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Paleobiological and isotopic studies of eggshells from a declining dinosaur species

Published online by Cambridge University Press:  08 February 2016

H. K. Erben ,
J. Hoefs  and
K. H. Wedepohl
H. K. Erben
Affiliation:
Institut für Paläontologie, Universität Bonn, Nussallee 8, D-5300 Bonn 1, Bundesrepublik Deutschland
J. Hoefs
Affiliation:
Geochemisches Institut, Universität Göttingen, Goldschmidtstrasse 1, D-3400 Göttingen, Bundesrepublik Deutschland
K. H. Wedepohl
Affiliation:
Geochemisches Institut, Universität Göttingen, Goldschmidtstrasse 1, D-3400 Göttingen, Bundesrepublik Deutschland
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Abstract

Late Cretaceous dinosaur eggshells from southern France and the Spanish Pyrenees, presumably belonging to the sauropod Hypselosaurus priscus Matheron, are almost exclusively composed of primary calcite. Besides normal development of these eggshells, there appear two kinds of pathologic tendencies: bi- or multi-shells (infrequent), and shells with a reduced thickness (increasing in frequency until, in the uppermost horizon, they represent more than 90% of the sample). The extinction of the species is attributed primarily to the consequences of thinning of the eggshells.

The physiological mechanisms producing pathologic dinosaur eggshells are evaluated in the light of homologous phenomena occurring in living birds and reptiles. On this basis, it is concluded that in the late Maastrichtian populations of “Hypselosaurus,” pathologic eggshells were caused by hormonal imbalances of the vasotocin and of the estrogen levels. On the same basis it is postulated that the teratological shell repetition led to embryo suffocation and that the pathological reduction in shell thickness caused shell breakage and dehydration of the embryo. The lethal results are evident from the frequent absence of “resorption craters” in the mammillary knobs of pathologic shells, a fact which indicates either lack of fertilization of the eggs or the perishing of the embryo prior to the calcification of its skeletal bones. A change in environmental conditions is the ultimate factor which caused hormonal imbalances and extinction. Such a change is indicated by a shift of the mean oxygen isotopic composition (δ18O) of eggshell carbonates from −0.6%o to −5.3%o, and by changes in Sr. Information of palaeo-climate is primarily derived from eggshells of living birds and reptiles. The correlation between temperature and oxygen isotopic composition of waters (and related carbonates) is less distinct than for marine carbonates. δ13C ranges from −16.5 to −4.5 of eggshells of extant species indicate food from “normal” C3 metabolism and from C4 metabolism of plants in a dry climate. “Hypselosaurus” populations probably consumed “normal” C3 plants. Using isotopic calibration of eggshell carbonates for the interpretation of δ13C and δ18O values of dinosaur eggshells, a slight change from higher to lower temperatures or a change from a dry to a more humid climate during the time from Lower (and Middle) to Late Maastrichtian can be assumed. The latter explanation is favored because the exceptionally high Sr in the Early Maastrichtian eggshells could be a potential indicator of co-existing evaporites.

