Early Jurassic Bivalvia of Northern Chile. Part III. Order Trigonioida

Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida

ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

PÉREZ, E., ABERHAN, M., REYES B., R. & HILLEBRANDT, A. VON 2008. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida. - Beringeria 39: 51-102, 3 text-figs., 16 pls.; Würzburg.

Abstract. In this work, 238 specimens of the bivalve order Trigonioida have been studied. They belong to the Early to early Middle Jurassic fauna collected at 23 localities of northern Chile, between 21º39’S (II Región de Antofagasta) and 32º25,5’S (V Región de Valparaíso). Thirty-one taxa belonging to 11 genera are described. Three genera, Neuquenitrigonia, Prosogyrotrigonia, and Psilotrigonia, are recorded from Chile for the first time. Eight species are new: Neuquenitrigonia plazaensis, Prosogyrotrigonia tenuis, Quadratojaworskiella acarinata, Psilotrigonia vegaensis, Myophorella (M.) bolitoensis, Myophorella (M.) reginae, Scaphorella susanae, and Vaugonia hectorleanzai. The described species are from the Hettangian to Early Aalenian and occur most frequently in the Sinemurian, Pliensbachian, and Toarcian. Most of the stratigraphic ages of species are controlled through the association with ammonites.

Mollusca, Bivalvia, Trigonioida, new species, Early Jurassic, Early Aalenian, northern Chile, South America

Zusammenfassung: Diese Arbeit basiert auf 238 Individuen der Muschelordnung Trigonioida aus dem Unterjura und unteren Mitteljura von Nordchile. Insgesamt wurden 23 Lokalitäten zwischen 21º39’S (II Región de Antofagasta) und 32º25,5’S (V Región de Valparaíso) beprobt. 31 Taxa, die elf Gattungen angehören, werden beschrieben und ihre stratigraphischen Reichweiten rekonstruiert. Drei Arten, Neuquenitrigonia, Prosogyrotrigonia und Psilotrigonia, werden zum erstenmal aus Chile beschrieben. Acht Arten werden neu aufgestellt: Neuquenitrigonia plazaensis, Prosogyrotrigonia tenuis, Quadratojaworskiella acarinata, Psilotrigonia vegaensis, Myophorella (M.) bolitoensis, Myophorella (M.) reginae, Scaphorella susanae und Vaugonia hectorleanzai Die beschriebenen Arten stammen aus dem Hettangium bis Unteren Aalenium und sind im Sinemurium, Pliensbachium und Toarcium am häufigsten. Die Ermittlung der stratigraphischen Reichweiten ist größtenteils durch die Vergesellschaftung mit Ammoniten des Hettangium bis Aalenium abgesichert.

Mollusca, Bivalvia, Trigonioida, neue Arten, Unterer Jura, Unteres Aalenium, nördliches Chile, Südamerika

Resumen: En este trabajo se estudiaron 238 ejemplares de Trigonioida que forman parte de la fauna recolectada en los perfiles estratigráficos levantados en 23 localidades jurásicas del norte de Chile, comprendidas entre los 21°39’S (II Región de Antofagasta) y 32°25,5’S (V Región de Valparaíso). Se describen 31 taxones asignados a 11 géneros. En este conjunto se reconocen tres géneros no citados hasta ahora para Chile: Neuquenitrigonia, Prosogyrotrigonia y Psilotrigonia, y se proponen ocho especies nuevas: Neuquenitrigonia plazaensis, Prosogyrotrigonia tenuis, Quadratojaworskiella acarinata, Psilotrigonia vegaensis, Myophorella (M.) bolitoensis, Myophorella (M.) reginae, Scaphorella susanae y Vaugonia hectorleanzai. Las especies descritas corresponden en su mayoría al Jurásico Inferior (en algunos casos alcanzan al Aaleniano inferior), con una mayor incidencia en los pisos Sinemuriano, Pliensbachiano y Toarciano. Las edades asignadas se basan en la asociación con ammonites de Zona.

Mollusca, Bivalvia, Trigonioida, especies nuevas, Jurásico Inferior, Aaleniano inferior, norte de Chile, América del Sur

Addresses of the authors: ERNESTO PÉREZ, Servicio Nacional de Geología y Minería, Casilla 10465, Santiago, Chile. e- mail: [email protected]; MARTIN ABERHAN, Museum für Naturkunde, Humboldt-Universität, Invalidenstr. 43, D-10115 Berlin, Germany; RENATO REYES, Diego Portales 936, Depto. 6, Viña del Mar, Chile; AXEL VON HILLEBRANDT, Technische Universität Berlin, Institut für Angewandte Geowissenschaften – Sekr. EB 10, Ernst-Reuter-Platz 1, D- 10587 Berlin, Germany.

Contents

Introduction ...... 52 Temporal distribution of Early Jurassic Trigonioida from northern Chile ...... 54 Taxonomy ...... 58 52 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Genus Groeberella LEANZA 1993 ...... 58 Groeberella neuquensis (GROEBER 1924) ...... 58 Genus Trigonia BRUGUIÈRE 1789 ...... 59 Trigonia sp. 1 ...... 59 Trigonia sp. 2 ...... 60 Trigonia sp. 3 ...... 60 Genus Neuquenitrigonia LEANZA & GARATE 1987 ...... 62 Neuquenitrigonia huenickeni (LEANZA & GARATE 1985) ...... 62 Neuquenitrigonia plazaensis sp. nov...... 62 Genus Prosogyrotrigonia KRUMBECK 1924...... 64 Prosogyrotrigonia tenuis sp. nov...... 64 Prosogyrotrigonia sp. 1 ...... 66 Prosogyrotrigonia sp. 2 ...... 68 Prosogyrotrigonia sp. 3 ...... 68 Genus Frenguelliella LEANZA 1942 ...... 70 Frenguelliella tapiai (LAMBERT 1944)...... 70 Frenguelliella poultoni LEANZA 1993 ...... 72 Frenguelliella inexspectata (JAWORSKI 1916) ...... 74 Genus Jaworskiella LEANZA 1942 ...... 74 Jaworskiella gryphitica (MÖRICKE 1894) ...... 74 Jaworskiella burckhardti (JAWORSKI 1916) ...... 75 Jaworskiella sp...... 76 Genus Quadratojaworskiella REYES & PÉREZ 1980 ...... 76 Quadratojaworskiella pustulata REYES & PÉREZ 1980 ...... 76 Quadratojaworskiella acarinata sp. nov...... 78 Genus Psilotrigonia COX 1952 ...... 80 Psilotrigonia vegaensis sp. nov...... 80 Genus Myophorella BAYLE 1878 ...... 82 Myophorella (Myophorella) araucana (LEANZA 1942) ...... 82 Myophorella (Myophorella) bolitoensis sp. nov...... 84 Myophorella (Myophorella) reginae sp. nov...... 86 Myophorella (Myophorella) sp. 1 ...... 88 Myophorella (Myophorella) sp. 2 ...... 88 Genus Scaphorella LEANZA, PÉREZ & REYES 1987...... 90 Scaphorella susanae sp. nov...... 90 Genus Vaugonia CRICKMAY 1930 ...... 91 Vaugonia hectorleanzai sp. nov...... 91 Vaugonia cf. gottschei (MÖRICKE 1894) ...... 92 Vaugonia cf. substriata (BURMEISTER & GIEBEL 1861) ...... 92 Vaugonia sp. 1 ...... 94 Vaugonia sp. 2 ...... 96 ?Trigonioida indet...... 96 Acknowledgements ...... 96 References ...... 96 Appendix ...... 99

Introduction

This study continues the taxonomic and biostratigraphic widen and detail our knowledge of the taxonomy and work on the Early Jurassic trigonioid bivalve fauna of chronostratigraphy of the order Trigonioida. Based on Chile, as previously reported by PÉREZ & REYES (1977, 238 specimens of different degrees of preservation we 1979, 1997) and PÉREZ et al. (1995). Following the taxo- recognise 31 taxa, grouped in 11 genera, three of which nomic analyses of the bivalve subclasses Palaeotaxo- are reported from Chile for the first time. Eight new donta, Pteriomorphia, and Isofilibranchia (ABERHAN 1994) species are introduced. The fauna is distributed over the and the Anomalodesmata (ABERHAN 2004), it is also the following 23 localities in northern Chile between 21º39’S third part of a monograph on Early Jurassic and earliest (II Región de Antofagasta) and 32º25,5’S (V Región de Middle Jurassic bivalves of northern Chile. Herein, we Valparaíso) (Text-fig. 1): West of Quillagua (21°39’S; Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 53

Text-fig. 1. Map of localities from which trigonioid bivalves were collected. 54 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

69°32’W), Moctezuma (22°36’S; 68°56’W), Sierra erected by HUPÉ (1854), BURMEISTER & GIEBEL (1861), Limón Verde, eastern hill (22°42’S; 68°58’W), Cerros GOTTSCHE (1878), MÖRICKE (1894), PHILIPPI (1899), JA- de Cuevitas (23°34’S; 69°55’W), Quebrada Cachina (25° WORSKI (1916), GROEBER (1924), LEANZA (1942), LAMBERT 54’S; 70°35’W), Quebrada Doña Inés Chica (26°00’S; (1944), and REYES & PÉREZ (1980). 69°10’W), Quebrada Pan de Azúcar (26°02’S; 70° In this monograph, we adopted the classification 28,5’’W), Portezuelo Pedernales (26°20’S; 69°16’W), scheme proposed by COOPER (1991) for the Trigonioida. Quebrada Asientos (26°27’S; 69°20’W), Quebrada Yer- Morphological terms and measured dimensions are bas Buenas (27°03’42"S; 69°37’12"W), Vega Redonda detailed in Text-fig. 3. The size of specimens is expressed (27°08’S; 69°00’W), Quebrada El Bolito (27°09’S; 69° using the scale of SAVELIEV (1958), and the description 33’W), Quebrada San Pedrito/Quebrada Pelado (27° of the dentition follows DOUVILLÉ (1912, 1913). In speci- 15’S; 69°40’W), La Guardia (27°42’S; 69°37’W), Ha- mens lacking a true marginal carina, we use the term ‘mar- cienda Manflas (28°08’S; 69°58’W), Río Manflas (28° ginal angulation’ in the sense of COOPER (1989). The de- 12’S; 70°01’W), Quebrada La Totora/Quebrada El Corral scription of species is accompanied by tables of measure- (28°44’S; 70°15’W), Quebrada Chanchoquín (28º47’S; ments using the following abbreviations: H = height; L = 70º15’40"W), Quebrada Chanchoquín/Paitepén (28° length; W = inflation of single valve; lv = left valve; rv = 47’S; 70°15’W), Quebrada Plaza (28°52’23"S; 70° right valve; 2v = double-valved; [ ] = estimated value. 14’18"W), Quebrada Las Pircas (28°55’S; 70°22’W), The studied specimens were prepared mechanically. Quebrada Pinte (28°58’S; 70°17’W), eastern Punilla In silicified shells the non-silicified rock matrix was (eastern flank) (29°40’S; 70°16’W), and Quebrada del dissolved using diluted acetic acid. This technique yielded Pobre (32°25,5’S; 71°12’W). valves with complete hinge structures and details of the Collection of trigonioids and their associated fauna ornamentation. For optimal contrast the specimens were (see Appendix) in the field, as well as their stratigraphic coated with magnesium oxide prior to taking photographs. assignments (Text-fig. 2) are part of the systematic and The material is deposited in the Museo Geológico del stratigraphic studies on Jurassic ammonites from South Servicio Nacional de Geología y Minería, Chile (acronym America by one of us (A. v. H.) since 1966. The studied SNGM), No. 1993, Ñuñoa, Santiago. E. PÉREZ and R. fauna is completed by specimens collected by the co- REYES carried out the systematic descriptions, whereas authors (M. A. and E. P.) and by the geologists LUIS BAEZA, A. VON HILLEBRANDT and M. ABERHAN contributed the geo- VLADIMIR COVACEVICH†, HANS WILKE, and FERNANDO ESCO- logical background, determination of the associated fauna BAR. Corresponding original field numbers are given in and the stratigraphic assignments of the fauna. The pre- the explanations of the Plates. viously studied and illustrated specimens SNGM 8264 Prior to the present study, knowledge of Early Jurassic and SNGM 8265 of Groeberella neuquensis (GROEBER Trigonioida from northern Chile and their chrono- 1924) (PÉREZ et al. 1995) are reillustrated herein (Pl. 1, stratigraphic distribution (PÉREZ & REYES 1997) was con- Figs. 1-5). fined to nine genera and 18 species, which have been

Temporal distribution of Early Jurassic Trigonioida from northern Chile

In previous studies on this topic, PÉREZ & REYES (1977, (KOBAYASHI & MORI 1954) and the Hettangian of Yukon, 1991, 1997) reported the absence of trigonioids from the Canada (POULTON 1979). Quadratojaworskiella appears Hettangian, a strong increase in abundance and richness to be endemic to Chile and previously was only known in the Sinemurian and the use of Frenguelliella, Jawors- from the Sinemurian and Pliensbachian. The following kiella, and Quadratojaworskiella as guide fossils for the species occur in the Hettangian (Text-figs. 1-2): Proso- Early Jurassic of Chile. In the following, we present an gyrotrigonia tenuis sp. nov., Late Hettangian, Badouxia updated account of the temporal distribution of the Tri- canadensis Zone, Cerros de Cuevitas (loc. 4), and west gonioida from the Early Jurassic of northern Chile. of Quillagua (loc. 1); Prosogyrotrigonia sp. 3, Late Hettangian or earliest Sinemurian, Quebrada Doña Inés Hettangian

We now recognise the genera Prosogyrotrigonia KRUM- Text-fig. 2. Stratigraphic distribution of Jurassic trigonioid bi- BECK (1924) and Quadratojaworskiella REYES & PÉREZ valves of northern Chile described herein. Correlation between (1980) in this stage. ammonite standard zones and Southamerican ammonite zones, During the Late Triassic, Prosogyrotrigonia was re- subzones and horizons follows HILLEBRANDT (1987, 2000a, c, stricted to the east and southeast of Asia (FLEMING 1987). 2002, 2006) and HILLEBRANDT & WESTERMANN (1985). Z. = It has been recorded from the Early Jurassic of Japan Zone; Sz. = Subzone; H. = Horizon. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 55 56 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Chica (loc. 6); Quadratojaworskiella acarinata sp. nov., Kimmeridgian, and is common in the Early and Middle Middle/Late Hettangian, Sunrisites peruvianus Zone, Jurassic but rare above the Early Oxfordian (POULTON Quebrada Cachina (loc. 5). 1979). It is particularly well represented in the Middle Jurassic of Europe. It ranges from the Early to the Middle Sinemurian Jurassic in Chile and occurs in the Middle Jurassic of In addition to Prosogyrotrigonia and Quadrato- Argentina (LEANZA 1996; PÉREZ & REYES 1997). jaworskiella, the genera Groeberella LEANZA (1993), ?Trigonioida indet. is so far only known from the Frenguelliella LEANZA (1942), Jaworskiella LEANZA Upper Sinemurian of Chile. (1942), Psilotrigonia COX (1952), and Vaugonia CRICK- The following species occur in the Sinemurian of nor- MAY (1930) occur in the Sinemurian. thern Chile (Text-figs. 1-2): Groeberella neuquensis Groeberella appears to be endemic to South America (GROEBER 1924), Late Sinemurian, Quebrada Chan- (Argentina and Chile), where it is most abundant in the choquín (loc. 18a); Prosogyrotrigonia tenuis sp. nov., Sinemurian and Pliensbachian, but is also known from earliest Sinemurian, Cerros de Cuevitas (loc. 4); Proso- the Lower Bajocian of Argentina (PÉREZ et al. 1995) and gyrotrigonia sp. 1, earliest Sinemurian, west of Quillagua the Toarcian to Early Aalenian of Chile (this study). The (loc. 1); Prosogyrotrigonia sp. 2, earliest Late Sine- possible occurrence of this genus in the North American murian, Asteroceras obtusum Zone, Sierra Limón Verde Triassic (LEANZA 1993) is as yet unconfirmed. (loc. 3); Quadratojaworskiella acarinata sp. nov., earliest Frenguelliella is a cosmopolitan genus. According to Late Sinemurian, Asteroceras obtusum Zone, Quebrada TAMURA (1959) and NAKANO (1960), the oldest repre- Yerbas Buenas (loc. 10); Frenguelliella poultoni LEANZA sentative would be Trigonia (Kumatrigonia) tanourensis (1993), Sinemurian, Quebrada Pan de Azúcar (loc. 7), TAMURA (1959) from the Carnian of Japan. Frenguelliella Late Sinemurian, Quebrada Pinte (loc. 21); Jaworskiella extends into the Late Cretaceous, although the Early gryphitica (MÖRICKE 1894), Río Manflas (loc. 16) and Cretaceous species are poorly known (NAKANO 1963). Quebrada del Pobre (loc. 23), Late Sinemurian; Jawors- Frenguelliella is unknown from Japan after the Triassic kiella sp., earliest Late Sinemurian, Asteroceras obtusum (NAKANO 1960, 1963). In Europe, this genus flourished Zone, Sierra Limón Verde (loc. 3); Psilotrigonia vega- during the Jurassic and declined in the Cretaceous (NAKA- ensis sp. nov., Late Sinemurian or Early Pliensbachian, NO 1960, 1963). It has been reported from the Middle Vega Redonda (loc. 11); Vaugonia hectorleanzai sp. nov., Jurassic and the Late Cretaceous of India (NAKANO 1960, earliest Late Sinemurian, Asteroceras obtusum Zone, 1963). Frenguelliella has been documented from the Sierra Limón Verde (loc. 3); ?Trigonioida indet., Late Sinemurian and Toarcian of North America (POULTON Sinemurian, Quebrada Pinte (loc. 21). 1979), and in South America (Peru, Chile and Argentina) this taxon also appears to be confined to the Early Jurassic Pliensbachian (PÉREZ & REYES 1991). The genera Groeberella, Frenguelliella, Jaworskiella, Jaworskiella is present in the Sinemurian-Pliens- Quadratojaworskiella, Psilotrigonia, and Vaugonia bachian of North America (POULTON 1979), whereas in persist, whereas the oldest records of Myophorella BAYLE Portugal, it occurred during the Late Jurassic (COX 1952, (1878) are from the Pliensbachian. 1969b). In South America (Argentina and Chile) it ex- Myophorella is a cosmopolitan genus ranging from tends from the Sinemurian to the Toarcian (PÉREZ & REYES the Early Jurassic to the Early Cretaceous. In Europe, it 1991). is the most common trigonioid of the Jurassic (GILLET Psilotrigonia apparently occurred in the Early Pliens- 1965). In Japan, Myophorella appears in the Middle bachian in Canada (POULTON 1979). In Europe (England Jurassic and is common in the Upper Jurassic. It is known and Italy), it is present in the Bajocian (COX 1952, 1969a; from the Pliensbachian to the Kimmeridgian of North NAKANO 1963; KOBAYASHI & MORI 1954). Psilotrigonia America where it is most abundant during the Middle apparently immigrated to New Zealand at the end of the Jurassic (POULTON 1979). In New Zealand, it occurs in Jurassic (Tithonian?) (FLEMING 1964, 1987). In South the Middle Jurassic (Temaikan) and persists into the America (Chile) its age is Late Sinemurian or Early Upper Jurassic (Puaroan; FLEMING 1964, 1987). In South Pliensbachian. America (Peru, Argentina, and Chile), it ranges from the Vaugonia has a cosmopolitan distribution during the Early Jurassic (Sinemurian, in Argentina and Peru) to the Jurassic. In Japan, from where it apparently spread to Early Cretaceous (PÉREZ & REYES 1991; LEANZA 1993). other parts of the world (KOBAYASHI & MORI 1955; GILLET The following species occur in the Pliensbachian of 1965), it ranges from the Hettangian to the Middle northern Chile (Text-figs. 1-2): Groeberella neuquensis Jurassic, becoming less common after the Bajocian. In (GROEBER 1924), Late Pliensbachian, Fanninoceras North America, it existed from the Sinemurian to the fannini Zone (horizon with F. fannini), Quebrada Asientos Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 57

Text-fig. 3. Explanation of morphological terms and dimensions that were measured in this study.

(loc. 9); Frenguelliella tapiai (LAMBERT 1944), Late Neuquenitrigonia is endemic to South America (Ar- Pliensbachian, Fanninoceras disciforme Zone, Portezuelo gentina and Chile) and is known from the Middle Toarcian Pedernales (loc. 8); Frenguelliella inexspectata (JAWORSKI to the Bajocian (LEANZA 1993 and this study). 1916), Early/Late Pliensbachian, Fanninoceras fannini Scaphorella is known from the Late Toarcian to the Zone, Quebrada Asientos (loc. 9); Jaworskiella burck- Early Callovian of South America (Argentina and Chile) hardti (JAWORSKI 1916), Early/Late and Late Pliensbach- (LEANZA et al. 1987 and this study) and from the Middle ian, Fanninoceras fannini Zone, and Late? Pliensbachian, Bajocian of North America (LEANZA et al. 1987). eastern Punilla (eastern flank) (loc. 22); Quadrato- Except for boreal regions, Trigonia is a cosmopolitan jaworskiella pustulata REYES & PÉREZ 1980, Early/Late genus, which ranges from the Middle Triassic (Anisian) Pliensbachian, Fanninoceras fannini Zone, Quebrada to the Late Cretaceous, and which has been widely dis- Asientos (loc. 9); Psilotrigonia vegaensis sp. nov., Late tributed since the Middle Jurassic (KOBAYASHI & MORI Sinemurian or Early Pliensbachian, Vega Redonda (loc. 1954). In Europe, it occurs from the Late Triassic to the 11); Vaugonia cf. gottschei (MÖRICKE 1894), Pliens- Middle Cretaceous (NAKANO 1961). It is known from the bachian?, Quebrada Las Pircas (loc. 20); Vaugonia sp. Early Jurassic to the Bajocian of Japan (NAKANO 1960) 2, Early/Late Pliensbachian, Fanninoceras fannini Zone, and the Middle and Late Jurassic of India (NAKANO 1961). Quebrada Asientos (loc. 9); Myophorella araucana In North America, it is relatively well represented in the (LEANZA 1942) and Myophorella sp. 2, Early/Late and Jurassic (POULTON 1979). Australian records are from the Late Pliensbachian, Fanninoceras fannini Zone, Quebrada Early and Middle Jurassic (NAKANO 1961). It is known Asientos (loc. 9). from New Zealand in the Anisian, Bajocian and Late Aptian (FLEMING 1987). The oldest records from South Toarcian America are from the Anisian (Chile) and Norian (Peru); The genera Groeberella, Myophorella, and Vaugonia it reappears in the Sinemurian (Peru) and the Toarcian persist, whereas Neuquenitrigonia LEANZA & GARATE (Chile) and extends into the Late Jurassic and Early 1987 and Scaphorella LEANZA, PÉREZ & REYES 1987 make Cretaceous (Colombia, Peru, Argentina and Chile) (PÉREZ their first appearance. Also Trigonia BRUGUIÈRE 1789 & REYES 1991). reappears, after having been absent form the Chilean The following species occur in the Toarcian of northern fossil record since the Anisian. Chile (Text-figs. 1-2): Groeberella neuquensis (GROEBER 58 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

1924), Middle Toarcian, Collina chilensis Zone, Que- nov. were collected at Quebrada San Pedrito/Quebrada brada Pinte (loc. 21); Myophorella reginae sp. nov., Late Pelado (loc. 13). At Quebrada El Bolito (loc. 12) we re- Toarcian, ‘Pleydelia lotharingica’ Zone, La Guardia (loc. cognise the species N. huenickeni and Myophorella 14) and Middle Toarcian, Phymatoceras toroense Zone?, bolitoensis sp. nov., and N. huenickeni is also recorded Quebrada Plaza (loc. 19); Vaugonia hectorleanzai sp. from Hacienda Manflas (loc. 15). nov., Early Toarcian, Dactylioceras hoelderi Zone, Que- brada Chanchoquín/Paitepén (loc. 18b) and Moctezuma The Early Jurassic trigonioids from Chile presented herein (Text-fig. 2) complete the information provided by PÉREZ (loc. 2); Vaugonia cf. gottschei (MÖRICKE 1894), Late Toarcian, Quebrada La Totora/Quebrada El Corral (loc. & REYES (1977, 1979, 1997) and PÉREZ et al. (1995), which is summarised as follows: 17); Vaugonia cf. substriata (BURMEISTER & GIEBEL 1861), Middle Toarcian, Collina chilensis Zone, Quebrada Pinte Groeberella sp. (PÉREZ et al. 1995). Early Sinemurian, (loc. 21); Vaugonia sp. 1, Middle Toarcian, Phymatoceras Quebrada Pan de Azúcar, III Región de Atacama. toroense Zone?, Quebrada Plaza (loc. 19); Neuqueni- Myophorella catenifera (HUPÉ 1854). Pliensbachian, trigonia huenickeni (LEANZA & GARATE 1985) and Neu- Quebrada Asientos, III Región de Atacama; Toarcian, quenitrigonia plazaensis sp. nov., Middle Toarcian, Phy- Cordillera de Doña Ana, IV Región de Coquimbo; Early matoceras toroense Zone, Quebrada Plaza (loc. 19); Sca- Jurassic, Quebrada Tres Cruces, IV Región de Coquimbo. phorella susanae sp. nov., Late Toarcian, ‘Pleydellia Trigonia stelzneri GOTTSCHE 1878. Early Jurassic, south- fluitans’ Zone, Quebrada El Bolito (loc. 12); Trigonia southeast of Calama, II Región de Antofagasta; Toarcian, sp. 1, Middle Toarcian, Collina chilensis Zone, Quebrada Cordillera de Punilla and Cordillera de Doña Ana, IV La Totora/Quebrada El Corral (loc. 17) and Middle Región de Coquimbo. Toarcian, Collina chilensis Zone, Quebrada Pinte (loc. Vaugonia cf. substriata (BURMEISTER & GIEBEL 1861). 21); Trigonia sp. 2, Middle Toarcian, Collina chilensis Toarcian, La Guardia, Quebrada Las Trancas and Juntas, Zone, Quebrada Pinte (loc. 21). III Región de Atacama. Early Aalenian Trigonia aff. bella LYCETT 1877. Toarcian, La Guardia, III Región de Atacama. In addition to the Early Jurassic Trigonioida of Chile described herein, we include some Middle Jurassic taxa Jaworskiella infraclavellata (MÖRICKE 1894). Middle to (Early Aalenian, Bredyia manflasensis Zone; Text-figs. late Early Jurassic, Sierra de La Ternera, III Región de 1-2). Groeberella neuquensis (GROEBER 1924), Trigonia Atacama. sp. 3, Neuquenitrigonia huenickeni (LEANZA & GARATE Trigonia flühmanni PHILIPPI 1899. Early Jurassic, Amo- 1985), Myophorella sp. 1, and Scaphorella susanae sp. lanas, III Región de Atacama.

