Identificación de tejido óseo en tres ejemplares del Orden Testudines del período cretácico hallados en Villa de Leyva-Colombia

Abstract

Paleohistological studies have increased over the last few years, these have focused on implementation of techniques that allow the exploration of bone tissues and cells which have been preserved in individuals for millions of years. In addition, technological and scientific advances have allowed collection of a large amount of information, helping to understand the ecology and possible phylogenetic relationships of ancient individuals. This research project undertook identification and comparison of bone tissue in three fragmentsof three marine tortoises fossils of approximately 125 million years found in the localities of ‘Loma la Cabrera’ and ‘Loma la Catalina’ located in the surroundings of Villa de Leyva, Colombia. Two paleohistological techniques were implemented for the study: In situ (thin sections for petrographic analysis and controls for analysis in scanning electron microscopy) and Ex situ (demineralization and analysis in optic microscopy of transmitted light). For the technique In situ, for the petrographic analysis, the preservation of bone tissue was determined for the three samples studied in which structures such as secondary osteones, laminar bone, spongy bone tissue, compact bone tissue, among others were identified. In contrast, the analysis in the scanning electron microscopy did not allow identification of bone structures. However, the EDS analysis showed the presence of elements related to organic material and mineralization processes. As for the Ex situ technique, the presence of embedded fossil cells (osteocytes with canaliculi) was evinced in bone matrix.