Brachiopoda and Ostracoda of the Cobleskill Limestone (Upper Silurian) of Central New York GEOLOGICAL SURVEY PROFESSIONAL PAPER 730 Brachiopoda and Ostracoda of the Cobleskill Limestone (Upper Silurian) of Central New York By JEAN M. BERDAN GEOLOGICAL SURVEY PROFESSIONAL PAPER 730 Descriptions and illustrations of 12 species of brachiopods (including one new species \ and 2$ species of ostracodes (including four new genera and 14. new species \ UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1972 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress catalog-card No. 70-189150 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 31 (paper cover) Stock Number 2401-2056 CONTENTS Page Page Abstract_ _ _______________________________________ 1 Systematic paleontology Continued Introduction.______________________________________ 1 Phyllum Arthropoda Continued Previous work__________________________________ 1 Class Crustacea Continued Acknowledgments.-.-- __________________________ 3 Subclass Ostracoda Continued Scope of the report____________________________ 3 Genus Hammariella Martinsson_____ 24 List of localities.____-_---_--__-_---___-___-________ 5 Genus Kloedeniopsis n. gen__________ 24 Paleoecology_ ________-__--_-__-_-_-___-____________ Genus Tikiopsis n. gen ______________ 27 Age and correlation.__-_-______-_---__--__-_________ Genus Welleriopsis Swartz and Whit- Systematic paleontology.____________________________ 9 more. _________--__-___-_____--__ 28 Phylum Brachiopoda__-_-_-____-__-_-__-_____-__ 10 Kirkbyellid?, gen. and sp. indet______ 29 Class Inarticulata...________________________ 10 Hollinid?, gen. and sp. indet_________ 29 Genus Craniops HalL_______________ 10 Genus Leiocyamus Martinsson________ 29 Class Articulata.___________________________ 10 Genus Primitiopsis Jones ____________ 30 Genus Leptostrophia Hall and Clarke.- 10 Genus Hattiella Ulrich______________ 30 Genus Morinorhynchus Havlfc"ek______ 11 Genus Dizygopleura Ulrich and Bassler. 31 Genus Eccentricosta Berdan__________ 12 Genus Kloedenella Ulrich and Bassler, _ 37 Genus Machaeraria Cooper._________ 13 Genus Eukloedenella Ulrich and Bass- Genus Microsphaeridiorhynchus Sar- 37 tenaer.__________________________ 14 Genus Marginia Polenova.__________ 38 Genus Lanceomyonia Havlic"ek_ _______ 15 Genus Bonneprimites Swartz and Whit- Genus Protathyris Kozlowski_________ 16 more. _-_-_-__--_------_---_---_- 38 Genus Howellella KozlowskL_________ 18 Genus Thlipsuropsis Swartz and Whit- Phylum Arthropoda.____________________________ 21 more. ___________________________ 38 Class Crustacea.___________________________ 21 Subclass Ostracoda.______-_-____-_--___ 21 Genus Thlipsurella Swartz___________ 39 Genus Leperditia Rouault-__________ 21 Genus Cytherellina Jones and Holl____ 39 Genus Garniella Martinsson________ 22 Genus Nunculina n. gen.____________ 40 Genus Migmatella n. gen___________ 22 References cited. 41 Genus Dibolbina Ulrich and Bassler__ 23 Index..________ 45 ILLUSTRATIONS [Plates follow index] PLATE 1. Morinorhynchus?, Craniops, Eccentricosta, and Leptostrophia. 2. Lanceomyonia?, Machaeraria?, Microsphaeridiorhynchus, Protathyris, and Howellella. 3. "Kloedenia," Kloedeniopsis, Welleriopsis?, Tikiopsis, and Leperditia. 4. Hammariella, Garniella, Migmatella, and Dibolbina. a. Dizygopleura. 6. Thlipsurella, Thlipsuropsis, Nunculina, hollinid?, kirkbyellid?, Halliellaf, Marginia?, Cytherellina, Eukloedenella?, Bonneprimites?, Leiocyamus, Kloedenella, and Primitiopsis?. IV CONTENTS Page FIGURE 1. Index map showing generalized outcrop belt of Cobleskill Limestone and approximately equivalent formations in New York State showing fossil localities________________________________________________ 4 2-5. Diagrams showing: 2. Nine transverse sections of Lanceomyonia? duribarin.. sp_________ 15 3. Twelve transverse sections of Protathyris sulcata.. ______________ 17 4. Twelve transverse sections of Protathyris nucleolata. - ___________ 19 5. Inferred cross sections of three groups of North American beyrich- iaceans_ ___ ______________________________________________ 25 6. Scatter diagram showing length versus height of Dizygopleura hallii. _____ 32 7. Scatter diagram showing length versus height of Dizygopleura monostigma n. sp_________________________________________________________ 35 8. Drawing showing interior of left valve of Cytherellina crepiduloides n. sp_ 40 9. Drawings showing transverse sections of Nunculina striatopuncta n. sp___ 41 TABLE TABLE 1. Distribution of brachiopods and ostracodes from the Cobleskill Limestone (Upper Silurian) of central New York____________________________ BRACHIOPODA AND OSTRACODA OF THE COBLESKILL LIMESTONE (UPPER SILURIAN) OF CENTRAL