Taxonomy

1967 Myophorigonia neuquensis (GROEBER) - LEVY: 14-15, pl. Order Trigonioida DALL 1899 on p. 16, figs. 1a-f. 1981 Myophorigonia neuquensis (GROEBER) - HILLEBRANDT & Suborder Trigoniina DALL 1899 SCHMIDT-EFFING: 10. 1982 Myophorigonia aff. neuquensis (GROEBER) - PÉREZ: 40, Superfamily Trigoniacea LAMARCK 1819 pl. 15, figs. 2-5, appendix 1. 1992 ‘Myophorigonia’ neuquensis (GROEBER) - DAMBORENEA Family Groeberellidae PÉREZ, REYES & & MANCEÑIDO: 134, pl. 1, fig. 5a. DAMBORENEA 1995 1992 Myophorigonia neuquensis (GROEBER) - DAMBORENEA et al.: pl. 115, fig. 14. Genus Groeberella LEANZA 1993 1993 Groeberella neuquensis (GROEBER) - LEANZA: 18-19, pl. 1, figs. 2-3. Type species. Myophoria neuquensis GROEBER 1924, 1995 Groeberella neuquensis (GROEBER) - PÉREZ et al.: 147, Early Jurassic (Pliensbachian), Neuquén, Argentina. pl. 1, figs. 1-3, 5-13, 15,16, 18-22. 1997 Groeberella neuquensis (GROEBER) - PÉREZ & REYES: 573, Groeberella neuquensis (GROEBER 1924) 576. Pl. 1, Figs. 1-13, 15, 17-18 Material. 10 specimens from Quebrada Asientos (SNGM 436-437, 1924 Myophoria neuquensis sp. nov. - GROEBER: 92-94, pl. 1, 439-442, 445, 7368, 8264-8265), 2 from Quebrada Pinte (SNGM figs. a-b. 443-444), 1 from Quebrada San Pedrito/Quebrada Pelado (SNGM 1931 Myophoria neuquensis GROEBER - WINDHAUSEN: 179, fig. 435), and 1 from Quebrada Chanchoquín (SNGM 438). SNGM 435- 71. 436, 439, 441-443, 7368 (articulated specimens, in part incomplete); 1942 Myophoria neuquensis GROEBER - WANISH DE CARRAL SNGM 437-438, 440, 444-445, 8264 (incomplete left valves); SNGM TOLOSA: 59-60, pl. 6, figs. 3a-c. 8265 (incomplete right valve). Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 59

Localities and age. Quebrada Asientos (locality 9), III Región de Family Trigoniidae LAMARCK 1819 Atacama, Late Pliensbachian, Fanninoceras fannini Zone, horizon with F. fannini (HILLEBRANDT 1987: 120; 2006: 14, 261, 262); Subfamily Trigoniinae LAMARCK 1819 Quebrada San Pedrito/Quebrada Pelado (locality 13), III Región de RUGUIÈRE Atacama, Early Aalenian, Bredyia manflasensis Zone (HILLEBRANDT Genus Trigonia B 1789 & WESTERMANN 1985: 20); Quebrada Chanchoquín (locality 18a), III Type species. Venus sulcata HERMANN 1781, early Late Región de Atacama, Late Sinemurian (HILLEBRANDT 1973: fig. 2; Jurassic, Alsace, France. 2002); Quebrada Pinte (locality 21), III Región de Atacama, Middle Toarcian, Collina chilensis Zone (HILLEBRANDT 1987: 120). PÉREZ et Trigonia sp. 1 al. (1995) assigned a Sinemurian-Pliensbachian age to this species, based on occurrences at Chilean localities (different from those Pl. 1, Figs. 14, 16, 19 mentioned above) and Argentine localities of this age. Material. 2 specimens from Quebrada La Totora/Quebrada El Corral (SNGM 446-447), and 13 from Quebrada Pinte (SNGM 449-453, Measurements (in mm). 459-466). SNGM 446, 460-461, 465 (incomplete right valves); SNGM Specimen valve H L W H/L W/L 447, 450-451, 453, 459, 462-464, 466 (incomplete left valves); SNGM SNGM 435 2v [32] [34] 16 0.94 0.47 449, 452 (articulated specimens, partly incomplete). SNGM 436 2v [34] [34] 18 1.00 0.52 SNGM 442 2v [24] [25] 12 0.96 0.48 Localities and age. Quebrada La Totora/Quebrada El Corral (locality 17), III Región de Atacama, Middle Toarcian, Collina chilensis Zone Description. Specimens thick-shelled, medium-sized, (HILLEBRANDT, this study); Quebrada Pinte (locality 21), III Región de Atacama, Middle Toarcian, Collina chilensis Zone (HILLEBRANDT subquadrate, slightly longer than high, inequivalved with 1987: 120). left valve slightly higher than right valve. Umbones weakly opisthogyrous, strongly incurved, situated Measurements (in mm). anteriorly, slightly displaced relative to each other in arti- Specimen valve H L W H/L W/L culated specimens. Dorsal and anterior margins moder- SNGM 446 rv [26] [31] 15 0.83 0.48 ately convex, the latter slightly longer than the former; SNGM 449 2v [25] [35] 13 0.71 0.37 posterior margin short, straight, forming an obtuse angle SNGM 466 2v [27] [33] [15] 0.81 0.45 (ca. 125º) with dorsal margin; antero-ventral margin oblique, forming an angle of ca. 110° with anterior margin; Description. Shell medium-sized, triangular. Umbo small, postero-ventral margin concave. Area wide, smooth, con- incurved, opisthogyrous. Anterior margin convex; dorsal cave, with slope strongly inclined toward flank. Marginal margin straight; posterior margin short and slightly carina forming most prominent part of shell; markedly convex; ventral margin not preserved. Area occupying convex in proximal third due to pronounced curvature of slightly less than one-fourth of the valve, forming an angle umbonal and post-umbonal part of shell; sharp in right of ca. 100° with the flank; with radial, beaded costellae, valve, blunt in left valve, in the latter also with transverse comprising a submedian carina and finer striae, which protuberances, which correspond to enlargements of form a reticulate pattern together with the growth lines; growth lines. Internal carina less developed, broad and three striae between marginal carina and submedian blunt, in left valve with longitudinal striae. Escutcheon carina and five striae between the latter and the internal wide and smooth except for growth lines. Flank convex, carina. Marginal carina low, blunt, with fine transverse carrying two divergent, broad (3 mm), blunt costae with nodes. Internal carina blunt and with small, distinct transverse crenulations in left valve; costae of right valve tubercles. Escutcheon relatively wide, about one-half the narrower, more acute and smooth. Intercostal spaces size of the area; with transverse striae near the umbo, much wider than costae; growth lines oblique between and with diagonal and discontinuous striae on the first and second costa and concave between second costa remainder of the escutcheon. Flank increasingly convex and marginal carina. toward anterior end; ornamented with smooth and blunt costae (3 per 5 mm in the median part of the flank), Remarks. Well preserved specimens of this species show separated by wider interspaces (1.5 mm); umbonal costae differences in the ornamentation of left and right valves concentric; post-umbonal costae subconcentric with a (PÉREZ et al. 1995). The flank costae and marginal carina pronounced undulation in the anterior part of the flank of the left valve exhibit transverse crenulations (Pl. 1, and a slight downward inflexion near the marginal carina. Figs. 1, 5), whereas in well preserved right valves these features are absent. The specimens from Chile and those Remarks. Because of their incomplete preservation, the from Argentina differ in the preservation of the orna- studied specimens cannot be identified at species level, mentation, which led to discrepancies in the descriptions and an open nomenclature is preferred. SNGM 446 is of this species by the various authors (GROEBER 1924; the best preserved specimen, and in the style of orna- WANISH DE CARRAL TOLOSA 1942; LEVY 1967; LEANZA mentation has affinities with T. stelzneri GOTTSCHE (1878: 1993; PÉREZ et al. 1995). 256, pl. 6, fig. 1) as the flank costae undulate toward the 60 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT anterior end and bend near the marginal carina. Due to widely spaced flank costae, which do not bend at the mar- the fragmentary state of this specimen, characteristic ginal carina. In these characters it differs from Trigonia features of the species of GOTTSCHE such as size and the sp.1 (this study), which was collected at the same stra- curvature of umbo and flank cannot be observed. The tigraphic level (Collina chilensis Zone) in Quebrada Pinte. downward bending of post-umbonal costae near the marginal carina is not observed in the specimens from Que- brada Pinte. Trigonia sp. 3 Trigonia sp. 2 Pl. 2, Figs. 2-3

Pl. 2, Fig. 1 Material. 1 incomplete right valve from Quebrada San Pedrito/Que- brada Pelado (SNGM 448). Material. 6 specimens from Quebrada Pinte (SNGM 454-458, 467). SNGM 454, 456-457, 467 (incomplete right valves); SNGM 455, Locality and age. Quebrada San Pedrito/Quebrada Pelado (locality 458 (incomplete left valves). 13), III Región de Atacama, Early Aalenian, Bredyia manflasensis Zone (HILLEBRANDT & WESTERMANN 1985: 20). Locality and age. Quebrada Pinte (locality 21), III Región de Atacama, Measurements (in mm). Middle Toarcian, Collina chilensis Zone (HILLEBRANDT 1987: 120). Specimen valve H L W H/L W/L Measurements (in mm). SNGM 448 rv [34] [40] [11] 0.85 0.77 Specimen valve H L W H/L W/L SNGM 454 rv [32] [40] [12] 0.80 0.30 Description. Shell medium-sized, triangular. Umbo not preserved. Dorsal, posterior and ventral margins poorly Description. Shell medium- to large-sized, triangular, with defined; anterior margin convex, forming an angle of 72° shell length exceeding height. Umbo slightly incurved with the marginal carina. No ornamentation observed on and opisthogyrous. Shell margins only partly preserved; area except for median carina, which is partly preserved. dorsal margin apparently straight; ventral margin convex. Marginal carina low, blunt, and with small, transverse Area covered with radial costae, which carry small crenulations. Internal carina of lesser relief, incomplete. tubercles; divided by submedian carina into two parts of Escutcheon poorly preserved. Flank moderately convex; unequal size; a narrower one, bordering the marginal with smooth, blunt costae separated by slightly wider carina, with two costae, and a wider one, adjoing to the interspaces; costae concentric to subconcentric, the latter internal carina, with four finer costae. Marginal carina undulating on the anterior flank. With respect to dentition, blunt and with transverse striae. Internal carina poorly tooth 3a is preserved (ca. 10.5 mm long, 3 mm thick); preserved and lower. Escutcheon excavated and with anterior adductor scar oval and deep (4 mm). widely spaced, transverse costae. Flank moderately convex; ornamented with prominent, blunt, concentric Remarks. The specimen cannot be assigned to any known to subconcentric costae with intercostal spaces equal to species. Strongest affinities exist to Trigonia sp. 1 (this the width of the costae. study) in terms of strength and spacing of the costae and their undulation on the anterior flank. However, the flank Remarks. Poor preservation of the specimens renders an is less convex in the anterior part, the marginal carina is identification at species level impossible. Distinct ob- less developed, and the costae do not bend when approa- servable features of Trigonia sp. 2 include the strong and ching the carina.

EXPLANATION OF PLATE 1

Figs. 1-13, 15, 17-18. Groeberella neuquensis (GROEBER 1924). Figs. 1-6, 9-13, 15, 18. Quebrada Asientos, east of Potrerillos, locality 9; Late Pliensbachian, Fanninoceras fannini Zone (F. fannini horizon). Figs. 1-2. SNGM 8264 (HILLEBRANDT 660707/2); left valve. 1: lateral view, x 1; 2: view of umbo and hinge, x 1.5. Figs. 3-5. SNGM 8265 (HILLEBRANDT 660708/1); right valve, x 1. 3: view of umbo and hinge; 4: lateral view; 5: postero-dorsal view. Figs. 6, 9-11. SNGM 436 (HILLEBRANDT 660708/1b); articulated specimen, x 1.5. 6: dorsal view; 9: anterior view; 10: right valve view; 11: left valve view. Figs. 12, 18. SNGM 439 (HILLEBRANDT 660708/1a); articulated specimen, x 1.5. 12: left valve view; 18: right valve view. Figs. 13, 15. SNGM 437 (HILLEBRANDT 660708/1c); right valve, x 2. 13: lateral view; 15: dorsal view. Figs. 7-8. Quebrada San Pedrito/Quebrada Pelado, northeast of Copiapó, locality 13; Early Aalenian, Bredyia manflasensis Zone. SNGM 435 (HILLEBRANDT 711215/5); articulated specimen, x 1.5. 7: right valve view; 8: left valve view. Fig. 17. Quebrada Chanchoquín, southeast of Vallenar, locality 18a; Late Sinemurian, Echioceras raricostum Zone. SNGM 438 (HILLEBRANDT 671008/2); left valve, lateral view, x 1.5. Figs. 14, 16, 19. Trigonia sp. 1. Figs. 14, 19. Quebrada La Totora/Quebrada El Corral, southeast of Vallenar, locality 17; Middle Toarcian, Collina chilensis Zone. SNGM 446 (ABERHAN 1992: appendix I + III, horizon 5-2); right valve, x 1.5. 14: dorsal view; 19: lateral view. Fig. 16. Quebrada Pinte, southeast of Vallenar, locality 21; Middle Toarcian, Collina chilensis Zone. SNGM 449 (HILLEBRANDT 670912/2); articulated specimen, left valve view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 61 62 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Subfamily Neuquenitrigoniinae LEANZA 1993 Anterior margin long and weakly convex; dorsal and posterior margins straight; ventral margin short and Genus Neuquenitrigonia LEANZA & GARATE 1987 convex; dorsal and anterior margins forming an acute Type species. Trigonia huenickeni LEANZA & GARATE angle of ca. 75°. Area wide, flat, with reticulate ornamen- 1985, Bajocian, Neuquén, Argentina. tation; radial costae well developed with a median carina Neuquenitrigonia huenickeni (LEANZA & GARATE 1985) and three to four costae of lesser strength on both sides of carina; transverse costae significantly weaker than ra- Pl. 2, Figs. 4-6, 9; Pl. 3, Figs. 4, 8-10, 13 dials ones; small tubercles developed at intersections of 1985 Trigonia huenickeni sp. nov. - LEANZA & GARATE: 290, both types of costae. Marginal carina well developed, pl. 1, figs. 1-3. wide, blunt, with closely spaced transverse nodes. Internal 1987 Neuquenitrigonia huenickeni (LEANZA & GARATE) - LEANZA & GARATE: 209, pl. 3, figs. 1-3. carina of lower relief and with more widely spaced 1992 Neuquenitrigonia huenickeni (LEANZA & GARATE) - tubercles. Escutcheon wide, subplanate, elevated and with DAMBORENEA et al.: pl. 118, fig. 4. widely spaced, continuous to irregular, transverse costae, 1993 Neuquenitrigonia huenickeni (LEANZA & GARATE) - which meet with the tubercles of the internal carina. Flank LEANZA: 25, pl. 3, figs. 10, 17. 1997 Neuquenitrigonia huenickeni (LEANZA & GARATE) - PÉREZ with high, rounded, widely spaced costae (5 costae per & REYES: 574, 575. 20 mm, measured in central part of specimen SNGM 469, Pl. 2, Figs. 4-6, 9) of variable strength; intercostal spaces Material. 7 specimens from Quebrada El Bolito (SNGM 468-474), 1 wide (3.5 mm) and excavated; costae slightly curved up- from Hacienda Manflas (SNGM 475), 1 from Quebrada San Pedrito/ Quebrada Pelado (SNGM 476), and 1 from Quebrada Plaza (SNGM ward at anterior end, declining in median part of flank 482). SNGM 469 (articulated specimens); SNGM 468, 470-471, 475 and becoming slightly concave close to marginal carina. (left valves, some incomplete); SNGM 473-474, 476, 482 (incomplete Antecarinal sulcus of left valve deep and wide; less de- right valves). veloped in right valve. Ligamental fossette wide.

Localities and age. Quebrada El Bolito (locality 12), III Región de Atacama, Early Aalenian, Bredyia manflasensis Zone (HILLEBRANDT Remarks. Compared with the specimens figured by & WESTERMANN 1985: 8); Quebrada San Pedrito/Quebrada Pelado LEANZA & GARATE (1987: pl. 3, figs. 1-3) and LEANZA (locality 13), III Región de Atacama, Early Aalenian, Bredyia (1993: pl. 3, figs. 10, 17), the flank costae of our speci- manflasensis Zone (HILLEBRANDT & WESTERMANN 1985: 20); Quebrada mens are more slender. Where we count an average of Plaza (locality 19), III Región de Atacama, Middle Toarcian, Phymatoceras toroense Zone?; Hacienda Manflas (locality 15), III three costae every 10 mm, measured on the central part Región de Atacama, Early Aalenian, Bredyia manflasensis Zone of the flank close to the carina, the Argentine specimens (HILLEBRANDT & WESTERMANN 1985; HILLEBRANDT 2001: fig. 2). only carry two costae. DAMBORENEA et al. (1992) and LEANZA (1993) recorded this species from the Lower Bajocian (Emileia giebeli Zone and Stephanoceras humphriesianum Zone) of Argentina. Neuquenitrigonia plazaensis sp. nov.

Measurements (in mm). Pl. 2, Figs. 7-8, 10-11 Specimen valve H L W H/L W/L 1980 Trigonia n. sp. - HILLEBRANDT: pl. 2, figs. 6-7. SNGM 469 2v 44 55 22 0.8 0.40 1997 Trigonia n. sp. HILLEBRANDT - PÉREZ & REYES: 574. SNGM 468 lv [47] [61] [29] 0.78 0.48 SNGM 475 lv 42 57 20 0.74 0.35 Derivation of name. From Quebrada Plaza, the type locality of the species.

Description. Shell large-sized, trigonal-ovate, inequi- Material. 1 right valve (SNGM 477) and 4 mostly incomplete left lateral, longer than high. Umbo incurved, opisthogyrous. valves from Quebrada Plaza (SNGM 478-481).