Type
Research Article
Information
Paleobiology , Volume 5 , Issue 4 , Fall 1979 , pp. 380 - 414
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Axelrod, D. I. and Bayley, H. P. 1968. Cretaceous dinosaur extinction. Evolution. 224:595.CrossRefGoogle Scholar
Bakker, R. T. 1972. Anatomical and ecological evidence of endothermy in dinosaurs. Nature. 238:81.CrossRefGoogle Scholar
Bakker, R. T. 1975. Dinosaur renaissance. Sci. Am. 232.CrossRefGoogle Scholar
Bazhanov, V. S. 1961. (A new occurrence of dinosaur eggshells in the USSR.). Trudy Akad. Nauk KazSSR, Inst. Zool. 15:177.Google Scholar
Bellairs, A. d'A. 1970. The Life of Reptiles. Vol. 2. Universe Books; New York.Google Scholar
Bennett, A. F. and Dalzell, B. 1973. Dinosaur physiology: a critique. Evolution. 27:170.CrossRefGoogle Scholar
Bitman, J., Cecil, H. C., Harris, S. J., and Fries, G. F. 1968. Estrogenic activity of o,p'-DDT in the mammalian uterus and avian oviduct. Science. 162:371.CrossRefGoogle Scholar
Bitman, J., Cecil, H. C., and Fries, G. F. 1970. DDT-induced inhibition of avian shell gland carbonic anhydrase: a mechanism for thin eggshells. Science. 168:594.CrossRefGoogle ScholarPubMed
Calhoun, J. B. 1952. The social aspects of population dynamics. J. Mammal. 33:139.CrossRefGoogle Scholar
Calhoun, J. B. and Christian, J. J. 1963. Mammalian populations. In: Mayer, W. V. and van Gelders, R. G., eds. Physiological Mammalogy. Vol. 1, Academic Press; New York.Google Scholar
Case, T. J. 1978. Speculations on the growth rate and reproduction of some dinosaurs. Paleobiology. 4(3):320.CrossRefGoogle Scholar
Chao, T. K. 1975. (Chinese title). Vertebrata Palasiatica. 13(2):105.Google Scholar
Chao, T. K. and Chiang, Y.-K. 1974. Microscopic studies on the dinosaurian eggshells from Laiyang, Shantung Province. Scientia Sinica. 17(1):74.Google Scholar
Chao, T. K. and Chao, N. N. 1976. (Chinese title). Vertebrata Palasiatica. 14(1):42.Google Scholar
Clauss, B. and Acker, L. 1978. Chlorierte Kohlenwasserstoffe, insbesondere polychlorierte Biphenyle, in Hühnereiern—Einfluß auf Schalendicke und Bruchfestigkeit. Forschg. Bericht Deutsche Forsch. Gem. (Kolloquium “Rückstände im Geflügel und Eiern,” Mai 1975), Vlg. Boldt, Boppard.Google Scholar
Christian, J. J. 1963. Endocrine adaptive mechanisms and the physiologic regulation of population growth. In: Mayer, W. V. and van Gelders, R. G., eds. Physiological Mammalogy. Academic Press; New York.Google Scholar
Christian, J. J. 1970. Social subordination, population density and mammalian evolution. Science. 168:84.CrossRefGoogle ScholarPubMed
Colbert, E. H. 1962. The weights of dinosaurs. Am. Mus. Novitates, No. 2076, 1.Google Scholar
Colbert, E. H. 1965. The Age of Reptiles. Norton & Co.; New York.Google Scholar
Craig, H. 1961. Isotopic variation in meteoric waters. Science. 133:1702.CrossRefGoogle ScholarPubMed
Cys, J. M. 1967. On the inability of the dinosaurs to hibernate as a possible key factor in their extinction. J. Paleontol. 41:226.Google Scholar
Dansgaard, W. 1964. Stable isotopes in precipitation. Tellus. 16:436.CrossRefGoogle Scholar
