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Cenomanian Brachiopods from the Vezk Section (South of Yasuj, Iran)
Journal of Sciences, Islamic Republic of Iran 28(4): 337 - 347 (2017) http://jsciences.ut.ac.ir University of Tehran, ISSN 1016-1104 First Record of Aptian- Cenomanian Brachiopods from the Vezk Section (South of Yasuj, Iran) T. Binazadeh* Department of Geology, Faculty of Sciences, Shahid Bahonar University, Kerman, Islamic Republic of Iran Received: 8 June 2016 / Revised: 25 September 2016 / Accepted: 25 December 2016 Abstract Brachiopod faunas from the Aptian- Cenomanian Vezk section in southwestern Iran comprise ten species in six genera, namely Sellithyris cenomanensis, Sellithyris tornacensis, Sellithyris phaseolina, Phaseolina phaseolina, Tropeothyris sp., Concinnithyris subundata, Kingena arenosa, Cyclothyris difformis, Cyclothyris sp. and Cyclothyris compressa. All species are recorded for the first time from the lower Cretaceous of Vezk section (South of Yasuj). These deposits are composed of an alternation of green marls and thin layers of yellow shaly or sandy limestone, which overlain by thick bedded black limestone. The thickness of these deposits are 74 meters, which covers the Jurassic sediments, while its upper boundary ends with erosion surface that covered by Neogene deposits. These deposits consist of different fossil groups such as brachiopods, echinoids, corals, gastropods and orbitolinids that confirm the Aptian- Cenomanian ages for these sediments. The fauna assemblages suggest at shallow and suitable environment prevailed during the deposition of the strata. Keywords: Brachiopods; Aptian; Cenomanian; Yasuj; Iran. small amount of organic matrix [8]. Brachiopods, also Introduction known as ‘lamp shells’, are marine metazoans that Brachiopods are marine organisms which have two elaborate a bivalved shell, similar to the molluscs of shells or valves of different sizes, shape and the class Bivalvia [12]. -
New Barremian Rhynchonellide Brachiopod from Serbia and The
New Barremian rhynchonellide brachiopod genus from Serbia and the shell microstructure of Tetrarhynchiidae BARBARA RADULOVIĆ, NEDA MOTCHUROVA−DEKOVA, and VLADAN RADULOVIĆ Radulović, B., Motchurova−Dekova, N., and Radulović, V. 2007. New Barremian rhynchonellide brachiopod from Ser− bia and the shell microstructure of Tetrarhynchiidae. Acta Palaeontologica Polonica 52 (4): 761–782. A new rhynchonellide brachiopod genus Antulanella is erected based on the examination of the external and internal morphologies and shell microstructure of “Rhynchonella pancici”, a common species in the Barremian shallow−water limestones of the Carpatho−Balkanides of eastern Serbia. The new genus is assigned to the subfamily Viarhynchiinae, family Tetrarhynchiidae. The shell of Antulanella is small to rarely medium−sized, subglobose, subcircular, fully costate, with hypothyrid rimmed foramen. The dorsal euseptoidum is much reduced. The dental plates are thin, ventrally diver− gent. The hinge plates are straight to ventrally convex. The crura possess widened distal ends, rarely raduliform or canaliform. The shell is composed of two calcitic layers. The secondary layer is fine fibrous, homogeneous built up of predominantly anisometric anvil−like fibres. Although data on the shell microstructure of post−Palaeozoic rhyncho− nellides are still incomplete, it is possible to distinguish two types of secondary layer: (i) fine fibrous typical of the superfamilies Rhynchonelloidea and Hemithiridoidea and (ii) coarse fibrous typical of the superfamilies Pugnacoidea, Wellerelloidea, and Norelloidea. The new genus Antulanella has a fine fibrous microstructure of the secondary layer, which is consistent with its allocation in the Hemithiridoidea. Antulanella pancici occurs in association with other brachi− opods showing strong Peritethyan affinity and close resemblance to the Jura fauna (= Subtethyan fauna). -
