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Phenotypic evolution in a lineage of the Eocene ostracod Echinocythereis

Published online by Cambridge University Press:  08 April 2016

Richard A. Reyment
Richard A. Reyment*
Affiliation:
Paleontologiska Institutionen, Uppsala Universitet, Box 558, S75122, Uppsala, Sweden
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Abstract

Two speciation events occurred in the Eocene lineage beginning with Echinocythereis isabenana Oertli (Aragon, Spain). After a long period of stasis in ornament and shape/size, this species underwent a relatively rapid decrease in size, accompanied by ornamental changes. The transition required about 30,000 yr. The new species E. aragonensis Oertli is significantly smaller (20% decrease in size). The lateral papillation is denser and less regular, the papillae being significantly smaller than in the ancestral form. This ornament gradually yields to increasing frequencies of individuals with reduced papillae superimposed on a progressively better developed network of filaments. This change, which is regionally valid, is ultimately replaced by fully expressed reticulations, on which minute pustules may occur; this development typifies the third species, E. posterior Oertli. Some ornamental characteristics of E. aragonensis are anticipated in rare individuals of E. isabenana. Ornamental features of E. posterior appear in late larvae of E. isabenana. Generally, E. aragonensis and E. posterior do not differ significantly in size. A trend toward smaller carapaces in the upper samples of E. posterior could be related to ecophenotypic effects.

All species are highly polymorphic for both shape and ornament; the morphs are not sharply bounded and are mostly of uncertain evolutionary status. The transition from isabenana to aragonensis is heralded by a sharp rise in the coefficient of variation for length measures of the carapace. There is a pronounced multivariate morphometric discontinuity between isabenana and the descendant forms, which are largely multivariately homogeneous. The isabenana-aragonensis transition could have occurred by selection or by random genetic drift. Both models can be accommodated by the data; however, the weight of evidence favors the former hypothesis. Evolution in the Echinocythereis lineage seems to have occurred by two different mechanisms. The first transition was rather rapid, with many disjunct features. The second was slow, the changes being more of degree than of kind.

