Ordovician Echinoderms of Argentina

Guillermo F. ACEÑOLAZA1 and Juan Carlos GUTIÉRREZ-MARCO2

Abstract: ORDOVICIAN ECHINODERMS OF ARGENTINA. The record of Ordovician echinoderms in Argentina is restricted to the Pelmatozoans, and has not been deeply studied yet. They commonly appear as fragmentary samples represented by isolated ossicles as thecal plates and columnals with the exception of a single locality with few complete specimens. Among the recognized taxa are: Macrocystella sp., Macrocystella? durandi Aceñolaza and Lingulocystis cf. elongata Thoral. In addition, a variety of unidentified stem and cup plates from six new localities of the Cordillera Oriental, the Famatina System and the Precordillera are illustrated. An early radiation of the group is inferred from the Central Andean Basin, with a posterior migration to other sectors of Gondwana.

Resumen: EQUINODERMOS ORDOVÍCICOS DE ARGENTINA. El registro de equinodermos ordovícicos en la República Argentina está limitado a los pelmatozoos, sin que se haya abordado aún el estudio detallado de los mismos. Los fósiles suelen aparecer fragmentariamente como placas tecales aisladas y segmentos columnares, siendo escasos los ejemplares completos. Entre los taxa reconocidos se cita a Macrocystella sp.; Macrocystella? durandi Aceñolaza y Lingulocystis cf. elongata Thoral. Complementando al conocimiento de los pelmatozoos ordovícicos, se figura material de algunas nuevas localidades fosilíferas de la Cordillera Oriental, así como del Sistema de Famatina y la Precordillera. En base a su registro cronoestratigráfico desde el Cámbrico Superior en las plataformas de la Cuenca Central Andina, se plantea una posible radiación temprana del grupo en la región, con una posterior migración hacia otros sectores en el margen Gondwánico.

Key words: Echinodermata. Rhombifera. Eocrinoidea. Pelmatozoans. Ordovician. Argentina.

Palabras clave: Equinodermos. Rhombifera. Eocrinoidea. Plematozoos. Ordovícico. Argentina.

Introduction

Echinoderm evolution started during Cambrian times, becoming the pelmatozoans common elements in mid to high latitude Ordovician seas (Sprinkle, 1995). Platforms covering the western margin of Gondwana were no exception to the early referred trend, so fossils are found generally as fragmentary samples within siliciclastic rocks (sandstones and shales) and limestones.

It is well known the large outcrops of Ordovician sedimentary rocks in Argentina, as well as its abundant fossiliferous content. We must highlight the thick Cambro-Ordovician clastic sequences, of over 9.000 meters, outcropping in the Cordillera Oriental of NW Argentina, and the Cambro- Ordovician limestone sequences that characterize the Precordillera of Western Argentina (Bordonaro, 1992; Aceñolaza, 1992; Astini et al., 1995; Aceñolaza and Toselli, 1999; Aceñolaza et al., 1999; Peralta, 2000 with references).

Although echinoderm debris are common in the above mentioned strata, only one locality yielded so far complete echinoderm specimens, coming from Arenig strata in the Cordillera Oriental of northern Argentina (Gutiérrez-Marco and Aceñolaza, 1999) (Fig. 1 C, 2 G-I).

A variety of stem fragments with distinctive columnal or pluricolumnal morphology tell us about an extensive echinoderm fauna that inhabited the South American margin of Gondwana during the Ordovician. Due to the fragility of their morphological elements, most commonly highly disarticulated, and to the fact that they have been regularly considered as “complementary fauna”, the knowledge of the Argentine Ordovician echinoderms is scarce but promising.

History of research

Kayser (1876; Spanish version of 1925) is the first author who mentions the occurrence of “cylindrical articulations of a few millimeters of thickness” in the “Lower Silurian” limestones (“calizas infrasilurianas”) of Huaco, Precordillera of San Juan. The figured specimens lack any diagnostic elements and are unrecognizable/undeterminable. Harrington (1937, 1938) presents the first description with figures of stem fragments from different Tremadocian and Arenig localities from the Cordillera Oriental of Northwestern Argentina (San Bernardo Hill in the province of Salta, and Coquena and Chalala creeks in the provinces of Jujuy). In both publications, Harrington identified these echinoderms remains in open nomenclature, describing them as “Cystoidea gen. sp. indet.”.