Brachiopoda, Rhynchonellida): Examples from the Late Cretaceous of Western Europe
BSGF - Earth Sciences Bulletin 2020, 191, 1 © D. Gaspard and S. Charbonnier, Published by EDP Sciences 2019 https://doi.org/10.1051/bsgf/2019016 urn:lsid:zoobank.org:pub:EA4C26EB-8371-433D-8696-6E402D5D3B0A Available online at: www.bsgf.fr The debated question of asymmetrical rhynchonellids (Brachiopoda, Rhynchonellida): examples from the Late Cretaceous of Western Europe Danièle Gaspard* and Sylvain Charbonnier UMR 7207, Centre de Recherche en Paléontologie, Paris, MNHN-Sorbonne Université-CNRS, Muséum national d’Histoire naturelle, 8 rue Buffon, CP 38, 75005 Paris, France Received: 22 February 2019 / Accepted: 13 November 2019 / Published online: 22 December 2020 Abstract – Many Cretaceous asymmetrical rhynchonellid brachiopods (Brachiopoda, Rhynchonellida) have long been considered as Rhynchonella difformis (Valenciennes in Lamarck, 1819). After a revision, Owen (1962) included the Cenomanian specimens from Europe in Cyclothyris M’Coy, 1844. Later, Manceñido et al. (2002) confirmed this decision and critically mentioned the name of another asymmetrical rhynchonellid genus from Spain, Owenirhynchia Calzada in Calzada and Pocovi, 1980. Specimens with an asymmetrical anterior margin (non particularly ecophenotypical), from the Late Coniacian and the Santonian of Les Corbières (Aude, France) and Basse-Provence (SE France) are here compared to specimens of the original Cenomanian species C. difformis. They are also compared to new material from the Northern Castilian Platform (Coniacian-Santonian, N Spain) and to Rhynchonella globata Arnaud, 1877 (Campanian, Les Charentes, Dordogne, SW France) and Rh. vesicularis Coquand, 1860 (Campanian, Charente, SW France). These observations document the great morphological diversity among all these species and lead us to erect a new species: Cyclothyris grimargina nov. sp. from the type material of Arnaud, and two new genera: Contortithyris nov. -
Late Cretaceous Rhynchonellida (Brachiopoda) from Bulgaria. I
GEOLOGICA BALCANICA, 25.3-4, Sofia, August . 1995, p. 35-74 Late Cretaceous Rhynchonellida (Brachiopoda) from Bulgaria. I. Genus Cyclothyris M'C o y N eda M otchurova -Dekova National Museum of Natural History, Sofia 1000 (received 24. 08. 1994; accepted 21. 09. 1994) Heoa MollypoBa-/(eKoBa - IloJOHeMe/IOBble puHXOHeAAUObl (Brachiopoda) uJ EioMapuu. / . PoiJ Cyclothyris M'Coy. lipaXHono.nbl liBJiliiOTCll o.nHoii HJ caMbiX pacnpocTpaHeHHbiX lfloccHJibH'biX rpynn cpe,nH nOJ,nHeMeJIOBOH MaKpolflayHbl Ha TeppHTOpHH DOJirapHH. C 3TOH CTaTbH Ha'IHHaeTCll cepHll naneoHTonoruqecrilx onucaHuii npe.ncnsuTeneii OTpll.na Rhynchonellida. 3.necL npe.ncnsneHbl pe JYJILTaTbl .neTanbHbiX TaKCOHOMH'IeCKHX uccne.nosaHHii ceMH su.nos po.na Cyclothyris M'Coy HJ ceHo MaHcKoro, caHTOHCKoro u KaMnaHcKoro llpycos lionrapuu. C.nenaH JIHTepaTypHblii o6Jop u o6cToli TeJILHO AHCKYTHPYfOTCll o6'beM H rpaHHI{bl HJMeH'fHBOCTH po.na Cyclothyris. llpe.nnoJICeHo 6onee lliH poKo nOHHMaHHe 06'beMa 3TOfO po.na, no.n.nepliCHBall CTaHOBHille aBTOpOB, paCCMaTpHBaiOillHX Lamel/aerhynchia KaK MJia)llllero CHHOHHMa Cyclothyris. lhy'lall BHyTpeHHIOIO MoplflonoruJO noJ.nHe MeJIOBbiX pHHXOHeJIJIHJl BnepBble B DOJirapHH npHMeHlleTCll MeTOJl cepHHHbiX npepeJOB. 3THM cnoco- 60M ycTaHOBJieHbl rpaHHI..\bl BHYTPHBHJlOBoii HJMeH'IHBOCTH B cny'fal!X HaJIH'fHll npe.ncTaBHTeJILHoro KOJIHlfeCTBa MaTepHana. fipeJlCTaBJieHbl .naHHble 06 3KOJIOfHH HCCJie)lOBaHHbiX pHHXOHeJIJIHJl H MHK pOCTpyKrypa paKOBHH JlByx BHJlOB. Abstract. Brachiopods are one of the most widespread fossil groups among the Late Cretaceous macrofauna in Northern Bulgaria. This article is the first from a series of palaeontological descriptions of the Rhynchonellida representatives. The results from detailed taxonomic studies of seven species of the genus Cyclothyris M'Coy from the Cenomanian, Santonian and Campanian are presented. -
