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Middle Cambrian of Avalonian Massachusetts: Stratigraphy and correlation of the Braintree trilobites

Published online by Cambridge University Press:  20 May 2016

Gerd Geyer  and
Ed Landing
Gerd Geyer
Affiliation:
Institut für Paläontologie, Universität Würzburg, Pleicherwall 1, D-97070 Würzburg, Germany,
Ed Landing
Affiliation:
Center for Stratigraphy and Paleontology, New York State Museum, The State Education Department, Albany, NY 12230,
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Abstract

Although Middle Cambrian trilobites of the Braintree Member in eastern Massachusetts were among the first published on in North America, re-examination of this fauna has led to wholesale taxonomic and biostratigraphic re-evaluation. This low diversity fauna now includes at least seven species, with the first report of agnostoids (three poorly preserved taxa) and the ellipsocephalid Kingaspis avalonensis new species. Paradoxides (Acadoparadoxides) harlani Green emend., a senior synonym of P. (A.) haywardi Raymond, allows correlation into the lowest Middle Cambrian elsewhere in Avalon. However, all the polymeroid species are endemic, and this precludes a highly resolved correlation into other Cambrian paleocontinents. A breakdown of provincial barriers in the late Early Cambrian as western Gondwana passed from equatorial to the higher south latitudes of Avalon led to faunal exchanges between these continents. Paradoxides (Acadoparadoxides) and Kingaspis of the Braintree fauna are shared with western Gondwana, while Braintreella and “Agraulos” quadrangularis are closest to genera known from the Spanish, Moroccan, and Perunican (Bohemian) margins of Gondwana.

Type
Research Article
Information
Journal of Paleontology , Volume 75 , Issue 1 , January 2001 , pp. 116 - 135
Copyright
Copyright © The Paleontological Society

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References

Ahlberg, P. 1980. Early Cambrian trilobites from northern Scandinavia. Norsk Geologisk Tidsskrift, 60:153–159.Google Scholar
Ahlberg, P. 1981. Ptychopariid trilobites in the Lower Cambrian of Scandinavia, p. 5–7. In Taylor, M. E. (ed.), Short Papers for the Second International Symposium on the Cambrian System 1981. U.S. Geological Survey Open-File Report 81–743.Google Scholar
Ahlberg, P. 1984. Lower Cambrian trilobites and biostratigraphy of Scandinavia. Lund Publications in Geology, 22, 37 p.Google Scholar
Ahlberg, P., and Bergström, J. 1978. Lower Cambrian ptychopariid trilobites from Scandinavia. Sveriges Geologiska Undersökning, Avhandlingar och Uppsatser, 14:o, Ser. Ca, 49, 40 p.Google Scholar
Ahlberg, P., and Bergström, J. 1983. Lower Cambrian trilobites from southern Swedish Lappland. Geologiska Föreningens i Stockholm Förhandlingar, 104(3) (for 1982):241–246CrossRefGoogle Scholar
Angelin, N. P. 1851. Palaeontologica Scandinavica. Pars I, Iconographia Crustaceorum Formationis Transitionis. Fasc. 1. Academiae Regiae Scientiarum Suecanae:1–19, Lund (“Lundae”).Google Scholar
Angelin, N. P. 1854. Palaeontologia Scandinavica. Pars I. Crustacea Formationis Transitionis. Fasc. II. Academiae Regiae Scientiarum Suecanae: I–IX+21–92, T.O. Weigel, Leipzig (“Lipsiae”).Google Scholar
Barrande, J. 1846. Nouveaux Trilobites. Supplément à la notice préliminaire sur le système silurien et les Trilobites de Bohěme. Prague and Leipzig, 97 p.CrossRefGoogle Scholar