DeNiro, M. J. and Epstein, S. 1978. Influence of diet on the distribution of carbon isotopes in animals. Geochim. Cosmochim. Acta. 42:495.CrossRefGoogle Scholar
Desmond, A. 1975. The Hot-blooded Dinosaurs: A Revolution in Paleontology. Blond and Briggs; London.Google Scholar
Dughi, R. and Sirugue, F. 1957. Les oeufs de dinosauriens du bassin d'Aix-en-Provence. C. R. Acad. Sci. Paris. 245:707.Google Scholar
Dughi, R. and Sirugue, F. 1958. Sur les oeufs de dinosaures du bassin fluviolacustre de Basse-Provence. C.R.83e Congr. sav. Paris et Dépts. 183, Aix.Google Scholar
Dughi, R. and Sirugue, F. 1958. Observations sur les oeufs de dinosaures du bassin d'Aix-en-Provence: les oeufs à coquille bistratifiées. C. R. Acad. Sci. Paris. 246:2271.Google Scholar
Dughi, R. and Sirugue, F. 1962. Distribution verticale des oeufs d'oiseaux fossiles de Basse-Provence. Bull. géol. Soc. France. 7(4):69.CrossRefGoogle Scholar
Dughi, R. and Sirugue, F. 1966. Sur la fossilisation des oeufs de dinosaures. C. R. Acad. Sci. Paris. 262:2330.Google Scholar
Dughi, R. and Sirugue, F. 1976. L'extinction des dinosaures à la lumière des gisements d'oeufs du Crétacé terminal du Sud de la France, principalement dans le Bassin d'Aix-en-Provence. Paléobiol. continentale. 7(1):1.Google Scholar
El-Boushi, A. R., Simons, P. C. M., and Wiertz, G. 1968. Structure and ultrastructure of the hen's eggshell as influenced by environmental temperature, humidity and vitamin C additions. Poultry Sci. 47:456.CrossRefGoogle Scholar
Eliseyev, V. 1977. (On rickets in dinosaurs). Soviet Weekly. April 23th.Google Scholar
Erben, H. K. 1969. Dinosaurier: Pathologische Strukturen ihrer Eischale als Letalfaktor. Umschau Wiss. Techn. 17/69:552.Google Scholar
Erben, H. K. 1970. Ultrastruktur und Mineralisation rezenter und fossiler Eischalen bei Vögeln und Reptilien. Biominer. Res. Repts. 1:1.Google Scholar
Erben, H. K. 1972. Ultrastrukturen und Dicke der Wand pathologischer Eischalen. Abh. Akad. Wiss. Lit. Mainz, math.-nat. Kl. 1972/6:193.Google Scholar
Erben, H. K. 1975. Die Entwicklung der Lebewesen; Spielregeln der Evolution. Vlg. Piper & Co.; München.Google Scholar
Erben, H. K. and Krampitz, G. 1971. Eischalen DDT-verseuchter Vögel: Ultrastruktur und organische Substanz. Abh. Akad. Wiss. Lit. Mainz, math.-nat. Kl. 1971/2:31.Google Scholar
Erben, H. K. and Kriesten, K. 1973. Mikromorphologie der Frühstadien bei der Bildung normaler und anormaler Hühner-Eischalen. Biominer. Res. Repts. 7:28.Google Scholar
Erben, H. K. and Newesely, H. 1973. Kristalline Bausteine und Mineralbestand von kalkigen Eischalen. Biominer. Res. Repts. 6:32.Google Scholar
Faber, H. v. 1978. Das Ende vieler Vogelarten. Deutsche Forsch. Gemeinsch. Mitt. 2:21.Google Scholar
Flügel, H. W. and Wedepohl, K. H. 1967. Die Verteilung des Strontiums in oberjurassischen Karbonatgesteinen der nördlichen Kalkalpen. Ein Beitrag zur Diagenese von Karbonatgesteinen. Contr. Miner. Petrol. 14:229.CrossRefGoogle Scholar
Folinsbee, R. E., Fritz, P., Krouse, H. R., and Robblee, A. R. 1970. Carbon-13 and Oxygen-18 in dinosaur, crocodile and bird eggshells indicate environmental conditions. Science. 168(3937):1553.CrossRefGoogle ScholarPubMed
