bearing formational units. The oldest marine deposits belong to the

Cuyo Group, which

represented by a system of marine, transitional and continental sediments deposited between the Intrais

liassic

and Intracallovian tectonic episodes. During the

Trigoniid Bivalves of Argentina: Leanza

Pliensbachian, deposition of near-shore marine tuffaceous sediments (Piedra Pintada Formation) occurred in southern Neuquen and siHcified limestones and tuffs (Chachil Formation) in central Neuquen. During the Toarcian to Aalenian, thick, mostly anoxic shales (Los Molles Formation) were deposited, from which no trigoniids have been recovered. Therefore the Toarcian extinction event could not be analyzed from the point

of view of trigoniid evolution in this region. A subsequent gradual fall of sea level is indicated by the presence of shore-face arenaceous sediments with several well developed hardgound tops containing abundant trigoniids (Lajas Formation). This unit extends from the Lower Bajocian to the early Bathonian, depending on the area considered. The regression reaches its maximum expression with the accumulation, during the early Callovian, of a redbed facies (Challaco Formation), but again no trigoniid-bearing strata have been recorded in this sequence. After the Intermalmic tectonic episode took place, the widespread marine transgression of the Mendoza Group, ranging in age from Kimmeridgian

s.s.

to early Bar-

remian occurred. The Mendoza Group extends widely from southern Neuquen to southern Mendoza Provinces, and contains several formational units with abundant trigoniids (Tordillo, Vaca Muerta, Picun Leufu, Mulichinco, and Agrio Formations). The Rayoso Group follows conformably, ranging in age from Hauterivian-Barremian to Aptian-Albian. The Patagonidic tectonic episode broke for the first time the connection of this region of Neuquen with the Pacific, and extensive continental dinosaur-bearing strata of the Neuquen Group were deposited. The last Mesozoic marine transgression connects the Atlantic with the Pacific through the Malargiie Group. In the shallow marine Maastrichtian sediments (Jagiiel Formation) some important trigoniid species are present. The Cenomanian/Turonian extinction event could not be analyzed in this study, because in west-central Argentina thick continental dinosaur-bearing deposits of the Neuquen Group were deposited during that time.

Age

Formations

PALEOCENE

Roca

MAASTRICHTIAN

Jaguel

TRIGONIID BIVALVES IN

WEST-CENTRAL ARGENTINA Lower Jurassic

species

Lower Jurassic trigoniid species in west-central Argentina have been described by Burckhardt (1901), Jaworski (1916, 1925, 1926), Groeber (1924), A. F. Leanza (1942), Lambert (1944), Levy (1967a) and Leanza and Garate (1987). In the present paper eight Lower Jurassic (Liassic) species from western central Argentina are described. These are distributed among the genera Gweberella, n. gen., Myophorella, Jawor-

Malargue

Allen

Rio Colorado

Rfo Neuquen

Neuquen

CENOMANIAN Rio LImay

Rayoso

Rayoso Huitrin

Agrio

HAUTERIVIAN

Muiicliinco

VALANGINIAN

Picun Leufu

Mendoza

Vaca Muerta Tordillo

KIMMERIDGIAN

Auquiico

OXFORDIAN

La Manga Lotena

CALLOVIAN

Lotena

Cfiallaco

BAJOCIAN

Lajas

Cuyo AALENIAN

Los Molles TOARCIAN PLIENSBACHIAN

Chachil/PPintada

SINEMURIAN

Lcpa

Precuyano

Choiyoi

Ctioiyoi

HETTANGIAN

Text-figure

2.

— Schematic

stratigraphic section for the Jurassic

and Cretaceous of west-central Argentina.

and Frengiielliel/a. These taxa have been found Formation (Stipanicic et al., 1978) which is approximately equivalent to the Lower and Upper Pliensbachian Otapiha neuquensis and Radiilonectites sosneadensis Zones recently established by Damborenea (in Riccardi, Damborenea and Manceiiido, 1990); and in the Chachil Formation (Weaver, 1942) which is equivalent to the Pliensbachian "Fa/jninoceras Zone" as recently established by Riccardi (in Riccardi, Manceiiido and Damborenea, 1990). Gweberella, n. gen. has been erected, with Myophoria neuquensis Groeber (1924) as the type species, to differentiate species with only radial ornament from the Triassic Myophorigonia Cox (1952), which is characterized by both radial and transverse ornament. The skiella,

in the Piedra Pintada

TEMPORAL DISTRIBUTION OF

Groups

Bulletin 343

10

genus is represented by its type species from the Pliensbachian Piedra Pintada Formation at La Amarga, near Rincon del Aguila, and by Groeberella. sp. indet. from the Middle (now Early) Bajocian Lajas Formation at Barda Negra Sur. The genus Myophorella is represented by its subgenus Myophorella sensu stricto [e.g.. Myophorella (A/.) araucana (A. F. Leanza), Myophorella (M.) catenifera (Hupe) and M. (M.) cf. M. tuberculata (Agassiz)]; the last

two taxa are

cited for the

first

time in Argentina. The genus Jaworskiella is represented by very well preserved adult and juvenile specimens of the type species Jaworskiella burckhardti (Ja-

The genus

by the type species Frenguelliella inexspectata (Jaworski) and by a new species named Frenguelliella poultoni, n. sp. which appears to be identical to Frenguelliella, sp. B of Poulton (1979, p. 18, pi. 1, fig. 10) from the early Sinemurian Laberge Group, Yukon Territory, Canada. Myophorella (A/.) araucana, M. (M.) catenifera, M. {M.) cf M. tuberculata, Jaworskiella burckhardti, Frenguelliella inexspectata, and Groeberella neuquensis have been found in the near-shore Piedra Pintada Formation. Frenguelliella tapiai, Frenguelliella poultoni, n. sp. and also Myophorella (M.) catenifera are found in the Chachil Formation (Weaver, 1942). worski).

Frengiielliella is represented

Middle Jurassic The

first

species

description of a trigoniid species in west-

was made by Gottsche (1878) from Middle Jurassic strata at the Espinacito Pass region in the High Cordillera de Los Andes, followed by work of Tomquist (1898) and Behrendsen (1891-1892). In this century Middle Jurassic trigoniid species have been described by Weaver (1931), Lambert (1944), Leanza and Garate (1983, 1985, 1986, 1987) and Leanza, Perez and Reyes (1987). The present study provides the description of 21 Middle Jurassic trigoniid species distributed among eleven genera and subgenera, all of which have been found in the Lajas Formation (Weavcentral Argentina

The following

trigoniid genera are present in the

Middle Jurassic Lajas Formation: Groeberella,

n. gen.,

Frenguelliella, Trigonia, Neuquenitrigonia, Vaugonia,

Andivaugonia, n. gen., Myophorella (Myophorella), Myophorella (Promyophorella), Scaphorella, Scaphotrigonia and Anditrigonia (Eoanditrigonia). Groeberella is represented by a single undetermined Early Bajocian species at Barda Negra Sur. Although the poor preservation of the specimen precludes any further tax-

onomic determination, it has a relatively small size and thin shell in comparison with the Pliensbachian G. neuquensis (Groeber). Frenguelliella

is

represented

by a new Early Bajocian species, F. perezreyesi, which is characterized by small size and relatively flat and transversely costate area.