Barrande, J. 1852. Système Silurien du Centre de la Bohěme. lère Partie. Recherche paléontologiques. Crustacés, Trilobites, 1. Prague and Paris, 935 p.Google Scholar
Barrande, J. 1860. Neue Beweise einer weiteren Verbreitung der Primordial-Fauna in Nord-America. Neues lahrbuch für Mineralogie, etc., 1860:113–143.Google Scholar
Barrande, J. 1861. Documents anciens et nouveaux sur la faune primordial et le système taconique en Amérique. Bulletin de la Société Géologique de France, Series 2, 18:203–321.Google Scholar
Barrande, J. 1871. Trilobites. Systěme Silurien du centre de la Bohěme, Supplement au Vol. 1, Prague and Paris, 282 p.Google Scholar
Bassett, M. G., Owens, R. M., and Rushton, A. W. A. 1976. Lower Cambrian fossils from the Hell's Mouth Grits, St. Tudwal's Peninsula, north Wales. Geological Society of London Journal, 132:623–644.CrossRefGoogle Scholar
Bengtson, S., and Fletcher, T. P. 1983. The oldest sequence of skeletal fossils in the Lower Cambrian of southeast Newfoundland. Canadian Journal of Earth Sciences, 20:525–536.CrossRefGoogle Scholar
Bergström, J., and Ahlberg, P. 1981. Uppermost Lower Cambrian biostratigraphy in Scania, Sweden. Geologiska Föreningens i Stockholm Förhandlingar, 103(2):193–214.CrossRefGoogle Scholar
Billings, E. 1874. Paleozoic Fossils, Volume 2, Pt. 1. Geological Survey of Canada, 144 p.CrossRefGoogle Scholar
Bowring, S. A., and Erwin, D. H. 1998. A new look at evolutionary rates in deep time: uniting paleontology and high-precision geochronology. GSA Today, 8(9):1–8.Google Scholar
Brasier, M. D., and Sukhov, S. S. 1998. The falling amplitude of carbon isotopic oscillations through the Lower to Middle Cambrian: northern Siberia data. Canadian Journal of Earth Sciences, 35:353–373.CrossRefGoogle Scholar
Brongniart, A. 1822. Histoire naturelle des Crustacés fossiles sous les rapports zoologique et géologique, savoir le Trilobites. Les Crustacés proprement dits par A.-G. Desmarest. F. G. Levrault, Paris, 154 p.CrossRefGoogle Scholar
Burr, H. T. 1900. A new Lower Cambrian fauna from eastern Massachusetts. American Geologist, 25:42–50.Google Scholar
Chute, N. E. 1969. Bedrock geology of the Blue Hills quadrangle, Norfolk, Suffolk, and Plymouth counties. U.S. Geological Survey, Geologic Quadrangle Map, GQ-796.Google Scholar
Dana, J. 1863. Manual of Geology. Theodore Bliss & Co., Philadelphia, and Trübner & Co., London.Google Scholar
Dawson, J. W. 1868. Acadian Geology: The Geological Structure. Organic Remains and Mineral Resources of Nova Scotia, New Brunswick, and Prince Edward Island, London.Google Scholar
Dean, W. T., and Rushton, A. W. A. 1997. Superfamily Paradoxidoidea Hawle & Corda, 1847, p. 470–481. In Whittington, H. B. et al. (eds.), Treatise on Invertebrate Paleontology. Part O, Arthropoda. Trilobita, Revised-Volume 1: Introduction, Order Agnostida, Order Redlichiida. The Geological Society of America and The University of Kansas, Lawrence.Google Scholar
Eldredge, N. 1985. Life Pulse—Episodes from the Story of the Fossil Record. Facts on File Publications, New York.Google Scholar
Emmrich, H. F. 1839. De trilobitis dissertatio petrefactologia quam consensu et auctoritate amplissimi philosorum ordinis, etc. “Berolini”, Berlin.Google Scholar
Fletcher, T. P. 1972. Geology and Lower to Middle Cambrian trilobite faunas of the southwest Avalon, Newfoundland. Unpublished Ph.D. dissertation, University of Cambridge, 520 p.Google Scholar
