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Analysis of trans-specific evolution in Cretaceous ostracods

Published online by Cambridge University Press:  08 February 2016

Richard A. Reyment*
Paleontologiska Institutionen, Uppsala Universitet, Box 558 S-75122 Uppsala, Sweden


During the middle Cretaceous, exceptional ecologic conditions developed in the Tarfayan Basin (SW Morocco) marked by the deposition of marls and limestones, rich in organic matter. The ostracod fauna of the Cenomanian to Coniacian consisted of a few ornamentally stable species. Towards the close of the Turonian, Oertliella? tarfayaensis became dimorphic at the top of its range, the new morph with smooth lateral zones being the undoubted ancestor of Oertliella? chouberti. The multivariate morphometric evolutionary pattern for O.? tarfayaensis fluctuates about a stationary value in a manner which could reflect evolutionary stasis. The passage from the ancestral to the descendant species took between 1 × 105 and 2 × 105 yr. At the multivariate level, the transition could have taken place by random genetic drift with, or without, selective effects. At the univariate level, there is no clear evidence for either of these mechanisms. The phenotype is regionally stable which suggests that a non-genetic origin of the change is unlikely. An alternative model for the speciation event is allopatric speciation in a peripheral isolate and immigration. The Late Turonian morph may have resulted from environmentally cued polymorphism with elimination of the original morph due to a long term ecologic change, possibly connected with an increase in silica in the environment.