The genus Trigonia

is

well

represented at several localities from the Early Bajocian to the Middle Bathonian by Trigonia corderoi

Lambert, Trigonia mollesensis Lambert, Trigonia denBehrendsen, and the new species Trigonia losadai from Los Pozones which shows close affinities with the group of Trigonia costata Agassiz. Neuquenitrigonia is represented in Barda Negra Sur by some fragmentary specimens belonging to its type species A'^. huenickeni. The genus I 'augonia is represented by two rectangidaris typical elongated Vaugoniinae species: (Gottsche, 1878) and r. chunumayensis (Jaworski), both occurring in association at Barda Negra Sur. The genus Andivaugonia, n. gen. has been erected with sestriata

1

'.

""Trigonia" radixscripta in

Lambert

as the type species

order to group somewhat large and inflated species

characterized by a non- to poorly developed marginal

and an area that is usually smooth or ornamented only by growth lines. This new genus constitutes a homogeneous stock including Andivaugonia radixscripta (Lambert), Andivaugonia covuncoensis (Lambert). Andivaugonia fuenzalidai (Reyes and Perez) and Andivaugonia lissocostata (Reyes and Perez); the last two species were originally described from the Middle Jurassic of Chile, and are recorded herein for carina,

Argentina at the localities of Chacaico

er,

1931). This unit outcrops in the southern part of

the

the

Neuquen Basin and

and Fortin 1^ de Mayo. The genus Myophorella is represented by the subgenus Myophorella {Myophorella),

is

represented by a well de-

veloped shoreface unit characterized by

fine- to coarse-

grained sandstones. This facies was very favorable to habitation by trigoniid bivalves, and reflects a

number

of marine oscillations belonging to eustatic fourth order cycles. In a previous paper (Leanza and Garate, 1987) the author considered the specimens from Los Pozones and Covunco Pavia to range between Middle to early Callovian.

According

to its

ammonite content

(Westermann and Riccardi, 1985, p. 12, fig. 3), however, the age of the Lajas Formation in these localities ranges from the Early Bajocian to the Early Bathonian, and is approximately equivalent to the Emiliea giebeli to the Ca^ow/Y^-Tulitidae Assemblage Zones (Riccardi, Westermann and Damborenea, 1990).

first

time

in

with the single species

M.

(A/.) argentinica (Jaworski),

and by the subgenus Myophorella {Promyophorella) containing A/. (P .) praescabroidea (Jaworski). Both occur in association at the Early Bajocian locality of Bar-

da Negra Sur. This

last species is

Jurassic ancestor of the

considered as the

Upper Jurassic and Cretaceous

The genus Scaphorella is well documented by Scaphorella leanzai (Lambert), Scaphorella kruusei Leanza and Garate, and by the new species Pterotrigoniinae.

Scaphorella camachoi: the in size

and shape

last species is

to Trigonellina

Pames

very similar (1981), but

the shell area exhibits transverse instead of radial costellae.

The subgenus Eoanditrigonia,

n.

subgen., based

i

Trigoniid Bivalves of Argentina: Lean2A

on Anditrigonia keideli (Weaver), cality of Los Pozones.

Upper Jurassic Upper

present at the lo-

is

Jurassic trigoniids in west-central Argentina

have been described by Behrendsen (1892), Burckhardt (1900a, 1900b, 1903), Haupt (1907), Douville (1910),

Weaver

Lambert Levy (1967c) and Leanza

(1931), A. F. Leanza (1941),

(1944), Marinelarena(1959),

and Garate (1987). The present study treats 21 species and one subspecies of Upper Jurassic (Kimmeridgian to Upper Tithonian) Trigoniidae which occur in the Mendoza Group. The Kimmeridgian Tordillo Formation (Groeber, 946), yields trigoniids near Laguna Miranda and Los Catutos, Lambertrigonia pichiinoncolensis (Lambert) and Trigonia mirandaensis Lambert. Both species occur in association in coarse-grained to conglomeratic, brown sandstones. The remaining 1 9 species and one subspecies have been found in Middle and Upper Tithonian strata, namely in shoreface facies of the Carrin Cura (Leanza, Marchese and Riggi, 1977) and Piciin Leufii (Leanza, 1973) formations. These units interfinger with shales and marls of the Vaca Muerta Formation (Weaver, 1931). In this study the genera and subgenera Trigonia, Anditrigonia, An1

Steinmanella (SplenditrigoMyophorella (Myophorella), Myophorella (Promyophorella), Myophorella (Haidaia), Pterotrigonia

tutrigonia, Rutitrigonia, nia),

(Rineirigonia), Pterotrigonia (Scabrotrigonia),

and

Pterotrigonia (Notoscabrotrigonia) have been recognized.

The genus Trigonia

is

represented by T. carinata

Agassiz, T. levyi, n. sp., T. fortinensis sp. juv. indet.

Anditrigonia

genus Anditrigonia

s.s.,

is

Lambert and

with A. (A.) eximia (Philippi),

and A.

is

lamberti

Lower Cretaceous

species

trigoniid species

have been de-

scribed in west-central Argentina by Behrendsen

( 1

892),

Burckhardt (1900a, 1900b, 1903), Weaver (1931), Lambert ( 1 944), Leanza (1985), Camacho and Olivero (1985) and Leanza and Garate (1987). In the present paper, 2 species of Lower Cretaceous age (Berriasian to Hauterivian, and probably also Early Barremian) are described. The species are confined to the Mendoza 1

Group (Groeber,

1946),

and are present

in shoreface

and/or on the top of hardgrounds of the Vaca Muerta, Mulichinco and Agrio formations (Weaver, 1931). The recorded Lower Cretaceous genera and subgenera are mainly Steinmanella (Transitrigonia), Steinmanella (Macrotrigonia), Steinmanella (Splenditrigonia), Virgotrigonia, Antutrigonia, Trigonia, facies

Quoiecchia, Syrotrigonia, Rutitrigonia, Anditrigonia, Pterotrigonia (Pterotrigonia), Myophorella (Myopho-

Myophorella (Promyophorella) and Myophorella The genus Steinmanella is present in the Berriasian, Valanginian and Hauterivian, and probably the Early Barremian. The genera Virgotrigonia and Pterotrigonia have been found in the Berriasian, whereas .Antutrigonia has been found in the latest Berriasian/earliest Valanginian. Trigonia, Myophorella, rella),

(Haidaia).

and A. groeberi (Weaver).

Berriasian species are represented by Virgotrigonia

represented by the subgenus

hugoi (Leanza) formerly the type species of the genus Maputrigonia, and by Pterotrigonia (Pterotrigonia) al-

(A.)

Splenditrigonia, n. subgen. which groups an

neous stock composed by S.

homoge-

(Spl.) splendida (A. F.

Leanza), S. {Spl.) erycina (Philippi) and S. (Spl.) haupt

(Lambert).

Lower Cretaceous

Quoiecchia, Rutitrigonia, .Anditrigonia and Syrotrigo-

selicaiidata, n. ssp. Antutrigonia is

frenguellii (Marifielarena)

(^A.)

1

P. (Rinetrigonia), sp. juv. indet.

eximia tesrepresented by A.