Frech, F. 1897. Lethaea geognostica. I. Lethaea Palaeozoica, 2, 1. Lieferung. Schweizerbart, Stuttgart, 256 p.Google Scholar
Geyer, G. 1990a. Revised Lower to lower Middle Cambrian biostratigraphy of Morocco. Newsletters on Stratigraphy, 22(2/3):53–70Google Scholar
Geyer, G. 1990b. Die marokkanischen Ellipsocephalidae (Trilobita: Redlichiida). Beringeria, 3.Google Scholar
Geyer, G. 1993. The giant Cambrian trilobites of Morocco. Beringeria, 8:71–107.Google Scholar
Geyer, G. 1998. Intercontinental, trilobite-based correlation of the Moroccan early Middle Cambrian. Canadian Journal of Earth Sciences, 35:374–401.CrossRefGoogle Scholar
Geyer, G., and Landing, E. 1995. The Cambrian of the Moroccan Atlas regions, p. 7–46. In Geyer, G. and Landing, E. (eds.), Morocco '95—The Lower-Middle Cambrian Standard of Western Gondwana. Beringeria Special Issue 2.Google Scholar
Gigout, M. 1951. Etudes géologiques sur la Méséta marocaine occidentale (arrière-pays de Casablanca, Mazagan et Safi). Notes et Mémoires du Service géologique du Maroc, 86(2):1–18.Google Scholar
Goldsmith, R. 1991. Stratigraphy of the Milford–Dedham zone, eastern Massachusetts: an Avalonian terrane, p. E1–E62. In Hatch, N. L. Jr. (ed.), The Bedrock Geology of Massachusetts. U.S. Geological Survey, Professional Paper 1366-E–J.Google Scholar
Gozalo, R., Álvaro, J., Liñán, E., Sdzuy, K., and Truyols, J. 1993. La distribution de Paradoxides (Acadoparadoxides) mureroensis Sdzuy, 1958 (Cámbrico Medio basal), y sus implicaciones paleobiogeográficas. Cuaderno del Labratorio Xeolóxico de Laxe, 18:217–230.Google Scholar
Grabau, A. W. 1900. Palaeontology of the Cambrian terranes of the Boston Basin. Occasional Papers of the Boston Society of Natural History, 4:601–694.Google Scholar
Green, J. 1834. Descriptions of some new North American trilobites. American Journal of Science, 25:334–337.Google Scholar
Harrington, H. J., Henningsmoen, G., Howell, B. F., Jaanusson, V., Lochman-Balk, C., Moore, R. C., Poulsen, C., Rasetti, F., Richter, E., Richter, R., Schmidt, H., Sdzuy, K., Struve, W., Tripp, R., Weller, J. M., and Whittington, H. B. 1959. Systematic descriptions, p. 0170–0590. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology, Part O, Arthropoda 1. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Hawle, I., and Corda, A. J. C. 1847. Prodrom einer Monographie der böhmischen Trilobiten. Königliche Böhmische Gesellschaft der Wissenschaften, Abhandlungen, 5, 176 p. (119–225, 226–292).Google Scholar
Hayes, A. O., and Howell, B. F. 1937. Geology of the Saint John, New Brunswick, region. Geological Society of America, Special Paper 5.Google Scholar
Henningsmoen, G. 1959a. Superfamily Ellipsocephalacea Matthew, 1887, p. 0207–212. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology. Part O, Arthropoda 1. Geological Society of America and University of Kansas Press, Lawrence, Kansas.Google Scholar
Henningsmoen, G. 1959b. Family Agraulidae Raymond, 1913, p. 0278–279. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology. Part O, Arthropoda 1. Geological Society of America and University of Kansas Press, Lawrence.Google Scholar
Hepburn, J. C., Hon, R., Dunning, G. R., Bailey, R. H., and Galli, K. 1993. The Avalon and Nashoba terranes (eastern margin of the Appalachian orogen in southeastern New England) p. X.1–X.31. In Cheney, J. T. and Hepburn, J. C. (eds.), Field Trip Guidebook for the Northeastern United States, 1993 Boston GSA, Volume 2. Geology Department, University of Massachusetts, Contribution 67.Google Scholar
