Gkptarnostusj r o and Associated Trilobites in the United States GEOLOGICAL SURVEY PROFESSIONAL PAPER 374-F GhptamostusJr o and Associated Trilobites in the United States By ALLISON R. PALMER SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 374-F The systematics, faunal associations, and strati- graphic significance of American species of Glyptagnostus are discussed, and associated trilo- bites representing 21 genera and JI species are described and jigured UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1962 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. CONTENTS Page Page Abstract ______________________________ F-l Systematic paleontology Continued Introduction __________________________ 1 Crepicephalidae- _______________________________ F-27 Acknowledgments.------.--____________ 3 Kingstoniidae _________________ 29 Trilobites associated with Glyptagnostus _ _ 3 Leiostegiidae? _________________ 29 Stratigraphic significance of Glyptagnostus. 6 Menomoniidae. ______________ 30 Ecologic observations __________________ 10 Pterocephaliidae_ _____________ 31 Conclusion-. _ _________________________ 11 Aphelaspidinae____________ 32 Systematic paleontology._______________ 11 Pterocephaliinae, __________ 40 Agnostidae__ _ _____________________ 11 Locality information and faunal lists. 41 Clavagnostidae_ ___________________ 14 Alabama___________________ 42 Glyptagnostidae_ __________________ 15 Nevada_____--_------_--_---_ 42 Pseudagnostidae. __________________ 18 Tennessee_____ _______________ 43 Asaphiscidae. _ ____________________ 22 Texas _____________--__.___-- 43 Catillicephalidae___ _ _______________ 22 44 Cedariidae. _ ______________________ 23 Selected references. Cheilocephalidae_ __________________ 27 Index,___________ 47 ILLUSTRATIONS [Plates follow index] PLATE 1. Agnostidae and Clavagnostidae. 2. Glyptagnostidae and Pseudagnostidae. 3. Cedariidae, Crepicephalidae, Cheilocephalidae, Catillicephalidae, and Asaphiscidae. 4. Aphelaspidinae. 5. Aphelaspidinae. 6. Menomoniidae, Pterocephaliinae, Leiostegiidae?, Kingstoniidae, and rostral plates. p FIGURE 1. Global occurrences of species of Glyptagnostus. _______________________________________-----------------_ F-2 2. Occurrences of species of Glyptagnostus in Nevada. _____________________________________----------___-__ 3 3. Occurrences of species of Glyptagnostus in Alabama_________________-_____----_-____-__-_--------_--_--- 3 4. Ranges of identified species of trilobites in Glyptagnostus-beanng beds at Woodstock, Ala_----_______________ 4 5. Ranges of identified species of trilobites in Glyptagnostus-beanng beds at Cedar Bluff, Ala____________________ 4 6. Ranges of identified species of trilobites in Glyptagnostus-bearing beds at Cherry Creek, Nev_ ________________ 5 7. Ranges of identified species of trilobites in Glyptagnostus-bearing beds at McGill, Nev_______________________ 6 8. Correlation of faunal sequences in parts of early Upper Cambrian sections at McGill and the Snake Range, Nev_______-_____------------__________--____-__--____--_--____--____________________-----__--___ 8 9. Correlation of lower parts of Upper Cambrian faunal successions between North America and Sweden_________ 10 10. Stratigraphic relations of the Dunderberg and Hamburg formations between McGill and Cherry Creek, Nev___ 10 11. Evolutionary development of the pydidium of Glyptagnostus- _____________-___-__-_______-_--__----_----- 17 12. Partial reconstruction of Carinamala longispina n. sp__________________________________--_--_--_-------_ 23 13. Comparison of length of frontal area to length of glabella for the type lots of Aphelaspis walcotti Resser and A. brachyphasis n. sp--------------------------------------------------------------------------------- 34 14. Partial reconstruction of Listroa toxoura n. sp--,------------------------------------------------------- 41 TABLE Page TABLE 1. Summary of morphology, faunal associations, Stratigraphic range, and correlation of Glyptagnostus species in the United States.___-___________________________-__-________-___--_-__----__--------_-----.----.