Frank, F. 1955. Die ungelöste Problematik der Bekämpfung von Mäuseplagen. Nachrichtenbl. BBA. 7:5.Google Scholar
Freytet, P. 1965. Découverte d'oeufs de dinosaures à Saint-André-de-Roquelongue (Aude). Bull. Soc. Et. Sci. Aude. 65:121.Google Scholar
Freytet, P. 1971. Les dêpots continentaux et marins du Crétacé supérieur et les couches de passage à l'Eocène en Languedoc. Bull. BRGM. 2. sér. (4):1.Google Scholar
Freytet, P. and Plaziat, J.-C. 1970. Nouveaux éléments de corrélation lithologique et paléontologique entre les formations marines et continentales de l'Eocène inférieur languedocien; le problème de l'“Illerdien” continental. C. R. Acad. Sci. Paris. 270:1076.Google Scholar
Ginsburg, L. 1964. Les régressions marines et le problème du renouvellement des faunes au cours des temps géologiques. Bull. géol. Soc. France. 7. sér. 6:13.CrossRefGoogle Scholar
Gradzinski, R., Kazmierczak, J., and Lefeld, J. 1968. Results of the Polish-Mongolian Paleontological Expedition; Geographical and geological data. Paleontol. Polonica. 19:69.Google Scholar
Haines, E. B. 1976. Relation between the stable carbon isotope composition of fiddler crabs, plants and soils in a salt marsh. Limnol. Oceanogr. 21:880.CrossRefGoogle Scholar
Hardin, G. 1959. Naturgesetz und Menschenschicksal. Vlg. Cotta; Stuttgart. [Nature and Man's Fate].Google Scholar
Harzer, D., Pilot, J., and Rösler, H. J. 1968. Sauerstoff-Isotopenunter-suchungen an Oberflächen-und Niederschlagswässern des Harzes. Bergakad. 20:329.Google Scholar
Holst, D. v. 1969. Sozialer Stress bei Tupajas (Tupaia belangeri). Die Aktivierung des sympathischen Nervensystems und ihre Beziehung zu hormonal ausgelösten ethologischen und physiologischen Veränderungen. Z. vergl. Physiol. 63:1.CrossRefGoogle Scholar
Holst, D. v. 1972. Sozialverhalten und Stressreaktionen-eine populationsphysiologische Untersuchung an Tupajas. Deutsche Forsch. Gemeinsch., Mitt. 4:44.Google Scholar
Hopson, J. A. 1977. Relative brain size and behaviour in archosaurian reptiles. Ann. Rev. Ecol. Syst. 8:429.CrossRefGoogle Scholar
Jensen, J. A. 1966. Dinosaur eggs from the Upper Cretaceous North Horn Formation of Central Utah. Brigham Young Univ. Geol. Studies. 13:55.Google Scholar
Jensen, J. A. 1970. Fossil eggs in the Lower Cretaceous of Utah. Brigham Young Univ. Geol. Studies. 17:51.Google Scholar
Jepsen, G. L. 1931. Dinosaur eggshell fragments from Montana. Science. 73:12.CrossRefGoogle ScholarPubMed
Keeling, C. D. 1958. The concentration and isotopic abundance of carbon dioxide in rural areas. Geochim. Cosmochim. Acta. 13:322.CrossRefGoogle Scholar
Keith, M. L. and Weber, J. N. 1964. Carbon and oxygen isotopic composition of selected limestones and fossils. Geochim. Cosmochim. Acta. 28:1787.CrossRefGoogle Scholar
Kielan-Jaworowska, Z. 1969. Hunting for Dinosaurs. MIT Press; Cambridge, Mass.Google Scholar
Krampitz, G., Erben, H. K., and Kriesten, K. 1972. Über Aminosäurenzusammensetzung und Struktur von Eischalen. Biominer. Res. Repts. 4:87.Google Scholar
Krampitz, G., Weise, K., Potz, A., Engels, J., Samata, T., Becker, K., Hedding, M., and Flajs, G. 1977. Calcium binding peptide in dinosaur eggshells. Naturwissenschaften. 64:583.CrossRefGoogle Scholar