EXPLANATION OF PLATE 2

Fig. 1. Trigonia sp. 2. Quebrada Pinte, southeast of Vallenar, locality 21; Middle Toarcian, Collina chilensis Zone. SNGM 454 (HILLEBRANDT 670912/2); right valve, lateral view, x 1.5. Figs. 2-3. Trigonia sp. 3. Quebrada San Pedrito/Quebrada Pelado, northeast of Copiapó, locality 13; Early Aalenian, Bredyia manflasensis Zone. SNGM 448 (HILLEBRANDT 711215/5); right valve, x 1.5. 2: interior view; 3: lateral view. Figs. 4-6, 9. Neuquenitrigonia huenickeni (LEANZA & GARATE 1985). Quebrada El Bolito, northeast of Copiapó, locality 12. Early Aalenian, Bredyia manflasensis Zone. SNGM 469 (HILLEBRANDT 670222/11); articulated specimen, x 1.5. 4: left valve view; 5: dorsal view; 6: right valve view; 9: antero-dorsal view. Figs. 7-8, 10-11. Neuquenitrigonia plazaensis sp. nov. Quebrada Plaza, east of Embalse Lautaro, south of Copiapó, locality 19; Middle Toarcian, probably Phymatoceras toroense Zone. Figs. 7-8. SNGM 477 (holotype) (HILLEBRANDT 671013/2); right valve, x 1.5. 7: lateral view; 8: dorsal view. Figs. 10-11. SNGM 479 (paratype) (HILLEBRANDT 671013/2); left valve, x 1.5. 10: lateral view; 11: dorsal view. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 63 64 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Holotype. SNGM 477 (Pl. 2, Figs. 7-8), right valve with posterior flank, declining in median part of flank and subhorizontal and ventral margins incomplete; hinge partly visible. to weakly concave and widely spaced (3.5 mm) in pos- Paratypes. SNGM 478; SNGM 479 (Pl. 2, Figs. 10-11); SNGM 480- terior third of flank; left valve costae terminate at a wide 481. (2 mm in SNGM 479) antecarinal sulcus. Locality and age. Quebrada Plaza (locality 19), III Región de Atacama, Middle Toarcian, Phymatoceras toroense Zone? (HILLEBRANDT 1987). Remarks. N. plazaensis sp. nov. can be distinguished from Measurements (in mm). N. huenickeni (LEANZA & GARATE) by an obtuse angle Specimen valve H L W H/L W/L between the dorsal and anterior margins, a less convex Holotype flank surface with less prominent costae, a narrower area, SNGM 477 rv [28] [40] 17 0.70 0.43 a less distinct median carina, and by the costae of the es- Paratype cutcheon being more densely spaced. SNGM 479 lv 32 42 19 0.76 0.45

Diagnosis. Shell characterised by dorsal and anterior mar- Family Prosogyrotrigoniidae KOBAYASHI 1954 gins forming an obtuse angle; area occupying about one- fourth of the shell surface; ornamentation of area and Subfamily Prosogyrotrigoniinae KOBAYASHI 1954 flank of moderate strength; escutcheon with fine, trans- Genus Prosogyrotrigonia KRUMBECK 1924 verse costellae. Type species. Prosogyrotrigonia timorensis KRUMBECK Description. Shell medium-sized (SNGM 477; Pl. 2, Figs. 1924, Late Triassic, Timor. 7-8), subrectangular, longer than high. Umbo small and opisthogyrous. Dorsal margin straight; anterior margin Prosogyrotrigonia tenuis sp. nov. short and slightly convex, forming an angle of ca. 110° Pl. 3, Figs. 1-3, 5-7, 11-12; Pl. 4, Figs. 1-12, 14-15; Pl. 5, Figs. 2, 5 with dorsal margin; ventral margin convex; posterior 1997 Prosogyrotrigonia sp. - PÉREZ & REYES: 574, 576. margin poorly preserved. Area occupying about one- fourth of the shell surface; ornamented with a poorly Derivation of name. From the Latin tenuis (= thin), referring to the developed median carina, formed by small tubercles, the thin shell of the species. size of which increases slightly toward the distal end; Material. 12 specimens from Cerros de Cuevitas (SNGM 483-494) also ornamented with seven lines of small tubercles, four and 2 from west of Quillagua (SNGM 495-496). SNGM 484-485, on external side of area, three on internal side. Marginal 487, 490(1-4), 492(1), 494(2, 4), 495(1-2), 496 (incomplete left carina of moderate strength and with poorly developed valves); SNGM 483, 486, 488-489, 492(2), 494(1,3), 495(3) (incomplete right valves); SNGM 491, 493 (articulated specimens, in transverse crenulations. Internal carina composed of small part incomplete); SNGM 492(3-12) (various fragments). nodes. Escutcheon weakly excavated, reaching about one- half the width of the area with which it forms an obtuse Holotype. SNGM 486 (Pl. 4, Figs. 11-12), right valve with ventral angle; ornamented with fine, discontinuous transverse margin partly incomplete; hinge partly visible. costellae, which widen to form the tubercles of the internal Paratypes. SNGM 484 (Pl. 4, Figs. 14-15); SNGM 485 (Pl. 3, Fig. carina; costellae more densely spaced in proximal half 7); SNGM 488 (Pl. 4, Figs. 8-9). of escutcheon. Flank surface moderately convex; ornamented with blunt, widely spaced costae of moderate Localities and age. West of Quillagua (locality 1), II Región de Anto- strength; costae concentric in umbonal part, subconcentric fagasta, Late Hettangian, Badouxia canadensis Zone (Paracaloceras varaense Subzone) and horizon with Pseudaetomoceras arcuatum in central and ventral part of shell; post-umbonal costae (HILLEBRANDT 2000b: 104); Cerros de Cuevitas (locality 4), II Región slightly convex and tightly spaced in anterior third of de Antofagasta, Late Hettangian, Badouxia canadensis Zone, Schlot-

EXPLANATION OF PLATE 3 Figs. 1-3, 5-7, 11-12. Prosogyrotrigonia tenuis sp. nov. Figs. 1, 3, 5-7. Cerros de Cuevitas, northeast of Antofagasta, locality 4; Late Hettangian, Badouxia canadensis Zone. Figs. 1, 3, 5-6. SNGM 483 (HILLEBRANDT 841107/4); right valve, x 2. 1: lateral view; 3: interior view; 5: dorsal view; 6: antero-dorsal view. Fig. 7. SNGM 485 (paratype) (HILLEBRANDT 871105/1); left valve, lateral view, x 1.5. Figs. 2, 11-12. West of Quillagua, locality 1. Late Hettangian; Badouxia canadensis Zone. Figs. 2, 12. SNGM 495-1 (HILLEBRANDT 940303/6); left valve view, x 1.5. 2: lateral view; 12: interior view. Fig. 11. SNGM 495-2 (HILLEBRANDT 940303/6); left valve, lateral view, x 2.25. Figs. 4, 8-10, 13. Neuquenitrigonia huenickeni (LEANZA & GARATE 1985). Hacienda Manflas, southeast of Copiapó, locality 15. Early Aalenian, Bredyia manflasensis Zone. Figs. 4, 8-9. SNGM 475 (HILLEBRANDT 720104/6a); articulated specimen, x 1.5. 4: dorsal view; 8: left valve view; 9: interior view. Figs. 10, 13. Quebrada El Bolito, northeast of Copiapó, locality 12. Early Aalenian, Bredyia manflasensis Zone. SNGM 468 (HILLEBRANDT 670222/11); left valve, x 1.5. 10: dorsal view; 13: lateral view. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 65 66 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

heimia cuevitensis Subzone (HILLEBRANDT 2000b: 104) and earliest long, 1 mm thick) and tooth 2 (5.5 mm thick in ventral Sinemurian (horizon with Coroniceras aff. conybeari) (HILLEBRANDT part) are preserved. Anterior adductor scar oval and 2000a). excavated; posterior adductor scar less pronounced; pos- Measurements (in mm). terior pedal retractor scar small and oval. Specimen valve H L W H/L W/L Holotype Remarks. Prosogyrotrigonia tenuis sp. nov. can be dis- SNGM 486 rv 30 39 11 0.77 0.28 tinguished from the type species of the genus, P. timor- Paratype SNGM 485 lv 41 47 15 0.87 0.32 ensis KRUMBECK 1924 from the Rhaetian of Timor (KRUM- SNGM 488 lv 14 18 4 0.78 0.22 BECK 1924; KOBAYASHI & MORI 1954), by its subrectangular outline, the straight anterior margin, a less convex Diagnosis. Valves thin-shelled, subrectangular in outline; post-umbonal part of the flank and finer costae on the anterior and dorsal margins straight, forming a slightly flank. It differs from P. inouyei (YEHARA 1921) from the obtuse angle; flank and area ornamented with fine costae. Early Jurassic of Japan (YEHARA 1921; KOBAYASHI & MORI 1954) by its subrectangular outline and finer and more Description. Specimens very thin-shelled, medium-sized, densely spaced costae on the flank. With Proso- subrectangular, longer than high. Umbo small, prosogyrotrigonia(?) cf. P. inouyei (YEHARA 1921) from nor- gyrous, weakly incurved and situated anteriorly. Dorsal thern Yukon, Canada (FREBOLD & POULTON 1977: pl. 2, and anterior margins straight, forming an angle of ca. fig. 9) it shares the subrectangular outline but differs by 105°; posterior and ventral margins moderately convex. finer costae on the flank and by a more obtuse angle bet- Area wide, occupying one-third of the shell surface, ween flank and area. slightly concave and forming an angle of ca. 130° with ESCOBAR (1980: 57, pl. 2, fig. 4) reported Astarte sp. the flank; ornamented with transverse to oblique, occa- from the Sinemurian southeast of El Guindo, VII Región sionally dichotomizing costellae (less than 0.5 mm in del Maule, central Chile. Judging from the features of width), which are a continuation of the ornamentation of flank and area, this specimen may also belong to P. tenuis the flank and are separated by variable interspaces ranging sp. nov., but hinge characters are not preserved and there- from 0.5 to 1.0 mm. Marginal carina lacking and replaced fore this assignment remains uncertain. by a gentle marginal bend. Internal carina represented by small swellings of the costellae of the area. Escutcheon Prosogyrotrigonia sp. 1 narrow, slightly excavated and ornamented with oblique costellae continuing from the area. Flank moderately Pl. 4, Fig. 13 convex, with concentric costae in umbonal part, changing Material. 1 incomplete right valve from west of Quillagua (SNGM to subconcentric in median and ventral parts of flank; 497). subconcentric costae progressively more oblique and Locality and age. West of Quillagua (locality 1), II Región de more closely spaced toward anterior end; costae narrow Antofagasta, earliest? Sinemurian, horizon with Coroniceras aff. (0.5 mm wide in central part), prominent and blunt, conybeari (HILLEBRANDT 2000a). separated by much wider intercostal spaces (1.5 mm), Measurements (in mm). which, however, are reduced toward the ventral margin. Specimen valve H L W H/L W/L Holotype (SNGM 486; Pl. 4, Fig. 12) partly preserves SNGM 497 rv [25] [27] 8 0.93 0.30 teeth 3a (7 mm long, 3 mm thick) and 3b (7 mm long). Anterior adductor scar oval, posterior one ellipsoidal. In Description. Specimen medium-sized. Umbo small, paratype SNGM 484 (Pl. 4, Fig. 14), tooth 4a (ca. 5 mm slightly incurved and prosogyrous, situated anteriorly.

EXPLANATION OF PLATE 4 Figs. 1-12, 14-15. Prosogyrotrigonia tenuis sp. nov. Figs. 1-2, 4-5, 8-12, 14-15. Cerros de Cuevitas, northeast of Antofagasta, locality 4; Late Hettangian, Badouxia canadensis Zone. Figs. 1-2. SNGM 494-1 (HILLEBRANDT 841107/4); right valve, x 1.5. 1: lateral view; 2: interior view. Figs. 4-5, 10. SNGM 493 (HILLEBRANDT 841107/4); articulated specimen, x 1.5. 4: right valve view; 5: left valve view; 10: dorsal view. Figs. 8-9. SNGM 488 (paratype) (HILLEBRANDT 871105/1); right valve, x 3. 8: interior view; 9: lateral view. Figs. 11-12. SNGM 486 (holotype) (HILLEBRANDT 871105/1); right valve, x 2. 11: lateral view; 12: interior view. Figs. 14-15. SNGM 484 (paratype) (HILLEBRANDT 871105/1); left valve, x 2. 14: interior view; 15: lateral view. Figs. 3, 6-7. West of Quillagua, locality 1. Late Hettangian, Badouxia canadensis Zone. SNGM 496 (HILLEBRANDT 940303/1); left valve, x 1.5. 3: lateral view; 6: interior view; 7: dorsal view. Fig. 13. Prosogyrotrigonia sp. 1. West of Quillagua, locality 1; earliest? Sinemurian (?horizon with Coroniceras aff. conybeari). SNGM 497 (WILKE 29-1); right valve, lateral view, x 1. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 67 68 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Preserved parts of anterior and dorsal margins straight, Measurements (in mm). forming an angle of ca. 113°; posterior and ventral mar- Specimen valve H L W H/L W/L gins not preserved. Area occupying one-fourth of the shell SNGM 498 rv [40] [51] [9] 0.78 0.18 surface and forming an angle of ca. 100° with the flank; ornamented with fine, transverse to progressively oblique Description. Shell medium-sized. Umbo and anterior costellae (less than 1 mm in width), separated by slightly margin not preserved; dorsal margin partly preserved; wider (1 mm) interspaces; costellae continuing from the posterior margine weakly convex; ventral margin convex. costae of the flank, some of which dichotomizing on the Area occupying about one-third of the shell surface and area. Marginal carina lacking; separation of area and flank forming an angle of ca. 134° with the flank; with shallow, marked by a marginal angulation, which, in the median subcentral depression; ornamented with transverse to and distal part, exhibits small tubercles at the contact of oblique costellae of fine to medium strength, continuing the costae of flank and area. Internal carina demarcated from the costae of the flank, some of them dichotomizing; by small nodes of the costellae of the area. Escutcheon ornamentation denser and finer toward posterior margin. partly preserved, excavated and narrow. Flank moderately Area separated from flank by gentle marginal angulation. convex and ornamented with concentric to subconcentric, Escutcheon not preserved. Flank weakly convex in central smooth costae in umbonal part, which develop into rows part of shell; ornamented with subconcentric, relatively of elongated tubercles in median and distal part of valve; thick (1.5 mm) costae, which carry small tubercles; costae costae narrow (less than 1 mm in width) and progressively separated by somewhat wider interspaces and becoming more oblique toward anterior margin, separated by some- more oblique toward anterior margin; costae finer, more what wider interspaces (1 mm). Parts of teeth 3a and 3b densely spaced and lacking tubercles in distal part of preserved. flank. Hinge characters not preserved.

Remarks. The available incomplete specimen differs from Remarks. Prosogyrotrigonia sp. 2 differs from Proso- P. tenuis sp. nov. by the presence of costae, which in the gyrotrigonia tenuis sp. nov. by the presence of relatively median and distal parts of the flank are composed of rows thick, tubercle-bearing costae in the central part of the of elongated tubercles. This feature is also lacking in P. flank. They can be distinguished from Prosogyrotrigonia sp. 1 by stronger costae and the lack of tubercles in the timorensis KRUMBECK 1924 and P. inouyei (YEHARA 1921). distal part of the flank. Prosogyrotrigonia sp. 2 Prosogyrotrigonia sp. 3 Pl. 5, Fig. 14 Pl. 5, Fig. 15 Material. 3 specimens from Limón Verde (SNGM 498-499, 508). SNGM 498 (incomplete right valve); SNGM 499, 508 (incomplete Material. 1 incomplete right valve from Quebrada Doña Inés Chica left valves). (SNGM 500).

Locality and age. Sierra Limón Verde (locality 3), II Región de Locality and age. Quebrada Doña Inés Chica (locality 6), III Región Antofagasta, earliest Late Sinemurian, Asteroceras obtusum Zone de Atacama, Late Hettangian or earliest Sinemurian (HILLEBRANDT, this study). (HILLEBRANDT 2002: 42).

EXPLANATION OF PLATE 5

Figs. 1, 3-4, 9-13. Frenguelliella tapiai (LAMBERT 1944). Portezuelo Pedernales, northeast of Potrerillos, locality 8. Late Pliensbachian, Fanninoceras disciforme Zone. Figs. 1, 11, 13. SNGM 501 (HILLEBRANDT 660710/4); articulated specimen, x 1.5. 1: right valve view; 11: dorsal view; 13: left valve view. Figs. 3, 12. SNGM 504 (HILLEBRANDT 660710/4); left valve, x 2. 3: lateral view; 12: interior view. Fig. 4. SNGM 502 (HILLEBRANDT 660710/4); left valve, lateral view, x 2. Figs. 9-10. SNGM 503 (HILLEBRANDT 660710/4); right valve, x 2. 9: interior view; 10: lateral view. Figs. 2, 5. Prosogyrotrigonia tenuis sp. nov. Cerros de Cuevitas, northeast of Antofagasta, locality 4; Late Hettangian, Badouxia canadensis Zone (Schlotheimia cuevitensis Subzone). SNGM 487 (HILLEBRANDT 871105/1); left valve, x 2. 2: lateral view; 5: interior view. Figs. 6-8. Frenguelliella poultoni LEANZA 1993. Quebrada Pan de Azúcar, ca. 10 km southwest of Las Bombas, locality 7; Sinemurian. Fig. 6. SNGM 540 (PÉREZ & ESCOBAR Afos 7;3063-13); left valve, lateral view, x 1.5. Fig. 7. SNGM 527 (PÉREZ & ESCOBAR Afos7; 3063); left valve, lateral view, x 1.5. Fig. 8. SNGM 536 (PÉREZ & ESCOBAR Afos7; 3063-33); right valve, lateral view, x 1.5. Fig. 14. Prosogyrotrigonia sp. 2. Sierra Limón Verde, eastern hill, 17.5 km south of Calama, locality 3; Late Sinemurian, Asteroceras obtusum Zone. SNGM 498 (HILLEBRANDT 751211/1); right valve, lateral view, x 1.5. Fig. 15. Prosogyrotrigonia sp. 3. Quebrada Doña Inés Chica, northeast of El Salvador, locality 6; Late Hettangian or earliest Sinemurian. SNGM 500 (HILLEBRANDT 841114/4b); right valve, lateral view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 69 70 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Measurements (in mm). Type species. Trigonia inexspectata JAWORSKI 1916, Early Specimen valve H L W H/L W/L Jurassic, Neuquén, Argentina. SNGM 500 rv [36] 50 19 0.72 0.38 Frenguelliella tapiai (LAMBERT 1944) Description. Specimen large-sized, subrectangular in out- Pl. 5, Figs. 1, 3-4, 9-13 line, longer than high. Umbo and anterior margin not preserved; dorsal margin straight; posterior margin moder- 1944 Trigonia tapiai sp. nov. - LAMBERT: 358-359, pl. 13, fig. ately convex; ventral margin convex. Area representing 1. less than one-fourth of the shell surface and forming an 1977 Trigonia (Frenguelliella) tapiai LAMBERT - PÉREZ & angle of ca. 115° with the flank; ornamented with trans- REYES: 12, pl.1, fig. 2. 1980 Frenguelliella tapiai (LAMBERT) - HILLEBRANDT: pl. 2, verse, widely spaced costellae of increasing density figs. 8a, b. toward posterior margin; ornamentation continuing from 1987 Frenguelliella tapiai (LAMBERT) - LEANZA & GARATE: 210, the costae of the flank, occasionally dichotomizing on pl. 1, fig. 5. the area. Area separated from flank by marginal angula- 1992 Frenguelliella tapiai (LAMBERT) - DAMBORENEA et al.: pl. tion. Escutcheon not preserved. Flank convex and orna- 116, fig. 18. mented with thick (1 mm), subconcentric costae, becom- 1993 Frenguelliella tapiai (LAMBERT) - LEANZA: 26, pl. 1, fig. ing more oblique toward anterior margin and separated 8. by equally spaced interspaces. Hinge not preserved. 1997 Frenguelliella tapiai (LAMBERT) - PÉREZ & REYES: 574, 576. Remarks. Prosogyrotrigonia sp. 3 differs from P. tenuis Material. 7 specimens from Portezuelo Pedernales (SNGM 501-507). sp. nov. by its larger size, a less obtuse angle between SNGM 502, 504-505 (partly incomplete left valves); SNGM 503, flank and area, and a stronger ornamentation on both flank 506-507 (incomplete right valves); SNGM 501 (articulated specimens and area. It can be distinguished from Prosogyrotrigonia with partly deteriorated flanks). sp. 1 by its larger size and by stronger and more widely Locality and age. Portezuelo Pedernales (locality 8), III Región de spaced costae on the flank, which bend less markedly at Atacama, Late Pliensbachian, Fanninoceras disciforme Zone, horizon the anterior end and lack tubercles. Compared with Pro- with Reynesoceras americanum (HILLEBRANDT 1987: 116; 2002: 12). sogyrotrigonia sp. 2, the angle between flank and area is DAMBORENEA et al. (1992) and LEANZA (1993) reported this species less obtuse and the costae of the flank do not carry tuber- from the Pliensbachian of Argentina, the former author from the cles. Radulonectites sosneadoensis Zone (comprising the European Amaltheus margaritatus and Pleuroceras spinatum standard zones), In the arrangement of the costae of area and flank, the and the latter author from the Fanninoceras fannini Zone, which specimen assigned to Prosogyrotrigonia sp. 3 exhibits comprises part of these zones (HILLEBRANDT 1987: 120). some affinities with species of the genus Frenguelliella Measurements (in mm). LEANZA (1942), but lacks a marginal carina. Specimen valve H L W H/L W/L SNGM 501 2v 22 28 8 0.79 0.30 Suborder Myophorellina COOPER 1991 SNGM 502 lv 22 27 8 0.81 0.30 SNGM 504 lv 25 [29] 9 0.86 0.31

Superfamily Myophorellacea KOBAYASHI 1954 Description. Shell small- to medium-sized, oval to sub- Family Frenguelliellidae NAKANO 1960 quadrate, inequilateral. Umbo opisthogyrous, situated anteriorly. Dorsal margin straight, with a gentle, concave Subfamily Frenguelliellinae NAKANO 1960 inflexion at distal end; posterior margin straight in dorsal Genus Frenguelliella LEANZA 1942 half and convex in ventral half; both margins forming an

EXPLANATION OF PLATE 6

Figs. 1, 3-4, 7. Frenguelliella inexspectata (JAWORSKI 1916). Quebrada Asientos, east of Potrerillos, locality 9; Early/Late Pliensbachian, Fanninoceras fannini Zone. Figs. 1, 4, 7. SNGM 563 (HILLEBRANDT 660708/8); left valve, x 1.5.1: lateral view; 4: dorsal view; 7: interior view. Fig. 3. SNGM 562 (ABERHAN 1992: appendix I, horizon 2-62); right valve, lateral view, x 1.5. Figs. 2, 8-9. Jaworskiella burckhardti (JAWORSKI 1916). Quebrada Asientos, east of Potrerillos, locality 9; Late Pliensbachian, Fanninoceras fannini Zone (F. fannini horizon). SNGM 568 (HILLEBRANDT 660708/1); right valve,x 1.5. 2: lateral view; 8: dorsal view; 9: interior view. Figs. 5-6, 10-11. Jaworskiella gryphitica (MÖRICKE 1894). Figs. 5, 10-11. Quebrada del Pobre, northeast of La Ligua, locality 23; Late Sinemurian, Echioceras raricostatum Zone. SNGM 565 (COVACEVICH 61267/7); articulated specimen, x 1.5. 5: left valve view; 10: right valve view; 11: dorsal view. Fig. 6. Río Manflas, northeast of Vallenar, locality 16; Late Sinemurian. SNGM 564 (HILLEBRANDT 670106/2); right valve, lateral view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 71 72 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

obtuse angle of ca. 115°; anterior margin weakly convex; fers from F. perezreyesi LEANZA (1993: 27, pl. 2, figs. 1- ventral margin convex; dorsal and anterior margins 2, 7-8) by its larger size and by a more obtuse angle bet- forming a slightly obtuse angle of ca. 100°. Area wide, ween the surfaces of flank and area. occupying about one-third of the shell surface, asymmetrically divided by a subtle groove; ornamented with Frenguelliella poultoni LEANZA 1993 transverse costellae (6 per 5 mm), which are more numerous than flank costae, separated by somewhat wider inter- Pl. 5, Figs. 6-8 spaces; area and flank forming an angle of ca. 125º. 1979 Frenguelliella sp. B - POULTON: 18, pl. 1, fig. 10. Marginal carina low, rounded, slightly curved and with 1993 Frenguelliella poultoni sp. nov. - LEANZA: 26, pl. 2, figs. small nodes, which correspond to the costae of the area. 3-6.

Internal carina less developed, but also with small nodes. Material. 47 specimens from Quebrada Pan de Azúcar (SNGM 515- Escutcheon excavated, its length occupying almost all of 561, 690) and 6 from Quebrada Pinte (SNGM 509-514). SNGM 510- the dorsal margin; surface covered with four to five 511, 513-514, 518, 520(1), 522, 535(2), 536(1), 536(2), 537, 539(1), diagonal striae. Flank moderately convex, with narrow 544, 545(2), 551(3), 552(2), 558(2), 560 (right valves, some partly incomplete); SNGM 509, 512, 517, 519, 520(2), 520(3), 523(1), 525, antecarinal sulcus; ornamented with low costae (4 per 5 526(1), 526(2), 527, 528, 530, 532, 539(2), 540, 545(1), 547, 549(1), mm in central part of flank), separated by slightly wider 551(2), 558(1), 559, 561, 690 (left valves, some partly incomplete); interspaces. Course of costae variable (Pl. 5, Fig. 4): con- SNGM 515, 516(1), 516(2), 517(2), 518(2), 523(2), 524, 534, 535(1), centric in umbonal part; rising at anterior end in median 538, 541, 543, 548, 550, 551(1), 553(2), 554(1), 555(1), 556(1), 557 part to form a convex undulation; subconcentric in distal (external molds of left valves, some incomplete); SNGM 516(3), 521, 529, 531, 533, 542, 546(1), 546(2), 549(2), 553(1), 553(3), 554(2), part of flank. Costae interrupted at antecarinal sulcus in 555(2) (external molds of right valves, some incomplete); SNGM central part, but only attenuated in distal part. 552(1), 556(2) (external molds of articulated specimens).