Hicks, H. 1872. On some undescribed fossils from the Menevian Group, with a note on the Entomostraca by Prof. T. Rupert Jones. Quarterly Journal of the Geological Society, London, 28:173–185.CrossRefGoogle Scholar
Howell, B. F. 1925. Faunas of the Cambrian Paradoxides beds at Manuels, Newfoundland. Bulletins of American Paleontology, 11:1–140.Google Scholar
Howell, B. F. 1937. Cambrian Centropleura vermontensis fauna of northwestern Vermont. Bulletin of the Geological Society of America, 48:1147–1210.CrossRefGoogle Scholar
Howell, B. F. 1959. Subfamily Ptychopariinae Matthew, 1887, p. O233–O234. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology. Part O, Arthropoda 1. Geological Society of America and University of Kansas Press, Lawrence, Kansas.Google Scholar
Howell, B. F., and Mason, J. F. 1938. Correlation of Middle Cambrian faunas of North America. Journal of Paleontology, 12:295–297.Google Scholar
Hupé, P. 1953a. Contribution à l'étude du Cambrien inférieur et du Précambrien III de l'Anti-Atlas marocain. Notes et Mémoirs de la Service géologique du Maroc, 103.Google Scholar
Hupé, P. 1953b. Classification des trilobites. Annales de Paléontologie, 39:61–168.Google Scholar
Illing, V. C. 1916. The Paradoxidian fauna of a part of the Stockingford Shales. Quarterly Journal of the Geological Society of London, 283:386–450.Google Scholar
Jackson, C. T. 1856. Nouveau gisements de trilobites découvert près de Boston. Comptes Rendus de l'Academie des Science, Paris, 43:883.Google Scholar
Jackson, C. T. 1858. Sur un moule du Paradoxides harlani . Comptes Rendus de l'Academie des Science, Paris, 46:254.Google Scholar
Jackson, C. T. 1859a. Communication from Dr. Charles T. Jackson. Proceedings of the Boston Society of Natural History, 7:54.Google Scholar
Jackson, C. T. 1859b. Communication from Dr. Charles T. Jackson. Proceedings of the Boston Society of Natural History, 7:75.Google Scholar
Jackson, C. T. 1861. Communication from Dr. Charles T. Jackson. Proceedings of the Boston Society of Natural History, 9:58, 59.Google Scholar
King, W. B. R. 1923. Cambrian fossils from the Dead Sea. Geological Magazine, 60:507–514.CrossRefGoogle Scholar
Kobayashi, T. 1935. The Cambro-Ordovician formations and faunas of South Chosen. Paleontology. Part III. Cambrian faunas of South Chosen with a special study on the Cambrian trilobite genera and families. Journal of the Faculty of Science, Imperial University of Tokyo, Section II, 4(2):49–344Google Scholar
Kobayashi, T. 1939. On the agnostids (Part I). Journal of the Faculty of Science, Imperial University of Tokyo, Section II, 5(5):62–198Google Scholar
Laforge, L. 1932. Geology of the Boston area, Massachusetts. U.S. Geological Survey, Bulletin 839.Google Scholar
Landing, E. 1988. Lower Cambrian of eastern Massachusetts: stratigraphy and small shelly fossils. Journal of Paleontology, 62:661–695.Google Scholar
Landing, E. 1994. Precambrian–Cambrian boundary global stratotype ratified and a new perspective of Cambrian time. Geology, 22:179–182.2.3.CO;2>CrossRefGoogle Scholar
Landing, E. 1996. Avalon: insular terrane by the latest Precambrian, p. 29–63. In Nance, R. D. and Thompson, M. D. (eds.), Avalonian and Related Peri-Gondwanan Terrances of the Circum-North Atlantic. Geological Society of America, Special Paper 304.CrossRefGoogle Scholar