Krasovski, V. I. and Shklovski, I. S. 1957. (Possible influence of supernovae on the evolution of life on the earth.). Dokl. Akad. Nauk SSR. 116:197.Google Scholar
Kurtén, B. 1968. The Age of the Dinosaurs. McGraw-Hill; New York.Google Scholar
Kutchai, H. and Steen, J. B. 1971. Permeability of the shell membranes of hen's eggs during development. Respir. Physiol. 11:265.CrossRefGoogle Scholar
Lapparent, A. F. de. 1957. Les oeufs de dinosauriens fossiles de Rousset (Bouches du Rhône). C. R. Acad. Sci. Paris. 245:546.Google Scholar
Lapparent, A. F. de. 1958. Découverte d'un gisement d'oeufs de dinosauriens dans le Crétacé supérieur du Bassin de Tremp (Lérida). C. R. Acad. Sci. Paris. 247:247.Google Scholar
Lapparent, A. F. de. 1959. Descumbrimiento de un yacimiento de huevos de dinosaurios en el Cretáceo superior de la depresión de Tremp (Provincia de Lérida). Not. Com. Inst. Geol. Min. España. 54:51.Google Scholar
Lapparent, A. F. de. 1966. Nouveaux gisements des reptiles mesozoiques en Espagne. Not. Com. Inst. Geol. Min. España. 84:103.Google Scholar
Liebau, A. 1971. Die Ableitung der palökologischen Systematik einer oberkretazischen Lagune. Bull. Centre Rech. Pau, SNPA, suppl. 5:577.Google Scholar
Marx, J. L. 1978. Warm-blooded dinosaurs: evidence pro and contra. Science. 199:1424.CrossRefGoogle Scholar
Mattauer, M. and Thaler, L. 1961. Découverte d'oeufs de dinosaures dans le Crétacé terminal des environs de Montpellier (Hérault). C. R. som. Soc. géol. France. 196:7.Google Scholar
McFarland, L. Z. and Lacy, P. B. 1969. Physiologic and endocrinologic effects of the insecticide Kepone in the Japanese quail. Toxicol. Appl. Pharmacol. 15:441.CrossRefGoogle ScholarPubMed
McFarland, L. Z., Garret, R. L., and Nowell, J. A. 1971. Normal eggshells and thin eggshells caused by organochlorine insecticides viewed with the scanning electron microscope. Proc. 4th Ann. SEM Sympos., III Chicago. 337.Google Scholar
McLean, D. M. 1978. A terminal mesozoic “greenhouse”: lessons from the past. Science. 201(4354):401.CrossRefGoogle ScholarPubMed
Miller, M. F. II and Wyckoff, R. W. G. 1968. Proteins in Dinosaur bones. Proc. Nat. Acad. Sci. 60:176.CrossRefGoogle ScholarPubMed
Minson, D. J., Ludlow, M. M., and Troughton, J. H. 1975. Differences in natural carbon isotope ratios of milk and hair from cattle grazing tropical and temperate pastures. Nature 256:602.CrossRefGoogle ScholarPubMed
Müller, A. H. 1963. Über Dinosaurier-Eier aus der Oberkreide (Dan) Frankreichs, unter besonderer Berücksichtigung der elektronenmikroskopischen Strukturen. Monatsber. Deutsch. Akad. Wiss. Berlin. 5(2):75.Google Scholar
Müller, A. H. 1967. Erscheinungen und Probleme der weltweiten Fauneninzision an der Kreide/Tertiär-Grenze. Mitt. Leopoldina, Halle a.S. 12:152.Google Scholar
Nopcsa, F. v. 1917. Über Dinosaurier. Centralbl. Miner., Geol., Paläontol., Jg. 1917:332.Google Scholar
N. W. M. 1972. Persistent pesticides and PCBs in the environment. Nature. 240:319.CrossRefGoogle Scholar
Osmond, C. B. and Ziegler, H. 1975. Schwere Pflanzen und leichte Pflanzen: Stabile Isotope im Photosynthesestoffwechsel und in der biochemischen Ökologie. Naturw. Rundschau. 28:323.Google Scholar