{A.), sp. juv. indet.,

The genus Steinmanella

T.,

represented by the suh-

A. {A.) carrincurensis (A. F. Leanza), A.

Levy, A.

time since the original description in 892, The subgenus Notoscabrotrigonia is represented by P. (Notoscabrotrigonia) coheni, n. sp. The age of these taxa has been precisely determined by co-occurring ammonites in the .\ ulacosphinctes proximus, Windhauseniceras internispinosum (Middle Tithonian), Corongoceras alternans, and Suhsteueroceras koeneni (Upper Tithonian) Zones (Leanza, in Riccardi, Leanza and Volkheimer, 1990). for the first

and by

species

11

The genus Myophorella

is

represented by

Myophorella (M.) schulzi, n. sp., the subgenus Promyophorella by M. (P.) hillebrandti Reyes and Perez, and by the subgenus Haidaia containing the new species M. (H.) elguetai. Rutitrigonia appears in westcentral Argentina for the first time in the Upper Tithonian and is represented by an undetermined juvenile species from the Picun Leufii Formation at Cerro Caracoles. The genus Pterotrigonia appears for the first time in the Upper Tithonian, represented by the subgenera Scabrotrigonia, Rinetrigonia, and Notoscabrotrigonia. Scabrotrigonia is represented by P. (Scabrotrigonia) transatlantica (Behrendsen), redescribed here

nia are clearly

dominant

in the Hauterivian.

iformis (Parkinson). Both species occur in association

Mallin Quemado in the .Argentiniceras noduliferum Zone. In addition, a description oi Steinmanella (Transitrigonia) neuquensis (Burckhardt) from Trahuncura is presented. Late Berriasian/Early Valanginian species include .Antutrigonia opistolophophora (Lambert) from the Mulichinco Formation at Mallin Quemado in the Spiticeras damesi/Neocomites wichmanni Zones, and Steinmanella (Transitrigonia) quintucoensis (Weaver) and Steinmanella (Splenditrigonia) splendida (A. F. Leanza). Both species occur in association at Trahuncura in the same ammonite assemblage. The Valanginian Steinmanella (Transitrigonia) steinmanni (Phiat

lippi)

in

from the Mulichinco Formation

the Olcostephanus curacoensis

at

Puerta Curaco

Zone

is

also de-

Bulletin 343

12

scribed. Steinmanella (Transitrigonia) transitoria (Steinmann) is present in the Agrio Formation in the

Late Valanginian/Early Hauterivian locality of Cerro Pitren, whereas Lower Hauterivian species are described from Pichaihue Abajo, including Syrotrigonia brocardoi, n. sp. and Quoiecchia sigeli Leanza and Garate. Lower to Middle Hauterivian species are abundant and diverse. They are mostly found in the Agrio For-

mation of the Cerro Mesa and Cerro Negro (Covunco) areas.

The

list

includes Steinmanella (Transitrigonia)

raimondii (Lisson),

Myophorella (Promyophorella)

garatei Leanza, Myophorella (Haidaia) volkheimeri

Leanza and Garate, Trigonia wiedmanni Leanza and Garate,

T.

angustecostata Behrendsen, T. aliexpandita Riititrigonia agrioensis (Weaver),

Leanza and Garate,

sp., and undetermined spefrom the Arenal of Las Lajas. These the Lyticoceras pseudoregale and Hol-

Rutitrigonia kaitffmani, n.

cephalopods are not present, bivalve zonations have been used for reference. For the Lower Jurassic the bivalve zonation by Damborenea (in Riccardi, Damborenea and Mancenido, 990), and the ammonite zo1

nation by Riccardi

coptychites neuquensis Zones. In light of the revision

of Pterotrigoniinae by Cooper (1989), the Hauterivian species coihuicoensis of Weaver, formerly thought to be a representative of Myophorella (Myophorella), is herein placed in the subgenus Pterotrigonia (Rinetrigonia). Pterotrigonia (Rinetrigonia) coihuicoensis (Weaver) ranges throughout the Hauterivian, and probably the Early Barremian, whilst Steinmanella

(Macrotrigonia) vacaensis (Weaver)

is

found

in the

Up-

per Hauterivian Crioceratites (Paracrioceras) andinus

Riccardi,

Damborenea and

Manceiiido, 1990) have been used. For the Middle Jurassic the ammonite zonation proposed by Riccardi (in Riccardi, Westermann and Damborenea, 1 990) was utilized. The Upper Jurassic trigoniid occurrences in west-central Argentina were matched with the am-

monite zones proposed by Leanza (in Riccardi, Leanza and Volkheimer, 1 990), whereas the Lower Cretaceous were correlated with the ammonite zonation published by Leanza (1981a). The Upper Cretaceous trigoniid occurrences occur within the Maastrichtian Euhacu-

Assemblage Zone

lites

In Table

cies oCAnditrigonia

species occur in

(in

its first

to

(see Riccardi, 1984).

the vertical range of each species from

1

its last

occurrence has been plotted against

the linear time scale in millions of years before present of Haq et al. (1988), and the duration of species ranges

At the specific level, 27% of the trigoniid had durations of approximately one million

calculated.

species

The average

years.

trigoniids

species duration for

was approximately

all

described

3.8 million years.

It is

worth noting that 69% of the described species have durations of one to three million years, and the remaining 31% have longevities from three to 17.5 million years.

For practical purposes, the trigoniids discussed in paper have been divided into four groups, as fol-

Zone.

this

Upper Cretaceous

species

have been described in west-central Argentina, including Rio Negro and La Pampa Provinces, by Levy (1967b), Camacho (1967, 1968), Farinati, Quattrocchio and Labudia (1987) and Leanza and Casadio (1991). The species are usually found in the Maastrichtian Jagiiel Formation (Windhausen, 1914) and equivalents, mostly

Upper Cretaceous

lows:

trigoniid species

with Euhaculites argentinicus (Weaver). The present study describes three Upper Cretaceous trigoniid species. Pacitrigonia sobrali Leanza and Casin association

adio and Austrotrigonia

pampeana Leanza and Casa-

dio are from the Jagiiel Formation at the locality of

1)

Longevities up to one million year: 20 species

(27%). Groeberella, sp. indet., Trigonia densestriata. Trigonia, sp. juv. indet., Trigonia fortinensis, Neuquenitrigonia huenickeni.

Frenguelliella perezreyesi,

ophorella (Myophorella) argentinica.

M.

(Promyophorella) praescabroidea,

M. M.

(Haidaia)

guetai, Scaphotrigonia rierafonti, Scaphorella choi, S. kruusei,

My-

(M.) schulzi, el-

cama-

Steinmanella (Splenditrigonia) ery-

Vaugonia chunumayensis, V. rectangularis, Andivaugonia lissocostata, Syrotrigonia brocardoi, Pterotrigonia (Rinetrigonia) sp. juv. indet., and cina.

,

Barda Baya, La Pampa Province. The remaining species Pterotrigonia (Rinetrigonia)

windhauseniana

Quoiecchia

(Wilckens), was found by the authors in the Jagiiel

Formation at the

locality of Cerro Villegas in the north-

eastern part of the

Each of the 74 described Jurassic and Cretaceous and subspecies have been referred to known ammonite zones, and in the localities in which

Longevities from one to three million years: 30

species

Neuquen Province.

