New Superfamily and Three New Families of Tetraodontiform Fishes from the Upper Cretaceous: The Earliest and Most Morphologically Primitive Plectognaths T?*'M-£$; IW? SP*"* !«*&***' and iNZO SOR u \it*' >*mn. gUFVdl •-.-. a&, -*&.- ri ;. t%k m • -t--g - .< M%f -'if ' .^•»?r '*.:. k» K*: -'3TS3 ;JP SERIES PUBLICATIONS OF THE SMITHSONIAN INSTITUTION Emphasis upon publication as a means of "diffusing knowledge" was expressed by the first Secretary of the Smithsonian. In his formal plan for the institution, Joseph Henry outlined a program that included the following statement: "It is proposed to publish a series of reports, giving an account of the new discoveries in science, and of the changes made from year to year in all branches of knowledge." This theme of basic research has been adhered to through the years by thousands of titles issued in series publications under the Smithsonian imprint, commencing with Smithsonian Contributions to Knowledge in 1848 and continuing with the following active series: Smithsonian Contributions to Anthropology Smithsonian Contributions to Botany Smithsonian Contributions to the Earth Sciences Smithsonian Contributions to the Marine Sciences Smithsonian Contributions to Paleobiology Smithsonian Contributions to Zoology Smithsonian Folklife Studies Smithsonian Studies in Air and Space Smithsonian Studies in History and Technology In these series, the Institution publishes small papers and full-scale monographs that report the research and collections of its various museums and bureaux or of professional colleagues in the world of science and scholarship. The publications are distributed by mailing lists to libraries, universities, and similar institutions throughout the world. Papers or monographs submitted for series publication are received by the Smithsonian Institution Press, subject to its own review for format and style, only through departments of the various Smithsonian museums or bureaux, where the manuscripts are given substantive review. Press requirements for manuscript and art preparation are outlined on the inside back cover. I. Michael Heyman Secretary Smithsonian Institution SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY • NUMBER 82 New Superfamily and Three New Families of Tetraodontiform Fishes from the Upper Cretaceous: The Earliest and Most Morphologically Primitive Plectognaths James C. Tyler and Lorenzo Sorbini SMITHSONIAN INSTITUTION PRESS Washington, D.C. 1996 ABSTRACT Tyler, James C, and Lorenzo Sorbini. New Superfamily and Three New Families of Tetraodontiform Fishes from the Upper Cretaceous: The Earliest and Most Morphologically Primitive Plectognaths. Smithsonian Contributions to Paleobiology, number 82, 59 pages, 25 figures, 2 tables, 1996.—Fishes of the order Tetraodontiformes previously have been known with assurance from as early as the Lower Eocene, about 55 MYA. Two Upper Cretaceous taxa, Protriacanthus d'Erasmo (1946) from Comen, Slovenia, about 90 MYA, and Plectocretacicus Sorbini (1979) from Hakel, Lebanon, about 95 MYA, were referred by their authors to the tetraodontiforms, respectively in the vicinity of triacanthoids and ostracioids. Both of these taxa were originally based on single specimens in which insufficient details of critical osteological features were exposed, and their familial and ordinal placement were open to question. Based on additional specimens now available, including acid preparations of several specimens of both species, we believe that they represent two new families (Protriacanthidae and Plectocre- tacicidae) of tetraodontiforms with numerous features that are more primitive than previously reported for the order. We describe a third taxon, the new genus Cretatriacanthus (and new family Cretatriacanthidae), based on a single specimen from the Upper Cretaceous of Nardd, Italy, about 70 MYA. It shares most of the numerous primitive features of Protriacanthus and Plectocretacicus. Although many of their features are primitive, all three of these Upper Cretaceous taxa possess the most salient derived features of tetraodontiforms (e.g., reduced number of vertebrae, no anal-fin spines, reduced number of pelvic-fin rays, absence of certain skull bones, and, when present, long posterior process of pelvis with its halves in close contact or fused). The three Upper Cretaceous taxa share four derived features (absence of teeth, modified scales around base of pelvic spine, presence of subocular shelf, and diminutive size) that unite them in a clade herein recognized as the superfamily Plectocretacicoidea, whereas all other tetraodontiforms (those from the Lower Eocene to present) are united by seven derived features. Within the Plectocretacicoidea, five derived features support the sister-group