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Un fósil de ictidosaurio encontrado en América del Norte
Science (New York, N.Y.)
|June 10, 1983
Resumen
Los dientes fósiles descubiertos en Texas revelan una estrecha relación entre los ictidosaurios de América del Norte y los encontrados en América del Sur y África. Este hallazgo pone de relieve la dispersión significativa de los vertebrados del Triásico Tardío en todo el antiguo supercontinente Pangea.
Área de la Ciencia:
- Paleontología Paleontología.
- Paleontología de los Vertebrados.
- Paleontología del Cenozoico.
Sus antecedentes:
- Los ictidosaurios son extinguidos, pequeños cinodontes carnívoros del período Triásico.
- Estos cinodontes avanzados exhibían una mezcla de rasgos reptiles y mamíferos.
- Los ictidosaurios vivieron junto a los primeros mamíferos y se consideran estrechamente relacionados con ellos.
Objetivo del estudio:
- Para describir una nueva especie de ictidosaurio, Pachygenelus milleri, de América del Norte.
- Para comparar P. milleri con especies conocidas de ictidosaurios de otros continentes.
- Para inferir las capacidades de dispersión de los vertebrados del Triásico Tardío.
Principales métodos:
- Análisis de dientes fosilizados del Grupo Dockum del Triásico Superior en Texas.
- Morfología comparativa de las características dentales.
- Análisis biogeográfico basado en la distribución de los fósiles.
Principales resultados:
- Los dientes de Pachygenelus milleri de América del Norte son morfológicamente similares a los de Pachygenelus monus (África del Sur) y Chaliminia musteloides (América del Sur).
- Esta similitud sugiere una estrecha relación evolutiva y una ascendencia compartida.
- La presencia de un elemento de Gondwana en América del Norte indica una dispersión generalizada de vertebrados a través de Pangea durante el Triásico Tardío.
Conclusiones:
- El descubrimiento de Pachygenelus milleri proporciona evidencia de la facilidad de dispersión de los vertebrados a través de Pangea en el Triásico Tardío.
- Los ictidosaurios demuestran un grado significativo de conexión evolutiva entre Laurasia y Gondwana.
- Este hallazgo contribuye a nuestra comprensión de la paleobiogeografía de los vertebrados y la evolución de los primeros mamíferos.
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