In a same manner, Loss (1951) mentions the existence of small fragments of cylindrical stem of five elements that belong to “Cistoidea gen. et sp. ind.” (sic), from sandstones and shales outcropping in the locality of Portezuelo, south of San Bernardo Hill (Salta). Later, Turco Greco and Zardini (1984) describe from the wakes and shales of the Don Polo Formation, an isolated thecal plate without precise taxonomic atribution. The first paper focusing specifically on Argentine Ordovician Echinoderms is due to F.G. Aceñolaza (1986) who described and figured different thecal plates and stem fragments assigned to the genus Macrocystella, an early rhombiferan coming from three localities in the Cordillera Oriental (Alto de la Sierra and Santa Victoria in Salta and Sapagua in Jujuy). Recently, G.F. Aceñolaza (1999) introduces the new species M.? durandi Aceñolaza from Tremadocian rocks of the Jujuy province, summarizing the record of the genus in Argentina and presenting new localities from the Cordillera Oriental.

Localities, material and biostratigraphical framework

(Fig. 1 A 1-16)

Cordillera Oriental:

* Jujuy province: Cajas Range, Zenta Range, Sapagua, Alfarcito, Punta Corral, Huichaira, Chucalezna, Purmamarca, Coquena and Chalala creeks: Thecal plates assigned to Macrocystellids and undifferentiated stem fragments (columnals and pluricolumnals) in the Lower Ordovician shales and sandstones of the Santa Rosita Formation. Fossils are included in the range of the Parabolina (N.) frequens argentina, Kainella meridionalis trilobite biozones (Tremadocian) and of the Upper Tremadocian/Arenig Notopeltis orthometopa trilobite Biozone (Fig. 1, A 1-10, B; Fig. 2, B-C and E).

* Salta province: La Quesera locality, Parcha area and Mojotoro Range: Thecal plates of Macrocystella sp. thecal plates, associated to undeterminable columnals and pluricolumnals in all localities (Fig 1, A 11-13; Fig. 2, K, M). Lingulocystis cf. elongata Thoral was reported by Gutiérrez-Marco and Aceñolaza (1999) from the Mojotoro Range, within the greenish sandstones and shales of the San Bernardo Formation (Harrington in Harrington and Leanza, 1957 (Fig. 1, A 13, C; Fig. 2, G-J). Lingulocystis is accompanied by a rich graptolite assemblage belonging to the association IX of Moya et al. (1994) with Araneograptus murrayi, Clonograptus flexilis, Tetragraptus lavalensis, “Didymograptus v-fractus”, “D. nitidus” and “D. vacillans” among others (Loss, 1951; Harrington and Leanza, 1957; Moya et al., 1994

with references). Thysanopyge argentina, Megalaspidella (Kayseraspis) asaphelloides, Megalaspidella (Kayseraspis) brackebuschi, Nannopeltis modesta, Nanorthis grandis and Sanbernardaspis pygacantha conform the coeval trilobite association, indicative of the Megalaspidella (K.) asaphelloides Biozone (Harrington and Leanza, 1957; Aceñolaza, 1973; Moya et al., 1994).

Associated to the above mentioned fossils, an abundant ostracod fauna is also recorded, with Zygobolba asapha, Drepanellina ericksoni, Bernardite longisulcus, Bernardite asapha, Saltite erichseni, Saltite saltensis and Nortite elongatum (Harrington, 1938; García and Proserpio, 1976).

Famatina System:

Ordovician echinoderms in the Famatina System have only been mentioned from the province of Catamarca, at the locality of Chaschuil (Sierra de Narváez). Fragmentary plematozoan stems grouped and isolated columnals frequently appear in the middle sector of the Arenig Suri Formation.

No complete specimens or thecal plates have been recorded from the unit. Fossils are recognized within the Merlinia megacanta and Baltoniodus navis trilobite and conodont biozones, respectively (Harrington and Leanza, 1957; Aceñolaza and Toselli, 1977; Benedetto, 1994; Albanesi and Vaccari, 1994; Vaccari and Waisfeld, 1994 and Gutiérrez-Marco et al., 2000 with references) (Fig. 1, A 14).

Figure 1. A. Location map of Ordovician Echinoderm occurrences in Argentina. B. Reconstruction of Macrocystella cf. mariae Callaway. C. Reconstruction of Lingulocystis elongata Thoral (after Ubaghs, 1960).

