ESTONIAN ACADEMY
PUBLISHERS
eesti teaduste
akadeemia kirjastus
PUBLISHED
SINCE 1952
 
Earth Science cover
Estonian Journal of Earth Sciences
ISSN 1736-7557 (Electronic)
ISSN 1736-4728 (Print)
Impact Factor (2020): 0.789

Ostracods of the Ordovician–Silurian boundary beds: Jūrmala core (Latvia) and its implications for Baltic stratigraphy; pp. 233–247

Full article in PDF format | 10.3176/earth.2020.20

Authors
Tõnu Meidla, Karin Truuver, Oive Tinn, Leho Ainsaar

Abstract

Ostracods of the Ordovician and Silurian transition interval in the Jūrmala section, Latvia, were studied. The diverse pre-Hirnantian ostracod assemblage is replaced by the Harpabollia harparum association that has been recorded across the Baltoscandian region and northwestern Poland and is confined to the Hirnantian. The first complete ostracod succession throughout the Kuldīga and Saldus formations reveals a remarkable diversity decline and rise of dominance of ostracods in this interval. The appearance level of the H. harparum association in other sections is drawn distinctly above the range of Spinachitina taugourdeaui, nearly coinciding with the appearance of Conochitina scabra and Noixodontus girardeauensis. The transition from the Saldus Formation into the Stačiunai Formation marks a complete ostracod turnover. The newly appearing assemblage, dominated by Longiscula smithii, is of low diversity. Slow diversity rise may in part be ascribed to the overall low recovery rate of post-glaciation faunal assemblages. The shape of the stable carbon isotopic curve in the Jūrmala core suggests that this section is one of the most complete successions across the Ordovician–Silurian boundary in the Baltoscandian area. The correlation of this curve with that of the Monitor Range, Nevada, and comparison with other curves of Latvia and Estonia suggest that the well-known appearance level of the ‘Silurian faunas’ is confined to the upper M. persculptus graptolite Zone. Judging from the chemostratigraphic correlation, the latter zone ranges for more than 10 m into the Stačiūnai Formation in the Jūrmala core.


References

Ainsaar, L., Kaljo, D., Martma, T., Meidla, T, Männik, P., Nõlvak, J. & Tinn, O. 2010. Middle and Upper Ordovician carbon isotope chemostratigraphy in Baltoscandia: a correlation standard and clues to environmental history. Palaeogeography, Palaeoclimatology, Palaeoecology294, 189–201.
https://doi.org/10.1016/j.palaeo.2010.01.003

Ainsaar, L., Truumees, J. & Meidla, T. 2015. The position of the Ordovician–Silurian boundary in Estonia tested by high-resolution δ13C chemostratigraphic correlation. In Chemostratigraphy: Concepts, Techniques and Applications (Ramkumar, M., ed.), pp. 395–412. Elsevier, Amsterdam.
https://doi.org/10.1016/B978-0-12-419968-2.00015-7

Bauert, H., Ainsaar, L., Põldsaar, K. & Sepp, S. 2014. δ13C chemostratigraphy of the Middle and Upper Ordovician succession in the Tartu-453 drillcore, southern Estonia, and the significance of the HICE. Estonian Journal of Earth Sciences63, 195–200.
https://doi.org/10.3176/earth.2014.18

Bergström, S. M., Saltzman, M. R. & Schmitz, B. 2006. First record of the Hirnantian (Upper Ordovician) δ13C excursion in the North American Midcontinent and its regional implications. Geological Magazine143, 657–678. 
https://doi.org/10.1017/S0016756806002469

Birkis, A. P., Brangulis, A. P., Gavrilova, A. V., Gailīte, L. K., Danilans, I. Ya., Lunc, A. Ya., Lyarskaya, L. A., Menakre, E. A., Murnieks, L. É., Savvaitova, L. S., Sorokin, V. S., Ulst, R. Zh. & Fridrihsone, A. I. 1976. Stratigraficheskie skhemy Latvijskoj SSR [Stratigraphic Charts of the Latvian SSR]. Zinantne, Riga, 229 pp. [in Russian].