Copyright © The Paleontological Society 

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Barker, D. 1963. Size in relation to salinity in fossil and recent euryhaline ostracods. J. Mar. Biol. Assoc. 43:785795.CrossRefGoogle Scholar
Benson, R. H. 1972. The Bradleya problem, with descriptions of two new psychrospheric ostracode genera Agrenocythere and Poseidonomicus (Ostracoda: Crustacea). Smithsonian Contrib. Paleobiol. 12:1138.Google Scholar
Blackith, R. E. and Reyment, R. A. 1971. Multivariate Morphometrics. 412 pp. Academic Press; London.Google Scholar
Campbell, N. A. 1979. Canonical Variate Analysis: some practical aspects. Ph. D. Thesis, Imperial College, Univ. London.Google Scholar
Campbell, N. A. and Reyment, R. A. 1978. Discriminant analysis of a Cretaceous foraminifer using shrunken estimators. Math. Geol. 10:347359.CrossRefGoogle Scholar
Campbell, N. A. and Reyment, R. A. 1980. Robust multivariate procedures applied to the interpretation of atypical individuals of a Cretaceous foraminifer. Cretaceous Res. 1:207221.CrossRefGoogle Scholar
Choubert, G., Faure-Muret, H., and Hottinger, L. 1966. Le bassin côtier de Tarfaya (Maroc Méridional). Tome 1: Stratigraphie. Notes et Mémoires du Service Géologique du Maroc. 175:9219.Google Scholar
Cita, M. B. and Schlanger, S. O.In press. Nature and Origin of Organic Carbon-Rich Cretaceous Facies. Academic Press; London and New York.Google Scholar
Clark, W. C. 1976. The environment and the genotype in polymorphism. Zool. J. Linnean Soc. 58:255262.CrossRefGoogle Scholar
Crow, J. F. and Kimura, M. 1970. Introduction to Population Genetics Theory. Harper & Row; New York.Google Scholar
Eldredge, N. and Gould, S. J. 1972. Punctuated equilibria: an alternative to phyletic gradualism. Pp. 82115. In: Schopf, T., ed. Models in Paleobiology. Freeman, Cooper & Co.; San Francisco.Google Scholar
Futuyma, D. J. 1979. Evolutionary Biology. x + 565 pp. Sinauer and Associates Inc.; Mass.Google Scholar
Gilbert, N. 1973. Biometrical Interpretation. 175 pp. Clarendon; Oxford.Google Scholar
Gilchrist, B. M. 1960. Growth and form in the brine shrimp Artemia salina (L.) Proc. Zool. Soc. London. 134:221235.CrossRefGoogle Scholar
Haldane, J. B. S. 1949. Suggestions as to the quantitative measurement of rates of evolution. Evolution. 3:5156.CrossRefGoogle ScholarPubMed
Hallam, A. 1978. How rare is phyletic gradualism and what is its evolutionary significance? Evidence from Jurassic bivalves. Paleobiology. 4:1625.CrossRefGoogle Scholar
Hallauer, A. R. and Miranda, J. W. 1981. Quantitative Genetics in Maize Breeding. xii + 468 pp. Iowa State Press.Google Scholar
Hancock, J. M. and Kauffman, E. G. 1979. The great transgressions of the Late Cretaceous. J. Geol. Soc. London. 136:175186.CrossRefGoogle Scholar
Harris, D. L. 1964. Expected and predicted progress from index selection involving estimates of population parameters. Biometrics. 20:4672.CrossRefGoogle Scholar
Hartl, D. L. 1980. Principles of Population Genetics. xvi + 488 pp. Sinauer and Associates Inc.; Mass.Google Scholar
Hayes, J. F. and Hill, W. G. 1981. Modification of estimates of parameters in the construction of genetic selection indices (“bending”). Biometrics. 37:483493.CrossRefGoogle Scholar
Hegmann, N. J. P. and DeFries, J. C. 1970. Are genetic and environmental correlations correlated. Nature. 226:284285.CrossRefGoogle ScholarPubMed
Hill, W. G. and Thompson, R. 1978. Probabilities on non-positive definite between-group or genetic covariance matrices. Biometrics. 34:429439.CrossRefGoogle Scholar
Jaanusson, V. 1981. Functional thresholds in evolutionary progress. Lethaia. 14:251260.CrossRefGoogle Scholar
Jaenicke, J. E. D. Parker, and Selander, R. K. 1980. Clonal niche structure in the parthenogenetic earthworm Octolasion tyrtaeum. Am. Nat. 116:196205.CrossRefGoogle Scholar
Kirkpatrick, M. 1982. Quantum evolution and punctuated equilibria in continuous genetic characters. Am. Nat. 119:833848.CrossRefGoogle Scholar
Lande, R. 1976. Natural selection and random genetic drift in phenotype evolution. Evolution. 30:314334.CrossRefGoogle Scholar
Lande, R. 1979. Quantitative genetic analysis of multivariate evolution, applied to brain:body size allometry. Evolution. 33:402416.Google ScholarPubMed
Liebau, A. 1971. Homologe Skulpturmuster bei Trachyleberididae und verwandten Ostrakoden. Ph.D. Dissertation, Univ. Berlin (Published). 117 pp. (Modified English translation 1978).Google Scholar