Brachiopoda: Rhynchonellida) and Its Evolutionary Significance Author(S): Kenneth J
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by ESC Publications - Cambridge Univesity The Earliest Tegulorhynchia (Brachiopoda: Rhynchonellida) and Its Evolutionary Significance Author(s): Kenneth J. McNamara Source: Journal of Paleontology, Vol. 57, No. 3 (May, 1983), pp. 461-473 Published by: SEPM Society for Sedimentary Geology Stable URL: http://www.jstor.org/stable/1304689 Accessed: 16-07-2018 10:49 UTC REFERENCES Linked references are available on JSTOR for this article: http://www.jstor.org/stable/1304689?seq=1&cid=pdf-reference#references_tab_contents You may need to log in to JSTOR to access the linked references. JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://about.jstor.org/terms SEPM Society for Sedimentary Geology is collaborating with JSTOR to digitize, preserve and extend access to Journal of Paleontology This content downloaded from 131.111.64.116 on Mon, 16 Jul 2018 10:49:02 UTC All use subject to http://about.jstor.org/terms JOURNAL OF PALEONTOLOGY, V. 57, NO. 3, P. 461-473, 3 FIGS., MAY 1983 THE EARLIEST TEGULORHYNCHIA (BRACHIOPODA: RHYNCHONELLIDA) AND ITS EVOLUTIONARY SIGNIFICANCE KENNETH J. McNAMARA Western Australian Museum, Francis Street, Perth, Western Australia 6000 ABSTRACT- Tegulorhynchia boongeroodaensis n. -
First Record of Aptian- Cenomanian Brachiopods from the Vezk Section (South of Yasuj, Iran)
Journal of Sciences, Islamic Republic of Iran 28(4): 337 - 347 (2017) http://jsciences.ut.ac.ir University of Tehran, ISSN 1016-1104 First Record of Aptian- Cenomanian Brachiopods from the Vezk Section (South of Yasuj, Iran) T. Binazadeh* Department of Geology, Faculty of Sciences, Shahid Bahonar University, Kerman, Islamic Republic of Iran Received: 8 June 2016 / Revised: 25 September 2016 / Accepted: 25 December 2016 Abstract Brachiopod faunas from the Aptian- Cenomanian Vezk section in southwestern Iran comprise ten species in six genera, namely Sellithyris cenomanensis, Sellithyris tornacensis, Sellithyris phaseolina, Phaseolina phaseolina, Tropeothyris sp., Concinnithyris subundata, Kingena arenosa, Cyclothyris difformis, Cyclothyris sp. and Cyclothyris compressa. All species are recorded for the first time from the lower Cretaceous of Vezk section (South of Yasuj). These deposits are composed of an alternation of green marls and thin layers of yellow shaly or sandy limestone, which overlain by thick bedded black limestone. The thickness of these deposits are 74 meters, which covers the Jurassic sediments, while its upper boundary ends with erosion surface that covered by Neogene deposits. These deposits consist of different fossil groups such as brachiopods, echinoids, corals, gastropods and orbitolinids that confirm the Aptian- Cenomanian ages for these sediments. The fauna assemblages suggest at shallow and suitable environment prevailed during the deposition of the strata. Keywords: Brachiopods; Aptian; Cenomanian; Yasuj; Iran. small amount of organic matrix [8]. Brachiopods, also Introduction known as ‘lamp shells’, are marine metazoans that Brachiopods are marine organisms which have two elaborate a bivalved shell, similar to the molluscs of shells or valves of different sizes, shape and the class Bivalvia [12]. -
