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Scientists from the University of Manchester and the University of Bristol used powerful X-rays to scan the skeletons of some of our oldest parents, solving a 160-year-old mystery about the 39, origin of our skeletons. [19659002Lesvertébrésvivantsontdessquelettesconstruitsàpartirdequatretypesdetissusdifférents:l'osetlecartilage(lesprincipauxtissusdontsontfaitslessqueletteshumains)etladentineetl'enamel(lestissusàpartirdesquelsnosdentssontconstruites)Cestissussontuniquesparcequ'ilsseminéralisentaufuretàmesurequ'ilssedéveloppentdonnantàleursqueletteforceetrigidité
One can find evidence of & # 39; early evolution of our skeletons in a group fossil fish called heterostraceans, who lived more than 400 million years ago. These fish include some of the oldest vertebrates with a mineralized skeleton that have already been discovered. Researchers from the University of Manchester, the University of Bristol and the Paul Scherrer Institute in Switzerland have studied in detail the skeletons of heterostraceans using tomography synchrotron. a particular type of scanner using very high energy X-rays produced by a particle accelerator. Using this technique, the team has identified this mysterious fabric.
Dr. Joseph Keating, principal investigator of the School of Earth Environmental Scientists of Manchester, explains: "The heterostracial skeletons are made of a really weird tissue called "aspidine". It is crisscrossed by tiny tubes and is unlike any of the tissues found in vertebrates today. For 160 years, scientists have wondered if aspidine is a transitional stage in the evolution of mineralized tissues. "
The results of this study, published in Nature Ecology and Evolution show that the tiny tubes are voids that originally contained bundles of collagen fibers, a type of protein found in skin and bones. 19659003] These discoveries allowed Dr. Keating to exclude all but one hypothesis for tissue identity: aspidine is the first bone evidence in the fossil record.
Coauthor, Professor Phil Donoghue of the University of Bristol concludes: The results change our perspective on the evolution of the skeleton. It was once thought that aspirin was the precursor of mineralized tissues of vertebrates. We show that it is, in fact, one type of bone and that all these tissues have evolved millions of years ago. "
UNIVERSITY OF MANCHESTER
Header Image Credit: A fossil heterostracan, Errivaspis waynensis from the early Devonian (about 419 million years ago) of Herefordshire, United Kingdom Credit: Image from Keating et al., 2018
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