vendredi 27 février 2015

Eggshells (reptiles and Birds)

1- Bird eggshells



Modern eggshells:

a: descriptive terminologies of the structure of the avian eggshell. b: applied terminology. c: inner organic membrane and spherolitic cruystallisation. d: growth layers in the prismatic layer.

Numida: thin section

Chemical composition of some bird eggshells
Elemental composition of a giant eggshell - Organic sulfate is associated to acidic sugars

Fossil eggshells:

a: outer surface showing pores; Aepyornithid from Namibia. b: outer surface shoiwng a complex pore in Namornis from Namibia. c: inner surface showing the spherolites; France. d: outer surface of another complex pore in a giant eggshell from Namibia. e: vertical section in an aepyornithid eggshell from Spain. f: vertical section showing the spherolitic structure of a giant eggshell from Namibia.
Infrared spectra of the insoluble matrix extracted from 3 fossil eggshells (Diamantornis) from Namibia, showing the presence of siliceous phases and a true organic matrix.


Chemical composition of bird eggshells from the South of France