Some Middle Ordovician Brachiopods and Trilobites From the Basin Ranges, Western United States GEOLOGICAL SURVEY PROFESSIONAL PAPER 523-D Some Middle Ordovician Brachiopods and Trilobites From the Basin Ranges, Western United States By REUBEN JAMES ROSS, ]R. With stratigraphic sections A, north of Pyramid Peak, Calif., by R. J. ROSS, ]R., and B, in Specter Range, Nev., by HARLEY BARNES CONTRIBUTIONS TO PALEONTOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 523-D Species of I 4 genera of brachiopods and 3 2 genera of trilobites are described to support stratigraphic conclusions presented in Geological Survey Bulletin II8o-C UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1967 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page· Page Abstract __________________________________________ _ D1 Systematic paleontology-Continued · 1ntroduction ______________________________________ _ 1 Phylum Arthropoda-Continued i Purpose and scope of report _____________________ _ 1 Class Trilobita-Continued 1 Treatment of paleontological materiaL ___________ _ 1 Genus Raymondaspis ___________________ _ D15 Acknowledgments ______________________________ _ 1 lllaenus ____________________ ---- _ 16 Bathyurus _______________________ _ 1 Stratigraphic summary _________________________ _ 2 17 ~ystematic paleontOlogy ____________________________ _ 2 Bathyurellus _____________________ _ 18 Phylum Brachiopoda ___________________________ _ 2 Goniotelina ______________________ _ 19 Class Articulata ___________________________ _ 2 Acidiphorus ________________ ------ 20 Genus Orthambonites ___________________ _ 2 Strigigenalis ________________ - - _-_ - 21 Plaesiomys ______________________ _ 4 I schyrotoma __________________ - __ - 21 Hesperorthis ___ __________________ _ 4 Antpyx _________________________ _ 21 Ptychopleurella __________________ _ 4 Lonchodontas ____________________ _ 22 V alcourea _______________________ _ 5 Ceraurus ________________________ _ 23 Desmorthis ______________________ _ 5 Cydonocephalus __________________ _ 23 Skenidioides __ ___________________ _ 5 Cheirurid?, indet ________________ _ 23 Atelelasma _______________________ _ 6 H eliomeroides ____________________ _ 24 Oxoplecia _______________________ _ 6 Pseudomera ________ - _- _---------- 24 Stenocamara ____ _________________ _ 6 Ectenonotus __________________ - --- 24 Leptellina ___________________ ----- 6 Miracybele ______________________ _ 25 Sowerbyella ___ ___________________ _ 7 Protocalymene, n. gen _____________ _ 27 M acrocoelia _____________________ _ 7 Calyptaulax _____________________ _ 28 Laticrura _______________________ ~ 7 Apatolichas __________________ - _- _ 29 Phylum Arthropoda ____________________________ _ 8 Diacanthaspis __________________ - _ 30 Class Trilobita ____________________________ _ 8 Odontopleurid, indet _____________ _ 30 Genus Trinodus _______________________ _ 8 Clelandia _______________________ _ Shuntardia ______________________ _ 30 9 Stratigraphic sections _______________________ -------- 32 Carolinites ______________________ _ 10 Section A, north of Pyramid Peak, Calif_ _________ _ 32 Remopleurides ___________________ _ 12 I sotelus _________________________ _ 12 Fossils listed by USGS numbered collections __ _ 33 I soteloides _______________________ _ 12 Section B, Specter Range, Nev., by Harley Barnes __ 34 M egistaspis _____________________ _ 13 Fossils listed by USGS numbered collections __ _ 37 N ileus ___ _______________________ _ 13 References cited ____________________________ ~_-_---- 38 Il~enops~ __________ ___________ _ Index ____________________________________________ _ 41 7 14 ILLUSTRATIONS [Plates 1-10 follow index; plate 11 is in p(}Cket] 1. Brachiopods: OrthambonUes, Desmorthis, Ptychopleurella, Hesperorthis, and Plaesiomys? 2. Brachiopods: Skenidioides, Atelelasrna, Stenocantara ?, Macrocoelia ?, Laticrura, and Oxoplecia. 3. Brachiopods: LeptelUna, Sowerbyella, •and Valco1trea. Trilobites: Trinodus and OaroUnites. 4. Trilobites: Isotelus, Megistaspis?, Nileus, Raymondaspis, Isoteloides?, and Illaenopsis?. 5. Trilobites: Illaenus. 6. Trilobites: Bathyruru.s, Bathyurellus, GonioteUna, Aoidiphorus?, and Strigigenalis. 7. Trilobites: Ischyrotoma, _4mpyx, Oydonocephalus, Lonchodomas, Heliomeroides, Pseudomera, Oeraurus?, and Ectenonotus. S. Trilobites: Ectenonotus, Paracybeloides?, Miracybele, and Oalyptaulax. 9. Trilobites: Protocalymene, Diacanthaspis, Apatolichas ?, odontopleurid, and cheirurid ?. 10. Trilobites: Olelandia and Shumardia. 