Ostrom, J. H. 1969. Terrestrial vertebrates as indicators of Mesozoic climates. Proc. North. Am. Paleontol. Convention, Chicago:347.Google Scholar
Ostrom, J. H. 1974. Reply to “Dinosaurs as reptiles.” Evolution. 28:491.Google Scholar
Park, R. and Epstein, S. 1960. Carbon isotope fractionation during photosynthesis. Geochim. Cosmochim. Acta. 21:110.CrossRefGoogle Scholar
Peakall, D. B. 1970. p,p'-DDT: Effect on calcium metabolism and concentration of estradiol in the blood. Science. 168:592.CrossRefGoogle ScholarPubMed
Peakall, D. B. 1970. Pesticides and the reproduction of birds. Sci. Am. 222:72.CrossRefGoogle ScholarPubMed
Peakall, D. B., Miller, D. S., and Kintner, W. B. 1975. Prolonged eggshell thinning caused by DDE in the duck. Nature. 254:421.CrossRefGoogle ScholarPubMed
Plaziat, J.-C. 1961. Présence d'oeufs de dinosauriens dans le Crétacé supérieur des Corbières et existence d'un niveau marin dans le Thanétien aux environs d'Albas (Aude). C. R. Soc. géol. France. 1961(7):196.Google Scholar
Plaziat, J.-C. 1970. La limite Crétacé-Tertiaire en Alava méridionale (Pays basque espagnol): le Rognacien n'y est pas l'équivalent continental du Danien. C. R. Soc. géol. France. 1970:77.Google Scholar
Plaziat, J.-C. 1970. Conséquences stratigraphiques de l'interstratification de Rognacien dans le Maastrichtien supérieur d'Alava (Espagne). C. R. Acad. Sci. Paris. 270:2768.Google Scholar
Price, L. I. 1951. Um ovo de dinossáurio na Formação Baurú, do Cretácico do Estado de Minas Gerais. Notas Prelim. Estud. Div. Geol. Miner. 53:1.Google Scholar
Rauch, W. and Steinke, L. 1953. Über den Einfluß von Eischalenporosität und der Eischalendicke auf das Schlüpfergebnis von Bruteiern. Z. Tierzücht. Zücht. Biol. 62:61.CrossRefGoogle Scholar
Ricqlès, A. de. 1969. L'histologie osseuse envisagée comme indicateur de la physiologie thermique chez les tétrapodes fossiles. C. R. Acad. Sci. Paris. 268:782.Google Scholar
Ricqlès, A. de. 1974. Evolution of endothermy: histological evidence. Evol. Theory. 1:51.Google Scholar
Ricqlès, A. de. 1976. On the bone histology of fossil and living reptiles, with comments on its functional and evolutionary significance. In: Bellairs, A. d'A. and Fox, C. B., eds. Morphology and Biology of Reptiles. Academic Press; London.Google Scholar
Ricqlès, A. de. 1978. La vie au secondaire: plus d'hypothèses que de certitudes. La Recherche. 9(95):1138.Google Scholar
Riseborough, R. W., Rieche, P., Peakall, D. B., Herman, S. G., and Kirven, M. N. 1968. Polychlorinated biphenyls in the global system. Nature. 220:1098.CrossRefGoogle Scholar
Rosell, J. 1965. Estudio geológico del Sector del Prepireneo comprendido entre los ríos Segre y Noguera Ribagorzana (Provincia de Lérida). Rev. Inst. Estudios Pirinaicos. 75–78:1.Google Scholar
Roshdestvenski, A. K. 1960. Dinosaurierfunde in der Wüste Gobi. Umschau Wiss. Techn. 1960:367.Google Scholar
Russell, D. A. 1972. The Disappearance of the Dinosaurs. Publ. Nat. Mus. Nat. Sci.: Ottawa:1.Google Scholar
Russell, D. A. 1973. Ancient reptiles of northern Canada. (unpubl. paper, R. Canad. Inst., Toronto).Google Scholar