Smithsonian Miscellaneous Collections Volume 148, Number 2
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 148, NUMBER 2 ffifyarba S. attb Harg Bait* Halrntt THE BRACHIOPOD SUPERFAMILY STENOSCISMATACEA By RICHARD E. GRANT United States Geological Survey (Publication 4569) OS^. C/jp; CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION April 1, 1965 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 148, NUMBER 2 Barkis S. attb ifflan} Baux Maiwti Steward} iFunJn THE BRACHIOPOD SUPERFAMILY STENOSCISMATACEA By RICHARD E. GRANT United States Geological Survey (Publication 4569) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION April 1, 1965 CONNECTICUT PRINTERS, INC. HARTFORD, CONNECTICUT, U.S.A. CONTENTS Page Introduction 1 Type genus 2 Acknowledgments 3 External morphology 4 Size 4 Commissure 4 Plication 6 Costation 7 Stolidium 8 Delthyrium and deltidial plates 13 Internal morphology 14 Camarophorium 14 Spondylium 16 Musculature 18 Hinge plate and cardinal process 22 Crura 22 Lophophore 23 Pallial markings 23 Shell structure 25 Life habits 26 Phylogeny 29 Classification 33 Key 35 Systematics of superfamily Stenoscismatacea 37 Family Atriboniidae 37 Subfamily Atriboniinae 37 Subfamily Psilocamarinae 77 Family Stenoscismatidae 95 Subfamily Stenoscismatinae 95 Subfamily Torynechinae 152 Species doubtfully Stenoscismatacean 160 Genera no longer included in Stenoscismatacea 162 References cited 166 Explanations of plates 175 Index 187 ILLUSTRATIONS PLATES Exp™ Page 1. Atribonium 175 2. Atribonium 175 3. Atribonium 176 4. Sedenticellula, Septacamera, Camarophorinella 176 5. Sedenticellula 177 6. Cyrolexis 177 7. Cyclothyris, Camarophorina 177 8. Camerisma 178 9. Psilocamara, Coledium 178 10. Coledium 179 11. Coledium 179 12. Coledium 179 13. Coledium 180 14. Coledium 180 15. Coledium 180 16. Coledium 181 17. Coledium 181 18. Coledium 182 19. Stenoscisma 182 20. Stenoscisma 183 21. -
CURRÍCULUM ABREVIADO (CVA) – Extensión Máxima: 4 PÁGINAS
CURRÍCULUM ABREVIADO (CVA) – Extensión máxima: 4 PÁGINAS Parte A. DATOS PERSONALES Fecha del CVA 11/07/2020 Nombre y apellidos Fernando García Joral DNI/NIE/pasaporte 01897728K Edad 62 WoS Researcher ID H-2551-2015 Núm. identificación SCOPUS Author ID 6508279570 del/de la Open Researcher and Contributor ID investigador/a 0000-0001-6594-4561 (ORCID) A.1. Situación profesional actual Organismo Universidad Complutense de Madrid Dpto./Centro Geodinámica, Estratigrafía y Paleontología Dirección C/ José Antonio Novais 12, 28040 MADRID Teléfono 913944853 correo electrónico [email protected] Categoría profesional Profesor Titular de Universidad Fecha inicio 25/03/1988 Palabras clave Paleontología, Braquiópodos, Jurásico, Cretácico A.2. Formación académica (título, institución, fecha) Licenciatura/Grado/Doctorado Universidad Año Lic. CC. Geológicas Complutense de Madrid 1980 Grado Lic. CC. Geológicas Complutense de Madrid 1981 Doctor CC. Geológicas Complutense de Madrid 1986 A.3. Indicadores generales de calidad de la producción científica • Complementos de investigación (sexenios) y fecha del último otorgado: 2 (05/06/2019) • Tesis doctorales dirigidas en los últimos 10 años: 2 • Citas totales: 811 (Google Scholar) • Promedio de citas / año durante los últimos 5 años: 83 (GS) • Publicaciones totales en el primer cuartil (Q1): 12 • índice h: 18 (GS) Parte B. RESUMEN LIBRE DEL CURRÍCULUM Desde la licenciatura en 1980, se ha desarrollado una línea coherente de investigación centrada en los braquiópodos del Jurásico inferior y medio del Tethys occidental y recientemente también en los braquiópodos del Cretácico superior del norte de España, primero como becario predoctoral y postdoctoral y desde 1988 como Profesor titular de la Universidad Complutense de Madrid. -