Two localities have been recognized. a) Huaco, a classical Ordovician locality in western Argentina from where Kayser (1876) mentioned “cylindrical articulations of a few milimeters of thickness” within grey and whitish limestones. Material from Huaco has never been studied in detail and there is no record of complete samples from the locality (Fig. 1, A 15; Fig. 2, L). b) Quebrada del Carrizalito, where Turco Grecco and Zardini (1984) described an isolated thecal plate from the Don Polo Formation cropping out in the northeastern sector of the Sierra del Tontal (vicinity of Calingasta Village). In a general sense the plate resembles a rhombiferan low relief Macrocystella type. The absence of a repository for the described material did not allow the revision of the original specimen (Fig. 1, A 16; Fig. 2, F ). No other fossils have been recorded from Don Polo Formation, which has been interpreted to be partially equivalent to methamorphosed facies of the Llanvirn-Caradoc Alcaparrosa Formation (Bordonaro, 1999).

Description of material

Repository: Material described herein is housed in the invertebrate paleontological collection of the Facultad de Ciencias Naturales and Instituto Miguel Lillo, Universidad Nacional de Tucumán under a designated PIL (Paleontología Invertebrados Lillo).

Phylum Echinodermata Klein, 1734

Class Rhombifera Zittel, 1879

Order Dichoporita Jaekel, 1899

Family Macrocystellidae Bather, 1899; enmend. Jaekel, 1918

Genus Macrocystella Callaway, 1877

Type species: Macrocystella mariae Callaway, 1877

Macrocystella sp.

Fig. 2 B, C, E

v.1986 Macrocystella sp. - Aceñolaza, F.G. pág. 134, lám. 1, fig. A-F.

v.1996 Macrocystella sp. - Aceñolaza, G.F. pág 203, lám. 11, fig. A-D

Material. 16 moulds of internal and 8 external lateral plates. 2 moulds of internal infralateral plates, 1 mould of a internal probably marginal periproctal plate. Several isolated and connected stem segments. Complete thecae were not recovered. Samples from different sections of the provinces of Salta and Jujuy. PIL 14.475, PIL 14.476, PIL 14.477, PIL14.521, PIL 14.522, and PIL 14.523.

Description. Hexagonal thecal plates, with vaulted profile. Lenght varies from 5,8 to 7,3 and width from 4,9 to 7,5 mm. Umbo defined by a structure rised 1,3-2,1 mm above the plate. Straight and well delimitated main folds. Secondary folds of a variable number, from 3 to 4, subtriangular outline, parallel to main folds without contact between both.

Isolated and grouped stem fragments, with a variable length (1,8 to 12,2 mm and composed of up to 10 columnals), circular to sub-circular cross section, thick walled segments with small central lumen are the most common. No radially structures or ornamented surfaces were observed within the crenularium or areola.

Figure 2. Ordovician echinoderms of Argentina. A, D. Macrocystella? durandi (x5) Aceñolaza from Cerro Ronqui, Jujuy, Cordillera Oriental Argentina. B-C-E - Macrocystella sp. from Salta and Jujuy provinces (B x 2,5; C x 3,5; E x 4). F- Isolated plate from the Don Polo Fm., Argentine Precordillera (x 4, Turco Greco and Zardini, 1984). G-I. Lingulocystis cf. elongata from the Arenig Strata of the Cerro San Bernardo, Salta province (x5). J-M. Diverse columnals from argentine Ordovician strata.

Remarks. Macrocystella Callaway is the only genus of the family Macrocystellidae, characterized by a cylindrical theca with 6 radial plates, a large and flexible periproct with several small plates surrounded by 5 lateral and infralateral plates. Brachioles are restricted to the upper sector of the theca, rising from the ambulacra placed between the oral plates (Paul, 1968, 1984).

On the basis of morphological characters, Macrocystella has been assigned by several authors to Eocrinoidea (Moore, 1954; Ubaghs, 1967; Chauvel, 1969; Rosova et al., 1985 and Sprinkle, 1995) or to the Rhombifera (Bather, 1899; Thoral, 1935; Cuénot, 1948; Ubaghs, 1967; Paul, 1968, 1984; Gil Cid et al., 1996; Vizcaïno and Lefebvre, 1998 and Sdzuy et al., 2001). Broadhead (1982) analyzes Eocrinoidea as a group, rising it to a Class category, including Macrocystellidae in a new Order (Ascocystitida). But the genus Macrocystella is actually considered as an ancestor of cheirocrinid rhombiferans due to the lack of dichopores.

Cystidea Barrande, Mimocystites Barrande (Chauvel, 1966) and Mimocystis Barrande (invalid name, Carpenter, 1891, Haeckel, 1896 and Bather, 1900) have been sinonimized to Macrocystella Callaway (Cunéot, 1953; Havlicek y Vanek, 1966; Paul, 1967, 1968, 1973, 1984; Chauvel, 1969; Gil Cid et al., 1996; Aceñolaza, 1999).