Russell, D. A. and Tucker, W. 1971. Supernovae and the extinction of the dinosaurs. Nature. 229(5286):553.CrossRefGoogle ScholarPubMed
Russell, L. S. 1965. Body temperature of dinosaurs and its relationships to their extinction. J. Paleontol. 39:497.Google Scholar
Savin, S. M. 1977. The history of the earth's surface temperature during the past 100 million years. Ann. Rev. Earth Planet. Sci. 5:319.CrossRefGoogle Scholar
Schatz, A. 1965. Consideraciones bioquímicas y fisiológicas acerca de la extinción de los dinosaurios. Bol. Univ. Chile. 56:28.Google Scholar
Schindewolf, O. H. 1963. Neokatastrophismus? Z. deutsch. geol. Ges. 114:430.Google Scholar
Schmidt, W. J. 1967. Struktur des Eischalenkalkes von Dinosauriereiern. Z. Zellforsch. 82:136.CrossRefGoogle Scholar
Schmidt, W. J. 1967. Untersuchung der Kalkresorption an der Vogeleischale während der Bebrütung. Z. wiss. Mikrosk. 68:51.Google Scholar
Schmidt, W. J. 1968. Die Büschelsphäriten (Corymben) auf der Eischale von Lappentauchern. Z. Zellforsch. 88:408.CrossRefGoogle Scholar
Schwarz, L. and Fehse, F. 1957. Über die Unterschiede der Schalen unbebrüteter und bebrüteter Eier. Zool. Anz. 159:168.Google Scholar
Schwarz, L. and Fehse, F. 1958. Dto. I. Fortsetzg. Zool. Anz. 162:100.Google Scholar
Schwarz, L., Fehse, F., Müller, G., and Sieck, F. 1961. Untersuchungen an Dinosauriereischalen von Aix-en-Provence und der Mongolei (Shabarak Usu). Z. wiss. Zool. 165:344.Google Scholar
Seckbach, J. and Kaplan, I. R. 1973. Growth pattern and 13C/12C isotope fractionation of Cyanidium caldarum and hot spring algal mats. Chem. Geol. 12:161.CrossRefGoogle Scholar
Sergeyev, A. M. 1943. Evolution of the embryonic adaptions of reptiles. Izd-vo Sovj. Nauka:1.Google Scholar
Sigé, B. 1968. Dents de micromammifères et fragments de coquilles d'oeufs de dinosauriens dans la faune de vértebrés du Crétacé supérieur de Laguna Umayo (Andes péruviennes). C. R. Acad. Sci. Paris. D 267:1495.Google Scholar
Sittler, C. 1965. La sédimentation argilleuse fluvio-lacustre à la limite du Crétacé et de l'Eocène en Provence et au Languedoc rapport avec le problème de la disparition des dinosauriens. Bull. Serv. Carte géol. Alsace Lorraine. 18:3.CrossRefGoogle Scholar
Smith, B. N. and Epstein, S. 1971. Two categories of 13C/12C ratios for higher plants. Plant. Physiol. 47:380.CrossRefGoogle Scholar
Sochava, A. V. 1969. Yaitsa dinozavrov iz verkhnego mjela Gobi (Dinosaur eggs from the Upper Cretaceous of the Gobi). Paleontol. Zhurn. 1969(4):76.Google Scholar
Sochava, A. V. 1970. Mikrostruktura skorlupy yaits dinozavrov iz verkhnego mjela Severnoy Gobi (Microstructure of dinosaur eggshells from the Upper Cretaceous of the Northern Gobi). Dokl. Akad. Nauk SSSR. 192(5):1137.Google Scholar
Sochava, A. V. 1970. Yaitsa dinozavrov v pustyne Gobi (Dinosaur eggs in the Gobi Desert). Priroda. 10:65.Google Scholar
Sochava, A. V. 1971. Dva tipa skorlupy yaits senonskikh dinozavrov (Two types of eggshells of Senonian dinosaurs). Paleontol. Zhurn. 1971(3):80.Google Scholar
Sochava, A. V. 1972. Skelet embriona v yaitse dinozavra (The skeleton of an embryo in a dinosaur egg). Paleontol. Zhurn. 1972(4):88.Google Scholar