Type
Articles
Information
Paleobiology , Volume 11 , Issue 2 , Spring 1985 , pp. 174 - 194
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Abe, K. 1983. Population structure of Keijella bisanensis (Okubo) (Ostracoda, Crustacea). J. Fac. Sci., Univ. Tokyo. 20:443–488Google Scholar
Anderson, T. W. and Bahadur, R. R. 1958. Two sample comparisons of dispersion matrices for alternatives of immediate specificity. Ann. Math. Stat. 33:420–431.Google Scholar
Babinot, J. P. and Colin, J. P. 1979. Taxonomic and paleoecologic comments on the genus Trachyleberidea Bowen, 1953. Crpko Geol. Drushtvo. 1979:55–58.Google Scholar
Barker, D. 1963. Size in relation to salinity in fossil and recent euryhaline ostracods. J. Marine Biol. Assoc. 43:785–795.Google Scholar
Blackith, R. E. and Reyment, R. A. 1971. Multivariate Morphometrics. Academic Press; London.Google Scholar
Bodergat, A. M. 1983. Les Ostracodes, témoins de leur environnement: approche chimique et écologique en milieu lagunaire et océanique. Docum. Lab. Géol. Lyon. 88:1–246.Google Scholar
Bookstein, F. L. 1978. The measurement of biological shape and shape change. Lecture Notes in Biomathematics. 24:1–191. Springer-Verlag, New York.Google Scholar
Campbell, N. A. 1979. Canonical Variate Analysis: Some Practical Aspects. Ph.D. diss., Imperial College; London.Google Scholar
Carbonel, P. and Pujos, M. 1982. Les variations architecturales des microfaunes du lac de Tunis: relations avec l'environnement. Ocean. Acta (Supplement). Actes Symp. Int. Lagunes côtières. 1982:79–85.Google Scholar
Clark, W. C. 1976. The environment and the genotype in polymorphism. Zool. J. Linn. Soc. 58:255–262.Google Scholar
Dewis, F. J., Levinson, A. A., and Bayliss, P. 1972. Hydrogeochemistry of the surface waters of the Mackenzie River drainage basin, Canada—IV. Boron salinity-clay mineralogy relationships in modern deltas. Geochim. Cosmochim. Acta. 36:1359.Google Scholar
Ducasse, O. 1981. Etude populationniste du genre Cytherella (Ostracodes) dans les faciès bathyaux du Paléogène. Intérět dans la reconstitution des paléoenvironnements. Bull. Inst. Géol. Bassin d'Aquitaine, Bordeaux. 30:161–186.Google Scholar
Ducasse, O. 1983. Etude des populations du genre Protoargilloecia (Ostracodes) dans les faciès bathyaux du Paléogène aquitain. Geobios. 16:273–283.Google Scholar
Ducasse, O. and Cirac, P. 1981. La faune de Mutilus (Ostracodes: Hemicytheridae) de la région des Zemmours (Maroc nord occidental) à la fin du Miocène et au Pliocène. Géol. Méd. 8:87–100.CrossRefGoogle Scholar
Ducasse, O. and Coustillas, F. 1981. Les Ostracodes du genre Pokornyella dans le Paléogène aquitain. I. Etude systematique par analyse structurale des espèces en populations. Bull. Inst. Géol. Bassin d'Aquitaine, Bordeaux. 29:5–30.Google Scholar
Ducasse, O. and Rousselle, L. 1979. Les Hammatocythere (Ostracodes) de l'Oligocène aquitain. Bull. Inst. Géol. Bassin d'Aquitaine, Bordeaux. 25:221–255.Google Scholar
Falconer, D. S. 1981. Introduction to Quantitative Genetics, 2nd. ed. Longman; London.Google Scholar
Gould, S. J. and Eldredge, N. 1977. Punctuated equilibria: the tempo and mode of evolution reconsidered. Paleobiology. 3:115–151.Google Scholar
Grudzien, T. A. and Turner, B. J. 1984. Direct evidence that the Ilyodon morphs are a single biological species. Evolution. 38:402–407.Google Scholar
Hallauer, A. R. and Miranda, J. B. 1981. Quantitative genetics. In: Maize Breeding. Iowa State University Press; Ames.Google Scholar
Hand, D. J. 1981. Discrimination and Classification. Wiley; New York.Google Scholar
Harder, H. 1958. Beitrag zur Geochemie des Bors. Fortschr. Mineral. 37:82.Google Scholar
Hartmann, G. 1982. Variation in surface ornament of the valves of three ostracod species from Australia. Pp. 365–380. In: Bate, R. H., Robinson, E., and Sheppard, L. M., eds. Fossil and Recent Ostracods; Brit. Micropalaeontol. Ser.Google Scholar
Keen, M. C. 1982. Intraspecific variation in Tertiary ostracods. Pp. 380–405. In: Bate, R. H., Robinson, E., and Sheppard, L. M., eds. Fossil and Recent Ostracods; Brit. Micropalaeontol. Ser.Google Scholar
Keyser, D. 1982. Development of the sieve pores in Hirschmannia viridis (O. F. Müller, 1785). Pp. 51–60. In: Bate, R. H., Robinson, E., and Sheppard, L. M., eds. Fossil and Recent Ostracods. Brit. Micropalaeontol. Ser.Google Scholar
Krauskopf, K. B. 1956. Factors controlling the concentration of thirteen rare metals in sea-water. Geochim. Cosmochim. Acta. 9:1.CrossRefGoogle Scholar
Kullback, S. 1959. Information Theory and Statistics. Wiley; New York.Google Scholar
Lande, R. 1976. Natural selection and random genetic drift in phenotypic evolution. Evolution. 30:314–334.Google Scholar