SPECIES DURATIONS OF THE FAMILY TRIGONIIDAE IN WEST-CENTRAL ARGENTINA trigoniid species

2)

sigeli.

and

Trigonia

1

subspecies (42%). T. aliexpandita.

levyi,

T.

wiedmanni,

T.

angustecostata, T. mirandaensis. Frenguelliella tapiai, F. poultoni, Myophorella (Promyophorella) hillebrandti.

M.

(P.) garatei.

M.

(Haidaia) volkheimeri. Stein-

manella (Macrotrigonia) vacaensis. S. (Transitrigonia) raimondii, Anditrigonia (Anditrigonia) carrincurensis, (A.), sp. indet., A. (A.), sp. juv.

A. (A.) lamberti. A. indet., A. (A.)

eximia tesselicaudata, Antutrigonia op-

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sisuaAouinunQo piuoGnofl

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louopujpo oiiajoqdoos i3snnj>i oiiaJOi/dDOS

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9

Trigoniid Bivalves of Argentina: Leanza

Explanation of Plate

79

6

(All figures natural size, unless otherwise indicated)

Page

Figures 1 ,

2.

44

Steinmanclla (Splenditngonia) haupli (Lambert) I

,

Hypotype,

MOZ P09

1

3,

dorsal view; 2, lateral view of left valve of same specimen.

Aguada del Overo (Locality 9). Tngonia levyi. new species 3, Holotype, MOZ P53 14, dorsal view;

Upper Tithonian, Picun Leufu Formation,

1

3, 4.

Las Cortaderas (Locality 5,

22 4, lateral

36).

8-10. Plerolngonia (Noloscahrotngonia) coheni. 5,

Holotype,

P5765,

MOZ

lateral

P4723,

lateral

view of left valve.

Cerrito Caracoles (Locality 6, 7.

view of right valve of same specimen. Middle Tithonian, Picun Leufu Formation,

1

1

view of

new left

10, Paratype,

59

species valve. 8, Paratype,

MOZ P3073. lateral

MOZ

P5764, lateral view of right valve. 9, Paratype, MOZ view of left valve. Upper Tithonian, Piciin Leufu Formation,

).

Trigonia fortmensis Lambert

Hypotype, MOZ P3006, lateral view of left valve; Cerro Lotena (Locality 32). 6,

23 7,

dorsal view of same specimen.

Upper Tithonian, Picun

Leufii

Formation,

Bulletin 343

80

Explanation of Plate

7

(All figures natural size, unless otherwise indicated)

^^^e

Figures 1

.

Steinmanella (Splendttrigonia) erycina (Philippi) P0921, lateral view of left valve. Upper Tithonian, Piciin Leufu Formation. Caichigue. Charahuilla (Locality 1, Hypotype,

^'^

MOZ

22).

°0

2-6. Pterothgoma (Scahrotngoma) Iransatlanlica (Behrendsen)

P2486. lateral view of right valve. 3, Hypotype. MOZ P2953, lateral view of right valve. 4, Hypotype, MOZ P4399. lateral view of right valve. 5, Hypotype. MOZ P3189, dorsal view; 6, lateral view of left valve of same specimen. Upper Tithonian, Piciin Leufu Formation. Cerrito Caracoles (Locality 1). 2,

Hypotype.

MOZ

1

7-9.

Tngonia carinata Agassiz oyster on the posterior area; 8. dorsal 7. Hypotype. MOZ P0915. lateral view of right valve, showing the attachment of an epizoan view of same specimen; 9. ventral view of same specimen, showing a probable byssal slit. Upper Tithonian. Piciin Leufu Formation, Cerrito Caracoles (Locality

1

1 ).

11

Bulletins of American Paleontology,

Volume

Plate

105

H

*€

^ ^m^^

',«

:>J

7

Bulletins of American Paleontology, Volume 105

Plate 8

1

Trigoniid Bivalves of Argentina: Leanza

Explanation of Plate

8

8

(All figures natural size, unless otherwise indicated)

Page

Figures 1, 2.

3, 4, 7, 10.

Aniuthgonia frenguellii (Maririelarena) view of same specimen. Late Middle Tithonian, Picun Leufu 1, Topotype, MOZ P0918, lateral view the right valve; 2, dorsal Formation, Cafiadon del Sapo (Locality 20). Antutngonia grocbcn (Weaver) MOZ P0922/3, dorsal 3, Topotype, MOZ P2069, dorsal view; 4, lateral view of right valve of same specimen. 7, Topotype, view; 10, lateral view of left valve of same specimen. Upper Tithonian, Piciin Leufii Formation, Pictin Leufu creek and route

40 (Locality 5.

Type,

-"-

17).

^'

Trigonia. sp. juv. indet 5,

51

MOZ

P5466,

lateral

view of

right valve (x2).

Upper Tithonian, Picun

Leufii Formation,

Laguna Blanca (Locality

'3)6.

Myophorella (Prontyophorella) hillebrandti (Reyes and Perez) Formation, Fortin 6, Hypotype, MOZ P3075, lateral view of left valve (x 1.5). Middle Tithonian, Carrin Cura

32 1°

de

Mayo

(Locality 23). 8, 9.

Myophorella (Myophorella) schuhi. new species Tithonian, Picun Leufii 8, Holotype, MOZ P3075/1. dorsal view; 9, lateral view of right valve of same specimen. Upper Formation, Camino nuevo a Los MoUes (Locality 34).

30

Bulletin 343

82

Explanation of Plate

9

(All figures natural size, unless otherwise indicated)

^^*

Figures 1

,

2.

Anditrigonia (Anditngonia) exinua tesseltcaudata. new subspecies PI 901. dorsal view; 2, lateral view of right valve of same specimen. 1. Holotype,

MOZ

Camino nuevo 3, 4.

a

Los Molles (Locality

4,

Hypotype.

MOZ

PI 902/2,

lateral

view of

left

valve.

Upper Tithonian,

19).

Anditrigonia {Anditrigonia), sp. juv. indet 5,

MOZ

Type,

P3014,

Americana (Locality

lateral

Type,

MOZ P2489,

Lotena (Locality

view of

left

valve (x

1.5).

Upper Tithonian,

Piciin

Leufu Formation, Cerro Pancho, Bajada de La

31).

Pterotngonia {Rinelngonia), 6,

7.

Leufu Formation, '*°

MOZ

6.

Piciin

34).

Anditrigonia {Anditrigonia) eximia (Philippi) PI 902/1, lateral view of left valve. 3, Hypotype.

Picun Leufu Formation. Aguada del Overo (Locality 5.

50

Upper Tithonian,

°'

sp. juv. indct

umbonal view of left valve of a broken specimen (x

1.5).

Middle Tithonian, Picun Leufu Formation, Cerro

32).

Anditrigonia {Anditrigonia) lamberti Levy P09 14, dorsal view of both valves in butterfly position. 7, Hypotype,

MOZ

'*^

Upper Tithonian,

Piciin

Leufu Formation, Los Catutos

(Locality 12). 8.

Rutilrigonia. sp. juv. indet 8,

Type,

MOZ P5002, lateral

view of left valve

(

x 1.5).

9-11. Mvophorella {Haidaia) clguclai. new species P5767, lateral view of left valve. 9, Paratype,

MOZ

P2486/2,

lateral

view of

left

Upper Tithonian, Picun Leufu Formation,

Cerrito Caracoles (Ix>cality II).