Seven species are actually assigned to the genus: M. mariae Callaway from the Tremadocian of England and Wales, M. bavarica (Barrande) and M. greilingi Hammann and Sdzuy from the Tremadocian of Bavaria, Germany. M. bohemica (Barrande) from the Tremadocian of Bohemia (Czech Republic) and Lower Arenig of Morocco, M. azaisi (Thoral) from the Upper Tremadocian of the Montagne Noire (southeast France), M. tasseftensis Chauvel from the Lower Arenig of Morocco, M. pauli Gil Cid et al. from the Lower Caradoc of the Central Iberian Zone (Spain).

The last record of the genus is placed in Lower Caradoc strata in Spain (Gil Cid et al., 1996). The material from the Argentine Cordillera Oriental is all fragmentary and ranges from the Upper Cambrian to the Upper Tremadocian.

The earlier record of Macrocystella from the Central Andean Basin could be indicating an initial radiation of macrocystellids from the western margin of Gondwana, with a subsequent eastwards migration to other perigondwanan areas of Europe a North Africa. In a same sense, several other invertebrate groups enhanced this one-way migratory route (Aceñolaza, et al., 1999; Gutiérrez-Marco et al., 1999; Gutiérrez-Marco et al., 2000).

Macrocystella? durandi Aceñolaza

Fig. 2 A, D

1999 Macrocystella? durandi sp. nov. - Aceñolaza, G.F., pág. 95-98, fig. 2.1-2.5

Material. Several thecal plates with moulds associated to stem fragments that have been tentatively assigned as belonging to the genus. PIL 14.530, 14.531, 14.532, 14.533 y 14.534. Samples were recovered from the shales and sandstones of the Tremadocian Rupsaca Formation cropping out at the locality of Cerro Ronqui, Jujuy Province.

Description. Hexagonal plates of uneven sized lateral margins, without sutural pores and with radial folds merging from a clearly elevated central umbo (3,1 to 3,5 mm high). Principal folds display rounded borders, from 7,8 to 8,1 mm long. Several and delicate secondary folds characterize this species, they have 6,1 to 6,7 mm long and are arranged on a parallel setting respect to the main folds. Regular shallow rhomboidal figures appear when meeting lateral plates.

Remarks. Analyzed material is referred to thecal plates and moulds, with several diagnostic elements supporting its taxonomic differentiation from other species of Macrocystella Callaway (as the presence of probable pectinirhombs). More material is needed in order to ensure the correct assignation of this form to the genus. If general morphological characters stay coherent with samples herein described, this pelmatozoan will probably be assigned to a new genus.

Assignation to Macrocystella? is supported by the fact that plates do not show sutural pores, presenting an umbo elevated from the plate and radially arranged folds merging from it. Main thecal folds cut straight to sides of plates, and in a different manner of the late Cambrian Cambrocrinus, whose folds reach bifurcated the angles of plates (Dzik y Orlowski, 1993).

M.? durandi Aceñolaza differs from M. tasseftensis Chauvel, because main folds reach the umbo in the first situation, while a lack of granulation characterizes the second case (Chauvel, 1969).

M. bohemica (Barrande), M. mariae Callaway, M. pauli Gil Cid et al. and M. greilingi Hammann and Sdzuy (in Sdzuy et al., 2001) differs from M.? durandi Aceñolaza by the abundant delicated secondary folds that characterize the argentine species (reaching up to 30 folds per plate, compared to the 3 to 5 folds in the other species). M. azaisi (Thoral) display distinctive convergent basal secondary folds very different to the material here described.

Macrocystella? durandi Aceñolaza has been found in a single locality (Cerro Ronqui, Jujuy province) and probably represents an intermediate step on the evolution between Macrocystella and Cheirocrinus, being the last trend indicated by the presence of incipient pectinirhombs on the marginal sectors of thecal plates (Aceñolaza, 1999).

Class Eocrinoidea Jaeckel, 1918

Family Lingulocystidae Ubaghs, 1960

Genus Lingulocystis Thoral, 1935

Type specie: Lingulocystis elongata Thoral, 1935

Lingulocystis cf. elongata Thoral

Fig. 2 G-J

cf. 1935 Lingulocystis elongata n. sp. (var. typica et var. lata) - Thoral, pág. 94-95, lám. 8, fig. 3a-b, 4a-b, 6.

cf. 1960 Lingulocystis elongata Thoral - Ubaghs, pág 83-103, fig. 1-9; lám. 1, fig 1-6; lám. 2, fig. 1-4; lám. 3, fig. 1-5.