11. Diagrammatic st:rtatigraphic sections of Ordovician rocks, showing ranges of Middle Or~lovician fossils from the Arrow Canyon Range, Nevada, on the eas:t, to the Inyo Mountains, Catl'ifornia. III CONTRIBUTIONS TO PALEONTOLOGY 1SOME MIDDLE ORDOVICIAN BRACHIOPODS AND TRILOBITES FROM THE BASIN RANGES I WESTERN UNITED STATES By REUBEN JAMES Ross, Jr. ABSTRACT· spacing of both the lithologic units and the fossil assem­ Although not encompassing the entire available fossil assem­ blages in the Specter Range, Nev., is so like that at blage reported in U.S. Geological Survey Bulletin 1180-C, 14 Pyramid Peak that a section recorded by Harley Barnes g€~nera of brachiopods and 32 genera of trilobites described here is also included for comparison. support stratigraphic conclusions presented in that bulletin. With the exception of fossils from Pyramid Peak, Those conclusions call for a revision of the Middle Ordovician l'"~iterock, Marmor, and Ashby Stages of Cooper (1956). Eco- Calif., and Specter Range, Nev., no effort is made to 1log1c factors, rather than age, may account for differences be­ give detailed locality data for each species. Instead, ltween certain zonal assemblages of fossils from the Antelope reference is made to U.S. Geological Survey collections !Valley Limestone ( Pogonip Group) across southern Nevada. and pertinent pages in Ross ( 1964b) ; however, relative I:F'or example, ecologic control may explain the westerly substi­ positions of collections are indicated on plate 11. ltution of the Rhysostrophia zone assemblage in the stratigraphic !position of the Anomalorthis zone assemblage found farther east. TREATMENT OF PALEONTOLOGICAL MATERIAL Stratigraphic sections measured at Pyramid Peak, Calif., and in the Specter Range, Nev., supplement those sections already Formal classification of brachiopods and trilobites is I !PUblished to show distribution of fossils stratigraphically. not repeated here. The classification used by Cooper ( 1956) is followed, and the reader is referred to it for I INTRODUCTION suprageneric details. PURPOSE AND SCOPE OF REPORT Similarly; the classification of trilobites follows that This report presents descriptions of fossils that sup­ of the "Treatise on Invertebrate Paleontology" ( Geol. port conclusions of a preliminary study of Middle Soc. America, 1959, p. 160-167). Terminology used in Ordovician stratigraphy in southern Nevada and adja­ descriptions of trilobites also follows usage of the lcnnt California (Ross, 1964b, U.S. Geol. Survey Bull. treatise (p. 117-126), except that the occipital ring is !1180-C). As a result of that study, revisions were sug­ considered part of the glabella in all trilobites. lgested for the Middle Ordovician stages of Cooper ACKNOWLEDGMENTS !( 1956, p. 6-9). Fossil brachiopods and trilobites that lare critical to my conclusions, particularly species that Early in the study of brachiopods for this report, lare new, are described. Many genera and species-such G. A. Cooper examined most of the collections, checking las Orthidiella and Anomalorthis-have been fully de- on identifications; I am grateful to him not only for c:ribed and illustrated by Ulrich and Cooper ( 1938) corroborating most of the identifications, but also par­ 1nd by Cooper (1956), and their descriptions are not ticularly for calling my attention to those that were repeated here. incorrect. H. B. 'Vhittington gave similar assistance f Subsequent to completion of the manuscript for U.S. on a few selected trilobites. peological Survey Bulletin 1180-C, more than a dozen Type specimens of Phleger's ( 1933) brachiopods and rdditional stratigraphic sections were measured. Be­ trilobites from the Ordovician of the northern Inyo pause two very interesting trilobite assemblages were Mountains were loaned by Dr. Theodore Downs of the pbtained from the north side of Pyramid Peak in the Los Angeles County Museum. yan quadrangle, California, that section is presented The stratigraphic section of the Pogonip Group in the · n this report and is intended for use in conjunction Ryan quadrangle was located by J. F. McAllister on the ;vith sections included in Ross (1964b). Similarly, the north side of Pyramid Peak. McAllister conferred Dl D2 CONTRIBUTIONS TO PALE ONTOLOGY with me on the position of formation boundaries in this in the Orthidiella zone of the Specter Range (USGS area. L. A. Wilson has given me continued assistance colin. D1441 CO). From sections outside the area cov­ with fieldwork and has prepared and photographed ered by this report there are additional indications that much of the fauna studied. support correlation of the Anomalorthis and Rhysostro­ In 1964, Wilfrid Davis of San Jose State College phia zones. made available, through D. C. Ross, several collections Shortly before the manuscript for this report was from the Barrel Spring Formation of the northern Inyo completed,