Landing, E. 1998a. Cambrian subdivisions and correlations: introduction. Canadian Jouranl of Earth Sciences, 35:321–322.CrossRefGoogle Scholar
Landing, E. 1998b. Avalon and Gondwana—The antepodean dance of two Early Paleozoic continents. Geological Society of America, Abstracts with Programs, 30(7):A–150.Google Scholar
Landing, E., and Westrop, S. R. 1998a. Cambrian faunal sequence and depositional history of Avalonian Newfoundland and New Brunswick: field workshop, p. 5–75. In Landing, E. and Westrop, S. R. (eds.), Avalon 1997—The Cambrian standard. New York State Museum Bulletin 492.Google Scholar
Landing, E., and Westrop, S. R. 1998b. Revisions in stratigraphic nomenclature of the Cambrian of Avalonian North America and comparisons with Avalonian Britain, p. 76–87. In Landing, E. and Westrop, S. R. (eds.), Avalon 1997—The Cambrian standard. New York State Museum Bulletin 492.Google Scholar
Levi-Setti, R. 1975. Trilobites. University of Chicago Press, Chicago.Google Scholar
Liñán, E., and Gozalo, R. 1986. Trilobites del Cámbrico inferior y medio de Murero (Cordillera Ibérica). Memoria del Museo Paleontológico, Universidad de Zaragoza, 2, 104 p.Google Scholar
Lord, G. S. 1972. The geology of Weymouth. Weymouth 350th Anniversary, Town of Weymouth, p. 14–17.Google Scholar
Matthew, G. F. 1886. Illustrations of the fauna of the St. John Group continued. No. III.—Description of new genera and species, (including a description of a new species of Solenopleura by J. F. Whiteaves.). Transactions of the Royal Society of Canada, 1885, 3(4):29–84Google Scholar
Matthew, G. F. 1888. Illustrations of the fauna of the St. John Group. No. IV.—Part I. Description of a new species of Paradoxides (Paradoxides regina). Part II. The smaller trilobites with eyes (Ptychoparidae and Ellipsocephalidae). Proceedings and Transactions of the Royal Society of Canada, 1887, 5(4):115–166Google Scholar
Matthew, G. F. 1892. Protolenus—a new genus of Cambrian trilobites. Bulletin of the Natural Historical Society of New Brunswick, 10:34–37.Google Scholar
Matthew, G. F. 1896a. Faunas of the Paradoxides beds in eastern North America, no. 1. Transactions of the New York Academy of Sciences, 15:192–247.Google Scholar
Matthew, G. F. 1896b. Notes on the Cambrian faunas—The genus Microdiscus . American Geologist, 18:28–31.Google Scholar
McCoy, F. 1849. On the classification of some British fossil Crustacea, with notices of new forms in the university collection at Cambridge. Annals and Magazine of Natural History, Series 2. 4:161–179, 392–414.CrossRefGoogle Scholar
Murray, D. P. 1988. Post-Acadian metamorphism in the Appalachians, p. 597–609. In Harris, A. L. and Fettes, D. J. (eds.), The Caledonian-Appalachian Orogen. Geological Society, Special Publication 38.Google Scholar
Nellis, D. A., and Hellier, N. W. 1976. Geologic relationships of the southern portion of the Boston Basin from the Blue Hills eastward, p. 147–157. In Cameron, B. (ed.), Geology of Southeastern New England. New England Intercollegiate Geological Conference. Science Press, Princeton, New Jersey.Google Scholar
Nicholson, H. A. 1872. Contributions to the study of the errant annelids of the older Palaeozoic rock. Proceedings of the Royal Society of London, 21:288–290.Google Scholar
Ordway, A. 1861a. On the supposed identity of the Paradoxides Harlani, Green, with the Paradoxides spinosus, Boeck. Proceedings of the Boston Society of Natural History, 8:1–5.Google Scholar
