Fossils of the soft tissues of dinosaur tendons have been discovered

Fossils of the soft tissues of dinosaur tendons have been discovered

Tendons are elements connecting muscles and bones. In most vertebrates, they are flexible and elastic but in dinosaurs (including birds) some of them ossify. The excellent state of preservation of ossified tendons of three dinosaurs allowed discovery of fossilized soft tissues. Structures resembling fibril bundles, blood vessels, and bone cells were identified, resembling those present in ossified turkey tendons. The research indicates that dinosaur tendons ossified through metaplasia, i.e., mineralization of already differentiated soft tissues.

Illustration: On the left SEM image showing an osteocyte-like cell. On the right restoration of a blood vessel of an
remontowanie with cells on its surface based on the scanning microscopy imaging. Illustration: Jakub Zalewski

PUBLICATION: Surmik D., Słowiak-Morkovina J., Szczygielski T., Wojtyniak M., Środek D., Dulski M., Balin K., Krzykawski T., Pawlicki R. (2023) The first record of fossilized soft parts in ossified tendons and implications for the understanding of tendon mineralization, Zoological Journal of the Linnean Society: zlad001, doi: 10.1093/zoolinnean/zlad001