Morphological differentiation of the fossil dinosaur bone cells. Light, transmission electron-, and scanning electron-microscopic studies.
The investigation was carried out on the fossil dinosaur bone from before 80 million years. Samples for examination were prepared with specially elaborated methods. Thus the isolated osteocytes of the dinosaur bone, which had previously undergone natural fossilizing processes, were obtained. This permitted their morphological assessment. On the basis of the images obtained in the light, transmission electron, and scanning electron microscopes, two types of osteocytes were distinguished. Type I was characterized by an elongated shape, its length exceeding the width several times; the mean dimensions of this osteocyte amounted to 28.8/7.03 micron. Type II was shorter, its mean dimensions being equal to 20.28/6.88 micron. Moreover, two types of osteocytes processes were differentiated: the first was represented by thick processes, so-called 'axial processes', whose diameter ranged from 0.5 to 1.5 micron, and which, as a rule, departed from the pole of the cell. They ran farther from the mother cell body to more distant osteocytes. The other type consisted of thin processes departing from various points of the cell body in no particular arrangement but always extrapolarly. They branched off in a close vicinity of the mother osteocyte. Their diameter ranged between 0.076 and 0.35 micron.
D000818:Animals; D005580:Fossils; D049690:History, Ancient; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D010011:Osteocytes / Q000166:cytology* / Q000648:ultrastructure; D010163:Paleontology; D012104:Reptiles / Q000033:anatomy & histology*