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PubMed1987

X-ray microanalysis of fossil dinosaur bone: age differences in the calcium and phosphorus content of Gallimimus bullatus bones.

Bones of dinosaurs, Gallimimus bullatus, belonging to selected age groups were studied using an X-ray microanalyser. Content of calcium and phosphorus, their distribution in the investigated areas and Ca/P ratio were determined. The obtained results revealed that the Ca/P ratio highest in the bones of young and middle-aged animals and decreased with age.

Aging↗
PubMed1985

Metabolic pathways of the fossil dinosaur bones. Part V. Morphological differentiation of osteocyte lacunae and bone canaliculi and their significance in the system of extracellular communication.

The study was carried out on dinosaur bones nearly 80 million years old. Samples for examination were prepared with specially elaborated methods. The light and transmission electron microscopic images permitted two kinds of bone lacunae and two types of paralacunar canalicular endings to be distinguished. The lacunae of the first kind were characterized by their elongated shape, their length exceeding their width several times, their dimensions being 31.2/9.4 microns. The lacunae of the other kind were not so long, their mean measurements amounting to 21.32/9.7 microns. Among the paralacunar canalicular endings those of small diameter were more numerous. The canaliculi of wider, funnel-shaped endings amounted to two or three, they were usually localized in the polar part of the lacuna, and were defined as the axial canaliculi. These were canaliculi of a large diameter. The canalicular wall was constructed of collagen fibres. The same fibres were found in the lacunar wall. Also a relationship between the structure of the lacunar wall and the localization of an osteocyte in the lacuna was analysed in the light and electron microscopes. In regard to the structure of the bone lacuna and the localization of an osteocyte in it, zones A and B were distinguished. Zone A had a characteristic loose and disorderly system of collagen fibres building the lacunar wall. The fibres in this area were by nature open to view. Besides, this region of the lacunar wall revealed specific terraced hollows. Zone B was distinguished by a compact system of parallelly arranged collagen fibres, which formed characteristic ridges in the lacunar wall. The localization of the osteocyte in the lacuna was irregular, the pericellular space around it being of variable width. This space was shown to contain mucopolysaccharides. The images obtained from dinosaur bone were compared with those already known for modern bone. These comparisons permitted it to be ascertained that zone A corresponds to a spot in the lacuna in which the osteocyte exhibits a decreased activity. Zone B is the area of the actual direction of the osteocyte's activity aiming at the shaping of the wall of its lacuna. It can be supposed that the widened endings of the paralacunar canaliculi perform more important functions in conveyance, this being evident from comparisons of analogous areas in modern bone.

Animals↗
PubMed1981

[Use, in craniology, of vectors for the demonstration of the degree of forehead and face inclination in the chimpanzee and present-day and fossilized man].

It is demonstrated, by mathematical method using vectors, that: (1) the inclination of the forehead, the sign of which is negative (simian type) in all Apes studied here, changes its sign and becomes positive (human type) in Plesianthropus, La Ferrassie I and contemporary Man. It remains negative (simian type) in Sinanthrope XI and La-Chapelle-aux-Saints; (2) the inclination of the face has a positive sign (simian type) in all Apes and Plesianthropus, but becomes negative (human type) in the genus Homo; (3) the fronto-gnathic angle which always remains less than 90 degrees in all Simians, becomes greater than 90 degrees in the genus Homo, and Plesianthropus.

Animals↗