INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
Long-necked chelid turtles from the Campanian of northwestern Patagonia with comments on K/P survivorship of the genus Yaminuechelys
MARCELO DE LA FUENTE; IGNACIO MANIEL; MARCOS JANNELLO; LEONARDO S. FILIPPI; IGNACIO A. CERDA
COMPTES RENDUS PALEVOL
ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER
Lugar: Paris; Año: 2015 vol. 14 p. 563 - 576
The long-necked chelid turtle Yaminuechelys aff. maior is described on thebasis of post-cranial material of two specimens from the lower-middle CampanianAnacleto Formation, nortwestern Patagonia (Argentina). These post-cranial remains aredescribed macroscopically (external morphology) andmicroscopically (histologicalsections of the shell). Although minor carapace and plastral differences are reported(e.g., extension of the axillary buttresses on visceral surfaces of the first costal bone,curled bridge peripheral bones,absence of a subrectangular fenestra retained in adults) the specimens exibit the shell morphology and surface ornamentation of specimensreferred to Y. maior (Staesche, 1929) from Paleocene levels of the Salamanca Formation(Central Patagonia). This assignment is supported by a phylogenetic analysis, in which the new material is the most closely related to Y. maior.As Yaminuechelys ishypothesized to be the sister taxon of Hydromedusa, the capabilitie of Hydromedusa tectifera to adapt to changing environments and the survivorship of Yaminuechelys genus in K/P boundary is discussed.