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El tallo Lagomorpha y la antigüedad de Glires
Robert J Asher1, Jin Meng, John R Wible
1Museum für Naturkunde, Humboldt Universität, Invalidenstrasse 43, 10115 Berlin, Germany. robert.asher@museum.hu-berlin.de
Science (New York, N.Y.)
|February 19, 2005
Resumen
Los fósiles de Gomphos elkema de Mongolia lo revelan como un lagomorfo temprano, ancestro de conejos y picas. Este hallazgo aclara la radiación del Cenozoico de los mamíferos cerca de la frontera Cretácico-Terciario.
Área de la Ciencia:
- Paleontología Paleontología.
- Evolución de los mamíferos Evolución de los mamíferos
- La bioestratigrafía es una estratigrafía biológica.
Sus antecedentes:
- Los lagomorfos (conejos, liebres, picas) son mamíferos placentarios clave con un registro fósil muy escaso.
- Comprender sus orígenes evolutivos es crucial para reconstruir la diversificación de los mamíferos del Cenozoico temprano.
Objetivo del estudio:
- Para describir los nuevos fósiles de los elkema Gomphos de Mongolia.
- Para determinar la posición filogenética de Gomphos dentro de los mamíferos placentarios.
- Para investigar el momento de la divergencia entre lagomorfos y roedores.
Principales métodos:
- Descripción del fósil y anatomía comparativa de Gomphos elkema.
- Análisis filogenético mediante el uso de caracteres craneosqueléticos.
- Datación biostratigráfica de depósitos fósiles cerca de la frontera entre el Paleoceno y el Eoceno.
Principales resultados:
- Se identificaron fósiles de gomphos elkema en Tsagan Khushu, Mongolia, que datan del límite entre el Paleoceno y el Eoceno.
- Gomphos exhibe rasgos de lagomorfos modernos, pero conserva la dentición primitiva y las estructuras de la mandíbula.
- Los análisis filogenéticos colocan a Gomphos como un lagomorfo del tallo, que es anterior a la radiación del grupo de la corona.
Conclusiones:
- Gomphos elkema representa un lagomorfo temprano, proporcionando información sobre los orígenes del grupo.
- Los hallazgos apoyan la hipótesis de la radiación de lagomorfos y roedores en el Cenozoico.
- La divergencia de los mamíferos placentarios, incluidos los lagomorfos, probablemente ocurrió cerca del límite entre el Cretácico y el Terciario.
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