Localities and age. Quebrada Pan de Azúcar (locality 7), III Región Remarks. LAMBERT (1944: 359) described the escutcheon de Atacama, Sinemurian (based on the co-occurrence with Arietites as apparently smooth. In contrast, the studied specimens sp. and Arnioceras sp.), probably Obtusum Zone, Stellare Subzone, agree with the descriptions of LEANZA & GARATE (1987: horizon with Asteroceras cf. stellare (HILLEBRANDT 2002: 46); 210) and LEANZA (1993: 26), who reported the presence Quebrada Pinte (locality 21), III Región de Atacama, Late Sinemurian of fine, albeit more numerous, oblique costellae. With (ABERHAN 1992: 139, appendix I). POULTON (1979) identified specimen GSC 9635 from the Early Sinemurian Laberge Group as Frenguelliella respect to the ornamentation of the flank, the specimen sp. B. LEANZA (1993: 26-27) considered this specimen to be figured by LEANZA (1993: 26, pl. 1, fig. 8) carries a larger synonymous with F. poultoni from the Late Pliensbachian number of costae than the specimens studied herein and (Fanninoceras fannini Zone) of Catán Lil, Argentina. those figured by LAMBERT (1944: 358, pl. 13, fig. 1), LEAN- Measurements (in mm). ZA & GARATE (1987: 210, pl. 1, fig. 5) and DAMBORENEA Specimen valve H L W H/L W/L et al. (1992: pl. 116, fig. 18). F. chubutensis (FERUGLIO SNGM 526(1) lv 9 13 - 0.69 - 1934: 34, pl. 4, figs. 9, 11) from the Pliensbachian (DAM- SNGM 536(1) rv 9 13 - 0.69 - BORENEA et al. 1992: pl. 116, fig. 17) of Valle del Río SNGM 561 lv 12 16 - 0.61 - Genua in Patagonia, has affinities with F. tapiai, but differs by a dorsal margin, which is curved at the distal end, Description. Shell small-sized and thin-shelled, sub- an area with a poorly developed submedian groove, and rectangular, highly inequilateral. Umbo orthogyrous. Dor- more densely spaced costae on the flank. LAMBERT (1944: sal margin moderately concave; posterior margin straight 359) also mentioned that the species of FERUGLIO is smal- and shorter than dorsal margin, both forming an obtuse ler sized. angle of ca. 105°; anterior margin weakly convex; ventral F. tapiai can be separated from F. poultoni LEANZA margin convex, changing to slightly concave close to (1993: 26, pl. 2, figs. 3-6) by its larger size, flank costae marginal carina; dorsal and anterior margin forming an which are more strongly subconcentric, and narrower in- angle of ca. 100°. Area wide, occupying about one-third tercostal spaces toward the anterior margin. F. tapiai dif- of shell; asymmetrically divided by shallow groove with

EXPLANATION OF PLATE 7

Figs. 1-3, 6-7. Jaworskiella burckhardti (JAWORSKI 1916). Figs. 1, 3. Eastern Punilla (eastern flank), northeast of La Serena, locality 22; Late Pliensbachian. SNGM 570 (THIELE P.E.4.05-1); right valve, x 1.5. 1: lateral view; 3: dorsal view. Figs. 2, 6-7. Quebrada Asientos, east of Potrerillos, locality 9; Early/Late Pliensbachian, Fanninoceras fannini Zone. SNGM 569 (HILLEBRANDT 660708/8); left valve, x 1.5. 2: lateral view; 6: interior view; 7: dorsal view. Figs. 4-5. Jaworskiella sp. Sierra Limón Verde, south of Calama, locality 3; Late Sinemurian, Asteroceras obtusum Zone. SNGM 567 (BAEZA B205); left valve, x 1.5. 4: dorsal view; 5: lateral view. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 73 74 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT dorsal part narrower than ventral part; ornamented with Material. 1 complete right valve (SNGM 562) and 1 complete left transverse costellae. Marginal carina distinct relative to valve with partly preserved hinge (SNGM 563) from Quebrada Asien- tos. size of shell; with small nodes where it meets the ornamentation of the area. Internal carina less developed; Locality and age. Quebrada Asientos (locality 9), III Región de Ata- cama, Early/Late Pliensbachian, Fanninoceras fannini Zone, ?horizon also with small nodes. Escutcheon lanceolate and exca- with Fanninoceras leptodiscus (HILLEBRANDT 1987: 120; 2002: 14). vated. Flank moderately convex, occupying two-thirds In Argentina, this species was reported from the Pliensbachian Radulo- of the shell surface; ornamented with low, blunt concentric nectites sosneadoensis Zone (corresponding to the Amaltheus margari- costae (5-6 per 5 mm), separated by intercostal spaces tatus and Pleuroceras spinatum European standard zones) (DAMBORE- which are somewhat wider in dorsal part of flank and of NEA et al. 1992), the Otapiria neuquensis Zone (corresponding to the Uptonia jamesoni and Prodactylioceras davoei standard zones) and equal width on ventral part. Costae bending upward at the Radulonectites sosneadoensis Zone (LEANZA 1993). anterior end of flank, forming a slightly convex undulation Measurements (in mm). before reaching the marginal carina; weakening distally; Specimen valve H L W H/L W/L narrow antecarinal sulcus present in dorsal and central SNGM 562 rv 35 [43] 16 0.81 0.37 part of flank. SNGM 563 lv 30 [46] 14 0.65 0.30

Remarks. This species exhibits a fair amount of intra- Description. Shell medium-sized to large, subrectangular, specific variability with respect to ornamentation. In inequilateral. Umbo small, opisthogyrous. Dorsal margin specimens of equal size the costellae of the area can vary straight, curved upward at the distal end; posterior margin in strength and spacing, and the antecarinal sulcus is weakly convex, much shorter than dorsal margin; both lacking in some specimens (see also POULTON 1979: 18; margins forming an angle of ca. 125°; anterior and ventral LEANZA 1993: 26). The small tubercles on the marginal margins convex. Area narrow, occupying about one-fifth and internal carinae, visible in specimen SNGM 538, are of shell surface; subdivided by shallow groove in two not present in the remaining specimens from Quebrada parts of subequal size; ornamented with transverse costae Pan de Azúcar, probably due to preservational reasons. of moderate strength, more numerous than flank costae, LEANZA (1993: 26) did not mention tubercles on the cari- separated by interspaces twice as wide than the costae. nae, whereas POULTON (1979: 18) reported their presence Carinae blunt; marginal carina stronger than internal on the internal carina. carina; both with small nodes at contact with orna- Most specimens of this species are very small (13-18 mentation of area. Escutcheon excavated, with diagonal, mm in length, 9-15 mm in height), such as those studied discontinuous striae. Flank convex, with antecarinal by POULTON (1979: GSC 9635) from Yukon, Canada, by depression widening toward ventral margin; ornamented LEANZA (1993: holotype MOZP 5315, paratype MOZP with blunt variable costae (3 per 5 mm), separated by 5317-1), from Arroyo Ñireco, Neuquén, Argentina, and slightly wider interspaces; umbonal costae concentric, the material from Pan de Azúcar, Chile, studied herein. post-umbonal costae slightly bending at the anterior end; LEANZA (1993: paratypes MOZP 5316 and 5317-2) also costae increasing in strength at border between flank and documented larger specimens (23-33 mm in length, 17- antecarinal depression, forming a small bulb, continuing 25 mm in height) from Argentina. Small specimens from across depression as much finer and markedly convex Argentina have a height/length ratio (H/L) of 0.83, where- costellae until meeting marginal carina. as larger specimens have a ratio of 0.74-0.75. In this respect the Chilean specimens (H/L = 0.61-0.69) have Remarks. Compared with specimens figured by JAWORSKI stronger affinity with the specimen from Canada (H/L = (1916: pl. 5, fig. 2a), LEANZA (1942: pl. 7, fig. 1), DAM- 0.66). BORENEA et al. (1992: pl. 116, fig. 16), and LEANZA (1993: pl. 2, fig. 9) the costae of the flank of the studied material Frenguelliella inexspectata (JAWORSKI 1916) from Chile are more densely spaced.

Pl. 6, Figs. 1, 3-4, 7 Genus Jaworskiella LEANZA 1942 1916 Trigonia inexspectata sp. nov. - JAWORSKI: 377-380, pl. 5, figs. 2a, b. Type species. Trigonia burckhardti JAWORSKI 1916, Early 1942 Trigonia (Frenguelliella) inexspectata JAWORSKI - Jurassic (Pliensbachian), Neuquén, Argentina. LEANZA: 165-166, pl. 7, fig. 1. 1992 Frenguelliella inexspectata (JAWORSKI) - DAMBORENEA et Jaworskiella gryphitica (MÖRICKE 1894) al.: pl. 116, fig. 16. 1993 Frenguelliella inexspectata JAWORSKI - LEANZA: 26, pl. Pl. 6, Figs. 5-6, 10-11 2, fig. 9. 1997 Frenguelliella inexspectata (JAWORSKI) - PÉREZ & REYES: 1894 Trigonia gryphitica sp. nov. - MÖRICKE: 45-46, pl. 3, fig. 574, 576. 5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 75

1977 Jaworskiella gryphitica (MÖRICKE) - PÉREZ & REYES: 15, Jaworskiella burckhardti (JAWORSKI 1916) pl. 3, fig. 4. 1997 Jaworskiella gryphitica (MÖRICKE) - PÉREZ & REYES: 574. Pl. 6, Figs. 2, 8-9; Pl. 7, Figs. 1-3, 6-7; Pl. 8, Fig. 3

Material. 1 specimen from Río Manflas (SNGM 564) and 3 specimens 1901 Trigonia gryphitica BURCKHARDT non STEINMANN - from Quebrada del Pobre (SNGM 565-566(1-2)). SNGM 564, 566-1 BURCKHARDT: 21-22, pl. 4, fig. 4. (right valves); SNGM 566-2 (left valve); SNGM 565 (incomplete 1916 Trigonia burckhardti sp. nov. - JAWORSKI: 380, pl. 5, fig. articulated specimen). 3. 1942 Trigonia (Jaworskiella) burckhardti JAWORSKI - LEANZA: Localities and age. Río Manflas (locality 16), III Región de Atacama, 166-168, pl. 6, figs. 2-3. Late Sinemurian (HILLEBRANDT & SCHMIDT-EFFING 1981: 24); Quebrada 1977 Jaworskiella burckhardti (JAWORSKI) - PÉREZ & REYES: del Pobre (locality 23), V Región de Valparaíso, Late Sinemurian? 14, pl. 2, figs. 1, 3, 6. (HILLEBRANDT 2002: 51; 2006: 27). The specimens of J. gryphitica 1980 Jaworskiella burckhardti (JAWORSKI) - HILLEBRANDT: pl. from Quebrada Las Vizcachas and Sierra de La Ternera, south of 2, figs. 5a, b. Copiapó, III Región de Atacama, were assigned to the Early Jurassic 1987 Jaworskiella burckhardti (JAWORSKI) - LEANZA & GARATE: by MÖRICKE (1894). 210, pl. 1, figs. 1-2. 1993 Jaworskiella burckhardti (JAWORSKI) - LEANZA: 28, pl. Measurements (in mm). 1, figs. 1, 6, 7, 10. Specimen valve H L W H/L W/L 1997 Jaworskiella burckhardti (JAWORSKI) - PÉREZ & REYES: SNGM 566(1) lv [20] [24] 6 0.83 0.25 574, 576. SNGM 566(2) rv [19] [23] 6 0.83 0.26 SNGM 778 rv [28] [35] 10 0.80 0.29 Material. 4 specimens from Quebrada Asientos (SNGM 568-569, 571- SNGM 779 2v [30] [39] [15] 0.77 0.38 572) and 1 from eastern Punilla (eastern flank) (SNGM 570). SNGM 568, 570-572 (partly incomplete right valves); SNGM 569 (partly Description. Shell small- to medium-sized, subrectangular incomplete left valve). to oval, longer than high. Umbo small, incurved, slightly Localities and age. Quebrada Asientos (locality 9), III Región de Ata- opisthogyrous. Anterior margin weakly convex; dorsal cama, Late Pliensbachian, Fanninoceras fannini Zone, horizon with and posterior margins straight; ventral margin convex. F. fannini (HILLEBRANDT 1987: 120; 2006: 14); eastern Punilla (eastern Area occupying abouth one-fourth of the shell surface; flank) (locality 22), IV Región de Coquimbo, Toarcian (THIELE 1964), Late? Pliensbachian (HILLEBRANDT, this study). In Argentina, LEANZA asymmetrically divided by shallow submedian groove, (1993) recorded this species from the Pliensbachian Otapiria neuquen- with the region bordering the marginal carina being the sis Zone (corresponding to the Uptonia jamesoni and Prodactylioceras larger one; ornamented with fine, transverse costellae, davoei zones) and the Radulonectites sosneadoensis Zone (corres- separated by somewhat wider interspaces. Marginal and ponding to the Amaltheus margaritatus and Pleuroceras spinatum zones). internal carinae blunt; with small tubercles, which are stronger in marginal carina, located at intersection with Measurements (in mm). costae of area. Escutcheon relatively wide compared to Specimen valve H L W H/L W/L area, slightly excavated, with oblique growth striae. Flank SNGM 568 rv [53] [66] 25 0.80 0.38 SNGM 569 lv 58 [68] 25 0.85 0.37 convex, with wide antecarinal sulcus; costae blunt, with small tubercles; umbonal costae concentric, post-umbonal Description. Shell medium-sized to large, trigonal-ovate. costae subconcentric, about 1 mm in strength, separated Umbo strongly incurved, opisthogyrous, situated sub- by larger interspaces (ca. 2 mm); ornamentation inter- mesially. Dorsal margin straight; anterior margin moder- rupted at antecarinal sulcus. ately convex; ventral margin convex; posterior margin short and straight. Area occupying about one-fifth of shell Remarks. J. gryphitica differs from J. infraclavellata surface; with median groove and ornamented with fine, (MÖRICKE 1894) by more widely spaced flank costae. It transverse costellae, separated by somewhat wider inter- can be distinguished from J. burckhardti (JAWORSKI 1916) spaces. Marginal carina with small tubercles, which meet by its smaller size and a moderately convex flank with with costellae of area. Internal carina formed by small costae which are tuberculated throughout. Jaworskiella tubercles, corresponding to swellings of costellae of area. sp. (this study) is larger and the costae of the flank are Escutcheon excavated, elongated, smooth. Flank convex, not tuberculated. POULTON (1979: 19-20, pl. 7, figs. 1-8) ornamented with narrow (1.5 mm), prominent costae, se- analysed the genus Jaworskiella and described two spe- parated by larger (2 mm) interspaces; umbonal costae cies from North America: J. siemonmulleri POULTON concentric; post-umbonal costae subconcentric, becom- (1979) and J. supleiensis POULTON (1979). Compared with ing subhorizontal toward anterior margin, slightly con- these species, J. gryphitica is smaller, ornamented with cave in median part of flank and moderately inclined to- wider spaced costae, and exhibits a marked antecarinal ward antecarinal sulcus; post-umbonal costae often more sulcus. or less sinuous, bifurcating at the anterior end in some cases, and with tubercles in median and precarinal parts of flank; antecarinal sulcus wider in left valve than in 76 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT right valve, interrupting or attenuating the contact bet- Measurements (in mm). ween ornamentation of flank and marginal carina. SNGM Specimen valve H L W H/L W/L 568 (Pl. 6, Fig. 9) with tooth 3a (14 mm long, 5 mm SNGM 567 lv [49] [63] 23 0.78 0.37 thick) and tooth 3b (14 mm long, 2 mm thick in median Description. Specimen large, longer than high. Umbo in- part); anterior adductor scar lenticular (11 mm in height, curved, weakly opisthogyrous. Dorsal margin straight; 6 mm in length); posterior pedal retractor scar ca. 2 mm anterior and ventral margins only partly preserved; pos- in diameter. Tooth 2 (19 mm long at base, 12 mm high) terior margin slightly convex. Area occupying one-fourth preserved in SNGM 569 (Pl. 7, Fig. 6). of flank surface; with median groove and ornamented with strong, transverse costae, separated by wider inter- Remarks. Specimens of J. burckhardti vary with respect spaces. Marginal carina slightly curved in umbonal part; to the ornamentation of the flank and the area. The type straight, wide and blunt in central and distal part, with specimen (JAWORSKI 1916: 380, pl. 5, fig. 3) lacks tuber- tubercles at contact with costae of area. Internal carina cles on the costae of the flank. However, tubercles are slightly concave; formed by tubercles which correspond well developed in the precarinal part of the flank in the to swellings of the costae of the area. Escutcheon shallow, specimens figured by LEANZA (1942: 166, pl. 6, figs. 2- very elongated, running along large part of dorsal margin; 3), LEANZA & GARATE (1987: 210, pl. 1, figs. 1-2), and relatively wide, approximately one-half the size of the LEANZA (1993: pl. 1, fig. 1). In specimens SNGM 568 area; mostly smooth, but with diagonal costellae at distal and 569 (this study), in contrast, the tubercles are small. end, which are prolongations of the costae of the area. Concerning the costellae of the area, these are strong and Flank moderately convex; upper third ornamented with widely spaced in the specimens figured by JAWORSKI concentric to subconcentric, blunt, smooth, densely (1916), LEANZA (1942), LEANZA & GARATE (1987), and spaced (3 in 5 mm) costae; costae stronger and more LEANZA (1993). They are of lesser strength and more widely spaced (2 in 5 mm) in central and distal part of densely arranged in the Chilean specimen SNGM 568 flank. Antecarinal depression shallow, widening distally, (Pl. 6, Figs. 2, 8), but not in specimens SNGM 569 (Pl. not interrupting ornamentation of flank. 7, Fig. 7) and SNGM 570 (Pl. 7, Fig. 3). Finally, costae dichotomizing near the anterior margin of the flank are Remarks. Jaworskiella sp. is of about the same size as J. present in the type specimen and were described by burckhardti (JAWORSKI 1916), but differs by a less in- LEANZA (1942), LEANZA & GARATE (1987), and LEANZA curved umbo, a straight marginal carina, stronger and (1993). This feature is present in some of the specimens more widely spaced costae of the area, and more regular studied herein (SNGM 569, Pl. 7, Fig. 2), but not in others flank costae; the antecarinal depression is weakly devel- (SNGM 568, Pl. 6, Fig. 2; SNGM 570, Pl. 7, Fig. 1). oped and widening distally. POULTON (1979: 20) compared J. burckhardti with J. siemonmulleri POULTON (1979) and pointed out that the latter is smaller and more regularly ornamented. Genus Quadratojaworskiella REYES & PÉREZ 1980

Jaworskiella sp. Type species. Jaworskiella (Quadratojaworskiella) pus- Pl. 7, Figs. 4-5 tulata REYES & PÉREZ 1980, Early Pliensbachian, northern Material. 1 incomplete left valve (SNGM 567) from Sierra Limón Chile. Verde. Quadratojaworskiella pustulata REYES & PÉREZ 1980 Locality and age. Sierra Limón Verde (locality 3), western flank east of eastern hill, II Región de Antofagasta, earliest Late Sinemurian, Pl. 8, Figs. 1, 4-6, 8; Pl. 9, Figs.1, 5; Pl. 10, Figs. 1-4; Asteroceras obtusum Zone (HILLEBRANDT 2002: 42). Pl. 12, Fig. 10

EXPLANATION OF PLATE 8

Figs. 1, 4-6, 8. Quadratojaworskiella pustulata REYES & PÉREZ 1980. Quebrada Asientos, east of Potrerillos, locality 9; Early/ Late Pliensbachian, Fanninoceras fannini Zone. Figs. 1, 8. SNGM 575 (HILLEBRANDT 660708/8); left valve, x 1.5. 1: interior view; 8: lateral view. Figs. 4-5. SNGM 576 (HILLEBRANDT 660708/8); right valve, x 1.5. 4: interior view; 5: lateral view. Fig. 6. SNGM 573 (HILLEBRANDT 660708/8); left valve, lateral view, x 1.5. Figs. 2, 7. ?Trigonioida indet. Quebrada Pinte, southeast of Vallenar, locality 21; Late Sinemurian. Fig. 2. SNGM 682 (ABERHAN 1992: appendix I + III, horizon 1-26); right valve, lateral view, x 1.5. Fig. 7. SNGM 679 (ABERHAN 1992: appendix I + III, horizon 4-30 B3); left valve, lateral view, x 1.5. Fig. 3. Jaworskiella burckhardti (JAWORSKI 1916). Quebrada Asientos, east of Potrerillos, locality 9; Early/Late Pliensbachian, Fanninoceras fannini Zone. SNGM 572 (HILLEBRANDT 660708/8); right valve, lateral view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 77 78 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

1980 Jaworskiella (Quadratojaworskiella) pustulata sp. nov. (SNGM 573; Pl. 8, Fig. 6). Ornamentation of flank ter- - REYES & PÉREZ: 89-93, pl. 1, figs. 1-4, pl. 2, figs. 1-4. minates at a narrow antecarinal sulcus. Hinge characters 1980 Quadratojaworskiella pustulata (REYES & PÉREZ) - preserved in several specimens (see figures). HILLEBRANDT: pl. 2, fig. 9. 1982 Jaworskiella (Quadratojaworskiella) pustulata REYES & PÉREZ - PÉREZ: pl. 15, figs. 7-10, appendix 1. Remarks. The type specimens together with the specimens 1997 Quadratojaworskiella pustulata REYES & PÉREZ - PÉREZ studied herein exhibit a fair amount of variation in the & REYES: 574. ornamentation of the flank. The course of the smooth Material. 13 specimens from Quebrada Asientos (SNGM 573-584, anterior costae can vary from regular and continuous to 586). SNGM 576-580, 584, 586 (incomplete right valves; 5 with parts irregular and discontinuous; tubercles occur in the anterior of the hinge preserved); SNGM 573-575, 581-583 (incomplete left third of the flank in some specimens and more mesially valves; 3 with parts of the hinge preserved). in others; and the smooth costae and their continuation Locality and age. Quebrada Asientos (locality 9), III Región de as rows of tubercles may have a subconcentric or a Vau- Atacama, Early/Late Pliensbachian, Fanninoceras fannini Zone, gonia-like arrangement. ?horizon with Fanninoceras leptodiscus (HILLEBRANDT 1987: 120; 2006: 14).