Ordway, A. 1861b. On the occurrence of other fossil forms at Braintree, Mass. Proceedings of the Boston Society of Natural History, 8:5, 6.Google Scholar
Raymond, P. E. 1913a. On the genera of the Eodiscidae. Ottawa Naturalist, 26:101–106.Google Scholar
Raymond, P. E. 1913b. Some changes in the names of genera. Trilobites. Ottawa Naturalist, 26:137–142.Google Scholar
Raymond, P. E. 1914. Notes on the ontogeny of Paradoxides with the description of a new species from Braintree, Mass. Bulletin of the Museum of Comparative Zoology, 58:225–244.Google Scholar
Resser, C. E. 1939. The Ptarmigania strata of the northwestern Wasatch Mountains. Smithsonian Miscellaneous Collections, 98(24):1–72.Google Scholar
Richter, R. 1933. Crustacea (Paläontologie), p. 840–863. In Handwörterbuch der Naturwissenschaften (second edition). Fischer-Verlag, Jena.Google Scholar
Richter, R., and Richter, E. 1941. Die Fauna des Unter-Kambriums von Cala in Andalusien. Abhandlungen der Senckenbergischen naturforschenden Gesellschaft, 455.Google Scholar
Rogers, H. D. 1858. Organic remains of the Palæzoic strata of Pennsylvania, p. 815–834. In Geology of Pennsylvania—A Government Survey, Volume II. J.B. Lippincott & Co., Philadelphia.Google Scholar
Rogers, W. B. 1856a. On the discovery of Paradoxides in the altered rocks of eastern Massachusetts. Edinburgh New Philosophical Journal, 4:301–304.Google Scholar
Rogers, W. B. 1856b. August 6, 1856. The President in the Chair. Proceedings of the Boston Society of Natural History, 6:27–30.Google Scholar
Rogers, W. B. 1856c. Communication from Prof. William B. Rogers. Proceedings of the Boston Society of Natural History, 6:40–44.Google Scholar
Rogers, W. B. 1856d. Discovery of Palaeozoic fossils in eastern Massachusetts. American Journal of Science, Series 2, 22:296–298.Google Scholar
Rogers, W. B. 1857. Discovery of Paradoxides in New England. Edinburgh New Philosophical Journal, 6:314–315.Google Scholar
Rogers, W. B. 1859. Communication from Prof. William B. Rogers. Proceedings of the Boston Society of Natural History, 7:86.Google Scholar
Rudolf, F. 1994. Die Trilobiten der mittelkambrischen Geschiebe. Systematic Morphologie und Ökologie. Verlag F. Rudolph, Wankendorf, 309 p.Google Scholar
Rushton, A. W. A. 1966. The Cambrian trilobites from the Purley Shales of Warwickshire. Palaeontological Society Monographs, No. 511, 55 p.Google Scholar
Rushton, A. W. A. 1974. The Cambrian of Wales and England, p. 43–121. In Holland, C. H. (ed.), Cambrian of the British Isles, Norden, and Spitsbergen. John Wiley and Sons, New York.Google Scholar
Rushton, A. W. A. 1979. A review of the Middle Cambrian Agnostida from the Abbey Shales, England. Alcheringa, 3:43–61.CrossRefGoogle Scholar
Rushton, A. W. A., and Powell, J. H. 1999. A review of the stratigraphy and trilobite faunas from the Cambrian Burj Formation in Jordan. Bulletin of the natural History Museum London (Geology), 54(2):131–146.Google Scholar
Ruzicka, R. 1946. O nekterych vyznacnych trilobitech skryjského kambria. Vestník Královské Ceské spolecnosti nauk, Trida matematik-prírod., for 1944:1–26.Google Scholar
Salter, J. W. 1859. Trilobites, p. 45–49. In Murchison, R. I., Siluria, second edition. London.Google Scholar
Salter, J. W. 1864. Figures and descriptions illustrative of British organic remains. Trilobites (chiefly Silurian). Memoir of the Geological Survey of the United Kingdom, Dec. XI.Google Scholar
Sdzuy, K. 1957. Revision der mittelkambrischen Trilobiten von Doberlug. Senckenbergiana Lethaea, 38(1/2):7–28Google Scholar