Brenchley, P. J., Marshall, J. D., Carden, G. A. F., Robertson, D. B. R., Long, D. G. F., Meidla, T., Hints, L. & Anderson, T. F. 1994. Bathymetric and isotopic evidence for a short-lived late Ordovician glaciation in a greenhouse period. Geology22, 295–298.
https://doi.org/10.1130/0091-7613(1994)022<0295:BAIEFA>2.3.CO;2

Brenchley, P. J., Carden, G. A., Hints, L., Kaljo, D., Marshall, J. D., Martma, T., Meidla, T. & Nõlvak, J. 2003. High-resolution stable isotope stratigraphy of Upper Ordovician sequences: constraints on the timing of bioevents and environmental changes associated with mass extinction and glaciation. Geological Society of America Bulletin115, 89–104.
https://doi.org/10.1130/0016-7606(2003)115<0089:HRSISO>2.0.CO;2

Finney, S. C., Berry, W. B. N., Cooper, J. D., Ripperdan, R. L., Sweet, W. C., Jacobson, S. R., Soufiane, A., Achab, A. & Noble, P. 1999. Late Ordovician mass extinction: a new perspective from stratigraphic sections in central Nevada. Geology27, 215–218.
https://doi.org/10.1130/0091-7613(1999)027<0215:LOMEAN>2.3.CO;2

Gailīte, L. K. 1968. Paleontologicheskaya kharakteristika pogranichnykh otlozhenij ordovika i silura v Latvii [Paleontological characteristic of adjacent Ordovician and Silurian deposits in Latvia]. In Stratigraphy of the Baltic Lower Paleozoic and Its Correlation with Other Areas (Grigelis, A., ed.), pp. 130–138. Mintis, Vilnius [in Russian, with English summary].

Gailīte, L. 1970. Ostrakody kuldigskoj pachki verkhnego ordovika Latvii [Ostracodes from the Kuldiga Member of the Upper Ordovician of Latvia]. In Paleontologiya i stratigrafiya Pribaltiki i Belorussii, 2 [Palaeontology and Stratigraphy of the Baltic and the Byelorussia, 2], pp. 19–32. Mintis, Vilnius [in Russian, with English summary].

Gailīte, L. K., Rybnikova, M. V. & Ulst, R. Zh. 1967. Stratigrafiya, fauna i usloviya obrazovaniya silurijskikh porod Srednej Pribaltiki [Stratigraphy, Fauna and Formation Conditions of Silurian Rocks of the Middle East Baltic]. Zinatne, Riga, 304 pp. [in Russian].

Gailīte, L. K., Ulst, R. Zh. & Yakovleva, V. I. 1987. Stratotipicheskie i tipovye razrezy silura Latvii [Stratotype and Type Sections of the Silurian of Latvia]. Zinatne, Riga, 183 pp. [in Russian].

Hammer, Ø., Harper, D. A. T. & Ryan, P. D. 2001. PAST: Paleontological Statistics software package for education and data analysis. Palaeontologica Electronica4(1), 1–9.

Harper, D. A. T. & Hints, L. 2016. Hirnantian (Late Ordovician) brachiopod faunas across Baltoscandia: a global and regional context. Palaeogeography, Palaeoclimatology, Palaeoecology444, 71–83.
https://doi.org/10.1016/j.palaeo.2015.11.044

Hints, L. & Harper, D. A. T. 2015. The Hirnantian (Late Ordovician) brachiopod fauna of the East Baltic: Tax­onomy of the key species. Acta Palaeontologica Polonica60, 395–420.

Hints, L. & Meidla, T. 1997. Porkuni Stage. In Geology and Mineral Resources of Estonia (Raukas, A. & Teedumäe, A., eds), pp. 85–88. Estonian Academy Publishers, Tallinn. 

Hints, L., Hints, O., Kaljo, D., Kiipli, T., Männik, P., Nõlvak, J. & Pärnaste, H. 2010. Hirnantian (latest Ordovician) bio- and chemostratigraphy of the Stirnas-18 core, western Latvia. Estonian Journal of Earth Sciences59, 1–24.
https://doi.org/10.3176/earth.2010.1.01

Hints, O., Martma, T., Männik, P., Nõlvak, J., Põldvere, A., Shen, Y. & Viira, V. 2014. New data on Ordovician stable isotope record and conodont biostratigraphy from the Viki reference drill core, Saaremaa Island, western Estonia. GFF136, 100–104.
https://doi.org/10.1080/11035897.2013.873989

Holland, C. H. 1985. Series and Stages of the Silurian System. Episodes8, 101–103.
https://doi.org/10.18814/epiiugs/1985/v8i2/005

Jaanusson, V. 1976. Faunal dynamics in the Middle Ordovician (Viruan) of Balto-Scandia. In The Ordovician System: Proceedings of a Palaeontological Association Symposium (Basset, M. G., ed.), pp. 301–326. University of Wales Press.