relationship of Protriacanthus and Plectocretacicus. Each of the three Upper Cretaceous taxa has a mosaic of primitive and specialized features, with some of the latter being independently derived relative to similar features of triacanthoids, balistoids, and ostracioids. The evidence indicates that the Plectocretacicoidea (presently known from 70 to 95 MYA) are the morphologically primitive sister group of all other tetraodontiforms (presently known from 55 MYA to Recent). OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: The trilobite Phaecops rana Green. Library of Congress Cataloging-in-Publication Data Tyler, James C, 1935- New superfamily and three new families of tetraodontiform fishes from the Upper Cretaceous . the earliest and most morphologically primitive plectognaths / James C. Tyler and Lorenzo Sorbini. p. cm. — (Smithsonian contributions to paleobiology ; no. 82) Includes bibliographical references. 1. Cretatriacanthus guidotti. 2. Plectocretacicus clarae. 3. Protriacanthus gortanii. 4. Paleontology— Cretaceous. 5. Fishes, Fossil. I. Sorbini, Lorenzo. II. Title. III. Series. QE701.S56 no. 82 [QE852.T48] 560 s—dc20 [567\5] 95-46251 © The paper used in this publication meets the minimum requirements of the American National Standard for Permanence of Paper for Printed Library Materials Z39.48—1984. Contents Page Introduction 1 Methods 2 Text and Figure Abbreviations 2 Acknowledgments 3 PLECTOCRETACICOIDEA, new superfamily 3 CRETATRIACANTHIDAE, new family 4 Cretatriacanthus, new genus 4 Cretatriacanthus guidottii, new species 5 PLECTOCRETACICIDAE, new family 16 Plectocretacicus Sorbini, 1979 16 Plectocretacicus clarae Sorbini, 1979 16 PROTRIACANTHIDAE, new family 27 Protriacanthus d'Erasmo, 1946 27 Protriacanthus gortanii d'Erasmo, 1946 27 Rationale for Outgroup Comparisons 36 Analysis of Characters 40 Synapomorphies of Tetraodontiformes 40 Synapomorphies of Non-plectocretacicoid Tetraodontiformes 44 Synapomorphies of Plectocretacicoidea 46 Synapomorphies of Plectocretacicidae + Protriacanthidae Clade 47 Autapomorphies of Cretatriacanthidae 49 Autapomorphies of Plectocretacicidae 51 Autapomorphies of Protriacanthidae 52 Comments on Other Features 53 Summary of Relationships 55 Conclusion 56 Literature Cited 58 in New Superfamily and Three New Families of Tetraodontiform Fishes from the Upper Cretaceous: The Earliest and Most Morphologically Primitive Plectognaths James C. Tyler and Lorenzo Sorbini Introduction Triacanthidae), in another, in a genus (Eospinus) that is placed Until now, the paleontological history of the tetraodontiform incertae sedis at the family level among balistoids; moreover, (plectognath) fishes was believed to begin in the Eocene. there are three extinct families. The single Eocene species of Five (Triacanthidae, Aracanidae, Ostraciidae, Tetraodontidae, Triodontidae is similar enough to the single Recent species of Diodontidae) of the 10 extant families of the order have the family to be accommodated in the same genus, Triodon. unquestioned representatives in the lower part of the Middle Only the Triacanthodidae, Balistidae, and Monacanthidae are Eocene (about 50 MYA) of Monte Bolca, Italy, as do three not yet known from the Eocene; triacanthodids and balistids are extinct tetraodontiform families (Spinacanthidae, Eoplectidae, first known from the Oligocene and monacanthids from the Zignoichthyidae). Two other families of tetraodontiforms are Pliocene (Tyler et al., 1993, and contained references; with found in other Eocene localities, the Molidae from the Upper monacanthids recently found by one of us, L.S., in the Miocene Eocene (about 40 MYA) of the North Caucasus, Russia, and the of Mondaino, central Italy). Triodontidae from the Lower Eocene (about 55 MYA) of the Two Upper Cretaceous fishes that have been described as London Clay, southern England, the Lower and Middle Eocene tetraodontiforms, but have not been widely accepted as such, of Belgium and France, and the Middle Eocene of Angola. A are Protriacanthus and Plectocretacicus. primitive balistoid (Eospinus), with features of both balistoids Protriacanthus gortanii d'Erasmo (1946), based on a single and ostracioids, is known from the Lower Eocene of specimen (single plate) from the Upper Cenomanian-Lower Turkmenistan (two new balistoid genera, similar to Eospinus, from the Upper Paleocene Moclay of Denmark and the Middle Turonian of Comen, northwestern Slovenia, near Trieste, Italy Eocene of Monte Bolca are under study by the authors and N. (about 90 MYA), was described as related to the Sclerodermi Bonde, University of Copenhagen). (triacanthoids, balistoids, ostracioids) and especially to triacan­ thoids. The incompleteness of the holotype
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