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Una ave del Cretácico de Brasil informa sobre la evolución del cráneo y el cerebro de las aves
Luis M Chiappe1, Guillermo Navalón2, Agustín G Martinelli3
1Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, CA, USA. lchiappe@nhm.org.
Nature
|November 13, 2024
Resumen
Un nuevo fósil, Navaornis hestiae, revela similitudes inesperadas entre las aves de troncos antiguos y las aves modernas. Este descubrimiento arroja luz sobre la evolución del cráneo y la anatomía del cerebro de las aves.
Área de la Ciencia:
- Paleontología
- Biología evolutiva
- Anatomía comparada
Sus antecedentes:
- La comprensión de la evolución de los cráneos y cerebros de las aves modernas está limitada por la escasez de fósiles bien conservados del Mesozoico.
- Las aves del tronco del Mesozoico (Enantiornithes) y las aves modernas (aves de la corona) representan linajes evolutivos distintos.
Objetivo del estudio:
- Para describir la morfología craneal y endocraneal de una nueva especie fósil, Navaornis hestiae, del Cretácico Tardío.
- Para investigar las relaciones evolutivas entre Navaornis, enantiornithines y las aves de la corona.
- Para aclarar el conjunto evolutivo de la neuroanatomía de las aves modernas.
Principales métodos:
- Análisis morfológico detallado del fósil de Navaornis hestiae excepcionalmente conservado.
- Análisis filogenéticos para determinar la posición evolutiva de *Navaornis*.
- Comparación cuantitativa de la geometría craneal y endocraneal entre * Navaornis *, enantiornithines y aves de la corona.
Principales resultados:
- *Navaornis hestiae* posee un cráneo sin dientes y de ojos grandes con un cráneo abovedado, parecido a las aves coronas.
- Los análisis filogenéticos colocan a *Navaornis* dentro de los Enantiornithes, un grupo de aves de tallo del Mesozoico.
- A pesar de la geometría general parecida a una corona, *Navaornis* conserva rasgos arcaicos (por ejemplo, el rostro dominado por el maxilar, el paladar akinético) junto con la flexión cerebral parecida a una corona y un gran laberinto óseo.
Conclusiones:
- La morfología craneal de *Navaornis* demuestra una notable convergencia entre las enantiornitinas y las aves de corona, desafiando las distinciones anteriores.
- *Navaornis* proporciona información crucial sobre la evolución del mosaico de la neuroanatomía de las aves, revelando que las características parecidas a las de las aves coronas evolucionaron de forma independiente en los linajes del tallo.
- Este descubrimiento refina nuestra comprensión del patrón y el tiempo de la evolución del cráneo y el cerebro de las aves modernas.
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