33

MOZ

P3067, lateral view of right valve. II, Paratype, I). valve. Upper Tithonian, Picun Leufu Formation, Cerrito Caracoles (Locality 10,

Holotype,

1

MOZ

Bulletins of American Paleontology, Volume 105

Plate 9

'^

"^^.

8

^

S Vr. J

Plate 10

Bulletins of American Paleontology, Volume 105

^ 1

^r^-^T-U^M.^" ^ri^^Mi^iKi^

eSfe. vuf"

ri^^'^'^fl

4

Trigoniid Bivalves of Argentina: Leanza

Explanation of Plate

83

1

(All figures natural size, unless otherwise indicated)

Figures 1,

2.

Page

Steinwanella (Transilrigonia) transiloria (Steinmann)

41

Hypotype, MOZ P0916, lateral view of left valve; 2, dorsal view of same specimen. Late Valanginian/Early Hauterivian, Agrio Formation. Cerro Pitren (Locality 1). Trigonia aliexpandita Leanza and Garate 3, Holotype. MOZ P0951/1. lateral view of left valve; 4, dorsal view of same specimen. Lower and Middle Hauterivian, Agrio Formation. Cerro Mesa. Covunco (Locality 8).

24

1,

3. 4.

1

Bulletin 343

84

Explanation of Plate

1

(All figures natural size, unless otherwise indicated)

Page

Figures

1^. Steinmanclla (Transitrigonia) raimondii (Lisson) 1,

4,

43

Hypotype. MOZ P1756/9, lateral view of left valve; 2, dorsal view of same specimen. 3, Hypotype, MOZ P1756/3, dorsal view. lateral view of right valve of same specimen. Lower and Middle Hauterivian, Agrio Formation, Cerro Mesa, Covunco (Locality

8).

5-8.

Stemmanella (Splendilrigonia) sptendida

(A. F. Leanza) Hypotype, MOZ P2553, lateral view of left valve; 6, dorsal view of same sf)ecimen; 7, posterior view of both valves of same specimen showing the exhalant aperture matching with the outer area; 8, lateral view of right valve of same specimen showing 5,

attachment of some Lycellia

sp.

epizoans. Early Valanginian, Cerrito de La Ventana, Trahuncura (Locality

4).

43

1

Bulletins of American Paleontology, Volume

1

Plate

05

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2

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tt

8

1

Bulletins of American Paleontology,

V...- ,.'-,'w\;,^

10

Volume

105

Plate 12

2

Trigoniid Bivalves of Argentina: Leanza

Explanation of Plate

85

1

(All figures natural size, unless otherwise indicated)

Page

Figures 1-4.

Myophorella (Promyophorella) garatei Leanza 1, Topotype, MOZ P0930/4, dorsal view; 2, lateral view of left valve of same specimen (x 1.5). 3, Topotype, MOZ P0930/6, dorsal view; 4, lateral view of right valve of same specimen (x 1.5). Lower and Middle Hauterivian, Agrio Formation, Cerro Mesa, Covunco (Locality

8).

22

5,13. Trigonia cannala Agassiz

Hypotype, MOZ P5607, lateral view of right valve; Formation, Cerro Mesa, Covunco (Locality 8). 5,

6, 7,

31

1

3,

dorsal view of

same specimen. Lower and Middle Hauterivian, Agrio

Steininanella (Transilrigonia) neuquensis (Burckhardt)

Hypotype, MOZ P2767, dorsal view; 7, lateral view of left valve of same specimen. Upper Berriasian, Vaca Muerta Formation, Cerrito de La Ventana, Trahuncura (Locality 4). 8-12. Myophorella (Haidaia) volkheimeri Leanza and Garate 8, original Paratype, MOZ Pi 752/2, lateral view of left valve (x 1.5). 9, original Paratype, MOZ PI 752/3, dorsal view; 10, lateral view of left valve of same specimen (x 1.5). 1, original Holotype, MOZ P1752/1, dorsal view; 12, lateral view of left valve of same specimen (x 1.5). Lower and Middle Hauterivian, Agrio Formation, Cerro Mesa, Covunco (Locality 8).

42

6,

1

32

3

Bulletin 343

86

Explanation of Plate

1

(All figures natural size, unless otherwise indicated)

Page

Figures

1,10. Steinmanella (Transitrigonia) sleinmanni (Philippi) 1,

Hypotype,

Valanginian, Mulichinco Formation, Puerta Curaco (Locality 2,

42

MOZ P0917, lateral view of left valve, showing attachment of serpulidepizoans;

10, dorsal

view of same specimen.

2).

6-9. Antutrigonia opislolophophora (Lambert)

MOZ P0903/2, dorsal view; 6, anterior view of same specimen;

51

view of left valve of same specimen. Late Berriasian/Iiarly Valanginian, Mulichinco Formation, Mallin Quemado, Sierra de la Vaca Muerta (Locality 7). 8, reproduction of the Holotype figured by Lambert (1944, pi. 3, figs. 5-6), dorsal view, showing transverse costulation on the area characteristic oi Antutrigonia Leanza and Garate; 9, lateral view of same specimen. Same age, horizon and locality than specimen MOZ P0903/ 2,

Topotype,

7, lateral

2.

3-5.

Trigonia angustecostata Behrendsen

MOZ

P0950, lateral view of left valve; 4, dorsal view of same specimen; 5, lateral view of specimen. Lower and Middle Hauterivian, Agrio Formation, Cerro Mesa, Covunco (Locality 8). 3,

Hypotype,

24 right valve

of same

Bulletins OF American Paleontology, Volume 105

Plate 13

:im)^

y

10

Bulletins of American Paleontology,

Volume

105

Plate 14

4

Trigoniid Bivalves of Argentina: Leanza

Explanation of Plate

87

1

(All figures natural size, unless otherwise indicated)

Page

Figures 1, 2,

4, 10.

Steinmanelta (Transilngonia) qumtucoensis (Weaver)

41

view of left valve; 2 dorsal view of same specimen. 4, Topotype MOZ P2552, lateral view of left valve; 10, lateral view of right valve of same specimen showing the attachment of three generation of Lycettia sp. epizoans. Late Berriasian/Early Valanginian, Vaca Muerta Formation, Cerrito de La Ventana, Trahuncura (Locality 4). 1,

3.

Topotype.

MOZ P0925,

lateral

Pterotrigonia (Pterotrigonia) aliformis (Parkinson)

58

Hypotype, MOZ P2687, lateral view of a mold of left valve. Berriasian, Vaca Muerta Fomation, Mallin Quemado, Sierra de la Vaca Muerta (Locality 7). 3,

5-9.

53

Virgotrigoma hiigoi (Leanza)

Topotype, P2733/1, lateral view of left valve. 8, Topotype, MOZ P2733/4, lateral view of a broken right valve; 9, dorsal view of same specimen. Berriasian. Vaca Muerta Formation. Mallin Quemado, Sierra de la Vaca Muerta (Locality 7). 6, Hypotype, MOZ P2332/2, lateral view of left valve; 7, dorsal view of same specimen. Berriasian, Vaca Muerta Formation,

MOZ

5,

Salitral

de

los

Alazanes (Locality

30).

