Egg paleopathology
Differences in preservation and diagenesis make it difficult to confidently identify eggshell pathologies in the fossil record.[1] Stacked eggshells from collapsed or compressed eggs may resemble multilayered eggshells but in thin cross-sections viewed under a microscope the stacked shell will have mammilae facing opposite directions whereas egg shells that developed in layers on top of each other will have mammilae facing the same direction.Later researchers found resorption craters in the basal caps at the base of the columns, meaning that the eggs hatched.Another potential explanation for variation in eggshell thickness is that the thinner eggs were laid by younger individuals than older ones.[8] Multilayered dinosaur eggs are known from, in order of discovery, France, Spain, Mongolia, India, Argentina, Canada, Montana, and Utah.Multilayered fossil eggs resemble those of modern forms in sometimes having incomplete extra layers and pore canals that don't properly align.In a 2001 survey of fossil eggshell pathologies, Karl F. Hirsch criticized these authors on the basis that multilayered eggs were "very unlikely" to allow embryos to hatch because even if the pores of the secondary shell layer were perfectly aligned with those of the primary layer the eggshell would still be too thick for the struggling neonate to break free.[13] Egg shell has been recovered from the Milk River area of Alberta which may have been partially dissolved and then had additional calcite deposited on it.[11] Hirsch concludes that the majority of pathological phenomena known to occur in modern eggs are not represented in the fossil record.
Hypselosaurus priscusfossilized eggspathologicalfossil recordmodifiedcathodoluminescencethin sectioningdiagenesispathologiesaragoniticembryoDehydratedmembranespermeabilityLate CretaceousstrataLate JurassicmegaloolithidoofamilymorphotypeprismaticcalciteOligoceneJurassicuteruspreservation potentialFossil eggPaleopathologyList of egg topicsMonotremeCephalopodReptiledinosaurAllergyEgg cellIchthyoplanktonOogamyOogenesisOothecaOviductOviparityOvoviviparityOvulationTrophicZygotemembraneChalazaAs foodList of egg dishesBenedictBoiledCenturyCoddledCustard dessertsDeep friedDeviledEggnogMeringueOmeletteOnsen tamagoPoachedPowderedPickledQuicheSaltedScotchScrambledShirredSmokedSouffléBalancingCartonDecoratingEaster eggEgg-and-spoon raceEgg drop competitionEggingFabergé eggFree rangeHowToBasicHumpty DumptyOologyOomancyOrganicOvo vegetarianismPysankaVegreville eggRollingTappingTossing