NEW YORK By JEAN M. BERDAN ABSTRACT mation is largely dolomite (Rickard, 1962, p. 26) except The Cobleskill Limestone is a thin unit that extends across for an area of limestone at Aurelius Station, Frontenac New York from the westernmost part of Albany County on the Island, and Seneca Falls in Cayuga County. Fossils are east to Seneca County on the west. It is considered to be not most abundant in the limestone, and especially in the younger than latest Silurian (Pridoli) in age, largely because it contains the coral Gystlhalysites. The fauna belong to the crinoidal limestone, which is commonly associated with Eccentricosta, Zone of the Appalachians, known elsewhere in biostromal beds of corals. West Virginia, Virginia, Maryland, Pennsylvania, New Jersey, eastern New York, and Maine. Twelve brachiopods are described PREVIOUS WORK and illustrated, of which one species is new. Twenty-five ostra- codes are also described and illustrated, of which four genera The stratigraphy of the Cobleskill Limestone has and 14 species are new. Kloedeniopsis n. gen. includes some of the been more thoroughly studied than its fauna, probably ostracodes formerly called Eloedenia in North America. Three in part because the dolomitic nature of the rock makes it o,stracode genera G-arnieUa, Hammariella, Leiocyamus difficult to extract satisfactory specimens of fossils, and previously known only from the Baltic province in Europe are reported from North America for the first time. in part because the more dolomitic parts of the forma­ tion have very few fossils. Hall (1852, p. 321-322) called INTRODUCTION it the "coralline limestone" and described it as "* * * The Cobleskill Limestone is the youngest f ossilif erous a thin mass of limestone, characterized by an immense formation of unquestioned Silurian age in central New number of corals, chiefly favosites * * * which forms York, and as such, its fauna, though small, is of excep­ a band so distinct from any other limestone that it has tional interest. It is a thin unit which extends from West been for many years known by this name." He consid­ Township in Albany County (Goldring, 1935, p. 78) ered it the eastern extension of the Niagara (Lock- on the east to Seneca Falls in Seneca County on the port) Limestone of Middle Silurian age, but recog­ west, a distance of about 130 miles. According to Rick- nized that the fauna was not exactly the same and so ard (1962, p. 26), its maximum thickness is about 15 described and illustrated the fossils separately (Hall, 1852, p. 322-338, pis. 72-78). According to Hartnagel feet, but at the type locality near Cobleskill Creek, along the road between Braymansville and Howes Cave (1903, p. 1113-1114), Clarke (in Merrill, 1902, p. r42) in Schoharie County, it is only 9 feet thick. In the east­ was the first to use the name Cobleskill for the "coral­ line limestone" of Hall and other geologists, but he did ern part of the outcrop belt the Cobleskill rests uncon- formably upon the Brayman Shale of Silurian age not discuss the formation or designate a type section. The most thorough stratigraphic study of the Coble- (Rickard, 1962, p. 26), but west of Deck in Herkimer skill was made by Hartnagel (1903), who demonstrated County the Oxbow Dolomite of Late Silurian age ap­ pears beneath it. Throughout its extent the Cobleskill for the first time that the Cobleskill was not the equiva­ is overlain by the Chrysler Limestone of Silurian and lent of the Lockport, but considerably younger, and published lists of fossils from the Cobleskill at 12 local­ Devonian age. ities in Schoharie County and three localities in the Lithologically the Cobleskill varies from an impure crinoidal limestone to a fine-grained dark-gray aphanitic vicinity of Union Springs in Cayuga County. limestone to buff-colored or drab dolomite. Limestone is Grabau (1906, p. 104-111) redescribed the Coble- more common in the eastern part of the outcrop belt, skill Limestone in the Schoharie and Cobleskill areas, although even in Schoharie County it tends to be dolo- and illustrated the more common fossils. In addition, mitic. West of Clockville in Madison County the for­ local details of the stratigraphy and descriptions of lo- calities are given in New York State Museum Bulletins indicated (1948, p. 3-4) that the trochoceroids described for the following quadrangles: Auburn-Genoa (Luther, by Hall (1852) as Trochoceras gebhardii and T. tur- 1910), Skaneateles (Smith, 1935), Tully (Clarke and binata should be reassigned to Mitroceras and Luther, 1905), Syracuse (Hopkins, 1914), Richfield Foersteoceras, respectively. Springs (Rickard and Zenger, 1964), and Berne (Gold- The only ostracode described originally as coming ring, 1935).