Measurements (in mm). Quadratojaworskiella acarinata sp. nov. Specimen valve H L W H/L W/L Pl. 11, Figs. 2-3, 6-7 SNGM 573 lv [64] [75] 19 0.85 0.25 SNGM 578 rv [80] [85] 19 0.94 0.22 1980 Quadratojaworskiella n. sp. - HILLEBRANDT: pl. 2, fig. 10. Description. Shell large-sized, subquadrate. Umbo small, 1997 Quadratojaworskiella n. sp. HILLEBRANDT - PÉREZ & moderately incurved, slightly opisthogyrous. Dorsal REYES: 574. margin straight; anterior margin weakly convex in Derivation of name. From the Latin a (without) and carina (keel), umbonal part, otherwise straight; both margins meet at referring to the absence of a marginal carina. an approximately right angle; posterior margin straight, forming a slightly obtuse angle of ca. 100-110° with Material. 2 right valves from Quebrada Yerbas Buenas (SNGM 585, 587) and 1 incomplete left valve from Quebrada Cachina (SNGM dorsal margin; ventral margin moderately convex. Area 588). occupying one-fourth of the valve surface; ornamented with thin, oblique, partly sinuous and discontinuous Holotype. SNGM 587 (Pl. 11, Fig. 2), right valve with dorsal part of costellae, forming an acute angle with the marginal carina; left valve; anterior and ventral margins are partly preserved. asymmetrically divided by a submedian groove. Marginal Paratypes. SNGM 585 (Pl. 11, Figs. 6-7); SNGM 588 (Pl. 11, Fig. 3). carina blunt, with nodes becoming more distinct toward ventral margin. Internal carina represented by well spaced Localities and age. Quebrada Cachina (locality 5), II Región de Anto- nodes of greater strength than those of marginal carina. fagasta, Middle/Late Hettangian, Sunrisites peruvianus Zone (HILLE- BRANDT 2000b: 126); Quebrada Yerbas Buenas (locality 10), III Región Escutcheon narrow, elongated, smooth. Flank weakly de Atacama, earliest Late Sinemurian, Asteroceras obtusum Zone, A. convex, ornamentation pattern varying in dorsal-ventral obtusum Subzone, horizon with Asteroceras cf. confusum and direction; dorsal quarter of flank with smooth, concentric Arnioceras cf. rejectum (HILLEBRANDT 2002). to subconcentric costae; anterior part of remainder of flank with smooth, declining, sinuous costae, which are Measurements (in mm). replaced by rows of triangular or irregular tubercles on Specimen valve H L W H/L W/L the median and precarinal part of the flank, and which Holotype SNGM 587 2v 51 61 15 0.84 0.25 are subconcentric (SNGM 578; Pl. 9, Figs. 1, 5) or have Paratype a tendency toward a Vaugonia-like ornamentation SNGM 588 lv 52 67 [19] 0.78 0.28

EXPLANATION OF PLATE 9

Figs. 1, 5. Quadratojaworskiella pustulata REYES & PÉREZ 1980. Quebrada Asientos, east of Potrerillos, locality 9; Early/Late Pliensbachian, Fanninoceras fannini Zone. SNGM 578 (HILLEBRANDT 660708/8); right valve, x 1.5. 1: lateral view; 5: interior view. Figs. 2, 4. Psilotrigonia vegaensis sp. nov. Vega Redonda, northeast of Copiapó, locality 11; Late Sinemurian or Early Pliensbachian. Fig. 2. SNGM 590 (HILLEBRANDT 720131/1); left valve, lateral view, x 1.5. Fig. 4. SNGM 591 (holotype) (HILLEBRANDT 720131/ 1); left valve, lateral view, x 1.5. Fig. 3. ?Trigonioida indet. Quebrada Pinte, southeast of Vallenar, locality 21; Late Sinemurian. SNGM 677 (ABERHAN 1992: appendix I + III, horizon 4-30 B3); right valve, lateral view, x 2.25. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 79 80 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Diagnosis. Shell without marginal carina and antecarinal Holotype. SNGM 591 (Pl. 9, Fig. 4), left valve, partially deteriorated sulcus; costae with triangular nodes occupying all of post- at the ventral and posterior margins. umbonal flank surface. Paratypes. SNGM 592 (Pl. 10, Fig. 6); SNGM 593 (Pl. 10, Fig. 5). Locality and age. Vega Redonda (locality 11), III Región de Atacama, Description. Shell large-sized, subquadrate in outline. Late Sinemurian or Early Pliensbachian (HILLEBRANDT, this study). Umbo small, incurved, slightly opisthogyrous. Anterior, Measurements (in mm). dorsal and posterior margins straight, the former two Specimen valve H L W H/L W/L forming an almost right angle, the latter two forming an Holotype obtuse angle of ca. 125°; ventral margin convex near SNGM 591 lv 26 [33] [11] 0.78 0.33 anterior end and weakly convex toward posterior margin. Paratypes Area wide, occupying about one-fourth of the valve sur- SNGM 592 rv 26 - [11] - - SNGM 593 rv 37 49 [13] 0.76 0.26 face; a shallow groove divides area into two assymetrical parts; area of holotype ornamented with fine, oblique, continuous costellae; area of paratype SNGM 588 with Diagnosis. Shell medium-sized; area slightly concave, well developed, widely spaced costellae. Area and flank ornamented with fine, dense costellae, which are strongly meet at an obtuse angle of ca. 130°. Area not separated curved toward the marginal angulation; surfaces of area from flank by carina or marginal angulation. Low, roun- and flank form a slightly obtuse angle; anterior half of ded internal carina with small, widely spaced tubercles. flank ornamented with fine, sinuous costae. Escutcheon wide, extending along all of dorsal margin; only with growth lines. Flank ornamented with smooth, Description. Shell medium-sized, oval. Umbo small, concentric to subconcentric costae in umbonal part, which weakly incurved, located in anterior third of valve. are replaced by rows of small, triangular nodes at early Anterior and ventral margins convex; dorsal margin post-umbonal stages, running parallel to the growth lines; straight; posterior margin moderately convex. Area wide, tubercles more prominent in the remaining three quarters slightly concave, occupying between one-third and one- of flank and occupying all of the flank surface. fourth of the valve surface; ornamented with fine, densely spaced (3 per 2 mm), subconcentric and strongly curved Remarks. Q. acarinata sp. nov. differs from Q. pustulata costellae; area and flank forming a slightly obtuse angle by the absence of both a marginal carina and an antecari- of ca. 103º. Marginal carina poorly developed, replaced nal sulcus, and by the extension of the tubercles of the in large parts of valve by marginal angulation. Escutcheon flank to the anterior margin. poorly preserved. Flank moderately convex; ornamentation of fine (1 mm thick), sinuous costae, restricted to anterior half of flank; costae separated by equally wide Subfamily Psilotrigoniinae FLEMING 1987 interspaces; remainder of shell smooth. Hinge characters

Genus Psilotrigonia COX 1952 not preserved.

Type species. Trigonia beesleyana LYCETT 1874, Bajoc- Remarks. POULTON (1976) separated Psilotrigonia bees- ian-Bathonian, England. leyana (LYCETT 1874: 91, pl. 17, figs. 2-4) and P. cana- Psilotrigonia vegaensis sp. nov. densis POULTON (1976: 45, pl. 8, fig. 1) from the group of species assigned to Psilotrigonia (P.) sanchuensis NAKA- Pl. 9, Figs. 2, 4; Pl. 10, Figs. 5-6; Pl. 12, Fig. 1 NO (1957), T. excentrica PARKINSON (LYCETT 1874), T. 1997 Psilotrigonia sp. - PÉREZ & REYES: 574. semiculta FORBES in STOLICZKA (1871), and T. beyrichi Derivation of name. From Vega Redonda, the type locality of the KRUMBECK (1906) by the presence of a smooth posterior species. part of the flank and diagonal costellae in the distal part Material. 4 incomplete right valves (SNGM 592-595) and 3 incom- of the area. Psilotrigonia vegaensis sp. nov. presents the plete left valves (SNGM 589-595) from Vega Redonda. features typical of the group beesleyana-canadensis, but

EXPLANATION OF PLATE 10

Figs. 1-4. Quadratojaworskiella pustulata REYES & PÉREZ 1980. Quebrada Asientos, east of Potrerillos, locality 9; Early/Late Pliensbachian, Fanninoceras fannini Zone. Figs. 1, 4. SNGM 574 (HILLEBRANDT 660708/8); left valve, x 1.5. 1: interior view; 4: lateral view. Figs. 2-3. SNGM 577 (HILLEBRANDT 660708/8); right valve, x 1.5. 2: interior view; 3: lateral view. Figs. 5-6. Psilotrigonia vegaensis sp. nov. Vega Redonda, northeast of Copiapó, locality 11; Late Sinemurian or Early Pliensbachian. Fig. 5. SNGM 593 (paratype) (HILLEBRANDT 720131/1); right valve, lateral view, x 1.5. Fig. 6. SNGM 592 (paratype) (HILLEBRANDT 720131/1); right valve, lateral view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 81 82 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT differs from P. beesleyana by the anteriorly placed umbo, Localities and age. Quebrada Asientos (locality 9), III Región de a more planate surface of the area, and a more obtuse Atacama, Late Pliensbachian, Fanninoceras fannini Zone, horizon with F. fannini and ?horizon with F. leptodicus (HILLEBRANDT 1987: angle between area and flank. It can be distinguished from 120; 2006: 14). In Neuquén, Argentina, this species is known from P. canadensis by the anteriorly situated umbo, a less ob- the Pliensbachian Otapiria neuquensis Zone (= „Apoderoceras“ to tuse angle between area and flank, and a more pronounced Fanninoceras behrendseni zones) and Radulonectites sosneadoensis marginal angulation. Furthermore, the costellae on the Zone (= Fanninoceras fannini to Fanninoceras disciforme zones) (DAMBORENEA et al. 1992; LEANZA 1993, 1996). area are finer, more densely arranged, and curved toward the marginal angulation. Measurements (in mm). Specimen valve H L W H/L W/L SNGM 596 rv 23 36 13 0.64 0.36 Family Myophorellidae KOBAYASHI 1954 SNGM 603 rv 30 40 12 0.75 0.30 SNGM 609 rv 26 39 12 0.66 0.30 Subfamily Myophorellinae KOBAYASHI 1954 Description. Shell medium-sized, longer than high, ovally Genus Myophorella BAYLE 1878 oblong in outline. Anterior margin moderately convex; Type species. Myophorella nodulosa BAYLE 1878, Late posterior margin short and truncated; dorsal margin con- Jurassic (Oxfordian), France. cave; ventral margin strongly convex in anterior half. Umbo opisthogyrous, located in anterior fifth of shell. Myophorella (Myophorella) araucana (LEANZA 1942) Area narrow, occupying about one-fourth of the shell surface; ornamented with transverse costellae, which are Pl. 11, Figs. 1, 4-5, 8; Pl. 12, Figs. 2-7, 9, 11-12; distinct, widely spaced and weakly convex in the dorsal Pl. 13, Figs. 1, 7 third of the area; remainder of area with finer, transverse

1901 Trigonia aff. angulata SOWERBY - BURCKHARDT: 22, pl. costellae and interspaces with very fine striae. Marginal 4, figs. 5-6. carina high, rounded, and with small tubercles where 1942 Trigonia (Clavitrigonia) araucana sp. nov. - LEANZA: meeting with the costellae of the area, which become more 162, pl. 6, figs. 4-6. distinct toward posterior margin of area. Internal carina 1966 Myophorella (Promyophorella) araucana (LEANZA) - LEVY: 240. less prominent than marginal carina, but with equally 1977 Myophorella (Myophorella) araucana (LEANZA) - PÉREZ strongly developed tubercles. Escutcheon wide, lan- & REYES: 13, 14, pl. 1, figs. 1-3. ceolate, excavated, smooth, extending along all of dorsal 1980 Myophorella catenifera (HUPÉ) - HILLEBRANDT: pl. 2, fig. 4. margin. Flank weakly convex; ornamented with sub- 1982 Myophorella (Myophorella) araucana (LEANZA) - PÉREZ: concentric, fine costae with small tubercles in umbonal pl. 14, fig. 9. part; costae in median part of flank moderately curved 1987 Myophorella (Myophorella) araucana (LEANZA) - toward anterior margin, with well developed tubercles LEANZA & GARATE: pl. 1, figs. 6-8. and with wider intercostal spaces (3 mm in median part 1992 Myophorella (Myophorella) araucana (LEANZA) - DAMBORENEA et al.: pl. 116, fig. 12. of flank, 6 mm at anterior margin); costae stronger and 1993 Myophorella (Myophorella) araucana (LEANZA) - less curved in posterior third of shell, and intercostal LEANZA: 29, pl. 1, figs. 4-5. spaces narrower (2 mm). Antecarinal sulcus widening 1997 Myophorella (Myophorella) araucana (LEANZA) - PÉREZ posteriorly, preventing the direct contact between costae & REYES: 574, 575. and marginal carina. Material. 21 specimens from Quebrada Asientos (SNGM 596-616). SNGM 596, 598-603, 606, 609-610, 615 (right valves, mostly Remarks. With respect to the ornamentation of the area, complete; 2 with partly preserved hinge); SNGM 597, 605, 607, 611, some specimens bear relatively strong and widely spaced 614, 616 (left valves, partly incomplete; 3 with partly preserved hinge); SNGM 604, 608, 612-613 (articulated specimens). costellae in the anterior and median parts (e.g. SNGM

EXPLANATION OF PLATE 11

Figs. 1, 4-5, 8. Myophorella (Myophorella) araucana (LEANZA 1942). Quebrada Asientos, east of Potrerillos, locality 9; Late Pliensbachian, Fanninoceras fannini Zone (F. fannini horizon). Figs. 1, 8. SNGM 600 (HILLEBRANDT 660708/1); right valve, x 1.5. 1: lateral view; 8: interior view. Figs. 4-5. SNGM 605 (HILLEBRANDT 660708/1); left valve, x 2. 4: lateral view; 5: interior view. Figs. 2-3, 6-7. Quadratojaworskiella acarinata sp. nov. Figs. 2, 6-7. Quebrada Yerbas Buenas, north of Vallenar, locality 10; Early Sinemurian, Asteroceras obtusum Zone. Fig. 2. SNGM 587 (holotype) (HILLEBRANDT 680221/2); right valve, lateral view, x 1.5. Figs. 6-7. SNGM 585 (paratype) (HILLEBRANDT 711210/2); right valve, x 1.5. 6: lateral view; 7: interior view. Fig. 3. Quebrada Cachina, south of Taltal, locality 5; Middle/Late Hettangian, Sunrisites peruvianus Zone. SNGM 588 (paratype) (HILLEBRANDT 841112/7); left valve, lateral view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 83 84 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

597, Pl. 13, Fig. 1), whereas in others (e.g. SNGM 596, Description. Shell large-sized, subrectangular-ovate, Pl. 12, Fig. 11; SNGM 601, Pl. 12, Fig. 12) the widely longer than high, strongly inequilateral. Umbo small, spaced costellae are restricted to the anterior part and incurved, opisthogyrous. Anterior margin moderately fine striae are developed between the costellae in the convex; dorsal margin straight, changing to slightly median and distal parts. This variation is also evident in concave at distal end; ventral margin convex; posterior previously figured specimens. Whereas in LEANZA´s margin weakly convex. Area becoming much wider (1942: pl. 6, figs. 4-5) figures the costellae are relatively toward posterior end, due to the curvature of dorsal strong and widely spaced, fine striae between the costellae margin and internal carina; area with subtle submedian are present in the specimen figured by LEANZA (1993: groove; ornamented with fine, dense, transverse striae. pl. 1, figs. 4-5). Marginal carina blunt, narrow (2 mm), with small tubercles from post-umbonal part onwards; in distal part Myophorella (Myophorella) bolitoensis sp. nov. more strongly curved and developing into a marginal Pl. 13, Figs. 2-3, 5-6 angulation. Internal carina blunt, with tubercles becoming more pronounced toward posterior margin. Escutcheon 1980 Myophorella n. sp. - HILLEBRANDT: 130, pl. 2, fig. 3. 1997 Myophorella n. sp. HILLEBRANDT - PÉREZ & REYES: 574. elongated, slightly excavated, relatively wide; with fine growth lines. Flank moderately convex; ornamented with Derivation of name. From Quebrada El Bolito, the type locality of thick (2.5 mm) costae of well developed nodes typical of the species. Myophorella, separated by larger interspaces (4 mm); um- Material. 4 left valves (SNGM 645-648) from Quebrada El Bolito bonal costae subconcentric; first post-umbonal costae (SNGM 645-648). moderately curved toward marginal carina in precarinal Holotype. SNGM 646 (Pl. 13, Fig. 3), left valve, partially incomplete part, forming an obtuse inflection with the anterior branch at the posterior margin. of the costae, which reach the anterior margin at an Paratype. SNGM 645 (Pl. 13, Figs. 2, 5-6) (= HILLEBRANDT 1980: pl. approximately right angle; costae of distal half of flank 2, fig.3). curved in an anterior direction, running subparallel to Locality and age. Quebrada El Bolito (locality 12), III Región de the ventral margin; ontogenetically latest costae weakly Atacama, Early Aalenian, Bredyia manflasensis Zone (HILLEBRANDT curved and running toward ventral margin. Wide ante- & WESTERMANN 1985: 8). carinal sulcus present, which prevents the direct contact Measurements (in mm). of the costae with the marginal carina. Specimen valve H L W H/L W/L Holotype Remarks. M. (M.) bolitoensis sp. nov. attains a larger size SNGM 646 lv 40 65 17 0.61 0.26 than all other species of this genus known from South Paratype SNGM 645 lv 42 63 17 0.67 0.27 America, i.e. M. (M.) catenifera (HUPÉ 1854), M. (M.) araucana (LEANZA 1942), M. clavellata (PARKINSON Diagnosis. Shell large-sized; first post-umbonal costae 1811), M. (M.) cf. tuberculata (AGASSIZ 1840 in LEANZA change their course in the anterior half of the flank, 1993), M. (M.) argentinica (JAWORSKI 1926), M. (M.) forming an obtuse angle between anterior and posterior schulzi LEANZA (1993), M. (Promyophorella) prae- branch of the flank costae; following costae curved in an scabroidea (JAWORSKI 1916), M. (P. ) garatei LEANZA anterior direction, subparallel to the ventral margin. (1981), M. (P. ) hillebrandti REYES & PÉREZ (1985), M.

EXPLANATION OF PLATE 12 Fig. 1. Psilotrigonia vegaensis sp. nov. Vega Redonda, northeast of Copiapó, locality 11; Late Sinemurian or Early Pliensbachian. SNGM 589 (HILLEBRANDT 720131/1); left valve, lateral view, x 1.5. Figs. 2-7, 9, 11-12. Myophorella (Myophorella) araucana (LEANZA 1942). Quebrada Asientos, east of Potrerillos, locality 9; Figs. 2-4, 6, 9: Early/Late Pliensbachian, Fanninoceras fannini Zone; Figs. 5, 7, 11-12: Late Pliensbachian, Fanninoceras fannini Zone (F. fannini horizon). Figs. 2, 6. SNGM 604 (HILLEBRANDT 660708/8); articulated specimen, x 2. 2: dorsal view; 6: left valve view. Fig. 3. SNGM 606 (HILLEBRANDT 660708/8); right valve, lateral view, x 2. Fig. 4. SNGM 609 (ABERHAN 1992: appendix I + III, horizon 2-81); right valve, lateral view, x 1.5. Fig. 5. SNGM 603 (HILLEBRANDT 660708/1); right valve, lateral view, x 1.5. Fig. 7. SNGM 598 (HILLEBRANDT 660708/1); right valve, lateral view, x 2. Fig. 9. SNGM 599 (HILLEBRANDT 660708/8); right valve, lateral view, x 2. Fig. 11. SNGM 596 (HILLEBRANDT 660708/1); right valve, lateral view, x 1.5. Fig. 12. SNGM 601 (HILLEBRANDT 660708/1); right valve, lateral view, x 1.5. Fig. 8. Myophorella (Myophorella) reginae sp. nov. La Guardia, 2.5 km west of Río Jorquera, south of Copiapó, locality 14; Late Toarcian, Pleydellia lotharingica Zone. SNGM 650 (paratype) (HILLEBRANDT 720108/8); left valve, lateral view, x 1.5. Fig. 10. Quadratojaworskiella pustulata REYES & PÉREZ 1980. Quebrada Asientos, east of Potrerillos, locality 9; Early/Late Pliensbachian, Fanninoceras fannini Zone. SNGM 573 (HILLEBRANDT 660708/8); left valve, interior view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 85 86 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

(Haidaia) volkheimeri LEANZA & GARATE (1987), and M. Diagnosis. Medium-sized Myophorella with moderately (H.) elguetai LEANZA (1993), with the exception of strong ornamentation; convex curvature of subumbonal Myophorella (M.) signata of AGASSIZ (1840: 18-19, pl. costae near anterior margin becomes more pronounced 3, fig. 8, pl. 9, fig. 5) but not of GOTTSCHE (1878: 26, pl. in costae of the median and lower part of the flank. 6, figs. 14a-b). In particular, the specimen figured by AGASSIZ (1840: pl. 9, fig. 5) corresponds well with M. Description. Shell medium-sized, ovate, inequilateral. bolitoensis in size and shape and the arrangement of the Umbo small, moderately incurved, opisthogyrous, located last costae in the median part of the flank, which bend in anteriorly. Dorsal margin straight; anterior margin weakly an anterior direction near the ventral margin. In contrast convex; posterior margin straight; ventral margin convex. to M. signata (AGASSIZ 1840), the first post-umbonal Area with narrow submedian groove, dividing area in a costae of M. bolitoensis are irregular anteriorly, and, in dorsal part and a ventral part, the latter being narrower; the precarinal part, are less curved, more widely spaced, ornamentation composed of fine, dense, transverse cos- and terminate at an antecarinal sulcus. In paratype SNGM tellae. Marginal carina low, blunt, curved, with small 645 (Pl. 13, Fig. 2) the costae are more regular. swellings. Internal carina with same characters as marginal carina. Escutcheon wide (4 mm), elongated, without ornamentation. Flank convex; costae with small tubercles, Myophorella (Myophorella) reginae sp. nov. separated by somewhat wider interspaces; umbonal and first post-umbonal costae subconcentric, 1.5 mm in thick- Pl. 12, Fig. 8; Pl. 14, Figs. 1, 3-6, 8 ness, strongly curved toward anterior margin and marginal

1980 Myophorella n. sp. - HILLEBRANDT: 130, pl. 2, fig. 2. carina; anterior branch of median and lower post-umbonal 1997 Myophorella n. sp. HILLEBRANDT - PÉREZ & REYES: 574. costae progressively more convex near anterior margin of flank; precarinal branch of these costae straight, form- Derivation of name. Dedicated to the Argentine palaeontologist Regina ing an acute angle with the marginal carina; distal costae Levi, in honour of her contributions to the systematics of South American species of the bivalve order Trigonioida. of flank straight, divergent, intersecting the ventral margin; most distal costae convex. Narrow antecarinal sulcus Material. 2 specimens from La Guardia (SNGM 649-650) and 3 from becoming better defined in middle and distal parts. Quebrada Plaza (SNGM 653-655). SNGM 649-650, 653-654 (left valves, in part incomplete); SNGM 655 (fragment of right valve). Remarks. Myophorella reginae sp. nov. differs from M. catenifera (HUPÉ 1854: pl. 5, fig. 8; PHILIPPI 1899: pl. 36, Holotype. SNGM 649 (Pl. 14, Figs. 1, 8), left valve with parts of the escutcheon poorly preserved (=HILLEBRANDT 1980: pl. 2, fig. 2). fig. 5) by its more elongated shape, a less convex ventral margin, a less strongly curved marginal carina, median Paratype. SNGM 650 (Pl. 12, Fig. 8). and lower post-umbonal costae that are convex near the anterior margin, and by the absence of bifurcating costae. Localities and age. La Guardia ( locality 14), III Región de Atacama, Late Toarcian, Pleydellia lotharingica Zone (HILLEBRANDT 1987); It can be distinguished from M. araucana (LEANZA 1942: Quebrada Plaza (locality 19), III Región de Atacama, Middle Toarcian, pl. 6, figs. 4-6) by a narrower antecarinal sulcus, finer Phymatoceras toroense Zone? (HILLEBRANDT 1987). and denser ornamentation of the area, more closely spaced flank costae with smaller tubercles, and by median and Measurements (in mm). lower post-umbonal costae, which are more convex near Specimen valve H L W H/L W/L the anterior margin. Compared with M. cf. tuberculata Holotype SNGM 649 lv 27 34 11 0.79 0.32 (AGASSIZ 1840) (in LEANZA 1993: pl. 1, fig. 9), the area is Paratype more finely ornamented, and the post-umbonal costae of SNGM 650 lv 20 25 9 0.80 0.36 the flank are not concentric.