Brachiopoda, Rhynchonellida): Examples from the Late Cretaceous of Western Europe
BSGF - Earth Sciences Bulletin 2020, 191, 1 © D. Gaspard and S. Charbonnier, Published by EDP Sciences 2019 https://doi.org/10.1051/bsgf/2019016 urn:lsid:zoobank.org:pub:EA4C26EB-8371-433D-8696-6E402D5D3B0A Available online at: www.bsgf.fr The debated question of asymmetrical rhynchonellids (Brachiopoda, Rhynchonellida): examples from the Late Cretaceous of Western Europe Danièle Gaspard* and Sylvain Charbonnier UMR 7207, Centre de Recherche en Paléontologie, Paris, MNHN-Sorbonne Université-CNRS, Muséum national d’Histoire naturelle, 8 rue Buffon, CP 38, 75005 Paris, France Received: 22 February 2019 / Accepted: 13 November 2019 / Published online: 22 December 2020 Abstract – Many Cretaceous asymmetrical rhynchonellid brachiopods (Brachiopoda, Rhynchonellida) have long been considered as Rhynchonella difformis (Valenciennes in Lamarck, 1819). After a revision, Owen (1962) included the Cenomanian specimens from Europe in Cyclothyris M’Coy, 1844. Later, Manceñido et al. (2002) confirmed this decision and critically mentioned the name of another asymmetrical rhynchonellid genus from Spain, Owenirhynchia Calzada in Calzada and Pocovi, 1980. Specimens with an asymmetrical anterior margin (non particularly ecophenotypical), from the Late Coniacian and the Santonian of Les Corbières (Aude, France) and Basse-Provence (SE France) are here compared to specimens of the original Cenomanian species C. difformis. They are also compared to new material from the Northern Castilian Platform (Coniacian-Santonian, N Spain) and to Rhynchonella globata Arnaud, 1877 (Campanian, Les Charentes, Dordogne, SW France) and Rh. vesicularis Coquand, 1860 (Campanian, Charente, SW France). These observations document the great morphological diversity among all these species and lead us to erect a new species: Cyclothyris grimargina nov. sp. from the type material of Arnaud, and two new genera: Contortithyris nov. -
Paleoenvironmental Reconstruction of the Late Cretaceous Eastern Gulf Coastal Plain in Georgia and Alabama
Columbus State University CSU ePress Theses and Dissertations Student Publications 12-2005 Paleoenvironmental Reconstruction of the Late Cretaceous Eastern Gulf Coastal Plain in Georgia and Alabama Tracy L. Hall Columbus State University Follow this and additional works at: https://csuepress.columbusstate.edu/theses_dissertations Part of the Earth Sciences Commons, and the Environmental Sciences Commons Recommended Citation Hall, Tracy L., "Paleoenvironmental Reconstruction of the Late Cretaceous Eastern Gulf Coastal Plain in Georgia and Alabama" (2005). Theses and Dissertations. 75. https://csuepress.columbusstate.edu/theses_dissertations/75 This Thesis is brought to you for free and open access by the Student Publications at CSU ePress. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of CSU ePress. Digitized by the Internet Archive in 2012 with funding from LYRASIS Members and Sloan Foundation http://archive.org/details/paleoenvironmentOOhall Columbus State University College of Science Graduate Program in Environmental Science Paleoenvironmental Reconstruction of the Late Cretaceous Eastern Gulf Coastal Plain in Georgia and Alabama A Thesis in Environmental Science by Tracy L. Hall Submitted in partial fulfillment of the requirements for the degree of Master of Science December 2005 © 2005 by Tracy L. Hall 11 I have submitted this thesis in partial fulfillment of the requirements for the degree of Master of Science. J ! a gjMfc. Li. l cAa U^pJ. H Date Traiy Leigfi Hall We approve the thesis -
