COMMUNITY STRUCTURE OF EOCENE TERRESTRIAL VERTEBRATES FROM ANTARCTIC PENINSULA
Abstract. The record of Paleogene terrestrial vertebrates from Antarctica is restricted to the shallow marine water sediments of the La Meseta Formation (Eocene) of Seyrnour Island (56° 43'W 64° 14'S). Marnmals are represented by marsupials, edentates and ungulates. Among birds, a falconid...
Main Authors: | , , , , |
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Format: | Article in Journal/Newspaper |
Language: | English Spanish |
Published: |
Asociación Paleontológica Argentina
2015
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Subjects: | |
Online Access: | https://doaj.org/article/35977a678dac4cb49056df29faa78513 |
Summary: | Abstract. The record of Paleogene terrestrial vertebrates from Antarctica is restricted to the shallow marine water sediments of the La Meseta Formation (Eocene) of Seyrnour Island (56° 43'W 64° 14'S). Marnmals are represented by marsupials, edentates and ungulates. Among birds, a falconid and two ground dwellers (a ratite and a ?phorusrhacoid) were recorded. Estimates of body mass and dietary specializations are proposed for these species. Medium- to large-sized carnivorous mammals (greater than 1 kg body mass), such as South American borhyaenid marsupials, are not yet recorded, although their presence is expected. Their absence is interpreted as a consequence of the low proportion of homeothermic carnivorous in all modern vertebrate communities and the relatively small sample recovered to date. The carnivorous role could have been partially fulfilled by some of the birds (falconid and ?phorusrhacoid). KEY WORDS. Seymour Island. Antarctica. Eocene. Land vertebrates. Palaeoecology. Resumen. ESTRUCTURA DE LA COMUNIDAD DE VERTEBRADOS TERRESTRES DEL EOCENO DE LA PENÍNSULA ANTÁRTICA. El registro de vertebrados terrestres del Paleógeno de Antártida está restringido a los sedimentos marinos someros de la Formación La Meseta (Eoceno) de la isla Seymour (Marambio; 56° 43'W 64° 14'S). Los mamíferos están representados por marsupiales, edentados y ungulados. Entre las aves se registraron un falcónido y dos formas no voladoras (una ratite y un probable fororraco). Se estimaron las masas corporales y los hábitos alimenticios de los distintos taxones. Aunque su presencia es esperable, no se registraron mamíferos carnívoros con masa corporal superior a 1 kg, como podrían ser los marsupiales boriénidos. Su ausencia se explica como una consecuencia de la baja proporción de carnívoros homeotérmicos, tal como lo reflejan las comunidades de vertebrados actuales, y la relativamente pequeña muestra recuperada. El papel de los carnívoros podría haber sido parcialmente cubierto por algunas aves (falcónido y fororraco). PALABRAS CLAVE. ... |
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