EXPLANATION OF PLATE 13

Figs. 1, 7. Myophorella (Myophorella) araucana (LEANZA 1942). Quebrada Asientos, east of Potrerillos, locality 9; Late Pliensbachian, Fanninoceras fannini Zone (F. fannini horizon). SNGM 597 (HILLEBRANDT 660708/1); left valve, x 2. 1: lateral view; 7: interior view. Figs. 2-3, 5-6. Myophorella (Myophorella) bolitoensis sp. nov. Quebrada El Bolito, northeast of Copiapó, locality 12; Early Aalenian, Bredyia manflasensis Zone. Figs. 2, 5-6. SNGM 645 (paratype) (HILLEBRANDT 670222/11); left valve, x 1.5. 2: lateral view; 5: dorsal view; 6: interior view. Fig. 3. SNGM 646 (holotype) (HILLEBRANDT 670222/11); left valve, lateral view, x 1.5. Figs. 4, 8, 10. Scaphorella susanae sp. nov. Quebrada El Bolito, northeast of Copiapó, locality 12; Late Toarcian, ‘Pleydellia fluitans’ Zone. SNGM 627 (HILLEBRANDT 670222/11); left valve, x 1.5. 4: dorsal view; 8: lateral view; 10: interior view. Fig. 9. Vaugonia hectorleanzai sp. nov. Sierra Limón Verde, south of Calama, locality 3; Late Sinemurian. SNGM 673 (HILLEBRANDT 751211/1a); left valve, interior view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 87 88 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Differences between M. reginae and Myophorella (M.) subconcentric, with radial striae typical of Haidaia; post- sp. 2 (this study) are pointed out below. M. reginae differs umbonal costae diverging from the marginal carina, from the specimen assigned to Trigonia signata AGASSIZ curved in median part of flank and slightly undulating (1840) by GOTTSCHE (1925: 258, pl. 6, figs. 14a-b) by a before meeting the anterior margin at an approximately less convex anterior and a more strongly curved ventral right angle; distal costae diverge slightly and reach the margin, more densely arranged flank costae, narrower ventral margin. intercostal spaces near the marginal carina, and a convex undulation of the median and lower post-umbonal costae Remarks. The shape of the shell and the ornamentation of the flank near the anterior margin. of the flank of the studied specimen exhibit some similarity with Myophorella (M.) tuberculata (AGASSIZ Myophorella (Myophorella) sp. 1 1840), in particular with the specimen figured on his plate

Pl. 14, Figs. 2, 7 9, figs. 6-7, but differs by more densely spaced costae of the flank and a narrower area. The same differences exist Material. 1 incomplete articulated specimen from Quebrada San to Myophorella (M.) cf. tuberculata in LEANZA (1993: Pedrito/Quebrada Pelado (SNGM 663). 29, pl. 1, fig. 9).

Locality and age. Quebrada San Pedrito/Quebrada Pelado (locality 13), III Región de Atacama, Early Aalenian, Bredyia manflasensis Myophorella (Myophorella) sp. 2 Zone (HILLEBRANDT & WESTERMANN 1985: 20). Pl. 14, Fig. 9 Measurements (in mm). Specimen valve H L W H/L W/L Material. 1 left valve from Quebrada Asientos (SNGM 665). SNGM 663 2v 14 22 7 0.64 0.32 Locality and age. Quebrada Asientos (locality 9), Región III de Atacama, Late Pliensbachian, Fanninoceras fannini Zone, horizon Description. Specimen small-sized, trigonal-ovate, longer with F. fannini (HILLEBRANDT 1987: 116; 2006: 14). than high, inequilateral. Umbo small, weakly incurved, Measurements (in mm). slightly opisthogyrous. Dorsal margin weakly concave; Specimen valve H L W H/L W/L anterior margin weakly convex; posterior and ventral SNGM 665 lv 27 36 14 0.75 0.39 margins not preserved. Area narrow (2.5 mm) in median part and 5 mm in distal part; ornamented with thin, trans- Description. Specimen medium-sized, trigonal-ovate, verse costellae, two of which are each connected to a longer than high, strongly inequilateral. Umbo not pre- tubercle of the carinae. Marginal carina low, blunt, with served. Dorsal margin concave; anterior and posterior small tubercles. Internal carina with widely spaced tu- margins moderately convex; ventral margin convex. Area bercles. Escutcheon elongated, excavated, smooth, 2 mm occupying one-fourth of valve; ornamented with fine (5 wide in median part. Anterior half of flank high and per 3 mm), transverse costellae, which thicken toward strongly convex; flank ornamented with thick (1.5 mm) posterior end (3 per 3 mm); intercostal spaces somewhat costae, which bear small tubercles and which are sepa- wider than costae. Marginal carina with medium-sized rated by interspaces of about equal width; umbonal costae tubercles at the contact with the costellae of the area.

EXPLANATION OF PLATE 14 Figs. 1, 3-6, 8. Myophorella (Myophorella) reginae sp. nov. Figs. 1, 4, 5, 8. La Guardia, 2.5 km to the west, Río Jorquera, south of Copiapó, locality 14; Late Toarcian, Pleydellia lotharingica Zone. Figs. 1, 8. SNGM 649 (holotype) (HILLEBRANDT 720108/8); left valve, x 1.5. 1: lateral view, 8: dorsal view. Figs. 4-5. SNGM 653 (HILLEBRANDT 671013/2); left valve, x 2. 4: interior view; 5: lateral view. Figs. 3, 6. Quebrada Plaza, east of Embalse Lautaro, south of Copiapó, locality 19; Middle Toarcian, probably Phymatoceras toroense Zone. SNGM 654 (HILLEBRANDT 671013/2); left valve, x 2. 3: lateral view; 6: hinge. Figs. 2, 7. Myophorella (Myophorella) sp. 1. Quebrada San Pedrito/Quebrada Pelado, northeast of Copiapó, locality 13; Early Aalenian, Bredyia manflasensis Zone. SNGM 663 (HILLEBRANDT 711215/5); articulated specimen, x 2.4. 2: left valve view; 7: right valve view. Fig. 9. Myophorella (Myophorella) sp. 2. Quebrada Asientos, east of Potrerillos, locality 9; Late Pliensbachian, Fanninoceras fannini Zone (F. fannini horizon). SNGM 665 (HILLEBRANDT 660708/1); left valve, lateral view, x 1.5. Figs. 10-14. Scaphorella susanae sp. nov. Quebrada San Pedrito/Quebrada Pelado, northeast of Copiapó, locality 13; Early Aalenian, Bredyia manflasensis Zone. Fig. 10. SNGM 621 (HILLEBRANDT 711215/5); left valve, lateral view, x 1.5. Fig. 11. SNGM 619 (HILLEBRANDT 711215/5); right valve, lateral view, x 2. Figs. 12, 14. SNGM 618 (paratype) (HILLEBRANDT 711215/5); right valve, x 1.5. 12: interior view; 14: lateral view. Fig. 13. SNGM 617 (holotype) (HILLEBRANDT 711215/5); right valve, lateral view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 89 90 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Only distal part of internal carina preserved; tubercles Diagnosis. Outline oval-elongated; anterior margin developed at the contact with the costellae of the area. moderately convex; distal part of area with dense orna- Escutcheon not observable. Anterior part of flank more mentation; marginal carina curved; flank costae bearing convex than posterior part; ornamented with strong (1.5 small tubercles; antecarinal sulcus wide; smooth band mm) costae with tubercles; costae of anterior half of flank between anterior and posterior costae lacking. subconcentric and progressively wider spaced (4 mm) toward anterior end; costae of posterior half straight, Description. Shell medium-sized, oval-elongated, longer divergent toward ventral margin, and with intercostal than high. Umbo small, weakly incurved, opisthogyrous, spaces equalling the width of costae. situated anteriorly. Dorsal margin straight; anterior margin moderately convex; ventral margin convex; posterior mar- Remarks. This specimen has affinities with Myophorella gin slightly convex. Area occupying about one-fourth of (M.) reginae sp. nov. However, the area lacks a submedian the valve surface; ornamented with very fine transverse groove and the costellae are stronger and more widely costellae, which become stronger in the distal half and spaced; the tubercles of the marginal carina are better are separated by interspaces of the same width as the developed; and the costae of the flank are more widely costellae; submedian groove divides area into two spaced, do not become convex at the anterior margin, asymmetrical parts: dorsal one narrower than ventral one, and bear more prominent tubercles. Myophorella (M.) occupying only one-third of the area. Marginal carina sp. 2 differs from Myophorella (M.) araucana by the lack narrow, markedly curved towards umbo; bearing small of an antecarinal sulcus, and by costae which are more tubercles, which are progressively better defined toward subconcentric on the anterior part of the flank and straight posterior end, and which correspond to swellings of the posteriorly. Compared with Myophorella sp. 1, the area costellae of the area. Internal carina of lesser relief, is wider, and the costae of the flank are stronger, more bearing widely spaced tubercles in anterior third, which widely spaced, and bear more prominent tubercles. change into obliquely arranged, clove-shaped swellings medially and posteriorly. Escutcheon elongated, ex- Genus Scaphorella LEANZA, PÉREZ & REYES 1987 cavated, smooth. Flank convex; distinctly demarcated from area by wide and subplanar antecarinal sulcus; Type species. Trigonia leanzai LAMBERT 1944, Middle ornamented with two sets of tuberculated costae. Um- Jurassic (Bajocian-Bathonian), Neuquén, Argentina. bonal costae of anterior fourth of valve subconcentric; Scaphorella susanae sp. nov. post-umbonal costae extending from antecarinal sulcus to anterior margin, sinuous, occasionally dichotomizing. Pl. 13, Figs. 4, 8, 10; Pl. 14, Figs. 10-14; Pl. 15, Figs. 1-2, 4 Posterior three-fourth of flank ornamented with moder- Derivation of name. Dedicated to the Argentine palaeontologist Susana ately retroverse costae, extending from antecarinal sulcus Damborenea, in honour of her valuable contributions to the knowledge to ventral margin. The holotype (SNGM 617; Pl. 15, Fig. of fossil bivalves in South America. 1) preserves tooth 3a (11 mm long, 1.5 mm thick) and Material. 9 specimens from Quebrada San Pedrito/Quebrada Pelado tooth 3b (10 mm long, 1 mm thick). (SNGM 617-624, 626) and 3 specimens from Quebrada El Bolito (SNGM 627-629). SNGM 617-620, 622, 624 (right valves, partly in- Remarks. Scaphorella susanae sp. nov. differs from Sca- complete, 3 with hinge preserved); SNGM 621, 623, 626-629 (left phorella leanzai (LAMBERT 1944: pl. 1, figs. 5-6), the type valves, partly incomplete, 3 with hinge preserved). species of the genus, by its ovally elongated outline, a Holotype. SNGM 617 (Pl. 14, Fig. 13; Pl. 15, Fig. 1), well preserved less convex shell surface, a more strongly curved anterior right valve with hinge. margin, finer and denser ornamentation of the distal part Paratypes. SNGM 618 (Pl. 14, Figs. 12, 14); SNGM 620 (Pl. 15, of the area, a curved marginal carina, and presence of a Figs. 2, 4). wide antecarinal sulcus. The anterior costae of the flank Localities and age. Quebrada El Bolito (locality 12), III Región de are more densely spaced and sinuous, and the costae of Atacama, Late Toarcian, ‘Pleydellia fluitans’ Zone (HILLEBRANDT & the mesial and posterior parts of the flank are more widely WESTERMANN 1985: 8; HILLEBRANDT 1987: 122); Quebrada San Pedrito/ spaced near the marginal carina. Myophorella cf. argo Quebrada Pelado (locality 13), III Región de Atacama, Early Aalenian, Bredyia manflasensis Zone (HILLEBRANDT & WESTERMANN 1985: 20). (POULTON 1979, non CRICKMAY 1930), was considered to be conspecific with Scaphorella leanzai (LAMBERT 1944) Measurements (in mm). by LEANZA et al. (1987). Scaphorella susanae sp. nov. Specimen valve H L W H/L W/L can be distinguished from Scaphorella kruusei (LEANZA Holotype & GARATE 1987: pl. 4, fig. 1) by a moderately convex an- SNGM 617 rv 30 41 13 0.73 0.32 Paratypes terior margin, a finer and denser ornamentation of the SNGM 620 rv 34 43 13 0.79 0.30 area, a curved marginal carina, the presence of an ante- SNGM 618 rv 34 - 14 - - carinal sulcus, and absence of a smooth band between Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 91 the anterior and posterior costae of the flank. It differs Paratype SNGM 632 lv 24 35 9 0.69 0.26 from Scaphorella camachoi (LEANZA 1993: pl. 3, figs. 12-13) by its larger size, a more strongly convex anterior Diagnosis. Shell medium-sized; carinae poorly devel- margin, a more densely ribbed flank both anteriorly and oped; costae smooth and narrow in anterior and median posteriorly, and less strongly developed tubercles. parts of flank, stronger and tuberculated in posterior part. The studied specimens of S. susanae exhibit variations First post-umbonal costae V-shaped; following costae in the anterior ornamentation of the flank. In paratype broadly curved, bending before reaching the anterior mar- SNGM 618 (Pl. 14, Fig. 14), the costae of the anterior gin, a feature which becomes less pronounced ventrally. fourth of the flank are more widely spaced, and the separation between anterior and posterior costae is less well Description. Shell medium-sized, longer than high, defined than in the holotype (Pl. 14, Fig. 13). subrectangular, inequilateral. Umbo small, opisthogyrous, weakly incurved. Anterior margin slightly convex; dorsal margin long and weakly concave; posterior margin short Family Vaugoniidae KOBAYASHI 1954 and straight; ventral margin moderately convex. Area representing about one-fourth of the valve surface; orna- Subfamily Vaugoniinae KOBAYASHI 1954 mented with dense, transverse costellae, becoming more Genus Vaugonia CRICKMAY 1930 irregular and sinuous toward distal end; costellae separated by interspaces of equal width; submedian sulcus Type species. Vaugonia veronica CRICKMAY 1930, Middle Jurassic, British Columbia, Canada. subtle, dividing area into two asymmetrical parts, the dorsal one smaller than ventral one. Marginal carina weakly Vaugonia hectorleanzai sp. nov. developed and with transverse swellings coinciding with the ornamentation of the area. Internal carina defined by Pl. 13, Fig. 9; Pl. 15, Figs. 3, 5-11; Pl. 16, Figs. 1, 3, 8-9, 11-12, 14-15 enlargements of the costae of the area. Escutcheon wide, excavated, elongated, with diagonal striae forming an 1980 Vaugonia n. sp. - HILLEBRANDT: 130, pl. 2, fig. 1. acute angle with dorsal margin. Flank moderately convex; 1981 Vaugonia n. sp. (cf. V. oregonensis POULTON) - HILLE- BRANDT: 30. umbonal costae concentric; first post-umbonal costae V- 1997 Vaugonia n. sp. HILLEBRANDT - PÉREZ & REYES: 575. shaped, forming an acute angle. Anterior branch of sub-

Derivation of name. In honour of the Argentine palaeontologist HÉCTOR sequent costae meeting anterior margin at a right angle, A. LEANZA for his valuable contributions to the knowledge of the undulating and declining toward central part of flank to bivalve order Trigonioida in South America. meet with the ascending posterior branch of costae; Material. 11 specimens from Quebrada Chanchoquín/Paitepén posterior costae stronger, tuberculated, meeting marginal (SNGM 630-640), 3 from Moctezuma (SNGM 641-643), and 2 from carina at an acute angle. Anterior set of ventral costae Sierra Limón Verde (SNGM 644, 673). SNGM 634-635, 637, 642- narrow, undulating or dichotomizing, running parallel to 644 (right valves, partly incomplete, 1 with part of the hinge preserved); SNGM 630, 632-633, 636, 638-639, 641, 673 (left valves, ventral margin and curving into posterior set of costae, some partly incomplete, 1 with hinge preserved); SNGM 631, 640 which are stronger, tuberculated and almost straight, (articulated specimens). before meeting the marginal carina at an acute angle. Para- Holotype. SNGM 631 (Pl. 15, Figs. 5-7), articulated specimen with type SNGM 632 (Pl. 15, Fig. 11) preserves tooth 2 (3.5 incomplete posterior margin (= HILLEBRANDT 1980: pl. 2, fig. 1). mm high, 7 mm long at base), tooth 4a (7 mm long, 1.5 Paratypes. SNGM 632 (Pl. 15, Figs. 3, 10-11); SNGM 644 (Pl. 16, mm thick) and tooth 4b (5 mm long, ca. 1 mm thick). Figs. 8, 14-15). Paratype SNGM 644 (Pl. 16, Fig. 8) exhibits tooth 3a Localities and age. Quebrada Chanchoquín/Paitepén (locality 18b), (ca. 11 mm long, 3 mm thick). III Región de Atacama, Early Toarcian, Dactylioceras hoelderi Zone (HILLEBRANDT & SCHMIDT-EFFING 1981: 30, fig. 11); Moctezuma Remarks. V. hectorleanzai sp. nov. has affinities with (locality 2), II Región de Antofagasta, Early Toarcian, between lime- Vaugonia lycetti (GOTTSCHE 1878) regarding the elongated stones with Late Pliensbachian ammonites (upper part of Fanninoceras outline and the poorly developed carinae. It differs by disciforme Zone, horizon with Protogrammoceras (Argutarpites) cf. less accentuated V-shaped inflections of the flank costae. meneghinii) and limestones with Early Toarcian ammonites (Dactylio- ceras hoelderi Zone?) (PEREZ & LEVY 1961; HILLEBRANDT 2002: 9 and Only the earliest costae form an acute angle, whereas the this study); Sierra Limón Verde (locality 3), II Región de Antofagasta, remaining costae form a wide curvature with an obtuse Late Sinemurian, lower part of Asteroceras obtusum Zone (HILLE- angle of divergence between anterior and posterior sets BRANDT 2002: 42). of costae. Furthermore, the anterior flank costae lack tu- Measurements (in mm). bercles and present a distinct trajectory, being perpen- Specimen valve H L W H/L W/L dicular to the anterior margin and undulating posteriorly Holotype before descending toward the median of the flank. The SNGM 631 2v 28 [38] 11 0.74 0.29 posterior costae are simpler, run parallel to the ventral 92 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT margin and exhibit a weak curvature when approaching Description. Shell (SNGM 652; Pl. 16, Figs. 2, 4) small- the marginal carina. In his description of Trigonia lycetti, sized, longer than high, subrectangular. Umbo opistho- GOTTSCHE (1878: 26, pl. 6, fig. 3a) mentioned the presence gyrous, incurved. Anterior margin moderately convex; of intercalated anterior costae which give rise to an ventral margin convex; dorsal margin weakly concave; irregular bifurcation pattern. The studied specimens of posterior margin straight. Area (SNGM 651-33; Pl. 16, V. hectorleanzai sp. nov. do not exhibit free secondary Figs. 5, 13) 5 mm wide in median part; ornamented with costae, but the holotype (SNGM 631, Pl. 15, Figs. 6, 7) transverse, widely separated costellae, which become fine displays bifurcating anterior costae. striae in median and distal parts of area. Marginal carina In shape and style of ornamentation V. hectorleanzai (SNGM 651-40) formed by row of small tubercles. Inter- sp. nov. resembles V. oregonensis POULTON (1979) from nal carina with transverse swellings, which are more the Upper Pliensbachian of Oregon (POULTON 1979: 23, widely spaced than tubercles of marginal carina. Escutch- pl. 10, figs. 14-19). V. hectorleanzai differs from this eon (SNGM 652; Pl. 16, Fig. 4) elongated, excavated, species by the presence of transverse tubercles on the in- 3.0 mm wide in median part; ornamented with fine radial ternal carina which correspond to expansions of the costae striae (SNGM 651-29). Flank (SNGM 651-33; Pl. 16, of the area. In contrast, the internal carina of V. ore - Fig. 5) moderately convex; with fine, tuberculated costae; gonensis, known from a single specimen only, forms a umbonal costae varying from subconcentric to angular; sharp but simple edge between the area and the es- remaining costae V-shaped, forming a variably acute cutcheon (POULTON 1979: 23). V. hectorleanzai also differs angle; trajectory of anterior set of costae subhorizontal, by more strongly V-shaped costae and by the posterior somewhat curved near the anterior margin; posterior set set of costae bearing small tubercles, which are neither of costae forming an acute angle with the marginal carina. observed on the specimens figured by POULTON nor are Latest posterior costae diverge and reach the ventral mar- mentioned in the text. gin. Antecarinal sulcus developed in distal part of flank.

Remarks. Vaugonia cf. gottschei differs from V. gottschei Vaugonia cf. gottschei (MÖRICKE 1894) (MÖRICKE 1894: pl. 6, figs. 7-8) by a lower number of V- Pl. 16, Figs. 2, 4-6, 13 shaped costae which also are more widely spaced. The latter is also true of the divergent distal costae. The studied cf. 1894 Trigonia gottschei sp. nov. - MÖRICKE: 49-50, pl. 6, figs. 7-8. specimens are similar to Vaugonia exotica (MÖRICKE cf. 1977 Vaugonia (Vaugonia) gottschei (MÖRICKE) - PÉREZ & 1894: pl. 1, fig. 9, pl. 6, fig. 9) regarding the subconcentric REYES: 16-17, pl. 3, fig. 15. umbonal costae of the flank, the intercostal spaces being Material. 42 specimens from Quebrada Las Pircas (SNGM 651(1- wider than the costae, and the presence of an antecarinal 42)) and 1 from Quebrada La Totora/Quebrada El Corral (SNGM sulcus in the distal part of the flank. They differ, however, 652). SNGM 651(11), 651(41) (incomplete right valves); SNGM 651 by the presence of markedly angular costae. (18) (fragment of the flank); SNGM 651(1-10), (12-17), (19-40), (42) (articulated specimens); SNGM 652 (articulated specimen).

Localities and age. Quebrada La Totora/Quebrada El Corral (locality Vaugonia cf. substriata (BURMEISTER & GIEBEL 1861) 17), III Región de Atacama, Late Toarcian (HILLEBRANDT, this study); Pl. 16, Fig. 7 Quebrada Las Pircas (locality 20), III Región de Atacama, Pliensbachian? (HILLEBRANDT, this study). cf. 1861 Trigonia substriata sp. nov. - BURMEISTER & GIEBEL: 24, Measurements (in mm). pl. 2, fig. 4. Specimen valve H L W H/L W/L cf. 1899 Trigonia substriata BURMEISTER & GIEBEL - PHILIPPI: 87, SNGM 651-3 2v 17 27 4.5 0.62 0.17 pl. 36, fig. 10. SNGM 651-3 2v 17 24 4.0 0.71 0.17 cf. 1977 Vaugonia (Vaugonia) substriata (BURMEISTER & GIEBEL) SNGM 652 2v 28 30 6.0 0.93 0.20 - PÉREZ & REYES: 19, pl. 3, fig. 7.

