Se describe la variación ontogenética del esqueleto de 13 embriones de Tupinambis merianae y 11 de Tupinambis rufescens, detectándose heterocronías entre ambas especies. Los resultados muestran que los elementos dermales (tanto del cráneo como de la cintura pectoral) osifican antes…

Background: Fieldwork has thoroughly established that most eggs are intensely predated. Among the few exceptions are the aerial egg clutches from the aquatic snail Pomacea canaliculata which have virtually no predators. Its defenses are advertised by the pigmented ovorubin perivitellin…

Me propongo analizar y discutir algunos resultados de una investigación etnográfica desarrollada en comunidades Mbya Guaraníes (Misiones, Argentina) acerca de las representaciones y prácticas relacionadas con la crianza y el desarrollo infantil.
En este trabajo caracterizo las categorías, representaciones y…

Tardigrades constitute one of three clades of Xenarthra. Whereas modern tree sloths are common in the Amazonian Basin, their giant ground sloth "kin" were abundant throughout the Americas. During the Miocene, sloths were conspicuous faunal elements in Patagonia, generally considered…

Recent contributions to the knowledge of Gondwanan cynodonts highlight the presence in Africa of taxa previously recognized in South America and vice-versa. This is the case for the Middle Triassic Namibian fauna from the upper Omingonde Formation, where the first…

Talampaya and Tarjados Formations correspond to the initial stage of the Ischigualasto-Villa Unión Basin filling, and record the oldest post-Permian events in the region. The sequence consists of red beds deposited essentially by ephemeral alluvial and fluvial systems, and overlay…

Lakes are excellent sensors of environmental change, including climate change. Chironomids (Insecta, Diptera) and ostracods (Crustacea) are among the most useful biological indicators for paleoenvironmental reconstruction found in lake sediments, due to their sensitiveness to environmental variables. However, the use…

Mediante técnicas paleoparasitológicas cuantitativas y cualitativas se examinaron los sedimentos de la cavidad pélvica de dos esqueletos humanos. Los individuos fueron hallados en dos enterratorios asociados al asentamiento español de fines de siglo XVI "Nombre de Jesús" (Cabo Vírgenes, provincia…

Mediante técnicas paleoparasitológicas cuantitativas y cualitativas se examinaron los sedimentos de la cavidad pélvica de dos esqueletos humanos. Los individuos fueron hallados en dos enterratorios asociados al asentamiento español de fines de siglo XVI "Nombre de Jesús" (Cabo Vírgenes, provincia…

During the last years the knowledge about derived eusuchian crocodiles has been increased. Anatomical and phylogenetic approaches as well as new fossil records have lighted the evolutive and biogeographic history of several groups. In this way, paleontological research on Miocene-Pliocene…