1999 Lingulocystis cf. elongata Thoral - Gutiérrez-Marco and Aceñolaza, pág. 351-353, fig. 1a-c.

Material. Four fairly complete samples of theca with fragmentary stem, one of them with attached brachioles and several isolated pieces of theca and stem. The material comes from the shales of the San Bernardo Formation (Arenig) cropping out at the Sierra de San Bernardo, Salta Province, northwestern Argentina. PIL 14.535-38.

Description. The body of Lingulocystis Thoral can be divided into three sectors, a long stem, a flattened theca and a number of biserial brachioles raising from the upper margin of the theca. The stem reaches up to 20 cm long, formed by numerous cylindrical crenulated columnals of uneven thickness. No basal segments of the stem has been observed. The theca is 2,2 to 3 cm long and 0,7 to 1,3 cm wide, formed by numerous small irregular plates limited by several thicker marginals.

These do not participate in the internal pavement, except for few ribbon like plates laterally displaced from the middle of the tegument that constituted the longitudinal carina so far characteristic of the species L. elongata. Anus is placed laterally in the upper third of flattened theca, covered by numerous small and elongated plates. Brachioles show a biserial organization and are inserted marginally in the framework of the oral face (Fig. 1C).

Remarks. Lingulocystis elongata was originally described by Thoral (1935) from Lower Ordovician shales of the Montagne Noire, southeastern France; being carefully reviewed by Ubaghs (1960), who adds new material. Later, Sprinkle (1973a) presents the first occurrence of the genus in South America, with the new species L. boliviana that occurs from a single locality placed in the southern Eastern Cordillera of Bolivia (Tarija area). Its type material was first considered to be of “Llanvirn” age (now reviewed as Arenig: Aceñolaza et al., 1999), and consists on the single specimen previously reported as an unidentified crinoid by Ahlfeld and Branisa (1960) and Branisa (1965). Recently, Ubaghs (1994) adds a second European species to the genus, L. deani, also from the Lower Ordovician of the Montagne Noire, France. Finally, Gutiérrez-Marco and Aceñolaza (1999) inform of the probable record of the type species of Lingulocystis in South America, being the first occurrence of the genus in Argentina, also considered herein.

Lingulocystis is the only genus of the Family Lingulocystidae Ubaghs, and is characterized by being the only known flattened pelmatozoan with a probably flexible theca covered by small irregular plates. Lingulocystis was assigned to different groups such as Carpoidea (Thoral, 1935) and Eocrinoidea (Ubaghs, 1960; Sprinkle, 1973a, 1973b, 1995; Sumrall et al., 2001), as well as to a new class closely allied to Paracrinoidea (Broadhead, 1982). In this paper we follow the analysis done by Sprinkle (1995), considering Lingulocystis as an Eocrinoid.

Acknowledgements. We thank D. Ruiz Holgado and E. Gómez (Tucumán) for the line drawings. This paper was finished thanks to the financial support of Fundación Antorchas and the Instituto Superior de Correlación Geológica (CONICET- UNT, Argentina), being also a contribution to the project “Dinámica faunística perigondwánica” of the current Scientific Cooperation Program between Spain and Argentina.

References

Aceñolaza, F.G., 1973. Sanbernardaspis pygacantha nov. gen. et nov. sp. (Trilobita-Asaphidae) del Cerro San Bernardo, Salta, República Argentina. Ameghiniana, 10 (2): 132-138.

Aceñolaza, F.G., 1986. El género Macrocystella (Cystoidea) en el Tremadoc de Salta y Jujuy. IV Congreso Argentino de Paleontología y Bioestratigrafía, 1: 133-135. Mendoza.

Aceñolaza, F.G., 1992. El Sistema Ordovícico de Latinoamérica. In: J.C. Gutiérrez-Marco, J. Saavedra and I. Rábano (Eds.), Paleozoico Inferior de Ibero-América. Publicación especial, Universidad de Extremadura: 85-118. España.

Aceñolaza, F.G. and Aceñolaza G.F., 1992. The genus Jujuyaspis as a world reference fossil for the Cambrian- Ordovician Boundary. In: B.D. Webby and J. R. Laurie (eds.), Global Perspectives in Ordovician Geology. Balkema, 115- 120, Rotterdam.

Aceñolaza, F.G. and Toselli, A.J., 1977. Observaciones geológicas sobre el Ordovícico de la Zona de Chaschuil, Provincia de Catamarca. Acta Geologica Lilloana, 14: 55-81.