EXPLANATION OF PLATE 15 Figs. 1-2, 4. Scaphorella susanae sp. nov. Quebrada San Pedrito/Quebrada Pelado, northeast of Copiapó, locality 13; Early Aalenian, Bredyia manflasensis Zone. Fig. 1. SNGM 617 (holotype) (HILLEBRANDT 711215/5); right valve, interior view, x 1.5. Figs. 2, 4. SNGM 620 (paratype) (HILLEBRANDT 711215/5); right valve, x 1.5. 2: interior view; 4: lateral view. Figs. 3, 5-11. Vaugonia hectorleanzai sp. nov. Figs. 3, 5-7, 9-11. Quebrada Chanchoquín-Paitepén, southeast of Vallenar, locality 18b; Early Toarcian, Dactylioceras hoelderi Zone. Figs. 3, 10-11. SNGM 632 (paratype) (HILLEBRANDT 671012/5b); left valve, x 2. 3: dorsal view; 10: lateral view; 11: interior view. Figs. 5-7. SNGM 631 (holotype) (HILLEBRANDT 671012/5b); articulated specimen, x 1.5.; 5: dorsal view; 6: right valve, lateral view; 7: left valve, lateral view. Fig. 9. SNGM 633 (HILLEBRANDT 671012/ 5b); left valve, lateral view, x 2. Fig. 8. Moctezuma, south of Calama, locality 2; Early Toarcian. SNGM 641 (HILLEBRANDT 860311/14); left valve, lateral view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 93 94 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Material. 4 variously incomplete right valves (SNGM 656-657, 659, In this species, however, the costae are not sinuous near 661) and 3 incomplete left valves (SNGM 658, 660, 662) from the anterior margin. Quebrada Pinte. Localities and age. Quebrada Pinte (locality 21), Región de Atacama, Vaugonia sp. 1 Middle Toarcian, Collina chilensis Zone (HILLEBRANDT 1987: 120). Pl. 16, Fig. 10 Measurements (in mm). Specimen valve H L W H/L W/L Material. 1 incomplete right valve from Quebrada Plaza (SNGM 664). SNGM 657 rv 31 41 16 0.75 0.39 Localities and age. Quebrada Plaza (locality 19), III Región de Description. Shell (SNGM 657; Pl. 16, Fig. 7) medium- Atacama, Middle Toarcian, Phymatoceras toroense Zone? (HILLEBRANDT 1987). sized, longer than high, subrectangular, inequilateral. Umbo small, opisthogyrous, incurved. Anterior and ven- Measurements (in mm). tral margins moderately convex; dorsal and posterior mar- Specimen valve H L W H/L W/L SNGM 664 rv 18 8 - 2.3 - gins not preserved. Area ocuppying about one-fourth of shell surface; ornamented with transverse striae. Marginal Description. Specimen medium-sized. Umbo small, carina narrow, moderately developed, blunt, with small opisthogyrous. Dorsal margin moderately concave; anter- nodes. Internal carina less developed, with somewhat ior margin weakly convex; ventral and posterior margins more prominent and widely spaced nodes. Escutcheon not preserved. Area occupying abouth one-fourth of the excavated, elongated, smooth; width in median part shell surface; ornamentation partly preserved with a few almost one-half the width of area. Flank moderately weak costellae in anterior third of area. Marginal and in- convex; ornamented with tuberculated costae (1.5-2.0 mm ternal carinae poorly preserved; the former is better devel- thick, interspaces 3.0 mm wide); umbonal costae subcon- oped, narrow and blunt. Escutcheon narrow, excavated. centric; post-umbonal costae weakly sinuous near anterior Flank with high, 1.5 mm wide, tuberculated costae, se- end; distal costae curved, moderately divergent, reaching parated by slightly wider (2 mm) interspaces. Umbonal the ventral margin. costae concentric to subconcentric; subsequent costae becoming more and more L-shaped with a better developed Remarks. Due to the poor preservation of the specimens, set of posterior costae diverging from the carina, and a the majority of which are fragmented and do not preserve less developed anterior set of costae, which bend to meet features of the area, the studied material can only be the anterior margin at a sub-perpendicular angle. Distal referred to V. substriata with reservation. Morphological part of flank not preserved. characters which agree with V. substriata include the elongated shell outline, arrangement of the flank costae Remarks. The single available fragment of a right valve and their undulation near the anterior margin, and the does not preserve sufficient diagnostic characters to allow presence of small tubercles. The specimens can also be an identification at species level. The style of orna- compared to Vaugonia exotica (MÖRICKE 1894) regarding mentation of the flank resembles that of the juvenile the style of ribbing and the development of the tubercles. specimen of Vaugonia lycetti figured by GOTTSCHE (1878:

EXPLANATION OF PLATE 16 Figs. 1, 3, 8-9, 11-12, 14-15. Vaugonia hectorleanzai sp. nov. Figs. 1, 3, 9, 11-12. Quebrada Chanchoquín-Paitepén, southeast of Vallenar, locality 18b; Early Toarcian, Dactylioceras hoelderi Zone. Fig. 1. SNGM 630 (HILLEBRANDT 671012/5b); left valve, lateral view, x 2. Fig. 3. SNGM 637 (HILLEBRANDT 671012/5b); right valve, lateral view, x 1.5. Figs. 9, 12. SNGM 636 (HILLEBRANDT 671012/5b); left valve, x 2. 9: lateral view; 12: interior view. Fig. 11. SNGM 635 (HILLEBRANDT 671012/5b); right valve, lateral view, x 2. Figs. 8, 14-15. Sierra Limón Verde, south of Calama, locality 3; Late Sinemurian, Asteroceras obtusum Zone. SNGM 644 (paratype) (HILLEBRANDT 751211/1a); right valve, x 1.5. 8: interior view; 14: lateral view; 15: dorsal view. Figs. 2, 4-6, 13. Vaugonia cf. gottschei (MÖRICKE 1894). Figs. 2, 4. Quebrada La Totora/Quebrada El Corral, southeast of Vallenar, locality 17; Late Toarcian. SNGM 652 (ABERHAN 1992: appendix I + III, horizon 5-3); articulated specimen, x 1.5. 2: dorsal view; 4: right valve view. Figs. 5-6, 13. Quebrada Las Pircas,southeast of Vallenar, locality 20; Pliensbachian?. Figs. 5, 13. SNGM 651- 33 (HILLEBRANDT 711219/2); articulated specimen, x 2.4. 5: left valve view; 13: right valve view. Fig. 6. SNGM 651-23 (HILLEBRANDT 711219/2); left valve, lateral view, x 2.4. Fig. 7. Vaugonia cf. substriata (BURMEISTER & GIEBEL 1861). Quebrada Pinte, southeast of Vallenar, locality 21; Middle Toarcian, Collina chilensis Zone. SNGM 657 (HILLEBRANDT 670912/2); right valve, lateral view, x 1. Fig. 10. Vaugonia sp. 1. Quebrada Plaza, near El Tránsito, locality 19; Middle Toarcian, probably Phymatoceras toroense Zone. SNGM 664 (HILLEBRANDT 671013/2); right valve, lateral view, x 2. Fig. 16. Vaugonia sp. 2. Quebrada Asientos, east of Potrerillos, locality 9; Early/Late Pliensbachian, Fanninoceras fannini Zone. SNGM 666 (ABERHAN 1992: appendix I + III, horizon 2-81 B3); left valve, lateral view, x 1.5. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 95 96 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT pl. 6, fig. 4). It differs by more widely spaced and less ?Trigonioida indet. angular costae. Pl. 8, Figs. 2, 7; Pl. 9, Fig. 3 Vaugonia sp. 2 1992 Trigoniidae gen. et sp. nov. - ABERHAN: 143, 147.

Pl. 16, Fig. 16 Material. 2 incomplete right valves (SNGM 677, 682) and 4 incom- Material. 1 incomplete left valve from Quebrada Asientos (SNGM plete left valves (SNGM 678-681) from Quebrada Pinte. 666). Localities and age. Quebrada Pinte (locality 21), III Región de Ata- Locality and age. Quebrada Asientos (locality 9), III Región de cama, Late Sinemurian (HILLEBRANDT, this study). Atacama, Late Pliensbachian, Fanninoceras fannini Zone, horizon with F. fannini (HILLEBRANDT 1987: 120; 2006). Measurements (in mm).

Measurements (in mm). Specimen valve H L W H/L W/L Specimen valve H L W H/L W/L SNGM 679 lv [11] 32 [7] 0.34 0.21 SNGM 677 rv [13] 20 [6] 0.65 0.30 SNGM 666 lv 28 49 [11] 0.57 0.22

Description. Specimen medium-sized, subrectangular, Description. Shell medium-sized, subrectangular, oblong, inequilateral. Umbo opisthogyrous. Anterior margin inequilateral. Umbo small, elevated, incurved, weakly moderately convex; ventral margin convex; posterior opisthogyrous. Anterior and ventral margins moderately margin straight; dorsal margin not preserved. Area occu- convex; posterior margin straight; dorsal margin poorly pying about one-fourth of the shell surface. Marginal preserved. Area occupying about one-third of shell carina blunt and apparently without tubercles. Internal surface, forming an obtuse angle with flank; smooth carina less developed, with small tubercles. Escutcheon except for fine growth lines. Marginal carina high, blunt, not observable. Flank moderately convex; post-umbonal smooth, curved toward umbo. Internal carina less de- part ornamented with strong costae, diverging from the veloped. Escutcheon moderately excavated. Flank sub- carina to form a V-shaped to L-shaped inflection in the planate anteriorly and inclined in antecarinal part. anterior half of the flank; toward the anterior margin Anterior part of flank ornamented with concentric, blunt costae continue in a zigzag pattern, which becomes sin- costae of about 1 mm thickness; intercostal spaces be- uous near the ventral margin; diverging costae reaching coming progressively wider than costae ventrally; orna- the ventral margin in the posterior half of the flank; inter- mentation weakening toward marginal carina, developing costal spaces equivalent to the width of the costae near into a wide and smooth precarinal zone. the marginal carina, increasing in anterior and ventral Remarks. The preserved morphological features suggest directions. an assignment to the Trigonioida, although this cannot Remarks. The zigzag pattern of the anterior costae of be confirmed at present, due to the incomplete preserva- Vaugonia sp. 2 is an outstanding feature, which has not tion and lack of information on hinge characters. Presence been observed in any other known species of this genus of a smooth area, a well developed marginal carina, con- in South America. It is only known from some specimens centric costae on the anterior half of the flank, and a wide of Andivaugonia fuenzalidai (REYES & PÉREZ 1984; precarinal zone without ornamentation tentatively suggest SNGM 7436). Andivaugonia is closely related to Vau- the existence of a new taxon within the subfamily Laevi- gonia, but so far is confined to the Lower Bajocian to trigoniinae SAVELIEV 1958. Lower Callovian of Chile and Argentina (LEANZA 1993).

Acknowledgements

We would like to thank F. T. FÜRSICH (Würzburg), H. A. Chile) for the offered facilities. F. MORALES and N. LEANZA (Buenos Aires), and T. P. POULTON (Calgary) for ESPINOZA (Sernageomin), and E. SIEBERT (Berlin) pro- reviewing the manuscript. We also wish to thank the duced the text-figures; W. HARRE (Berlin) and F. GUERRA Servicio Nacional de Geología y Minería (Sernageomin, (Sernageomin) carried out the photographic work.

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Appendix. Localities yielding the trigonioid bivalves decribed in this study, with information on associated faunas and stratigraphic position. See also text-fig. 1.

Locality 1. West of Quillagua (21°39’S; 69°32’W), II Región • Vaugonia hectorleanzai sp. nov. associated with Epophio- de Antofagasta, northern Chile (HILLEBRANDT 2000a, b). ceras sp., Cardinia sp., and Mesomiltha sp. Limestones with • Prosogyrotrigonia tenuis sp. nov. associated with Phylloceras silificied fauna. Late Sinemurian, Asteroceras obtusum Zone chilense, Badouxia canadensis, Badouxia cf. canadensis?, (HILLEBRANDT 2002). Paracaloceras sp., Pseudaetomoceras? sp., Schreinbachites? • Jaworskiella sp. No associated fauna. Sandstone. Late Sine- sp. B, and serpulids (HILLEBRANDT 2000a, b). Grey limestone. murian, Asteroceras obtusum Zone (HILLEBRANDT 2002). Late Hettangian, Badouxia canadensis Zone (Paracaloceras Locality 4. Cerros de Cuevitas (23°34’S; 69°55’W), northeast varaense Subzone) and horizon with Pseudaetomoceras of Antofagasta, II Región de Antofagasta, northern Chile arcuatum (HILLEBRANDT 2000a, b). (HILLEBRANDT 2000a, b). • Prosogyrotrigonia sp. 1. associated with Spiriferina sp., • Prosogyrotrigonia tenuis sp. nov. associated with Coroni- Angulaticeras cf. ventricosum, Phylloceras chilense, bivalves, ceras? sp. A and Angulaticeras cf. ventricosum (HILLEBRANDT and gastropods. Red limestone. Earliest Sinemurian, horizon 2000b). Late Hettangian, Badouxia canadensis Zone, Schlot- with Coroniceras aff. conybeari (HILLEBRANDT 2000a). heimia cuevitensis Subzone (HILLEBRANDT 2000b) and earliest Locality 2. Moctezuma (22°36’S; 68°56’W), south of Calama, Sinemurian, horizon with Coroniceras aff. conybeari (HILLE- II Región de Antofagasta, northern Chile. Pliensbachian- BRANDT 2000a: fig. 2, section 1). Middle Toarcian (PÉREZ & LEVI 1961; HILLEBRANDT 2006). Locality 5. Quebrada Cachina (25°54’S; 70°35’W), south of • Vaugonia hectorleanzai sp. nov. No associated fauna. Taltal, II Región de Antofagasta, northern Chile (HILLEBRANDT Limestone with Thalassinoides. Early Toarcian; between 2000b). limestones with Late Pliensbachian (upper part of Fanninoceras • Quadratojaworskiella acarinata sp. nov. associated with disciforme Zone) ammonites and limestones with Early Psiloceras perezi, Schlotheimia? cachinensis, Plagiostoma sp., Toarcian (probably Dactylioceras hoelderi Zone) ammonites and gastropods. Limestone with ammonites, bivalves, and gas- (HILLEBRANDT this study). tropods (HILLEBRANDT 2000b: 129). Middle/Late Hettangian, Locality 3. Sierra Limón Verde (22º42’S; 68°58’W), eastern Sunrisites peruvianus Zone (HILLEBRANDT 2000b). hill, 17.5 km south of Calama (BAEZA 1976), II Región de Locality 6. Quebrada Doña Inés Chica (26°00’S; 69°10’W), Antofagasta, northern Chile (HILLEBRANDT 2002). northeast of El Salvador, III Región de Atacama (HILLEBRANDT • Prosogyrotrigonia sp. 2. No associated fauna. Sandy 1990: 40; 2002: 46). limestone with silicified trigoniids. Late Sinemurian, Astero- • Prosogyrotrigonia sp. 3. No associated fauna. Sandstone. ceras obtusum Zone (HILLEBRANDT 2002). Late Hettangian or earliest Sinemurian (HILLEBRANDT 2002; 100 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT this study). • Quadratojaworskiella acarinata sp. nov. associated with Locality 7. Quebrada Pan de Azúcar (26°02’S; 70°28,5’W), Caenisites? sp., Asteroceras cf. confusum SPATH, Arnioceras ca. 10 km southwest of Las Bombas, III Región de Atacama. cf. rejectum FUCINI, and Cardinia sp. (HILLEBRANDT 2002: 48). • Frenguelliella poultoni LEANZA 1993 associated with Gram- Section Quebrada Yerbas Buenas, horizon with Asteroceras matodon sp., Gervillia sp., Gervillaria sp., Oxytoma? sp., cf. obtusum (HILLEBRANDT 1973: 175, fig. 1; HILLEBRANDT 1980: Chlamys sp. B., Chlamys sp. C, Weyla? sp., ‘Trigonia’ sp., pl. 2, fig. 10). Late Sinemurian, basal part of Asteroceras obtu- Astarte sp., Cardium sp., Protocardia sp., Pholadomya? sp., sum Zone, Asteroceras obtusum Subzone, horizon with Astero- Pleuromya sp., Cerithium? sp., Arietites sp., Arnioceras sp., ceras cf. confusum and Arnioceras cf. rejectum (HILLEBRANDT and Phylloceras? sp. Pan de Azúcar Formation (NARANJO 2002: 48). 1978); section A, level Afos 7. Sinemurian age based on the Locality 11. Vega Redonda (27°08’S; 69°00’W), northeast of association with Arietites sp. and Arnioceras sp. Copiapó, III Región de Atacama, northern Chile (HILLEBRANDT Locality 8. Portezuelo Pedernales (26°20’S; 69°16’W), north- 1973: 184, fig. 3). east of Potrerillos, III Región de Atacama, northern Chile • Psilotrigonia vegaensis sp. nov. associated with ‘Terebratula’ (HILLEBRANDT & SCHMIDT-EFFING 1981: fig. 2, section 16). sp. and Lithotrochus sp. Limestone. Late Sinemurian or Early • Frenguelliella tapiai (LAMBERT 1944) associated with ‘Rhyn- Pliensbachian (HILLEBRANDT this study). chonella’ sp., ‘Terebratula’ sp., Modiolus sp., Oxytoma sp., Locality 12. Quebrada El Bolito (27°09’S; 69°33’W), north- Mesomiltha cf. huayquimili (LEANZA), Cardinia andium east of Copiapó, III Región de Atacama, northern Chile (HILLE- (GIEBEL), Omphaloptycha sp. (= „Oonia-artige“ in GRÜNDEL BRANDT & SCHMIDT-EFFING 1981: fig. 5). 2001), Cenoceras sp. (HILLEBRANDT & SCHMIDT-EFFING 1981: • Neuquenitrigonia huenickeni (LEANZA & GARATE 1985) and 10), Zetoceras bonarellii (BETTONI), Partschiceras striato- Myophorella (M.) bolitoensis sp. nov. associated with Par- costatum (MENEGHINI), Audaxlytoceras cf. audax (MENEGHINI), ammatoceras sp., Bredyia sp., Terebratula sp., Grammatodon Fanninoceras carlottense MCLEARN, Fanninoceras disciforme sp., Gervilleioperna aurita ABERHAN & HILLEBRANDT, Meso- HILLEBRANDT, Reynesoceras americanum HILLEBRANDT, Rey- miltha cf. bellona (D’ORBIGNY), Mesomiltha sp., Neocrassina nesoceras? sp. A, Arieticeras cf. amalthei (OPPEL), Arieticeras andium (GOTTSCHE), Trigonastarte? steinmanni (TORNQUIST), cf. micrasterias (MENEGHINI), and Arieticeras sp. A. Late Pliens- and Pleuromya sp. (HILLEBRANDT this study). Section Quebrada bachian, Fanninoceras disciforme Zone, horizon with Rey- El Bolito, horizon 12 (HILLEBRANDT & SCHMIDT-EFFING 1981: nersoceras americanum (HILLEBRANDT 2006: 12). 16, fig. 5). Early Aalenian, Bredyia manflasensis Zone (HILLE- Locality 9. Quebrada Asientos (26°27’S; 69°20’W), east of BRANDT & WESTERMANN 1985: 8). Potrerillos, III Región de Atacama, northern Chile (HILLE- • Scaphorella susanae sp. nov. associated with Pleydellia cf. BRANDT & SCHMIDT-EFFING 1981). fluitans DUMORTIER, Neocrassina andium (GOTTSCHE), and • Groeberella neuquensis (GROEBER 1924), Frenguelliella inex- Trigonastarte? steinmanni (TORNQUIST). Section Quebrada El spectata (JAWORSKI 1916), Jaworskiella burckhardti (JAWORSKI Bolito, horizon 11 (HILLEBRANDT & SCHMIDT-EFFING 1981: 16, 1916), Quadratojaworskiella pustulata REYES & PÉREZ 1980, fig. 5). Latest Toarcian, ‘Pleydellia fluitans’ Zone (HILLEBRANDT Myophorella (M.) araucana (LEANZA 1942), Myophorella (M.) & WESTERMANN 1985: 8; HILLEBRANDT 1987: 122). sp. 2, and Vaugonia sp. 2 associated with Andenipora liasica Locality 13. Quebrada San Pedrito/Quebrada Pelado (27°15’S; GERTH, Montlivaltia sp., ‘Rhynchonella’ sp., ‘Terebratula’ sp., 69°40’W), III Región de Atacama, northern Chile (HILLEBRANDT Actinostreon longistriatum (JAWORSKI), Gryphaea cf. dumor- & WESTERMANN 1985: 9). tieri (JOLY), Oxytoma sp., Entolium corneolum (YOUNG & BIRD), • Groeberella neuquensis (GROEBER 1924), Trigonia sp. 3, Myo- Weyla alata (VON BUCH), Weyla titan (MÖRICKE), Modiolus phorella (M.) sp. 1, Scaphorella susanae sp. nov., and Neu- chilensis ABERHAN, Modiolus cf. scalprum (J. SOWERBY), Meso- quenitrigonia huenickeni (LEANZA & GARATE 1985) associated miltha cf. huayquimili (LEANZA), Astartidae gen. et sp. indet., with Bredyia spp., Terebratula sp., Entolium sp., Modiolus Cardinia andium (GIEBEL), Protocardia striatula (J. DE C. sp., Actinostreon sp., Vaugonia sp., Mesomiltha sp., Neo- SOWERBY), ‘Isocardia’ liasina CARRAL TOLOSA, Arcticidae gen. crassina andium (GOTTSCHE), Trigonastarte? steinmanni et sp. indet., Pholadomya corrugata KOCH & DUNKER, Phola- (TORNQUIST), and Myoconcha sp. (HILLEBRANDT this study). domya cf. plagemanni (MÖRICKE), Bucardiomya sp., Pachymya Limestone. Early Aalenian, Bredyia manflasensis Zone (HILLE- rotundocaudata (LEANZA), Pleuromya uniformis (J. SOWERBY), BRANDT & WESTERMANN 1985: 20). Amberleya cf. americana MÖRICKE (ABERHAN & HILLEBRANDT Locality 14. La Guardia (27°42’S; 69°37’W), 2.5 km to the this study), and Striactaeonina transatlantica (BEHRENDSEN) west, Río Jorquera, south of Copiapó, III Región de Atacama, (PEREZ 1982; GRÜNDEL 2001). For a revision of ammonites see northern Chile (HILLEBRANDT & SCHMIDT-EFFING 1981: 23, fig. HILLEBRANDT (2006: 14). Montandón Formation, sections 3, 1, section 14c). 6, 7, level 1 (HILLEBRANDT & SCHMIDT-EFFING 1981: fig. 2, 3 • Myophorella (M.) reginae sp. nov. associated with Gryphaea and section 2 (ABERHAN 1992: fig. 3). Early/Late Pliensbachian, sp., Actinostreon sp., Neocrassina aureliae (FERUGLIO), and Fanninoceras fannini Zone, ?horizon with Fanninoceras lepto- Pleydellia (Walkericeras) cf. lotharingica (HILLEBRANDT & discus and horizon with F. fannini (HILLEBRANDT 2006: 14). SCHMIDT-EFFING 1981: 23). Section Río Jorquera, horizon with Locality 10. Quebrada Yerbas Buenas (27°03’42"S; 69°37’ Pleydellia (Walkericeras) cf. lotharingica (HILLEBRANDT 1980: 12"W), north of Vallenar, III Región de Atacama, northern pl. 2, fig. 2). These horizons overlie the beds with Phyma- Chile (HILLEBRANDT & SCHMIDT- EFFING 1981: fig. 1, section toceras and Phlyseogrammoceras (HILLEBRANDT & SCHMIDT- 9). EFFING 1981: 23). Latest Toarcian, Pleydellia lotharingica Zone Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida 101