5

Bulletin 343

88

Explanation of Plate

1

(All figures natural size, unless otherwise indicated)

^^^e

"

Figures 1-5.

Rulilhgonia kauffmani. new species {x 1.5). 3, Paratype. MOZ P4295/2, lateral view of left valve (x 1.5). 2, Paratype MOZ P3527/3, lateral view of left valve (x 1.5). 5, Paratype. MOZ P4295'l, lateral view of nght valve (x 1.5). 4. Holotype. MOZ P3527/2, lateral view of left valve Mesa, Cerro Formation, Agno Hauterivian, (xl.5). Middle Lower and valve right view of lateral MOZ P3527/6, Paratype. 1.

Covunco 6, 7.

(Locality

8).

Sleinmanella (Macrolrigonia) vacaensis (Weaver) P2329, dorsal view showing in the posterior area the inhalant and exhalant apertures; 6, Hypotype, valve of same specimen. Middle Hauterivian, Agrio Formation, Los Homos, Covunco (Locality 29).

MOZ

'*5

7, lateral

view of

left

Bulletins OF American Paleontology, Volume 105

Plate 15

^t^M'tA^

,

Plate 16

Bulletins of American Paleontology, Volume 105

l/]^'^

^^A

.^^

^^^i^-y3^^.

7

-^^t-

»

^

10

8

6

Trigoniid Bivalves of Argentina: Leanza

Explanation of Plate

89

1

(All figures natural size, unless otherwise indicated)

Figures

Page 1-3.

Ruiitngonia agnoensis (Weaver)

54

Hypotype, MOZ P0920/3, lateral view of left valve; 2 dorsal view of same specimen. 3, Hypotype, MOZ P0920/1, view of left valve. Lower Hauterivian, Agrio Formation, Cerro Negro Chico de Picun Leufii (Locality 18). 1,

4, 7,

10, 12.

Syrolrigonia brocardoi. 4,

Paratype,

II.

3.

Type,

MOZ

P5236,

lateral

view of

left

valve; 8 dorsal view of

49

same specimen. Middle Hauterivian, Agrio Formation,

Arenal dc Las Lajas (Locality 28). Plcrolngonia (Rinetiigonia) coihuicoensis (Weaver)

Hypotype,

61

MOZ

P5313, anterior view of both valves; 9, lateral view of left valve of same specimen; 1 1, dorsal view of same specimen. Middle and Upper Hauterivian, Agrio Formation, Cerro Mesa, Covunco (Locality 8). Slcinmanella (Macrolngonia) vacaensis (Weaver) 13, Hypotype, MOZ P2329, anterior view of both valves, with a probable byssal slit below the beaks. Middle Hauterivian, Agno Formation, Los Homos, Covunco (Locality 29). 6,

1

P5318, dorsal view. 7, lateral view of right valve of same specimen. 10, Holotype, MOZ P5319, dorsal view of left valve of same specimen. Lower Hauterivian, Agrio Formation, Pichaihue Abajo (Locality 3).

Anditrigonia (Andilrigonia), species indeterminate 5,

6, 9,

57

species

MOZ

view; 12, lateral 5, 8.

new

lateral

45

7

Bulletin 343

90

Explanation of Plate

1

(All figures natural size, unless otherwise indicated)

Page

Figures

1

,

Holotype,

GHUNLPam

399, dorsal view showing radial costellae on the area;

Maastrichtian. Jagiiel Formation. Barda Baya, La 3.

Quoiecchia 3, original

sigeti

64

and Casadio

1,2. Pacilrigonia sobrali Leanza

Pampa

2, lateral

view of left valve of same specimen.

(Locality 41).

63

Leanza and Garate

Paratype,

MOZ P

1

6 0/ 0. lateral view of right valve. 1

1

Lower Hauteri vian, Agrio Fomation, Pichaihue Abajo (Locality

3).

4, 5.

Aiislrotrigonia 4,

Holotype,

63

pampeana Leanza and Casadio

GHLINLPam 400.

lateral

Barda Baya. La Pampa (Locality

view of right valve;

dorsal view of same specimen. Maastrichtinan, Jagiiel Formation,

5,

41).

24

7-10. Trigonia wiedinanni Leanza and Garate 7,

Holotype,

view; 10, lateral (Locality 6,

1

1-1 3.

P0942/1, dorsal view; 8, lateral view of right valve of same specimen. 9, Paratype MOZ P0942/2, dorsal view of left valve of same specimen. Lower and Middle Hauterivian, Agrio Formation, Cerro Negro, Covunco

MOZ

9).

Pterotngonia (Rmctrigonia) windhauscmana (Wilckens) P23 17/1, lateral view of right valve. 6, Hypotype,

MOZ

MOZ

P2317/2,

(Locality 27).

lateral

view of

left

62 1

1.

Hypotype,

valve; 13, dorsal view of

MOZ P23 17/3, lateral view of left valve.

same specimen. Maastrichtian,

Jagiiel

12,

Hypotype

Formation, Cerro Villegas

Bulletins of American Paleontology, Volume 105

Plate 17

^'^-''

*'

^«^

9

J

10

Trigoniid Bivalves of Argentina: Leanza

91

INDEX (Bold

numbers

to pages in

refer to plates in

which a taxon

is

which a taxon

is illustrated; italic

numbers

refer to pages in

which a taxon

is

described; plain

numbers

refer

cited)

B bajuranasi

abnipla

56,57

Buchorrigonia

31

Myophorella

12,14,54.16,55.56

Rutitrigonia

64

Paciirigonia

62,63

Quoiecchia

8,12,17,23,24.10

Trigonia

11,14,55,14,59

Ptewlngonia

10,11,12,16,36,38,46.47,60,51,52,53,54,57

carrincurensis

1

1,12,46,47.5,48

49

discors

eximia lamherli

1

57

47 12,49.16 11,12,49.9

sp.juv. indet

45,54

Anditrigoniinae

covuncoensis

10,36,i7,38,39,40 10,14,38,i9.4,40

fuenzalidai

10,14,38,i9.4

lissocostata

10,12,38,.?9.4,40

radixscripta

10,14,37,iS.4,39

29

Trigonia aff

angusta

48

Trigonia

12,22,23,24.13,25,27

63 11,16,46,50.51,52

frenguellii

1

groeberi

Apiolrigonia

1

1,14,5/.8,52

Scaphogonia Trigonia

17,36,63

8

carinata 8,1 1,14,22.7,23,24

Trigonia carrincurensis

Andilrigonia

1

1,12,46,47.5,48

24

Trigonia

10,14,29.2

Myophorella

57

Syrolrigonia

chunumavensis

Vaugoma

10,12,i6.2,37,38,53

chacaicoensis

47 29

coheni 11,14,59.6,60

Plerolrigonia

10,14,29.1

coihuecoensis

10,12,i0.2

conocardiiformis

Plerolrigonia

Trigonia

34,35 31

1

2, 14,6/, 16, 62

48

aff.

consangiiinea

48

Trigonia corderoi

48 56

costata

59

costatula

Trigonia

Trigonia

attenuala Plerolrigonia aliformis var

62

Plerolrigonia

Cardiidae

Trigonia

arnisoe

Asialolrigonia

10,12,i5.3

Scaphorella capricornia

Clavilngonia

argo

Myophorella cf

camachoi

1,12, 50, 5/. 13

argentinica

Myophorella

62

Plerolrigonia

11,14,51,52.8

araucana Myophorella

10,14,25.1

Jaworskiella

hustamantina

chilensis

Apiotrigoniinae

opislolophophora

burckhardti

calenifera

angustecostata

Antutrigonia

56,57

cassiope

angiilala

Trigonia

subfam

11,12,46,49.9,50

sp. indet

Andivaugoma

n.