------ F-7 in SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GLYPTAGNOSTUS AND ASSOCIATED TRILOBITES IN THE UNITED STATES By ALLISON R. PALMER ABSTRACT 1938), southwest Texas (Wilson, 1954), western Ten­ Glyptagnostus is represented in the United States by two nessee (Grohskopf, 1955), central Alabama (Butts, species, G. reticulatus (Angelin) and G. stolidotus Opik. The 1926; Resser, 1938), and Newfoundland (Kindle and former is further represented by two subspecies, G. reticulatus reticulatus (Angelin) and G. reticulatus angelini (Resser). The Whittington, 1959). During the past decade, and oldest species, G. stolidotus, has been found only in association particularly during the field seasons of 1958 and 1959, with species of Cedaria. The youngest subspecies, G. reticulatus Glyptagnostus was collected from the following areas in reticulatus, is known only in association with Aphelaspis and the Nevada (fig. 2): (a) Hot Springs Range; (b) Tybo; acrotretid brachiopod Angulotreta. G. reticulatus angelini occu­ (c) Hamilton district; (d) Cherry Creek; (e) McGill. pies an intermediate stratigraphic position in association with aphelaspinid trilobites and the acrotretid brachiopod Opisthotreta. Near McGill and Cherry Creek, fossiliferous sequences Comparison of faunal successions in the Snake Range and at including Glyptagnostus, from the lower part of the McGill, Nev., provides strong evidence to show that the beds Dunderberg formation, were intensively collected. with G. reticulatus angelini and aphelaspinid trilobites are Data obtained from these collections and from re­ contemporaneous with beds assigned to the Crepicephalus zone collection of previously known localities in the Cona- in central United States. Two biofacies, designated as the Crepicephalid and Pterocephaliid biofacies, are recognized. sauga formation at Woodstock and Cedar Bluff, Ala. The contact between beds with trilobites of the Crepicephalid (fig. 3) form the principal basis for the conclusions biofacies and younger beds with trilobites of the Pterocephaliid reached in this paper. biofacies, previously thought to be the same age over all of the Outside North America, Glyptagnostus has been re­ United States, is shown to be measureably older in parts of ported from the northeastern Siberian platform Nevada and Alabama than it is in central United States. Trans- gressive replacement of the Crepicephalid biofacies by the (Savizky and Lazarenko, 1959) northwestern Siberian Pterocephaliid biofacies is thus indicated during the early platform (Miroshbikov and others, 1959); south Korea Late Cambrian. (Kobayashi, 1949); southeastern China (Lu, 1956); Accurate placement of Glyptagnostus in the American Cam­ northeastern Australia (Whitehouse, 1939; Opik, 1956, brian section provides new evidence for correlating these beds, 1958, 1961); Tasmania (Banks, 1956); southern Sweden at least down through the Crepicephalus zone, with beds no older than the Olenus zone of the standard Upper Cambrian (Angelin, 1854; Westergard, 1922, 1947); southeastern section of Sweden. Norway (Brogger, 1882; Strand, 1929; Henningsmoen, Trilobites representing 21 genera and 31 species .found in 1958); Bornholm (Poulsen, 1923); and Great Britain association with Glyptagnostus, principally in eastern Nevada and (Belt, 1867; Lake, 1906). Kobayashi (1949) was im­ central Alabama, are described. New taxa include: Homagnos- pressed by the wide distribution of Glyptagnostus and tus comptus n. sp., Aspidagnostus laevis n. sp., Aspidagnostus rugosus n. sp., Pseudagnostina contracta n. gen. n. sp., Carinamala considered all the forms then known to him to represent longispina n. gen. n. sp., Cedaria brevifrons n. sp., Coosia longocula a single species, G. reticulatus (Angelin). He conceived n. sp., Komaspidella occidentalis n. sp., Deiracephalus unicornis of a "Glyptagnostus hemera, the oldest world instant," n. sp., Aphelaspis brachyphasis n. sp., Aphelaspis subditus n. sp., believing that "because morphic complexity (of G. Olenaspella regularis n. sp., Olenaspella separata n. sp., Listroa reticulatus) suggests high specialization, homotaxial dif­ toxoura n. gen., n. sp. ference of time may be expected to be slight * * *," INTRODUCTION and that all occurrences of Glyptagnostus reticulatvs Glyptagnostus is a bizarre genus of Upper Cambrian could therefore be considered contemporaneous. agnostid trilobites with a striking radial and generally Recently, Opik, working with the Glyptagnostus also reticulate ornament on the cephalic cheeks and faunas of Australia, and the writer, working with the pleural regions of the pygidium (pi. 2, fig. 1-8, 11). American material, have found evidence that seems to It has been recorded from North America at the require modification of Kobayashi's thesis. Opik (1958, following places (fig. 1): British Columbia (Kobayashi, 1961) has already published some of his observations F-l F-2 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY r'-^-^if-T ^>r (. ( \N U >' Cco K'/ (^ V V, ,-*£> f-^^ff S^ J^ \ ,-i<rto$ fel~^v- jf IV, L-,, >?, 4^^ ?' J» ^4^&i nx-^^' ($?-<r' * I 3 sr*^r ~ ^T m ,-( ) ^^ \W « ~ ft)7f\w^ ti Js -g S >P V =^r n \V <Ti "T^ vl/ &£? ,/v \ GLYPTAGNOSTUS AND ASSOCIATED TRILOBITES F-3 paper. Most of the photographs on the accompanying plates were prepared