Sturkie, P. D. 1965. Avian Physiology. 2nd ed., Cornell Univ. Press; Ithaca, N.Y.Google Scholar
Thaler, L. 1965. Les oeufs des dinosauriens du Midi de la France livrent le secret de leur extinction. Sci. Progrès. La Nature. 1965:41.Google Scholar
Thode, H. G., Shima, M., Rees, C. E., and Krishnamurty, K. V. 1965. Carbon-13 isotope effects in systems containing carbon dioxide, bicarbonate, carbonate and metal ions. Can. J. Chem. 43:582.CrossRefGoogle Scholar
Touraine, F. 1960. Oeufs d'oiseaux de très grande taille dans l'Eocène inférieur de Provence. Bull. Soc. géol. France. 7(2):783.CrossRefGoogle Scholar
Valtin, H., Sawyer, W. H., and Sokol, H. W. 1965. Neurohypophysial principles in rats homozygous and heterozygous for hypothalamic diabetes insipidus (Brattleboro strain). Endocrinology. 77:701.CrossRefGoogle ScholarPubMed
van Straelen, V. 1925. The microstructure of the dinosaurian egg shells from the Cretaceous beds of Mongolia. Nov. Am. Mus. 173.Google Scholar
van Straelen, V. 1928. Les oeufs de reptiles fossiles. Palaeobiologica. 1:295.Google Scholar
van Straelen, V. and Denaeyer, M. E. 1923. Sur les oeufs fossiles du Crétacé supérieur de Rognac en Provence. Bull. Cl. Sc. Acad. R. Belge. 9:14.Google Scholar
van Valen, L. and Sloan, R. E. 1972. Ecology and extinction of the dinosaurs. Repts. 24th Int. Geol. Congr., Sect. 7:214.Google Scholar
Vilatte, J. 1966. Découverte de fragments de coquilles d'oeufs d'oiseaux dans l'Eocène inférieur de l'Aude. C. R. Soc. géol. France. 1966:345.Google Scholar
Vogel, J. C. 1977. Isotopes and ungulates. Nuclear Active. 15.Google Scholar
Vogel, J. C. and Seely, M. K. 1977. Occurrence of C-4 plants in the Central Namib Desert. Madoqua. 10:75.Google Scholar
Voss-Foucart, M. F. 1968. Paleoproteines des coquilles fossiles d'oeufs de dinosauriens du Crétacé supérieur de Provence. Comp. Biochem. Physiol. 24:31.CrossRefGoogle Scholar
Wedepohl, K. H. 1970. Geochemische Daten von sedimentären Karbonaten und Karbonatgesteinen in ihrem faziellen und petrogenetischen Aussagewert. Verh. Geol. Bundesanst. Wien. 4:692.Google Scholar
Wellnhofer, P. 1977. Dinosaurier. Naturwiss. Rundschau. 30. Jg.(11):404.CrossRefGoogle Scholar
Wieland, G. R. 1942. Too hot for the dinosaur. Science. 96:359.CrossRefGoogle ScholarPubMed
Wyckoff, R. W. G. 1969. Sur la composition de quelques protéines dinosauriennes. C. R. Acad. Sci. Paris. 269 D:1489.Google Scholar
Wynne-Edwards, V. C. 1962. Animal dispersion in relation to social behaviour. Oliver & Boyd; London.Google Scholar
Wynne-Edwards, V. C. 1965. Self-regulating systems in populations of animals. Science. 147:1543.CrossRefGoogle ScholarPubMed
Young, C. C. 1954. Fossil reptilian eggs from Laiyang, Shantung, China. Sci. Sinica. 3:505.Google Scholar
Young, C. C. 1959. New fossil egg from Laiyang, Shantung. Vertebrata PalAsiatica. 3:34.Google Scholar
Young, C. C. 1965. Fossil eggs from Nanhsiung, Kwantung and Kanchou, Kiangsi. Vertebrata PalAsiatica. 9(2):141.Google Scholar
Young, J. D. 1950. The structure and some physical properties of the testudinian egg shell. Proc. Zool. Soc. London. 120:455.CrossRefGoogle Scholar