Omatsola, E. M. 1970. Podocopid Ostracoda from the Lagos Lagoon, Nigeria. Micropaleontology. 16:407445.CrossRefGoogle Scholar
Malmgren, B. A. and Kennett, J. P. 1981. Phyletic gradualism in a Late Cenozoic planktonic foraminiferal lineage. DSDP site 284, southwest Pacific. Paleobiology. 7:230240.CrossRefGoogle Scholar
Nordwijk, A. J. van, van Balen, J. H., and Scharloo, W. 1980. Heritability of ecologically important traits in the great tit. Ardea. 68:193203.Google Scholar
Rahhali, I. 1981. Le Cénomanien supérieur et le Turonien Inférieur bitumineux du bassin côtier de Tarfaya et du Haut Atlas. Mines, Géologie et Energie, Rabat (1979). 46:6369.Google Scholar
Raup, D. M. and Crick, R. E. 1981. Evolution of single characters in the Jurassic ammonite Kosmoceras. Paleobiology. 7:200215.CrossRefGoogle Scholar
Rendel, J. M. 1967. Canalisation and Gene Control. 166 pp. Academic Press; London.Google Scholar
Reyment, R. A. 1966. Studies on Nigerian Upper Cretaceous and Lower Tertiary Ostracoda: HI stratigraphical, paleoecological and biometrical conclusions. Stockholm Contrib. Geol. 14:1151.Google Scholar
Reyment, R. A. 1968. Interstitial ecology of the Niger Delta. Bull. Geol. Inst. Univ. Uppsala. NS1:121159.Google Scholar
Reyment, R. A. 1978. Quantitative biostratigraphical analysis exemplified by Moroccan Cretaceous ostracods. Micropaleontology. 24:2443.CrossRefGoogle Scholar
Reyment, R. A. 1979. Signification paléobiogéographique de la répartition de Oertliella tarfayaensis au Maroc. Revue de Micropaléontol. 22:186190.Google Scholar
Reyment, R. A. 1980. Morphometric Methods in Biostratigraphy. 178 pp. Academic Press; London.Google Scholar
Reyment, R. A.In press a. Mid-Cretaceous ostracods of the Tarfaya Basin, Morocco. Cretaceous Res.Google Scholar
Reyment, R. A.In press b. Phenotypic evolution in a Cretaceous foraminifer. Evolution.Google Scholar
Reyment, R. A. and Brännström, B. 1962. Certain aspects of the physiology of Cypridopsis (Ostracoda, Crustacea). Stockholm Contrib. Geol. 2:207242.Google Scholar
Roughgarden, J. 1979. Theory of Population Genetics and Evolutionary Ecology: an Introduction. 634 pp. MacMillan; New York.Google Scholar
Sachs, H. S. and Hasson, P. F. 1979. Comparison of species vs. character description for very high resolution biostratigraphy using cannartid radiolarians. J. Paleontol. 53:11121120.Google Scholar
Sadler, O. M. 1981. Sediment accumulation rates and the completeness of stratigraphic sections. J. Geol. 89:569584.CrossRefGoogle Scholar
Sandberg, P. A. 1964. The ostracod genus Cyprideis in the Americas. Stockholm Contrib. Geol. 12:1178.Google Scholar
Simpson, G. G. 1953. The Major Features of Evolution. 434 pp. Columbia Univ. Press; New York.Google Scholar
Smith, H. F. 1936. A discriminant function for plant selection. Annals Eugenics. 7:240250.CrossRefGoogle Scholar
Theisen, B. F. 1966. The life history of seven species of ostracods from a Danish brackish-water locality. Meddelelser fra Danmarks Fiskeri- og Havsundersøgelser NS. 4:215270.Google Scholar
Thorpe, R. S. and McCarthy, C. J. 1978. A preliminary study, using multivariate analysis, of a species complex of African house snakes (Boaedon fuligonosus). J. Zool. Soc. London. 184:489506.CrossRefGoogle Scholar
Uffenorde, H. 1972. Ökologie und jahreszeitliche Verteilung rezenter benthonischer Ostracoden des Limski-Kanal bei Rovinj (nördliche Adrie). Göttinger Arbeiten zur Geol. Paläontol. 13:1121.Google Scholar
Vølund, A. 1980. Multivariate bioassay. Biometrics. 36:225236.CrossRefGoogle ScholarPubMed
Wiedmann, J., Einsele, G., and Immel, H. 1978. Evidence faunistique et sédimentologique pour un upwelling dans le bassin côtier de Tarfaya, Maroc, dans le Crétacé Supérieur. Actes du VIème colloque africain de Micropaléontologie—Tunis (1974). Annales des Mines et de la Géologie, Tunis. 28:415441.Google Scholar
Williams, J. S. 1962. The evaluation of a selection index. Biometrics. 18:375393.CrossRefGoogle Scholar
Williamson, P. G. 1981. Palaeontological documentation of speciation in Cenozoic molluscs from Turkana Basin. Nature. 293:437443.CrossRefGoogle Scholar
Wright, S. 1968. Evolution and the Genetics of Populations: Vol. 1: Genetic and Biometric Foundations. vii + 469. Univ. Chicago Press; Chicago.Google Scholar
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