Kaljo, D. (ed.). 1970. Silur Éstonii [The Silurian of Estonia]. Valgus, Tallinn, 343 pp. [in Russian]. 

Kaljo, D. 1997. Graptolites. In Geology and Mineral Resources of Estonia (Raukas, A. & Teedumäe, A., eds), p. 241. Estonian Academy Publishers, Tallinn. 

Kaljo, D. & Jürgenson, E. 1977. Fatsial´naya zonal´nost´ silura Pribaltiki [Sedimentary facies of the East Baltic Silurian]. In Facies and Fauna of the Baltic Silurian (Kaljo, D., ed.), pp. 122–148. Academy of Sciences of the Estonian S. S. R., Institute of Geology, Tallinn [in Russian, with English summary].

Kaljo, D. & Rubel, M. 1982. Svyaz´ soobschestv brakhiopod s fatsial´noj zonal´nost´yu (silur Pribaltiki) [Relations of brachiopod communities to facial zones (Silurian, East Baltic)]. In Silurian Assemblages and Biozones in the East Baltic Region (Kaljo, D. & Klaamann, E., eds), pp. 11–34. Valgus, Tallinn [in Russian].

Kaljo, D., Nestor, H. & Põlma, L. 1988. East Baltic Region. In A global Analysis of the OrdovicianSilurian Boundary (Cocks, L. R. M. & Rickards, R. B., eds), Bulletin of the British Museum (Natural History) Geology43, 85–91. 

Kaljo, D., Hints, L., Martma, T. & Nõlvak, J. 2001. Carbon isotope stratigraphy in the latest Ordovician of Estonia. Chemical Geology175, 49–59.
https://doi.org/10.1016/S0009-2541(00)00363-6

Kaljo, D., Hints, L., Martma, T., Nõlvak, J. & Oraspõld, A. 2004. Late Ordovician carbon isotope trend in Estonia, its significance in stratigraphy and environmental analysis. Palaeogeography, Palaeoclimatology, Palaeoecology210, 165–185.
https://doi.org/10.1016/j.palaeo.2004.02.044

Kaljo, D., Hints, L., Männik, P. & Nõlvak, J. 2008. Succession of Hirnantian events based on data from Baltica: brachiopods, chitinozoans, conodonts and carbon isotopes. In Palaeozoic Climates: International Congress, August 2231, 2008, Lille, France (Kröger, B. & Servais, T., eds), p. 48. Lille.
https://doi.org/10.3176/earth.2008.4.01

Kaljo, D., Hints, L., Hints, O., Männik, P., Martma, T. & Nõlvak, J. 2011. Katian prelude to the Hirnantian (Late Ordovician) mass extinction: a Baltic perspective. Geological Journal46, 464–477. 
https://doi.org/10.1002/gj.1301

Kiipli, E. & Kiipli, T. 2020. Hirnantian sea-level changes in the Baltoscandian Basin, a review. Palaeogeography, Palaeoclimatology, Palaeoecology540, 109524.
https://doi.org/10.1016/j.palaeo.2019.109524

Krug, A. Z. & Patzkowsky, M. E. 2004. Rapid recovery from the Late Ordovician mass extinction. PNAS, 101, 17605–17610.
https://doi.org/10.1073/pnas.0405199102

LaPorte, D. F., Holmden, C., Patterson, W. P., Loxton, J. D., Melchin, M. J., Mitchell, C. E., Finney, S. C. & Sheets, H. D. 2009. Local and global perspectives on carbon and nitrogen cycling during the Hirnantian glaciation. Palaeogeography, Palaeoclimatology, Palaeoecology276, 182–195.
https://doi.org/10.1016/j.palaeo.2009.03.009

Loydell, D. K., Nestor, V. & Männik, P. 2010. Integrated biostratigraphy of the lower Silurian of the Kolka-54 core, Latvia. Geological Magazine147, 253–280.
https://doi.org/10.1017/S0016756809990574

Lukševičs, E., Stinkulis, Ģ., Mūrnieks, A. & Popovs, K. 2012. Geological evolution of the Baltic Artesian Basin. In Highlights of Groundwater Research in the Baltic Artesian Basin (Dēliņa, A., Kalvāns, A., Saks, T., Bethers, U. & Vircavs, V., eds), pp. 7–52. University of Latvia, Riga.

