INVESTIGADORES
BELLOSI Eduardo Sergio
congresos y reuniones científicas
Título:
Comparación preliminar del registro fósil e icnofósil de Scarabaeinae (Coleoptera: Scarabaeidae)
Autor/es:
SÁNCHEZ, M. , LAZA, J., BELLOSI, E. Y J. GENISE
Lugar:
Tucumán
Reunión:
Congreso; 6º Congreso Argentino de Entomología; 2005
Institución organizadora:
Sociedad Entomológica Argentina
Resumen:
ABSTRACT
One of the most important characteristics of insect trace fossils is that they can predate the oldest record of their own trace-makers, originating new hypothesis on the evolutionary history of the different taxa and complementing the body fossil record. The main objective of this work is to compare the fossil brood balls of dung beetles (ichnogenera Coprinisphaera and a new one) with their body fossil record. One hundred and fifty specimens from Argentinian and Uruguayan museums were sectioned and prepared for this study. Different types of Coprinisphaera, ichnogenus that is recorded since the Eocene, can be separated based on the presence and location of the egg chamber. Some specimens preserve remains of the egg chamber showing the shape of a cone or an inverted cone included in the wall of the brood ball; or spherical included in a mammillated protuberance or in a secondary smaller chamber connected with the provision chamber by a thin passage. These types of traces are comparable with those constructed by paracoprid beetles representative of the tribe Coprini (Dichotomiina and Phanaeina) and Scarabaeini (Canthonina). Other fossil balls show an emergence hole that is open in the middle of a flattened surface, which resemble balls of beetles of the genus Ontherus (Dichotomiina). Other ones suggest that the egg chamber was located inside the provision chamber, like in Canthonina and Dichotomiina. The new ichnogenus represents a compound nest also resembling those of Canthonina. The oldest record of body fossils for these subtribes comes from the Miocene of Japan (Dichotomiina) and Kenya (Canthonina) and the Pleistocene of USA (Phanaeina). Hence, the ichnofossil record predates body fossil record in about 30-50 m.y. a period in which it yields important paleobiological data for this subfamily.
