engleski

Histology of dinosaur bones from Kolone Bay (SW Istria, Croatia)

Dinosaur bones were found underwater in Upper Hauterivian / Lower Barremian (Lower Cretaceous) lacustrine limestones of Kolone Bay, southwest Istria, Croatia (Boscarolli et al., 1993). Although there are numerous sites with dinosaur footprints in Croatia, there is only one site with dinosaur bones. The material consists of bones and bone fragments, collected from the sea-bottom, where they were exposed to marine abrasion and encrustation by marine organisms. Some of the bones were recognized as sauropod bones belonging to different individuals (Dalla Vecchia, 1998). Histological analysis was made on four bones: one vertebra, one femur and two rib fragments (Kozarić et al., 1996). Compact bone of the vertebra, the femur and one rib fragment consists of primary osteonal tissue and therefore belongs to younger individuals, while the compact bone of the second rib consists of secondary bone. Recently, another ten bone fragments were analyzed. One of the bones did not give any results because it was completely chemically changed and histological structures could not be recognized. All analyzed bones belong to dinosaurs except one, which can be ascribed to an aquatic vertebrate. Eight analyzed bone fragments belong to different skeletal bones and display large amounts of primary bone tissue which means that all the bones belong to relatively young individuals who were growing rapidly. It can not be concluded whether these bone fragments belong to the same individual or many different individuals. One of the bones shows secondary osteons and belongs to an older individual. Several samples have lines of arrested growth (LAGs) and zonal bone which are indicators of changeable paleoecological conditions during life of the individual.

Dinosaurs; bone fragments; histology; SW Istria

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