1,14,16,47,45.9,50

plumasensis

Austrotrigoniinae

56,57 57

sp

Buchotrigoniinae

aliformis

secunda

36,56,57

abrupta topocalmensis

aliexpandita

prima

12,57,16,58

Syrolrigonia

Buchotrigonia

aliciae

pampeana

53

Turbitrigonia

brocardoi

alamensis

Auslrolrigonia

57,58

Syrolrigonia

houdiccae

agrioensis

Andilrigonia

20

Trigonia biroi

agniaensis

12,6i,64 12,14,6i,17,64

63,64

64 63

"Trigonia"

10. 14,3,4,5,

79.20,21

10,21

27

covuncoensis

Andivaugonia

10,14,38,i9.4,40

crassidens

Trigonia

48

Bulletin 343

92

garatei

crassitesla

37

lotrigonia

Myophorella

12,i/, 12,32

gerthi

crenutata

33,34

Myophorella

60

Pterotrigonia

57,58

Syrotrigonia

cristata

Pterotrigonia

58

gottschei

I'augonia

38

59

Groeberella

9,10,/S,19

cuhanica Pterolrigonia

9,10,14,/S,1,19

neuqtiensis

curacoensis

42

Trigonia iransitoria var

12,79,3

sp. indet

groeheri

D

Antutrigonia

11,14,51,52.8

gryphitica

dawsoni Haidaia

32

H

36

Thgonellina densestriala

10, 12,2/, 3,23, 27

Trigonia discors

28

Trigonia

delicata

Haidaia dawsoni

1

1,12,16,32,33,60,62

32

hanetiana

A ndilrigonia

49

dislans

64

Pacitrigonia

haupti

57

Trigonia diversicoslala

Sleinmanella

11,14,40,43,44.6,45

hcrzogi

53

Trigonia

45

Steinmanella Heterotrigonia

E

52,53,54,63

hillebrandti

Myophorella

elegans

33

Myophorella

1

40

Steinmanella

elguelai

Myophorella

1

l,12,ii,9,34

6,46.47

Trigonia

huenickeni

1

keideli

hondeana

11,14,46,47.2

Eoanditrigonia Eolrigonia

0,

1

8

41,44

epizoans

44

Neuquenitrigonia

10,12,25,3,26

hugoi

Virgotngoma

eufalensis

l,12,i2,8

holubi

1

l,14,37,5i.l4,59

32

Myophorella

I

erycina

Sleinmanella

1

1,12,40,43,44.7,45

inexspectata

1

1.14,16,47,45,9,50

lotrigonia

eximia

10,14,26,2

Frenguelliella

Anditrigonia exotica

36,37,38,46,52,57

37

crassitesla

38

Vaugonia

52

lotrigoniinae

F

J

feruglioi

62

Pterotrigonia

9,10,28

Jaworskiella

10,14,25,1

hurckhardti

fortinensis

11,12,2,^.6,25

Trigonia

K

fuenzalidai 10,14,38,iy.4

Andivaugonia

56,57

Syrotrigonia

9,10,17,26.27

Frenguelliella

10,14,26.2

mexspectata

10,12,21,27,2

perezreyesi

10,26.2,27

poulloni sp.

kauffmani 12,14,55.15,56

Rutitrigonia

fraasi

B

26,27 10,26,1,27

tapiai

kalterfeldensis

Eoanditrigonia

1

1,14,46,47,2

56

Korohkovilrigonia kruusei

10,12,i5,3,36

Scaphorella

26

Frenguelliellinae

L

frenguellii

Antutrigonia

1

1,14, 5/. 8, 52

Laevitrigonia

Laevitrigoniinae

G

63 62,63

lamberli

gampsorrhyncha Trigonia

45

Steinmanella keideli

Anditrigonia

48

Lambertiella

11,12,46,49.9,50

37

Trigoniid Bivalves of Argentina: Leanza

Lamherlrigonia pichimoncolensis

1

N

1,16,36,46,52, 5i,54

11,14,22,52,52,53,54.5

leanzai

navis

34

Trigonia 10,14,i4,3,35,36

Scaphoretla levyi

8

Neolrigonia

margarilacea

Trigonia

1,12,22,6,23

1

lihanotica

1

neuquensis

10.12,38,i9.4,40

neuquensis

tissocostata

literata

47

Trigonia losadai

lycetti

1

1,14,40,42.12

42

aff.

nodulosa

28

Myophorella 38

Vaugonia Lycetlia

Notoscabrotrigonia

1

oliveroi

Nototrigoniinae

M

1,59,60

64 64 64

Nololrigonia

41,44

epizoans on

7,25

9,10,14./S.1,19

Sleinmanella nodosa Trigonia

10,14,205,21

Trigonia

1

25,26

Groeberella

Andivaugonta

0,

10,12,25,3,26

Neuquenitrigoniinae

56

Lmotrigonia

O

macrorrhyncha 48

Trigonia

Macrotrigonia

1

1,12,40,45

manflarum

oliveroi

64

Nololrigonia

opislolophophora

38

Trigonia

Maputrigonia margaritacea

1

Aniulrigonia

1

1,12,50,57.13

1,46,52,53,54

P

8

Neolrigonia

pampeana

maxima 45

Sleinmanella

Myophorella Mediterraneotrigonia

Austrolrigonia

12,14,6i.l7,64

Pacilrigonia

12,64

30

alamensis

44

haneliana

64 64 64

mearnsi

Megalrigonia

46,57

palagonica

Megatrigoniinae

46,57

sohrali

Minelrigoniinae

18

sylvesleri

12,14,64,17

64

palagonica

mirundaensis Trigonia

1

1,2/, 5, 22

Pacilrigonia

64

paradisensis

mollesensis

Trigonia

10,14,19,20,2,21

Syrolrigonia aff Syrolrigonia

muhicostata

49

Trigonia eximia var

Myophorella

8

Neitquenilngonia

Inwmckcni 56,57

Syrotrigonia

....

9,10,11,12,16,25,29,30,31,32,33,34,35,36,62,63 31

agniaensis

araucana

10,14,29,1

argentinica

10, 12, JO. 2

cf.