Männik, P. 2001. Distribution of conodonts. In Valga (10) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 3, 10–12.

Männik, P. 2003. Distribution of conodonts. In Ruhnu (500) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 5, 17–23.

Männik, P. 2007. Recent developments in the Upper Ordovician and lower Silurian conodont biostratigraphy in Estonia. Estonian Journal of Earth Sciences56, 35–46.

Männik, P. 2010. Distribution of Upper Ordovician, Llandovery and Wenlock conodonts. In Viki Drill Core (Põldvere, A., ed.), Estonian Geological Sections,10, 21–24.

Männik, P. 2014. The Silurian System in Estonia. In 4th Annual Meeting of IGCP 591, Estonia, 10–19 June 2014, Abstracts and Field Guide (Bauert, H., Hints, O., Meidla, T. & Männik, P., eds), pp. 123–128. University of Tartu, Tartu.

Männil, R. M. 1966. Istoriya razvitiya Baltijskogo bassejna v ordovike [Evolution of the Baltic Basin During the Ordovician]. Valgus, Tallinn, 199 pp. [in Russian].

Männil, R. & Meidla, T. 1994. The Ordovician System of the East European Platform (Estonia, Latvia, Lithuania, Byelorussia, parts of Russia, the Ukraine and Moldova). In The Ordovician System of the East European Platform and Tuva (Southeastern Russia) (Webby, B. D., Ross, R. J. & Zhen, Y. Y., eds), International Union of Geological Sciences, Publication28A, 1–52.

Meidla, T. 1996a. Late Ordovician ostracodes of Estonia. Fossilia Baltica2, 1–222.

Meidla, T. 1996b. Latest Ordovician ostracodes of Baltoscandia. In WOGOGOB 94 Symposium: Working Group of Ordovician Geology of Baltoscandia, Bornholm, Denmark (Stouge, S., ed.), Geological Survey of Denmark and Greenland Reports, 98, 65–71.

Meidla, T. 2001. Distribution of ostracodes. In Valga (10) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 10, 14–16.

Meidla, T. 2003. Distribution of Ordovician ostracods. In Ruhnu (500) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 5, 25–28.

Meidla, T. 2007. Ostracods from the Upper Ordovician Borenshult fauna, Sweden. GFF129, 123–132.
https://doi.org/10.1080/11035890701292123

Meidla, T. & Tinn, O. 2008. Distribution of Upper Ordovician ostracods. In Männamaa (F-367) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 9,24–27.

Meidla, T., Ainsaar, L., Perrier, V. & Tinn, O. 2011. Ostracods and stable carbon isotopes across the Ordovician Silurian boundary in the Jūrmala core (Latvia). In The Eighth Baltic Stratigraphical Conference. Abstracts (Lukševičs, E., Stinkulis, G. & Vasilkova, J., eds), p. 46. University of Latvia, Riga.

Meidla, T., Ainsaar, L. & Hints, O. 2014. The Ordovician System in Estonia. In 4th Annual Meeting of IGCP 591, Estonia, 10–19 June 2014. Abstracts and Field Guide (Bauert, H., Hints, O., Meidla, T. & Männik, P., eds), pp. 116–122. University of Tartu, Tartu.

Nestor, H. 1997. Silurian. In Geology and Mineral Resources of Estonia (Raukas, A. & Teedumäe, A., eds), pp. 89–106. Estonian Academy Publishers, Tallinn.

Nestor, H. & Einasto, R. 1997. Ordovician and Silurian carbonate sedimentation basin. In Geology and Mineral Resources of Estonia (Raukas, A. & Teedumäe, A., eds), pp. 192–204. Estonian Academy Publishers, Tallinn. 

