Shell bone histology of the long-necked chelid Yaminuechelys (Testudines: Pleurodira) from the late Cretaceous-early Palaeocene of Patagonia
Publicado por Leonardo Filippi en 6:56
Juan
Marcos Jannello, Ignacio A. Cerda, Marcelo S. de la Fuente
Yaminuechelys is
a long-necked chelid turtle whose remains have been recovered from outcrops of
the Santonian- Maastrichtian and Danian of SouthAmerica.With the purpose of
providing data about shell sculpturing origin and palaeoecology, the bone
histology of several shell elements (including neural, costal, peripheral and
plastral plates) of Yaminuechelys is
described herein. Histological analysis reveals that Yaminuechelys shares with Chelidae the presence of interwoven
structural fibre bundles in the external cortex, and parallel-fibred bone of
the internal cortex. The presence of resorption lines in several samples
indicates that the particular ornamentation of the external surfaces
originated, at least in part, by focalized resorption and new bone deposition.
This mechanism for ornamentation origin and maintenance is here described for
the first time in a turtle. Compactness of the shell bones is consistent with
an aquatic habitat, which supports previous hypothesis based on palaeoenvironmental
and morphological data.
Janello, JM, Cerda, IA
& de la Fuente, MS. 2016. Shell bone histology of the long-necked chelid Yaminuechelys (Testudines: Pleurodira)
from the late Cretaceous—early Palaeocene of Patagonia with comments on the
histogenesis of bone ornamentation. Sci Nat. 103:26.DOI
10.1007/s00114-016-1346-3.
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