Aceñolaza, F.G., and Toselli, A.J., 1999. Argentine Precordillera: Allochthonous or Autochthonous gondwanic ?. Zentralblat für Geologie und Paläontologie. Teil 1, 1999, (7-8): 1-14.

Aceñolaza, F.G., Miller, H. and Toselli, A.J., 1999. Proterozoic – Lower Paleozoic terrane evolution in western South America. Geodinamica Andina. Forth ISAG. Expanded Abstracts: 6-7. Göttingen.

Aceñolaza, G. F. 1996. Bioestratigrafía del límite Cámbrico-Ordovícico y Ordovícico basal en la quebrada de Humahuaca, provoncia de Jujuy, República Argentina. Unpublished Doctoral Thesis. Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, 245 p.

Aceñolaza, G.F., 1999. Macrocystella? durandi sp. nov. (Echinodermata Rhombifera) y el registro del género Macrocystella en la cuenca Cambro-Ordovícica del norte argentino. Acta Geologica Hispanica, 34 (1): 89-101.

Aceñolaza, G. F., Gutiérrez-Marco, J.C., Rábano, I. and Díaz Martínez, E., 1999. Las lumaquelas de la Formación Sella (Ordovícico de la Cordillera Oriental boliviana) y su interés paleobiogeográfico. XIV Congreso Geológico Argentino, Salta, Actas I: 355-358.

Ahlfeld, F. and Branisa, L., 1960. Geología de Bolivia. Instituto Boliviano del Petróleo, 245 p. La Paz.

Albanesi, G.L. and Vaccari, N.E., 1994. Conodontos del Arenig en la Formación Suri, Sistema del Famatina, Argentina. Revista Española de Micropaleontología, 26 (2): 125-146.

Astini, R.A., Benedetto, J.L. and Vaccari, 1995. The Early paleozoic evolution of the Argentine Precordillera as a Laurentia rifted, drifted and collied terrane: a geodynamic model. GSA Bulletin, 107: 253-273.

Bather, F.A., 1899. A phylogenetic classification of Pelmatozoa. Report British Ass. Adv. Sciences, 68: 916-923. London.

Bather, F.A., 1900. The Echinodermata. In: E. Ray Lankester (Ed.). A treatise on Zoology (8): 1-344. London.

Benedetto, J.L., 1994. Braquiópodos Ordovícicos (Arenigiano) de la Formación Suri en la Región del Rio Chaschuil, Sistema de Famatina, Argentina. Ameghiniana 31 (3): 221-238.

Branisa, L., 1965. Los fósiles guía de Bolivia. I- Paleozoico. Boletín del Servicio Geológico de Bolivia 6: 282 p.

Broadhead, T.W., 1982. Reappraisal of class Eocrinoidea (Echinodermata). In: J.M. Laurence (Ed.). International Echinoderms Conference. 125-131. Tampa.

Bordonaro, O., 1992. El Cámbrico en Sudamérica. In: J.C. Gutiérrez-Marco, J. Saavedra Alonso and I. Rábano (Eds.). El Paleozoico Inferior de Iberoamérica. Publicación Especial, Universidad de Extremadura: 69-84.

Callaway, C., 1877. On new area of Upper Cambrian rocks in South Shropshire, with description of a new fauna. Quarterly Journal of the Geological Society, 33: 652-672. London.

Carpenter, P.H., 1891. On certain points in the morphology of the Cystidea. Journal of Linnean Society, Zoology, 24: 1-52. London.

Chauvel, J., 1966. Echinodermes de l’Ordovicien du Maroc. Cahiers de Paléontologie, 1966: 1-120. Paris.

Chauvel, J., 1969. Les echinodermes macrocystellides de l’Anti-Atlas marocain. Bulletin de la Société Géologique et Minéralogique de Bretagne, C, (1): 21-32.

Cúneot, L., 1948. Classe des Cystidés. In: P.P. Grassé (Ed.) Traité de Zoologie, 11: 15-25. Paris.

Cúneot, L., 1953. Classe des Cystidés. In: Traité de Paléontologie, III: 607-628. Paris.

Dzik, J. and Orlowski, S., 1993. The Late Cambrian eocrinoid Cambrocrinus. Acta Palaeontologica Polonica 38 (1,2): 21- 34.

García, E.R and Proserpio, C.A., 1976. Ostrácodos del Ordovícico (Arenigiano) del cerro San Bernardo - Provincia de Salta, República Argentina. VI Congreso Geológico Argentino, Actas I: 557-563. Bahía Blanca.