Nestor, H. E., Klaamann, E. R., Meidla, T. R., Männik, P. E., Nestor, V. V., Nõlvak, J. R., Rubel, M. P., Sarv, L. J. & Hints, L. M. 1991. Dinamika fauny v Baltijskom bassejne na granitse ordovika i silura [Dynamics of fauna in the Baltic Basin near the Ordovician–Silurian bound­ary]. In Major Biological Events in Earth History, Transactions of the XXXII Session of the All-Union Palaeontological Society (Kaljo, D., Modzalevskaya, T. & Bogdanova, T., eds), pp. 79–86. Institute of Geology of the Estonian Academy of Sciences, Tallinn [in Russian].

Nestor, V. 1994. Early Silurian chitinozoans of Estonia and North Latvia. Academia, 4, 1–163.

Nestor, V. 2003. Silurian chitinozoans. In Ruhnu (500) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 5, 13–14.

Nestor, V. 2012. A summary and revision of the East Baltic Silurian chitinozoan biozonation. Estonian Journal of Earth Sciences61, 242–260. 
https://doi.org/10.3176/earth.2012.4.05

Nõlvak, J. 1997. Ordovician. Introduction. In Geology and Mineral Resources of Estonia (Raukas, A. & Teedumäe, A., eds), pp. 54–55. Estonian Academy Publishers, Tallinn. 

Nõlvak, J. & Grahn, Y. 1993. Ordovician chitinozoan zones from Baltoscandia. Review of Palaeobotany and Palynology79, 245–269.
https://doi.org/10.1016/0034-6667(93)90025-P

Nõlvak, J., Hints, O. & Männik, P. 2006. Ordovician timescale in Estonia: recent developments. Proceedings of the Estonian Academy of Sciences, Geology55, 95–108.

Perrier, V., Meidla, T., Tinn, O. & Ainsaar, L. 2012. Biotic response to explosive volcanism: ostracod recovery after Ordovician ash-falls. Palaeogeography, Palaeoclimatology, Palaeoecology365–366, 166–183.
https://doi.org/10.1016/j.palaeo.2012.09.024

Põldvere, A. 2001. General geological setting and stratigraphy. In Valga (10) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 10, 5–6 and 25–41.

Põldvere, A., Meidla, T., Bauert, H., Bauert, G. & Stouge, S. 1998. Ordovician. In Tartu (453) Drill Core (Põldvere, A., ed.), Estonian Geological Sections, 1,21–24.

Pranskevičius, A. A. 1971. K paleontologicheskoj kharakteristike nizhnego silura Yuzhnoj Pribaltiki (dannye izucheniya ostrakod) [To the paleontological characteristic of the Lower Silurian of the Southern Baltic area (data of the Ostracoda study)]. In Paleontologiya i stratigrafiya Pribaltiki i Belorussi, 3 [Palaeontology and Stratigraphy of the Baltic and the Byelorussia, 3], pp. 61–70. Mintis Vilnius [in Russian, with English summary].

Pranskevičius, A. 1972. Ostrakody silura Yuzhnoj Pribaltiki [South Baltic Silurian Ostracoda]. Mintis, Vilnius, 280 pp. [in Russian].

Raukas, A. & Teedumäe, A. (eds). 1997. Geology and Mineral Resources of Estonia. Estonian Academy Publishers, Tallinn, 436 pp. 

Rõõmusoks, A., Puura, V., Raukas, A. & Mark-Kurik, E. 1997: History of geological research. In Geology and Mineral Resources of Estonia (Raukas, A. & Teedumäe, A., eds), pp. 15–26. Estonian Academy Publishers, Tallinn. 

Sarv, L. & Meidla, T. 1984. Osobennosti rasprostraneniya ostracod v pogranichnykh otlozheniyakh ordovika i silura Severnoj Pribaltiki [Ostracod Distribution Pattern in the OrdovicianSilurian Boundary Beds of the North East Baltic]Manuscript, deposited in the All-Union Institute of Scientific and Technical Information (VINITI), 3813-84 Dep. Tallinn, 21 pp. [in Russian].