Lande, R. 1979. Quantitative genetic analysis of multivariate evolution, applied to brain:body size allometry. Evolution. 33:402–416.Google ScholarPubMed
Liebau, A. 1971. Homologe Skulpturmuster bei Trachyleberididae und verwandten Ostrakoden. Dissertation, Berlin.Google Scholar
Malmgren, B. A. and Kennett, J. P. 1981. Phyletic gradualism in a Late Cenozoic planktonic foraminiferal lineage: DSDP Site 284, southwest Pacific. Paleobiology. 7:230–240.Google Scholar
Malmgren, B. A., Berggren, W. A., and Lohmann, G. P. 1984. Evidence for punctuated gradualism in the Late Neogene Globorotalia tumida lineage of planktonic foraminifera. Paleobiology. 9:377–389.CrossRefGoogle Scholar
Moore, J. R. 1963. Bottom sediment studies, Buzzards Bay, Massachusetts. J. Sed. Pet. 33:511.Google Scholar
Mosteller, F. and Tukey, J. W. 1977. Data Analysis and Regression. Addison-Wesley; Reading, Mass.Google Scholar
Oertli, H. 1960. Evolution d'une espèce d'Echinocythereis dans le Lutètien du Rio Isabena (Prov. Huesca, Espagne). Rev. Micropaleontol. 3:157–166.Google Scholar
Okada, Y. 1981. Development of cell arrangement in ostracod carapaces. Paleobiology. 7:276–280.CrossRefGoogle Scholar
Reyment, R. A. 1962. Observations on homogeneity of covariance matrices in paleontologic biometry. Biometrics. 18:1–11.Google Scholar
Reyment, R. A. 1963. Studies on Nigerian Upper Cretaceous and Lower Tertiary Ostracoda. II. Danian, Paleocene and Eocene Ostracoda. Stockh. Contr. Geol. 10:1–286.Google Scholar
Reyment, R. A. 1966. Studies on Nigerian Upper Cretaceous and Lower Tertiary Ostracoda. III. Stratigraphical, palaeoecological and biometrical conclusions: Stockh. Contr. Geol. 14:1–151.Google Scholar
Reyment, R. A. 1969. A multivariate paleontological growth problem. Biometrics. 25:1–8.Google Scholar
Reyment, R. A. 1970. Spectral breakdown of morphometric chronoclines. Math. Geol. 2:365–376.Google Scholar
Reyment, R. A. 1971. Introduction of Quantitative Paleoecology. Elsevier, Amsterdam.Google Scholar
Reyment, R. A. 1982a. Analysis of trans-specific evolution in Cretaceous ostracods. Paleobiology. 8:293–306.Google Scholar
Reyment, R. A. 1982b. Speciation in a Late Cretaceous lineage of Veenia (Ostracoda, Crustacea). J. Micropalaeontol. 1:37–44.Google Scholar
Reyment, R. A. 1982c. Threshold characters in a Cretaceous foraminifer. Palaeogeogr., Palaeoclimatol., Palaeoecol. 38:1–7.CrossRefGoogle Scholar
Reyment, R. A. 1982d. Phenotypic evolution in a Cretaceous foraminifer. Evolution. 36:1182–1199.Google Scholar
Reyment, R. A. 1983. Phenotypic evolution in microfossils. Evol. Biol. 16:209–254.Google Scholar
Reyment, R. A. and van Valen, L. 1969. Buntonia olokundudui sp. nov. (Ostracoda. Crustacea): a study of meristic variation in Paleocene and Recent ostracods. Bull. Geol. Inst. Univ. Uppsala, N.S. 1:83–94.Google Scholar
Reyment, R. A., Blackith, R. E., and Campbell, N. A. 1984. Multivariate Morphometrics, 2nd ed. Academic Press; London.Google Scholar
Reyment, R. A., Ramden, H. Å., and Wahlstedt, W. J. 1969. FORTRAN IV program for the generalized statistical distance and analysis of covariance matrices for the CDC 3600 computer. Computer Contr. 39, State Geol. Surv. Kansas; Lawrence.Google Scholar
Sandberg, P. A. 1964. The ostracod genus Cyprideis in the Americas. Stockh. Contr. Geol. 12:1–178.Google Scholar
Shiraki, K. 1966. Some aspects of the geochemistry of chromium. J. Earth Sci., Nagoya Univ. 14:10.Google Scholar
Stambolidis, E. A. 1984. Subrezente Ostracoden aus dem Evros-Delta (Griechenland) einschliesslich der Entwicklung des Schlosses gewisser Arten. Dissertation; Univ. Uppsala.Google Scholar
Theisen, B. F. 1966. The life history of seven species of ostracods from a Danish brackish-water locality. Medd. Danm. Fisk. Havunders, N.S. 4:215–270.Google Scholar
Triebel, E. 1941. Zur Morphologie und Ökologie der fossilen Ostracoden. Senckenbergiana. 23:294–400.Google Scholar
Ueda, S. 1957. Chemical studies on the ocean—LXIX. Chemical studies of the shallow-water deposits—22. Vanadium and chromium contents of the shallow-water deposits (2). J. Oceanograph. Soc. Japan. 13:99.Google Scholar
Uffenorde, H. 1972. Ökologie und jahreszeitliche Verteilung rezenter benthonischer Ostrakoden des Limski-Kanal bei Rovinj (nördliche Adrie). Göttinger Arb. Geol. Paläontol. 13:1–121.Google Scholar
Whatley, R. 1983. The application of Ostracoda to palaeoenvironmental analysis. In: Applications of Ostracoda. R. F. Maddocks, ed. Univ. Houston Geosci. 1983:51–77.Google Scholar
Williamson, P. G. 1981. Palaeontological documentation of speciation in Cenzoic molluscs from the Turkana Basin. Nature. 293:437–443.Google Scholar