Gil Cid, M.D., Domínguez Alonso, P., Cruz González, M.C. and Escribano Ródenas, M., 1996. Nuevo Macrocystellidae (Echinodermata, Cystoidea, Rhombifera) para el Ordovícico Español. Estudios Geológicos, 52: 175-183.

Gutiérrez-Marco, J.C. and Aceñolaza, G.F., 1999. Hallazgo de Lingulocystis (Echinodermata, Eocrinoidea) en el Ordovícico del Cerro San Bernardo. XIV Congreso Geológico Argentino, I: 350-354. Salta.

Gutiérrez-Marco, J.C. Aceñolaza, G.F. and Aceñolaza, F.G., 2000. Primer registro del gasterópodo Lesueurilla y euomphalomorfos afines en el Ordovícico Inferior de Argentina y España. Su interés paleobiogeográfico. Boletín Geológico y Minero, 111 (2-3): 85-94.

Gutiérrez-Marco, J.C., Rábano, I., Sarmiento, G.N., Aceñolaza, G.F., San José, M.A., Pieren, A., Herranz, P., Couto, H.M. and Piçarra, J.M., 1999. Faunal dynamics between Iberia and Bohemia during the Oretanian and Dobrotivian (late Middle-earliest Upper Ordovician), and biogeographic relations with Avalonia and Baltica. Acta Universitatis Carolinae – Geologica, 43 (1-2): 487-490.

Gutiérrez-Marco, J.C., Aceñolaza, F.G., Aceñolaza, G.F. and Rábano, I. 2000. Paleobiogeographical relations between south America and the north Gondwanan Biogeographic domain during the Ordovician. XXXI International

Geological Congress, Rio de Janeiro, Brasil. CD Rom - Electronic Abstracts.

Haeckel, E., 1896. Die Cambrische Stammgruppe des Echinoderman. Jena Z. Natur., 30: 393-404.

Harrington, H., 1937. On some Ordovician fossils from northern Argentina. Geological Magazine, 74: (873).

Harrington, H.J., 1938. Sobres las faunas del Ordovícico inferior del norte argentino. Revista del Museo de La Plata (Nueva Serie) I, Secc. Paleont.: 109-289.

Harrington, H. J. and Leanza, A.F., 1957. Ordovician Trilobites of Argentina. University of Kansas, Special Publication, 1: 276 p.

Havlicek, V. and Vanek, J., 1966. The biostratigraphy of the Ordovician of Bohemia. Sborník geologisky ved, Paleontologie, 8: 7-69.

Jaekel, O., 1899. Stammesgeschichte der Pelmatozoen 1: Thecoidea und Cystoidea, 1-442. Berlín.

Jaekel, O., 1918. Phylogenie and System der Pelmatozoen: Paläont. Zeitschrift, 3 (1): 1-128.

Kayser, E., 1876. Uber primordiale und untersilurische fossilien aus der Argentinischer Republik. Palaeontographica. Supp. 3 (2) Cassel. Berlin.

Kayser, E., 1925. Contribuciones a la Paleontología de la República Argentina. Sobre fósiles primordiales e infrasilurianos. Boletín de la Academia Nacional de Ciencias, Actas 9 (1-2): 297-332, Córdoba.

López, C.R. and Nullo, F.E., 1969. Geología de la margen izquierda de la Quebrada de Humahuaca, de Huacalera a Maimará, Dept. Tilcara, Provincia de Jujuy, República Argentina. Revista de la Asociación Geológica Argentina, 24 (3): 173-182.

Loss, R., 1951. Contribuciones al conocimiento de las faunas graptolíticas del norte argentino. I. Graptolites del Cerro San Bernardo (Salta) y de la zona del dique de La Ciénaga (Jujuy). Revista de la Asociación Geológica Argentina, 6: 21-61.

Moore, R.C., 1954. Status of invertebrate paleontology, 1953. IV Echinodermata: Pelmatozoa. Harvard Univrsity, Museum of Comparative Zoology, Bulletin, 112 (3): 125-149.

Moya, M.C., Malanca, S., Monteros, J.A. and Cuerda, A., 1994. Bioestratigrafía del Ordovícico Inferior en la Cordillera Oriental Argentina basada en graptolitos. Revista Española de Paleontología, 9 (1): 91-104.

Paul, C.R.C., 1967. Cystidea Barrande, 1868 (Cystoidea: Glyptocystitida): proposed suppresion under the plenary powers Z.N. (S.) 1913. Bulletin of Zoological Nomenclature, 24: 304-307.

Paul, C.R.C., 1968. Macrocystella Callaway, the earliest glyptocystitid cystoid. Palaeontology, 11: 580-600.

