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Embriones de un dinosaurio prosaurópodo del Jurásico temprano y su importancia evolutiva
Robert R Reisz1, Diane Scott, Hans-Dieter Sues
1Department of Biology, University of Toronto at Mississauga, Mississauga, ON L5L 1C6, Canada. rreisz@utm.utoronto.ca
Science (New York, N.Y.)
|July 30, 2005
Resumen
Los recién descubiertos embriones de Massospondylus carinatus revelan el desarrollo temprano de los dinosaurios. Las crías eran cuadrúpedas, a diferencia de los adultos, lo que sugiere vías evolutivas para los saurópodos gigantes posteriores y la necesidad de cuidado parental.
Área de la Ciencia:
- Paleontología Paleontología.
- Biología del desarrollo Biología del desarrollo.
- Zoología de los vertebrados Zoología de los vertebrados.
Sus antecedentes:
- La Formación Elliot del Jurásico Inferior en Sudáfrica ha producido embriones de dinosaurios articulados.
- Los prosaurópodos, como Massospondylus carinatus, representan los primeros linajes de dinosaurios.
- Comprender el desarrollo ontogenético es crucial para reconstruir la evolución de los dinosaurios.
Objetivo del estudio:
- Para investigar el desarrollo ontogenético de Massospondylus carinatus utilizando fósiles embrionarios.
- Para inferir la locomoción y las posibles necesidades de cuidado parental de los primeros dinosaurios.
Principales métodos:
- Análisis de fósiles embrionarios articulados de Massospondylus carinatus.
- Anatomía comparativa de las proporciones embrionarias y adultas de Massospondylus.
- Reconstrucción de la postura y la locomoción embrionarias.
Principales resultados:
- El embrionario Massospondylus carinatus poseía grandes extremidades delanteras y cabezas con cuellos sostenidos horizontalmente, lo que indica el obligado cuadrupedismo en las crías.
- Los adultos de Massospondylus carinatus eran al menos facultativamente bípedos.
- Las características embrionarias sugieren requisitos potenciales para el cuidado parental.
Conclusiones:
- La ontogenia de Massospondylus carinatus demuestra un cambio de crías cuadrúpedas a adultos facultativamente bípedos.
- Este patrón de desarrollo puede ofrecer información sobre la evolución del cuadrúpedo en los saurópodos gigantes a través de la alometría de las extremidades.
- Las primeras crías de dinosaurios probablemente dependían del cuidado de los padres debido a su etapa de desarrollo y morfología.
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