A generic revision and phylogenetic analysis of the Turbinoliidae (Cnidaria: Scleractinia)

Abstract

Cairns, Stephen D. A Generic Revision and Phylogenetic Analysis of the Turbinoliidae (Cnidaria: Scleractinia). Smithsonian Contributions to Zoology, number 591, 55 pages, 5 figures, 10 plates, 6 tables, 1997.—The monophyly of the Turbinoliidae is based on the unique (within the Caryophylliina) character of having its entire corallum invested with tissue, which is reflected in its well-formed costae from base to calice and its characteristically deep intercostal regions. All turbinoliids are solitary and free-living, and thus the complete investiture of its corallum might facilitate movement through or across a sandy substrate. The Turbinoliidae consists of 28 genera and 163 valid species, of which 22 genera and 49 species are extant. The earliest known turbinoliid is from the Late Cretaceous (Campanian) of Antarctica. All 28 genera are diagnosed and figured herein. The stratigraphic and geographic distributions are discussed for each genus, and a list of species known for each genus, including junior synonyms, is given. Two genera and two species are described as new: Pleotrochus, P. zibrowii, Foveolocyathus, and Sphenotrochus wellsi. Peponocyathus is restricted to those species having transverse division, which requires the resurrection of' Deltocyathoides Yabe and Eguchi, 1932, for those species that do not reproduce by transverse division, and it also requires the synonymy of Truncatocyathus Stolarski, 1992. Tropidocyathus is divided into two genera, allowing the resurrection of Cyathotrochus Bourne, 1905. Oryzotrochus stephensoni Wells, 1959, is identified as a Turbinolia, which synonymizes Oryzotrochus and extends the stratigraphic range of Turbinolia from the Oligocene to Recent. Phylogenetic analysis of the 28 turbinoliid genera was carried out using 16 characters, comprising 49 character states. Relationships among taxa were determined based on parsimony and successive weighting of characters. Subfamilies of the Caryophylliidae were used as outgroups. Characters that contributed highly to the phylogenetic hypothesis were costal ornamentation, costal origination, and septal number. Characteristics of thecal structure (i.e., imperforate, externally pitted, perforate) were re-examined in all genera. The resulting phylogenetic hypothesis (Figure 2) suggests that the turbinoliids are divided into two major clades. One (clade 2) contains 12 genera including all six Late Cretaceous Antarctic genera, as well as genera first recorded from the Eocene of New Zealand and Oligocene of South Australia. Coralla of this clade are characterized by having trifurcate costal origination and serrate costal ornamentation. The other major clade (clade 3) contains 14 genera, including one from the Late Cretaceous of New Zealand, five with first occurrences in the Paleocene to Miocene of Europe and North America, and three from the Eocene to Oligocene of South Australia. These are genera characterized by coralla with less than 48 septa and granular or smooth costae. It is cautioned that the results of this analysis are considered preliminary, as it is based exclusively on skeletal characters. Consequently, clades are not highly supported, nonetheless, this analysis suggests which skeletal characters should be examined more carefully in the future, and it serves as a comparison for future analyses that might include tissue and/or molecular characters. The status of the Early Cretaceous genus Platytrochopsis Sikharulidze, 1975, is also discussed. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Annals of the Smithsonian Institution. SERIES COVER DESIGN: The coral Montastrea cavernosa (Linnaeus). Library of Congress Cataloging-in-Publication Data Cairns, Stephen. A generic revision and phylogenetic analysis of the Turbinoliidae (Cnidaria: Scleractinia) / Stephen D. Cairns, p. cm.—(Smithsonian contributions to zoology ; no. 591) Includes bibliographical references (p. ). I. Turbinolidae—Classification. 2. Turbinolidae—Phylogeny. I. Title. II. Series. QLI.S54 no. 591 [QL377.C7] 590s-dc2! [593.6] 97-28316 CIP 5 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.