Schallreuter, R. 1990. Ordovizische Ostrakoden und Seeigel der Karnischen Alpen und ihre Beziehungen zu Böhmen und Baltoskandien. Neues Jahrbuch der Geologie und Paläontologie, Monatshefte, 2, 120–128.
https://doi.org/10.1127/njgpm/1990/1990/120

Sepkoski, J. J. Jr. 1998. Rates of speciation in the fossil record. Philosophical Transactions of the Royal Society LondonB353, 315–326.
https://doi.org/10.1098/rstb.1998.0212

Sorci, A., Cirilli, S., Clayton, G., Corrado, S., Hints, O., Goodhue, R., Schito, A. & Spina, A. 2020. Palynomorph optical analyses for thermal maturity assessment of Upper Ordovician (Katian–Hirnantian) rocks from Southern Estonia. Marine and Petroleum Geology120, 104574.
https://doi.org/10.1016/j.marpetgeo.2020.104574

Sztejn, J. 1989. Stratygrafia mikropaleontologiczna ordowiku Lubelszczyzny i zahodniej Cze´sci obnizenia Podlaskiego [Micropalaeontological stratigraphy of the Ordovician of the Lublin region and western part of the Podlasie Depression]. Biuletyn Państwowego Instytutu Geo­logicznego363, 69–92 [in Polish].

Tinn, O. & Meidla, T. 1999. Ordovician ostracodes from the Komstad Limestone. Bulletin of the Geological Society of Denmark46, 25–30.

Tolmacheva, T., Egerquist, E., Meidla, T. & Holmer, L. 2001. Spatial variations in faunal composition, Middle Ordovician, Volkhov Stage, East Baltic. GFF123, 65–72.
https://doi.org/10.1080/11035890101232065

Tolmacheva, T., Egerquist, E., Meidla, T., Tinn, O. & Holmer, L. 2003. Faunal composition and dynamics in uncon­solidated sediments: a case study from the Middle Ordovician of the East Baltic. Geological Magazine140, 31–44.
https://doi.org/10.1017/S001675680200701X

Troedsson, G. T. 1918. Om Skånes brachiopodskiffer [About the brachiopod shale of Scania]. Lunds Universitets Årsskrift, N. F. 2, 15, 3, 1–110 [in Swedish].

Truuver, K. & Meidla, T. 2015. A Hirnantian deep-water refuge for warm-water ostracods in Baltoscandia. Geological Quarterly59, 738–749. 
https://doi.org/10.7306/gq.1258

Truuver, K., Meidla, T., Ainsaar, L., Bergström, J. & Tinn, O. 2012. Stratigraphy of the Ordovician–Silurian boundary interval in Östergötland, Sweden, based on ostracod distribution and stable carbon isotopic data. GFF134, 295–308.
https://doi.org/10.1080/11035897.2012.762550

Truuver, K., Meidla, T. & Tinn, O. in press. End-Ordovician ostracod faunal dynamics in the Baltic Palaeobasin. Estonian Journal of Earth Sciences [accepted]. 

Ulst, R. 1992. Ordovik i silur v razrezakh glubokikh skvazhin na shel´fe Baltijskogo morya [Ordovician and Silurian in the deep boring sections on the Baltic Sea]. In Paleontologiya i stratigrafiya fanerozoya Latvii i Baltijskogo morya [Phanerozoic Palaeontology and Stratigraphy of Latvia and the Baltic Sea] (Sorokin, S., ed.), pp. 120–138. Zinatne, Riga [in Russian].

Ulst, R. Zh., Gailite, L. K. & Yakovleva, V. I. 1982. Ordovik Latvii [The Ordovician of Latvia]. Zinatne, Riga, 94 pp. [in Russian].

Verniers, J., Maletz, J., Kříž, J., Žigaité, Ž., Paris, F., Schönlaub, H.-P. & Wrona, R. 2008. Silurian. In The Geology of Central Europe, Volume 1: Precambrian and Palaeozoic (McCann, T., ed.), pp. 249–302. Geological Society, London.
https://doi.org/10.1144/CEV1P.6

Zhang, S. & Barnes, C. R. 2007. Late Ordovician to Early Silurian conodont faunas from the Kolyma Terrane, Omulev Mountains, Northeast Russia, and their paleobiogeographic affinity. Journal of Paleontology81, 490–512.
https://doi.org/10.1666/05077.1


Back to Issue