Sdzuy, K. 1958. Neue Trilobiten aus dem Mittelkambrium von Spanien. Senckenbergiana Lethaea, 39(3–4):235–253Google Scholar
Sdzuy, K. 1961. Das Kambrium Spaniens. Teil II: Trilobiten. I. Abschnitt. Akademie der Wissenschaften und Literatur, Mainz, Abhandlungen der mathematisch-naturwissenschaftlichen Klasse, 1961(7):499–594.Google Scholar
Sdzuy, K. 1967. Trilobites del Cámbrico medio de Asturias. Trabajos de Geología, Facultad de Ciencias, Universidad de Oviedo, 1:77–133.Google Scholar
Sdzuy, K. 1970. Mittelkambrische Fossilien aus neuen Bohrungen bei Doberlug und bei Delitzscher Geologie, 19(9):1066–1091.Google Scholar
Shaler, N. S. 1871. Remarks on the relations of the rocks in the vicinity of Boston. Proceedings of the Boston Society of Natural History, 13:172–178.Google Scholar
Shaler, N. S., and Foerste, A. F. 1888. Preliminary description of North Attleboro fossils. Harvard Museum of Comparative Zoology Bulletin, 16:27–41.Google Scholar
Shaw, A. B. 1950. A revision of several Early Cambrian trilobites from eastern Massachusetts. Journal of Paleontology, 24:577–590.Google Scholar
Shimer, H. W. 1907a. A Lower–Middle Cambrian transition fauna from Braintree, Mass. American Journal of Science, 174:176–178.CrossRefGoogle Scholar
Shimer, H. W. 1907b. An almost complete specimen of Strenuella strenua (Billings). American Journal of Science, 173:199–201.CrossRefGoogle Scholar
Shimer, H. W., and Shrock, R. R. 1944. Index Fossils of North America. M.I.T. Press, Cambridge, Mass.Google Scholar
Sjögren, A. 1872. Om några försteningar i Ölands kambriska lager [On some petrifications in the Cambrian strata of Öland]. Geologiska Föreningens i Stockholm Förhandlingar, 1(5) (1872–1873):67–80CrossRefGoogle Scholar
Skehan, J. W., Murphy, D. P., Palmer, A. R., Smith, A. T., and Belt, E. S. 1978. Significance of Middle Cambrian rocks of Rhode Island to the history of the Avalonian microcontinent. Geology, 6:694–698.2.0.CO;2>CrossRefGoogle Scholar
Šnajdr, M. 1950. Aculeodiscus nov. gen. ze stredoceského stredního kambria (Trilobitae) [Aculeodiscus nov. gen. from the Middle Cambrian of Central Bohemia (Trilobitae)]. Sbornik statního geologického Ustavu Ceskoslovenska Republik, oddíl paleontologicky, 17:201–212. (In Czech with English summary)Google Scholar
Šnajdr, M. 1957. O novych trilobitech z ceského kambria [The trilobites of the Middle Cambrian of Bohemia]. Vestnik Ustredního ústavu Geologicky, 32(4):235–244Google Scholar
Šnajdr, M. 1958. Trilobiti ceského stredního kambria [The trilobites of the Middle Cambrian of Bohemia]. Nakl. ceského Akadmie Véd, Rozpravy Ustredního ústavu geologického, 24:1–236 (Czech), 237–280 (In Czech with English).Google Scholar
Šnajdr, M. 1986. Two new paradoxid trilobites from the Jince Formation (Middle Cambrian, Czechoslovakia). Vestnik Ustredniho ústavu geologickych, 61(3):169–174Google Scholar
Šnajdr, M. 1987. The genera Paradoxides Brongniart and Hydrocephalus Barrande (Trilobita). Vestník Ustredního ustavu geologického, 62(2):97–104Google Scholar
Solov'ev, I. A. 1969. Novye vidy Paradoxides (trilobity) iz goryuchikh slantsev amginskogo yarusa Severnoj Yakutii. Uchenie zapijski, NII-GA, paleontologiya i biostratigrafiya, 25:9–20.Google Scholar
Solov'ev, I. A. 1980. Biostratigraphy of deposits in the Amga Stage in the north of the Siberian Platform. Geologiya i Geofizika, 22(5):26–38. (In Russian)Google Scholar