(HILLEBRANDT 1987). dolimea duplicata (J. DE C. SOWERBY), Weyla sp., Mesomiltha Locality 15. Hacienda Manflas (28°08’S; 69°58’W), northeast sp., Cardinia sp., Lithotrochus sp., ‘Terebratula’ sp., and of Vallenar, III Región de Atacama, northern Chile (HILLE- ‘Rhynchonella’ sp. Late Sinemurian, horizon with Paltechio- BRANDT & WESTERMANN 1985: 12, locality 4). ceras div. sp. (HILLEBRANDT 1973: fig. 2; 2002: 50). • Neuquenitrigonia huenickeni (LEANZA & GARATE 1985) asso- Locality 18b. Quebrada Chanchoquín/Paitepén (28°47’S; ciated with Mesomiltha sp., Protocardia sp., Neocrassina 70°15’W), southeast of Vallenar, III Región de Atacama, north- andium (GOTTSCHE), Trigonastarte? steinmanni (MÖRICKE), ern Chile (HILLEBRANDT & SCHMIDT-EFFING 1981: 30, fig. 11). Sphaerocoeloceras brochiiformis JAWORSKI, Bredyia man- • Vaugonia hectorleanzai sp. nov. associated with Harpo- flasensis HILLEBRANDT & WESTERMANN, and B. delicata HILLE- ceratoides sp., Bouleiceras chilense HILLEBRANDT, Bouleiceras BRANDT & WESTERMANN (HILLEBRANDT this study). Early cf. chilense HILLEBRANDT, Mesomiltha cf. huayquimili (LEANZA), Aalenian, Bredyia manflasensis Zone (HILLEBRANDT & WESTER- Discohelix sp., Cenoceras sp., and Hildaites sp. (HILLEBRANDT MANN 1985; HILLEBRANDT 2001). & SCHMIDT-EFFING 1981: 30, fig. 11). Section Quebrada Chan- Locality 16. Río Manflas (28°12’S; 70°01’W), northeast of choquín/Paitepén, horizon 5 (HILLEBRANDT & SCHMIDT-EFFING Vallenar, III Región de Atacama, northern Chile (HILLEBRANDT 1981: 30, fig. 11, horizon 5). Early Toarcian, Dactylioceras & SCHMIDT-EFFING 1981: 24, fig. 1, section 16). hoelderi Zone (HILLEBRANDT & SCHMIDT-EFFING 1981: 30, fig. • Jaworskiella gryphitica (MÖRICKE 1894) associated with 11). Spiriferina sp., ‘Rhynchonella’ sp., Gryphaea tricarinata Locality 19. Quebrada Plaza (28º52’23"S; 70º14’18"W), PHILIPPI, Plicatula rapa BAYLE & COQUAND, Cardinia sp., southeast of Vallenar, III Región de Atacama, northern Chile Lithotrochus humboldti VON BUCH, and L. andinus MÖRICKE. (HILLEBRANDT 1973: fig. 2). Section between Río Manflas and Portezuelo El Padre, 130 m • Neuquenitrigonia huenickeni (LEANZA & GARATE 1985), Neu- above the base (HILLEBRANDT & SCHMIDT-EFFING 1981: 24). Late quenitrigonia plazaensis sp. nov., Myophorella (M.) reginae Sinemurian (HILLEBRANDT & SCHMIDT-EFFING 1981: 24). sp. nov., and Vaugonia sp. 1 associated with Phymatoceras Locality 17. Quebrada La Totora/Quebrada El Corral (28°44’S; spp., Trigonastarte? steinmanni (TORNQUIST), Zygopleura cf. 70°15’W), southeast of Vallenar, III Región de Atacama, north- quinetta (PIETTE), and ‘Rhynchonella’ sp. (HILLEBRANDT this ern Chile (ABERHAN 1992: section 4). study). Section Quebrada Plaza, horizon with Phymatoceras • Trigonia sp. 1 associated with Gervillaria hartmanni sp. (ca. 200 m above the base) (HILLEBRANDT 1980: pl. 2, figs. (MÜNSTER), Ctenostreon cf. rugosum (SMITH), Plagiostoma sp., 6-7). Middle Toarcian, probably Phymatoceras toroense Zone Pseudolimea cf. duplicata (J. DE C. SOWERBY), Gryphaea sp., (HILLEBRANDT 1987). Actinostreon solitarium (J. DE C. SOWERBY), Camptonectes Locality 20. Quebrada Las Pircas (28°55’S; 70°22’W), south- auritus (SCHLOTHEIM), Modiolus imbricatus J. SOWERBY, east of Vallenar, III Región de Atacama, northern Chile (HILLE- Vaugonia sp., Mesomiltha cf. huayquimili (LEANZA), Gresslya BRANDT 1973: 184). peregrina (PHILLIPS), Pholadomya fidicula (J. SOWERBY), • Vaugonia cf. gottschei (MÖRICKE 1894) associated with Pleuromya uniformis (J. SOWERBY), trochiform gastropod, Gryphaea sp. and Mesomiltha sp. Marls with Vaugonia and Lobothyris subpunctata (DAVIDSON), and Rhynchonelloidea sp. intercalated, thin-bedded limestones (HILLEBRANDT this study). (ABERHAN this study). Section Quebrada La Totora, horizon 5- Pliensbachian? (HILLEBRANDT this study). 2 (ABERHAN 1992; = level of Collina chilensis in HILLEBRANDT Locality 21. Quebrada Pinte (28°58’S; 70°17’W), southeast & SCHMIDT-EFFING 1981: 29). Middle Toarcian, Collina chilen- of Vallenar, III Región de Atacama, northern Chile (HILLE- sis Zone (HILLEBRANDT this study). BRANDT 1973, fig. 1; ABERHAN 1992: section 6b). • Vaugonia cf. gottschei (MÖRICKE 1894) associated with Cu- • Groeberella neuquensis (GROEBER 1924), Trigonia sp. 1, cullaea cf. rothi LEANZA, Gervillaria hartmanni (MÜNSTER), Trigonia sp. 2, and Vaugonia cf. substriata (BURMEISTER & Ctenostreon cf. rugosum (SMITH), Pseudolimea cf. duplicata GIEBEL 1861) associated with ‘Terebratula’ sp., Plagiostoma (J. DE C. SOWERBY), Plicatula sp., Gryphaea sp., Actinostreon giganteum J. SOWERBY, Pholadomya sp., Pleuromya sp., solitarium (J. DE C. SOWERBY), Modiolus imbricatus J. SOWER- Atacamiceras glabrum HILLEBRANDT, and Catacoeloceras sp. BY, Trigonia sp., Mesomiltha cf. huayquimili (LEANZA), Gress- (HILLEBRANDT this study). Sandy, bioclastic limestone, 336 m lya peregrina (PHILLIPS), Pleuromya uniformis (J. SOWERBY), above the base of the section (HILLEBRANDT 1973: fig. 2; HILLE- ‘Natica’ sp., Lobothyris subpunctata (DAVIDSON), and Rhyn- BRANDT 1987: 124). Middle Toarcian, Collina chilensis Zone chonelloidea sp. (ABERHAN this study). Section Quebrada La (HILLEBRANDT 1987: 120). Totora, horizon 5-3 (ABERHAN 1992). Late Toarcian (HILLE- • Frenguelliella poultoni LEANZA 1993. No associated fauna. BRANDT this study). Late Sinemurian (ABERHAN 1992: Appendix I: 139). Locality 18a. Quebrada Chanchoquín (28º47’S; 70º15’40"W), • ?Trigonioida indet. associated with Anisocardia sp., Bake- between Quebrada Chanchoquín and Quebrada Acevedo, vellia waltoni (LYCETT), Chlamys textoria (SCHLOTHEIM), Cu- southeast of Vallenar, III Región de Atacama, northern Chile cullaea cf. rothi LEANZA, Entolium corneolum (YOUNG & BIRD), (HILLEBRANDT 1973: fig. 2, section to the left, about 140 m Gervillella araucana DAMBORENEA, Actinostreon costatum (J. above the base; HILLEBRANDT 2002: fig. 2b, loc. 21; 2006: fig. DE C. SOWERBY), Modiolus baylei (PHILIPPI), Modiolus gigan- 8). teus QUENSTEDT, Nerinella? sp., Parallelodon hirsonensis • Groeberella neuquensis (GROEBER 1924) associated with (D’ARCHIAC), Placunopsis radiata (PHILLIPS), Plagiostoma sp., Gryphaea tricarinata PHILIPPI, Actinostreon costatum (J. DE Pseudolimea duplicata (J. DE C. SOWERBY), Protocardia sp., C. SOWERBY), Pseudolimea duplicata (J. DE C. SOWERBY), Pseu- Pteriacea gen. et sp. indet., Quenstedtia? sp., Unicardium sp., 102 ERNESTO PÉREZ, MARTIN ABERHAN, RENATO REYES & AXEL VON HILLEBRANDT

Weyla alata (VON BUCH), and Lucina chubutensis WANISH. Late ganteum J. SOWERBY, Plagiostoma sp., Weyla alata (VON BUCH), Sinemurian (HILLEBRANDT this study). Weyla unca (PHILIPPI), Natica philippii MÖRICKE, Natica catan- Locality 22. Eastern Punilla (eastern flank) (29°40’S; 70° lilensis WEAVER, Nerinea sp., Isocardia? sp., Astarte? sp., and 16’W), northeast of La Serena, IV Región de Coquimbo, north- Phymatoceras lillii (HAUER). Section Punilla, lower level ern Chile (THIELE 1964). (collection THIELE 1964: 196-197; ABERHAN & HILLEBRANDT • Jaworskiella burckhardti (JAWORSKI 1916) associated with 1996: figs. 1, 2). Late? Pliensbachian (HILLEBRANDT this study). Trigonia stelzneri GOTTSCHE, ‘Terebratula’ domeykana BAYLE Locality 23. Quebrada del Pobre (32°25,5’S; 71°12’W), north- & COQUAND, ‘Terebratula’ sp., ‘Rhynchonella’ tetraedra east of La Ligua, V Región de Valparaíso, central Chile. SOWERBY, ‘Rhynchonella’ cf. aenigma D’ORBIGNY, ‘Rhyn- • Jaworskiella gryphitica (MÖRICKE 1894) associated with chonella’ sp., Pleuromya jurassi AGASSIZ, Pleuromya sp., Car- Paltechioceras sp. Quebrada del Pobre Formation (THOMAS dinia domeykoi PHILIPPI, Pholadomya fidicula J. DE C. SOWERBY, 1958). Late Sinemurian, Echioceras raricostatum Zone (HILLE- Modiolus scalprum J. SOWERBY, Mesomiltha payllalefi LEANZA, BRANDT 2002: 52). ‘Lucina’? sp., ‘Arctica’? sp., Protocardia sp., Plagiostoma gi- Seit 1989 geben die Freunde der Würzburger Geowissenschaften e. V. unter der Schriftleitung der Institute für Paläontologie und Geologie die Zeitschrift Beringeria heraus. Beringeria steht vor allem größeren Artikeln aus allen Bereichen der Geowissenschaften offen. Pro Jahr erscheinen mindestens zwei Hefte. Interessenten wenden sich an: Freunde der Würzburger Geowissenschaften e. V., Pleicherwall 1, 97070 Würzburg, oder E-Mail: [email protected]. Beringeria ist zu beziehen zum Selbstkostenpreis (für Mitglieder der Freunde der Würzburger Geowissenschaften e. V.; derzeitiger Jahresbeitrag • 12,—, für Studenten • 6,—) zum Subskriptionspreis (25 % Rabatt auf den Einzelpreis) zum unten angegebenen Einzelpreis im Schriftentausch

Bereits erschienen:

Beringeria 1 (1989): J. STEPANEK & G. GEYER: Spurenfossilien aus dem Kulm (Unterkarbon) des Frankenwaldes. W. HAMMANN, C. HEUNISCH & U. SCHÜSSLER: Organische Mikrofossilien aus dem Unterdevon des Frankenwaldes. G. GEYER. Late Precambrian to early Middle Cambrian Lithostratigraphy of southern Morocco. 143 S., 12 Taf., 17,— • Beringeria 2 (1990): SHANCHI PENG. Tremadoc stratigraphy and trilobite faunas of northwestern Hunan (China). 172 S., 33 Taf., 20,— • Beringeria 3 (1990): G. GEYER: Die marokkanischen Ellipsocephalidae (Trilobita: Redlichiida). 363 S., 56 Taf., 30,— • Beringeria 4 (1991): M. HEINZE: Evolution benthonischer Faunengemeinschaften im Jura des Pariser Beckens. J. YIN & F. T. FÜRSICH. Jurassic bivalves from the Tanggula Mountains, W-China. J. H. SHERGOLD & K. SDZUY. Late Cambrian trilobites from Spain. 235 S., 16 Taf.; 25,— • Beringeria 5 (1992): M. ABERHAN. Benthische Faunengemeinschaften im Unterjura von Chile. 174 S., 2 Taf., 22,— • Beringeria 6 (1992): W. HAMMANN. The Ordovician trilobites of the Cystoid Limestone of Aragón, NE-Spain. 219 S., 37 Taf., 27,— • Beringeria 7 (1993): W.-P. FRIEDRICH: Systematik und Funktionsmorphologie mittelkambrischer Cincta (Carpoidea). 190 S., 24 Taf.; 27,— • Beringeria 8 (1993): D. K. PANDEY & F. T. FÜRSICH. Contributions to the Jurassic of Kachchh, western India. I. Jurassic corals of Kachchh (W-India). G. G EYER. The giant Cambrian trilobites of Morocco. A. D’ALESSANDRO & A. DE MARCO. Bionomic analysis of two Upper Pliocene communities from southern Italy. JINGENG SHA & F. T. FÜRSICH. Non-marine (Lower Cretaceous) bivalves of eastern Heilongjiang (northeastern China). K. SDZUY. Early Cincta (Carpoidea) from the Middle Cambrian of Spain. 207 S., 32 Taf.; 30,— • Beringeria 9 (1994): W. OSCHMANN: Der Kimmeridge Clay als Beispiel eines fossilen Sauerstoff-kontrollierten Milieus. 153 S., 16 Taf.; 29,— • Beringeria 10 (1994): Z. VAŠÍÈEK, J. MICHALÍK & D. REHÁKOVÁ. Early Cretaceous stratigraphy, palaeogeography and life in western Carpathians. 169 S., 30 Taf.; 35,— • Beringeria 11 (1994): H. HÜSSNER. Reefs, an elementary principle with many complex realizations. 99 S., 11 Taf.; 30,— • Beringeria 12 (1994): JINGENG SHA & F. T. FÜRSICH. The Late Jurassic and Early Cretaceous buchiid fauna of eastern Heilongjiang (northeastern China). F. T. FÜRSICH et al. Contributions to the Jurassic of Kachchh, western India. II. Bathonian of Sadhara Dome, Kachchh. 125 S., 11 Taf.; 27,— • Beringeria 13 (1994): M. ABERHAN. Early Jurassic Bivalvia of northern Chile. Part I. Subclasses Palaeotaxodonta, Pteriomorphia, and Isofilibranchia. 115 S., 28 Taf.; 27,— • Beringeria 14 (1995): H. MUSTER: Taxonomie und Paläobiogeographie der Bakevelliidae (Bivalvia). 161 S., 17 Taf.; 32,— • Beringeria 15 (1995): A. UCHMAN. Taxonomy and palaeoecology of flysch trace fossils (Miocene, northern Apennines, Italy). 115 S., 16 Taf.; 30,— • Beringeria 16 (1995): CHUNLIAN LIU. Jurassic bivalve palaeobiogeography of the Proto-Atlantic and the application of multivariate analysis methods to palaeobiogeography. D. K. PANDEY & J. CALLOMON. Contributions to the Jurassic of Kachchh, western India. III. Middle Bathonian ammonite families Clydoniceratidae and Perisphinctidae from Pachchham Island, India. A. K. JAITLY, F. T. FÜRSICH & M. HEINZE. Contributions to the Jurassic of Kachchh, western India. IV. The bivalve fauna. Part I. Subclasses Palaeotaxodonta, Pteriomorphia, and Isofilibranchia. W. METTE. Ostracods from the Middle Jurassic of southern Tunisia. 348 S., 60 Taf.; 63,— • Beringeria 17 (1996): U. DITTMAR: Profilbilanzierung und Verformungsanalyse im SW’ Rheinischen Schiefergebirge. 346 S., 15 Taf.; 63,— • Beringeria 18 (1996): M. PATZAK: Die Metabasite der KTB-Vorbohrung: Petrographie, Mineralchemie, Geochemie und PT-Bedingungen. D. K. PANDEY, F. T. FÜRSICH & M. HEINZE. Contributions to the Jurassic of Kachchh, western India. V. The bivalve fauna. Part II. Subclass Anomalodesmata. G. G EYER. Moroccan fallotaspidid trilobites revisited. Y. ALMÉRAS & S. ELMI. Le genre Cymatorhynchia BUCKMAN (Brachiopoda) dans le Bajocien- Bathonien de la bordure vivaro-cévenole (Bassin de Sud-Est, France). 245 S., 15 Taf.; 59,— • Beringeria 19 (1997): H. GRILL. The Permo-Carboniferous glacial to marine Karoo record in southern Namibia. 98 S., 1 Taf.; 38.— • Beringeria 20 (1997): W. HAMMANN & F. LEONE. Upper Ordovician trilobites of southern Sardinia. Part I. 218 S., 32 Taf., 59,— • Beringeria 21 (1998): J. SHA, F. T. FÜRSICH, P. L. SMITH & L. WAN. Palaeotaxodonta, Pteriomorphia, and Isofilibranchia (Bivalvia) from the Jurassic of the Tanggula Mountains, China. M. ABERHAN. Early Jurassic bivalves of western Canada. Subclasses Palaeotaxodonta, Pteriomorphia, and Isofilibranchia. F. T. FÜRSICH & M. HEINZE. Contributions to the Jurassic of Kachchh, western India. VI. The bivalve fauna. Part III. Order Trigonioida. 168 S., 32 Taf.; 50,— • Beringeria 22 (1998): S. HOLZAPFEL: Palökologie benthischer Faunengemeinschaften und Taxonomie der Bivalven im Jura von Südtunesien. 200 S., 11 Taf.; 54,— • Beringeria 23 (1999): F. AHMAD. Middle Jurassic macroinvertebrates from Jordan. B. NIEBUHR. Cyclostratigraphic correlation of Middle Campanian marl/limestone rhythmites of North Germany. C. GAUCHER & P. SPRECHMANN. Upper Vendian skeletal fauna of the Arroyo del Soldado Group, Uruguay. A. NÜTZEL & B. SENOWBARI-DARYAN. Gastropods from the Late Triassic Nayband Formation of central Iran. 132 S., 28 Taf.; 43,— • Beringeria 24 (1999): B. V. RÜTZEN-KOSITZKAU. Ökologie, Taphonomie und Biogeographie des hartteiltragenden Makrobenthos im Tiefwasser des Roten Meeres. 150 S.; 47,— • Beringeria 25 (1999): SHANCHI PENG, G. GEYER & B. HAMDI. Trilobites from the Shahmirzad section, Alborz Mountains, Iran. A. UCHMAN. Ichnology of the Rhenodanubian Flysch (Lower Cretaceous-Eocene) in Austria and Germany. 173 S. 20 Taf.; 54,— • Beringeria 26 (2000): C. GAUCHER. Sedimentology, palaeontology, and stratigraphy of the Arroyo del Soldado Group (Vendian to Cambrian, Uruguay). 120 S., 21 Taf.; 42,— • Beringeria 27 (2000): D. K. PANDEY, F. AHMAD & F. T. FÜRSICH. Middle Jurassic scleractinian corals from northwestern Jordan. A. K. JAITLY, J. SZABÓ & F. T. FÜRSICH. Contributions to the Jurassic of Kachchh, western India. VII. The gastropod fauna. Part I. Pleurotomarioidea, Fissurelloidea, Trochoidea and Eucycloidea. F. T. FÜRSICH, M. HEINZE & A. K. JAITLY. Contributions to the Jurassic of Kachchh, western India. VIII. The bivalve fauna. Part IV. Subclass Heterodonta. 146 S., 29 Taf.; 47,— • Beringeria 28 (2001): A. UCHMAN. Eocene flysch trace fossils from the Hecho Group of the Pyrenees, northern Spain. G. DELVENE. Middle and Upper Jurassic bivalves from the Iberian Range, Spain. 105 S., 22 Taf.; 42,— • Beringeria 29 (2001): M. HAUTMANN: Die Muschelfauna der Nayband Formation (Obertrias, Nor - Rhät) des östlichen Zentraliran. 181 S., 37 Taf.; 63,— • Beringeria 30 (2002): F. HOLZFÖRSTER. Sedimentology, stratigraphy and synsedimentary tectonics of the Karoo Supergroup, N-Namibia. 144 S.; 48,—• Beringeria 31 (2002): M. GAHR: Palökologie des Makrobenthos aus dem Unter-Toarc SW-Europas. 204 S., 7 Taf.; 72,—• Beringeria 32 (2003): D. K. PANDEY & F. T. FÜRSICH. Jurassic corals of east-central Iran. 138 S., 40 Taf.; 48,—• Beringeria 33 (2003): H. SCHOLZ. Taxonomy, ecology, ecomorphology, and morphodynamics of the Unionoida (Bivalvia) of Lake Malawi (East- Africa) 86 S., 8 Taf.; 34,—• Beringeria 34 (2004): W. METTE. Jurassic diversity and distribution of ostracods in Gondwana. W. METTE & M. GEIGER. Bajocian to Kimmeridgian ostracoda of south-west Madagascar. M. ABERHAN. Early Jurassic Bivalvia of northern Chile. Part II: Subclass Anomalodesmata. 154 S., 31 Taf.; 54,—• Beringeria 35 (2005): H. SCHOLZ:. Taxonomie der Muschelfauna aus dem Oberjura von Hildesheim (Norddeutschland). F. T. FÜRSICH, M. HAUTMANN, B. SENOWBARI-DARYAN & K. SEYED-EMAMI. The Upper Triassic Nayband and Darkuh formations of east-central Iran. 135 S., 20 Taf.; 52,—• Beringeria 36 (2006): G. El Qot. Late Cretaceous macrofossils from Sinai, Egypt. 163 S., 34 Taf.; 62,—• Beringeria 37 (2007): Micellanea Wirceburgensis - Franz T. Fürsich zum 60. Geburtstag (mit 21 Einzelbeiträgen). VI+266 S., 126 Abb., 14 Taf.; 75,—• Beringeria 38 (2007): W. HAMMANN & F. LEONE. Upper Ordovician trilobites of southern Sardinia. Part II. 138 S., 22 Taf.; 58,—• Beringeria 39 (2007): M. R. MAJIDIFARD. Stratigraphy and facies analysis of the Dalichai and Lar formations (Middle - Upper Jurassic) of NNE Iran. E. PÉREZ, M. ABERHAN, B. R. REYES & A. VON HILLEBRAND. Early Jurassic bivalvia of northern Chile. 102 S. 29 Taf.; 48,—•

Sonderhefte:

Beringeria Sonderheft 1 (1990): K.-P. KELBER: Die versunkene Pflanzenwelt aus den Deltasümpfen Mainfrankens vor 230 Millionen Jahren. 67 S., 100 Abb. (vergriffen!) Beringeria Sonderheft 2 (1995). G. GEYER & E. LANDING (Hrsg.). Morocco ‘95. The Lower-Middle Cambrian standard of western Gondwana. 269 S., 8 Taf.; 48,—• Beringeria Sonderheft 3 (1999): H. W. FISCHER: Wissenschaftliches Zeichnen und Illustrieren. 202 S.; 19,90,—• Beringeria Sonderheft 4 (2003):D. KLEINSCHROT: Meteorite – Steine, die vom Himmel fallen. 89 S., 27 Abb.; 10,—• Beringeria Sonderheft 5, Teil I (2005): J.B.A. BERINGER & G.L. HUEBER. Lithographiae Wirceburgensis. Nachdruck der 1. Aufl. von 1726. 98+1 S., 22 Taf.; 45,—• Beringeria Sonderheft 5, Teil II (2005): B. NIEBUHR &. G. GEYER. Die Würzburger Lügensteine: 493 Corpora Delicti zwischen Dichtung und Wahrheit. 188 S., 506 Fig.; 25,—• Beringeria Sonderheft 6 (2006). G. GEYER & E. LANDING. Morocco 2006 - Ediacaran-Cambrian depositional environments and stratigraphy of the western Atlas regions. 120 S., 42. Abb.; 30,—•

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