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Mandibulas y dientes de los primeros peces óseos
Hector Botella1, Henning Blom, Markus Dorka
1Departamento de Geología, Universitat de València, Dr Moliner 50, 46100 Burjassot, Valencia, Spain.
Nature
|August 3, 2007
Resumen
Los osteictianos más antiguos, Andreolepis y Lophosteus, del período Silúrico Tardío, muestran características clave de peces óseos. Estos vertebrados de mandíbula basal proporcionan nuevos conocimientos sobre la evolución temprana de los vertebrados.
Área de la Ciencia:
- Paleontología Paleontología.
- Evolución de los vertebrados.
- Ictiología Ictiología.
Sus antecedentes:
- Los vertebrados con mandíbula (gnatostomas) incluyen peces cartilaginosos y óseos.
- Los fósiles del grupo de la corona de los osteictianos (peces óseos y tetrápodos) datan de hace 418 millones de años.
- Los primeros linajes de grupos madre siguen siendo poco conocidos.
Objetivo del estudio:
- Para investigar las afinidades de los peces fósiles Andreolepis hedei y Lophosteus superbus.
- Para identificar caracteres osteichthyan inequívocos en sus huesos de la mandíbula fosilizados.
- Para establecer la posición filogenética y la edad de estos primeros vertebrados.
Principales métodos:
- Análisis de huesos de mandíbula fósiles (maxilares y dentales) de peces del Silurio tardío.
- Examen anatómico comparativo de la organización denticular y la morfología dental.
- Colocación filogenética basada en las características osteictianas identificadas.
Principales resultados:
- Se identificaron caracteres osteictianos inequívocos en los huesos maxilares y dentales de Andreolepis y Lophosteus.
- La organización única de sus denticles en forma de dientes los distingue de los osteictianos del grupo de la corona.
- Estos fósiles representan los osteictianos más antiguos conocidos, que datan de hace 423-416 millones de años.
Conclusiones:
- Andreolepis y Lophosteus se identifican con seguridad como osteictianos del tallo.
- Este estudio proporciona la evidencia definitiva más temprana para el linaje osteictiano.
- Los hallazgos avanzan significativamente en nuestra comprensión de la evolución temprana de los vertebrados y el origen de los peces óseos.
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