Stodder, C. 1858. Communication from Mr. Charles Stodder. Proceedings of the Boston Society of Natural History, 6:369.Google Scholar
Sundberg, F. A. and Mccollum, L. B. 1997. Oryctocephalids (Corynexochida: Trilobite) of the Lower–Middle Cambrian boundary interval from California and Nevada. Journal of Paleontology, 71:1065–1090.CrossRefGoogle Scholar
Swinnerton, H. H. 1915. Suggestions for a revised classification of trilobites. Geological Magazine, (VI), 2:487–496, 538–545.CrossRefGoogle Scholar
Vogdes, A. W. 1921. Palaeozoic Crustacea. Part II. An alphabetical list of the genera and subgenera of the Trilobita. San Diego Society of Natural History, Transactions, 3:87–115.Google Scholar
Wahlenberc, G. 1821. Petrificata telluris Suecanae examinata a Georgio Wahlenberg. Nova Acta Societa Regiae Sociale Sciences, Upsaliae, Series 2, 8:1–116.Google Scholar
Walch, J. E. I. 1771. Die Naturgeschichte der Versteinerungen, zur Erläuterung der Knorrischen Sammlung von Merkwürdigkeiten der Natur. Dritter Theil. Paul Jonathan Felstecker, Nürnberg, 235 p.Google Scholar
Walcott, C. D. 1884. On the Cambrian faunas of North America. U.S. Geological Survey, Bulletin 10, p. 289–355.Google Scholar
Walcott, C. D. 1886. Second contribution to studies on the Cambrian faunas of North America. U.S. Geological Survey, Bulletin 30.Google Scholar
Walcott, C. D. 1890. The fauna of the Lower Cambrian or Olenellus Zone. U.S. Geological Survey, 10th Annual report, p. 509–774.Google Scholar
Walcott, C. D. 1910. Olenellus and other genera of the Mesonacidae. Cambrian Geology and Paleontology No. 6. Smithsonian Miscellaneous Collections, 53(6):231–422Google Scholar
Westergård, A. H. 1936. Paradoxides oelandicus Beds of Öland with the account of a diamond boring through the Cambrian at Mössberga. Sveriges Geologiska Undersökning, Series C, 394(1):1–66Google Scholar
Westergård, A. H. 1953. Non-agnostidean trilobites of the Middle Cambrian of Sweden. III. Sveriges Geologiska Undersökning, Series C, 46(2):1–58.Google Scholar
Westrop, S. R., and Landing, E. 2000. Lower Cambrian (Branchian) trilobites and biostratigraphy of the Hanford Brook Formation, southern New Brunswick. Journal of Paleontology, 74:858–878.CrossRefGoogle Scholar
Wheeler, R. R. 1942. New Mid-Cambrian ptychoparid. American Journal of Science, 240:567–570.CrossRefGoogle Scholar
Whitfield, R. P. 1884. Notice of some new species of Primordial fossils in the collection of the Museum, and corrections of previously described species. Bulletin of the American Museum of Natural History, 1(5):139–152.Google Scholar
Williams, H. (compiler). 1978. Tectonic lithofacies map of the Appalachian orogen. Memorial University of Newfoundland, Department of Geology, Map 1.Google Scholar
Wones, D. R., and Goldsmith, R. 1991. Intrusive rocks of eastern Massachusetts, p. 11–167. In Hatch, N. L. Jr. (ed.), The Bedrock Geology of Massachusetts. U.S. Geological Survey Professional Paper 1366-E-J.Google Scholar
Zenker, J. C. 1833. Beiträge zur Naturgeschichte der Urwelt. Organische Reste (Petrofacten) aus der Altenburger Braunkohlen-Formation, dem Blankenburger Quadersandstein, jenaischen bunten Sandstein und böhmischen Uebergangesgebirge, mit 6 illuminirten Kupfertafeln, Jena, 67 p.Google Scholar
Zhou, T. M., Liu, Y. R., Mono, X. S., and Sun, Z. H. 1977. Trilobita, p. 104–266. In Palaeontological Atlas of Central and South China. Volume 1. Geological Publishing House, Beijing. (In Chinese)Google Scholar