CRILAR   12590
CENTRO REGIONAL DE INVESTIGACIONES CIENTIFICAS Y TRANSFERENCIA TECNOLOGICA DE LA RIOJA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
WATER VAPOR CONDUCTANCE AND EGGSHELL THICKNESS IN DINOSAUR EGGS FROM SANAGASTA, LA RIOJA, ARGENTINA: IMPLICATIONS FOR REPRODUCTIVE STRATEGIES AND BEHAVIOR
Autor/es:
SALVADOR, R.B. & FIORELLI, L.E.
Lugar:
Teruel, España
Reunión:
Simposio; 10th Mesozoic Terrestrial Ecosystems Symposium; 2009
Resumen:
The structural and functional properties of the eggshell (such as eggshell thickness and
water vapor conductance) alongside parental nesting behavior are the main factors
affecting success of the embryo. Dinosaur eggs from Sanagasta, La Rioja, Argentina,
show a wide variation in shell thickness (inclusively within individual eggs), therefore
this work aims to study shell properties (focusing on water vapor conductance) and their
relation to thickness. Moreover, the reproductive strategies and behavior of these
dinosaurs is hypothesized. Measures of egg radius, pore density and pore diameter were
taken and water vapor conductance (GH2O) was calculated. All values were compared
regarding eggshell thickness through statistical tests. The eggs show great intra-specific
variability regarding radius and shell thickness (from less than 2 mm at the top portion
to more than 7 mm around the equator and at the bottom portion). Thick eggshells have
greater pore density and pore diameter, while thin ones have greater conductance. GH2O
regarding eggshell thickness through statistical tests. The eggs show great intra-specific
variability regarding radius and shell thickness (from less than 2 mm at the top portion
to more than 7 mm around the equator and at the bottom portion). Thick eggshells have
greater pore density and pore diameter, while thin ones have greater conductance. GH2O
H2O) was calculated. All values were compared
regarding eggshell thickness through statistical tests. The eggs show great intra-specific
variability regarding radius and shell thickness (from less than 2 mm at the top portion
to more than 7 mm around the equator and at the bottom portion). Thick eggshells have
greater pore density and pore diameter, while thin ones have greater conductance. GH2OH2O
values for the Sanagasta eggs approximates values known for other sauropods and
crocodiles, suggesting they nested in holes or mounds; while taphonomic data from the
nesting site implies on a hole. The great thickness indicates great mechanical resistance,
which could imply on diminished (or lack of) parental care. The high concentration and
proximity of egg clutches points towards a gregarious nesting behavior, but it is not
possible to infer site-fidelity. Additionally, GH2O is closer to values for megaloolithid
eggs (as well as the microstructure of thin eggshells) which can indicate some
relationship among them.
eggs (as well as the microstructure of thin eggshells) which can indicate some
relationship among them.
H2O is closer to values for megaloolithid
eggs (as well as the microstructure of thin eggshells) which can indicate some
relationship among them.