Brachiopoda, Rhynchonellida): Examples from the Late Cretaceous of Western Europe Danièle Gaspard, Sylvain Charbonnier
The debated question of asymmetrical rhynchonellids (Brachiopoda, Rhynchonellida): examples from the Late Cretaceous of Western Europe Danièle Gaspard, Sylvain Charbonnier To cite this version: Danièle Gaspard, Sylvain Charbonnier. The debated question of asymmetrical rhynchonellids (Bra- chiopoda, Rhynchonellida): examples from the Late Cretaceous of Western Europe. Bulletin de la Société Géologique de France, Société géologique de France, 2020, 191, pp.1. 10.1051/bsgf/2019016. hal-02445932v2 HAL Id: hal-02445932 https://hal.sorbonne-universite.fr/hal-02445932v2 Submitted on 4 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. BSGF - Earth Sciences Bulletin 2020, 191, 1 © D. Gaspard and S. Charbonnier, Published by EDP Sciences 2019 https://doi.org/10.1051/bsgf/2019016 urn:lsid:zoobank.org:pub:EA4C26EB-8371-433D-8696-6E402D5D3B0A Available online at: www.bsgf.fr The debated question of asymmetrical rhynchonellids (Brachiopoda, Rhynchonellida): examples from the Late Cretaceous of Western Europe Danièle Gaspard* and Sylvain Charbonnier UMR 7207, Centre de Recherche en Paléontologie, Paris, MNHN-Sorbonne Université-CNRS, Muséum national d’Histoire naturelle, 8 rue Buffon, CP 38, 75005 Paris, France Received: 22 February 2019 / Accepted: 13 November 2019 / Published online: 22 December 2020 Abstract – Many Cretaceous asymmetrical rhynchonellid brachiopods (Brachiopoda, Rhynchonellida) have long been considered as Rhynchonella difformis (Valenciennes in Lamarck, 1819). -
Upper Cretaceous) Rhynchonellide Brachiopods from Northern Spain
Cretaceous Research 79 (2017) 77e90 Contents lists available at ScienceDirect Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes Functional meaning of asymmetrical commissures in Coniacian (Upper Cretaceous) rhynchonellide brachiopods from Northern Spain * Melani Berrocal-Casero a, , Fernando Barroso-Barcenilla a, b, Fernando García Joral a, Manuel Segura b a Departamento de Paleontología (Grupo de Investigacion Procesos Bioticos Mesozoicos), Universidad Complutense de Madrid, 28040, Madrid, Spain b Departamento de Geología y Geografía (Grupo de Investigacion IberCreta), Universidad de Alcala, 28871, Alcala de Henares, Spain article info abstract Article history: The functional meaning of asymmetry in brachiopods has been a matter of discussion for over a century. Received 1 March 2017 Several hypotheses have been proposed to explain why these morphologies appear, the predominant Received in revised form idea in the literature being that it might be a non-adaptive characteristic. Here we present an in-depth 28 June 2017 study of the asymmetry present in the commissure of the rhynchonellide brachiopod Cyclothyris aff. Accepted in revised form 20 July 2017 globata from three Upper Cretaceous sections of northern Spain, with the aim to establish whether it is Available online 25 July 2017 correlated to some kind of palaeoenvironmental factor. A new hypothesis interpreting this asymmetry as a functional feature is proposed after the results obtained from the palaeoecological and taphonomical Keywords: Rhynchonellida study of the specimens. A noteworthy aspect of the asymmetry displayed by this species is that juvenile Asymmetry forms are fully symmetric while adult specimens are asymmetrical, but internal structures remain Geometric morphometrics symmetric throughout ontogeny. In adult forms, asymmetry is expressed as the division of the shell into Functional morphology two vertically displaced lobes, one of which is invariably shorter than the other.