Paul, C.R.C., 1973. British Ordovician Cystoids, Part 1. Monograph of the Palaeontgraphical Society (Publ. 604, part of vol. 151 for 1997): 1-64. London.

Paul, C.R.C., 1984. British Ordovician Cystoids, Part 2: Dichoporita-Rhombifera. Monograph of the Palaeontographical Society, (Publ. 604, part of vol. 151 for 1997): 65-152. London.

Peralta, S.H., 2000. An introduction to geology of the Precordillera, western Argentina. In: G.F. Aceñolaza and S.H.

Peralta (Eds.), Cambrian from the southern edge. Instituto Superior de Correlación Geológica, Miscelánea, 6: 14-20.

Rosova, A.V., Rosov, S.N., and Dubatolova, Yu. A., 1985. Stratigraphy and fauna of the Ordovician of the North- Western Salair. Transactions Academy of Sciences of the USSR, Siberian Branch, Institute of Geology and Geophysics, 637: 134-251.

Sdzuy, K., Hammann, W. and Villas, E., 2001. The Upper Tremadoc fauna from Vogtendorf and the Bavarian Ordovician of the Frankenwald (Germany). Senckenbergiana lethaea, 81 (1): 207-261.

Sprinkle, J., 1973a. New occurrence of the Ordovician Eocrinoid Lingulocystis from Bolivia, South America. Journal of Paleontology, 47 (6): 1113-1116.

Sprinkle, J., 1973b. Morphology and Evolution of Blastozoan Echinoderms. Special publication, The Museum of Comparative Zoology, Harvard University, Cambridge, Massachusets. 122 p.

Sprinkle, J., 1995. Do Eocrinoids belong to the Cambrian or to the Paleozoic evolutionary fauna ?. In: J. Cooper, M. Drosser and S. Finney (Eds.) Ordovician Oddyssey: Short papers for the Seventh International Symposium on the Ordovician System. SEMP book 47: 397-400. Fullerton.

Sumrall, C.D., Sprinkle, J. and Guensburg, T.E., 2001. Comparison of flattened blastozoan echinoderms: insights from the new early Ordovician eocrinoid Haimacystis rozhnovi. Journal of Paleontology, 75 (5): 985-992.

Thoral, M., 1935. Contribution à l‘étude paléontologique de l‘Ordovicien infèrieur de la Montagne Noire et revision sommarie de la faune Cambrienne de la Montagne Noire. Montpellier: 362 p.

Turco Greco, E.J. and Zardini, R.A., 1984. Un equinodermo del Paleozoico Inferior en la Precordillera de San Juan, Departamento Calingasta, Provincia de San Juan. Revista de la Asociación Geológica Argentina, 39 (3-4): 300-303.

Turner, J.C.M., 1960. Estratigrafía de la Sierra de Santa Victoria y adyacencias. Boletín Instituto Nacional de Geología y Minería, 104: 1-99. Buenos Aires.

Ubaghs, G., 1960. Le genre Lingulocystis Thoral (Echinodermata, Eocrinoidea), avec des remarques critiques sur la position systematique du genere Rhipidocystis Jaekel. Annales de Paléontologie, 46: 81-116.

Ubaghs, G., 1967. Eocrinoidea. In: R.C., Moore (Ed.) Treatise on Invertebrate Paleontology, Part S, Echinodermata 1 (2): 455- 495; Lawrence, Kansas.

Ubaghs, G., 1994. Echinodermes nouveaux (Stylophora, Eocrinoidea) de l‘Ordovicien inferiéur de la Montagne Noire (France). Annales de Paléontologie, 80: 107-141.

Ubaghs, G., 1999. Échinodermes nouveaux du Cambrien Supérieur de la Montagne Noire (France Méridionale). Geobios, 31 (6): 809-829.

Vaccari, N.E. and Waisfeld, B.G., 1994. Nuevos trilobites de la Formación Suri (Ordovícico temprano) en la región de Chaschuil, Provincia de Catamarca. Implicancias bioestratigráficas. Ameghiniana, 31 (1): 73-86.

Vizcaïno, D. and Lefebvre, B., 1999. Les échinodermes du Paléozoïque inférieur de Montagne Noire: biostratigraphie et paléodiversité. Geobios, 32(2): 353-364.

Zittel, K. A. Von., 1879. Handbuch der Palaeontologie. 1 Protozoa, Coelenterata, Echinodermata und Molluscoidea. viii + 765 pp., München & Leipzig.

Recibido: 15 de Septiembre de 2002

Aceptado: 3 de Diciembre de 2002