93

argo

34,35

catenifera

10,14,29,2

crenulata

33,34 33

elegans elguetai

1

l,12,ii,9.34

32

eufalensis

garatei hillehrandii

12,iy, 12,32 1

luherculata

volkheimeri

Myophorellinae

Myophorigonia

Myophorigonia Frenguelliella

30 12,i2, 12,33,34

28,56,57,63 9,19

paucicostala

19

Myophoriidae

7

10,12,21,27,2

Virgolrigonia

52,53,54

peregrina Ruttlrigonia

54,55

pichimoncolensis

Lamherlrigonia

11,14,22,52,52,53,54,5

picunensis

plumasensis

l,12,i0.8

19

pelerseni

10, 12,30,i7,3 1

49,54

perezreyesi

Pisolrigonia

nodulosa schulzi

polrerillensis

58 16,36,38,46,49,52,53,59

paucicostala

30 28

mearnsi praescahroidea

l,12,i2,8

Parandilrigonia

57

Trigonia

Andilrigonia

48 61

47

posadensis

Sleinmanella

45

polrerillensis

Parandilrigonia

49,54

poulloni Frenguelliella

10,26.2,27

2

Bulletin 343

94

Scabrotrigonia

praescabroidea

Myophorella prima

10.12,30.i;.3

11,60

Scaphogonia

31

argo

A usirotngonia Promyophorella

Scaphorella

10,34

10.1 l,12,16,29,30,i7,32,34

camachoi knmsei

10,12,55.3,36

31

siginoidalis

11,31.55,59,60,61,62

Pterolrtgonia

31

63,64

11,14,55,14,59

aliformis aliformis var. attenuata

59

bustamantina

62 62

capricornia

coheni

1

1,14,59.6,60

12,14,67,16,62

coihuecoensis

leanzai

schuizi

Myophorella

feruglioi

62 60

sigeli

vectiana

wmdhauseniana

12,14,62.17 12,58,62

Pterotrigoniinae

1.12,i0,8

64

Auslrolrigonia

semicostala

60 59

1

secunda

59

12,67.9

10,34 12,i4.3

rierafonii

58

sp. juv. indet

34,35

Scaphotrigonia

cubanica

stolleyi

10,14,i4,3,35,36

somensis

cristata

gerthi

10.12,35,3

48

Trigonia

Quoiecchia

12,6i,17

sigmoidalis

Promyophorella

31

similis

Trigonia

21

sobrali

pusilla

48

Tngonia

Pacilrigonia

12,14.64,17

somensis

puslulala

28

Quadralojaworskiella

34,35

Scaphorella splendida

Q Quadrajaworskiella

28 28

pustulata

Quadra to trigoniinae

56,57

Slemmanella

1

1,1

Splendilngonia

1

1,14,40,45,44.45

Slemmanella erycma haupli

qmnlucoensis Stcinmanella

1

1,14,40,'^/. 14,42

Quoiecchia

1

1.62,63

62,63

aticiae

12,6i. 17

sigeli

8.11,12.30,40.41.42.43.45 11.12,40,43,44,7,45 1

1,14,40,43,44,6,45

herzogi

45

holubi

40

kallcrfeldensis

45 45

maxima neuquensis

11, 1 4,40,42, 1

45

posadensis

R

quintucoensis radixscripta

1

1,14,40,47.14,42

1

l,14,49,4i,ll,44

raimondii

Andivaugonia raimondii Slemmanella

4,49,4i.l 1,44

10.l4.37,i5.4.39

splendida

12, 40, 4 J. 11

slemmanni 12,40,4^.11

rectangidtans

laugonia

10,12,i7,2,38

reesidei

1

1,40,42.13

Iransitoria

12.14,40,47,10

vacaensis

12,40,45,15,16

40

Steinmanellinae

sleinmanni

Trigonia

57

rierafonii

Slemmanella

1

Syrolrigonia

Scaphotrigonia

12,i4.3

Rinetrigonia

1

Rutiingonia

1

1.12.61,62

1,12,54.55.56

agrioensis

12,14,54.16.55.56

kauffmani

12,14,55,15,56

peregrina

54,55

sanchuensis

56

sp. juv. indet

14,56,9

weaveri

55

Rutitrigoniinae

54.56

1,40,42,13

57,58

slelzneri

20,22

Trigonia slolleyi

60

Plerolrigonia

suhsinaia

Vaugonia

38

sulcala

Venus

19

sylvesleri

64

Pacilrigonia syriaca

S Rulitrigonia

56

hiroi

brocardoi

scabra Trigonia

57

Trigonia Svrolrigonia

sanchuensis

60

chilensis

1

1,12,36,56,57,58

57,58 12,57,16,58

57

Trigoniid Bivalves of Argentina: Leanza

95

21

fraasi

56,57

si mills

steinmanni

57,58

sp. juv. indet

gerthi

57,58

slelzneri

Uhanotica

56,57

syrlaca

57

Iransitoria var. curacoensis

42

ventricosa

61

58 57

paradisensis aff paradisensis

T

11,12,23,8

20,22

vyschetzkii

41

wiedmanni

12,24,17

"Trigonia" lapiai

10.26.1,27

FrengiwUietIa

27

coslal ula

Trigoniaceae tesselicaudata

Amiitngonia eximia

1

1,12,16,60,9

6,7,18

Tngoniidae Tngoniina

6,7,8,1 1,18,20,46,57

Trigonioida

18

18

ihoracica

60

Plerotrigonia

luberculala

locaimaana Tngonia

59,60

Myophoreila

30

luberculala

topocalmensis

57

Buchotrigonia

Myophoreila

10,14,29,1

cf.

Turbilrigonia transallantica

Plerotrigonia

1

1,14,60,7,61

boudiccae

iransiloria

1

1,1 2,'/0.4

1,42,43,44

10,36

Trigonellina

36

delicata

Tngonia

10,1 1,12,17, /9.26,37

aliexpandita

8,12,17,23,24, 10

angidata

29 48

aff.

angiisia

angiistecoslata

12,22,23,24.13,25,27

48 20

arnisoe

bajuranasi carinata

8,1 1,14,22,7,23,24

cassiope

24 47 48 48

chacaicoensis aff.

conocardiiformis

consanguinea corderoi

10,14,3,4,5,/9,20,21 10,21

costala

48

crassidens densestriata

V

12, 14,40,4/, 10

Sleinmanella Transitrigonia

10,1 2,2/. 3, 23, 27

vacaensis

Sleinmanella Vaugonia chunumayensis

38

38 38

lycelti

reclangularis

48

Trigonia

hugoi

48

manflarum

38

mirandaensis mollesensis

11, 2/. 5, 22

10,14,19,20,2,21

pusilla

34 42 48 48

reesidei

57

scahra

60 48

navis aff.

nodosa

picunensis

semicostala

Il,14,37,5i.l4,59

52,53,54

volkheimeri

Myophoreila Trigonia

10,14,20,5,21

36,37 11,16,46,52,53,54,59

peterseni

1,12,22,6,23

macrorrhyncha

61

veronica

vyschetzkii

losadai

19

ventricosa

28

47

19

sulcata

44 1

59

Plerolrigonia

Venus

hondeana lilerala

36,52,56,57

vecliana

gryphitica

levyi

36

Vaugoniinae

Vaugonia

gampsorrhyncha

36,37

vaugonic costation

Virgotngonia

49

38

veronica

53 l,12,2i.6,25

10,12,^7.2,38

subslriala

57

1

10. 12, i6. 2, 3 7. 38, 53

goltschei

diversicostata

eximia var. multicostata

12,40,45,15,16 10,i6,37, 38,40,52, 57

exotica

dislans

fortinensis

53

12,i2, 12,33,34

41

W weaver i

55

Rutilrigonia

wiedmanni Trigonia

12,24.17

windhauseniana 12,14,62,17

Plerotrigonia

Y Yaadia

42

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