Title
Eurhinodelphinids from the early Miocene of Peru: First unambiguous records of these hyper-longirostrine dolphins outside the North Atlantic realm
Date Issued
01 March 2021
Access level
metadata only access
Resource Type
journal article
Author(s)
Publisher(s)
Universita degli Studi di Milano
Abstract
Among the many hyper-longirostrine dolphins (Odontoceti) from the Miocene, members of the family Eurhinodelphinidae bear two highly distinctive cranial features: a long and edentulous premaxillary portion of the rostrum and a mandible that is significantly shorter than the rostrum. Until now, unambiguously attributed members of this clade were only recorded from early to middle Miocene deposits of the North Atlantic realm (east coast U.S.A., North Sea Basin, and Mediterranean). In this work we describe and compare two partial skulls of longirostrine dolphins from late early Miocene (Burdigalian, 19.25-18 Ma) marine deposits of the Chilcatay Formation, in the East Pisco Basin (southern coast of Peru), preserving rostral and mandibular material, as well as ear bones. Based on these specimens we report diagnostic remains attributable to this family for the first time for the whole Southern Hemisphere and the whole Pacific Ocean. This major expansion of eurhinodelphinids’ palaeogeographic distribution contrasts with their proposed shallow-water, coastal environments; it suggests a new dispersal route for members of the family across the Central American Seaway; and it further highlights the similarities between the odontocete faunas of the southeastern Pacific and North Atlantic realm during the Miocene. Better-preserved eurhinodelphinid specimens from the odontocete-rich Chilcatay Formation will allow for a more detailed comparison with North Atlantic members of the family.
Start page
17
End page
32
Volume
127
Issue
1
Language
English
OCDE Knowledge area
Paleontología
Subjects
Scopus EID
2-s2.0-85106728444
Source
Rivista Italiana di Paleontologia e Stratigrafia
ISSN of the container
00356883
Sponsor(s)
This research was supported by funding from the University of Pisa (PRA_2017_0032) to G.B., a grant from the Italian Min-istero dell’Istruzione, dell’Università e della Ricerca (MIUR) (PRIN Project, 2012YJSBMK EAR-9317031) to G.B., and a National Geographic Society Committee for Research Exploration grant (GEFNE 177-16) to O.L.
Acknowledgements: We wish to warmly thank W. Aguirre and R. Salas-Gismondi (MUSM) for the preparation of the specimens described here and for their help during our successive visits at the MUSM, D.J. Bohaska, J.G. Mead, C. Potter, and N.D. Pyenson (USNM), S. Bruaux, G. Lenglet, and O. Pauwels (IRSNB), L.G. Barnes and V.R. Rhue (LACM), R.E. Fordyce (OU), L. del Favero and M. Fornasiero (MGP), and Z. Gasparini and L.H. Pomi (MLP) for facilitating the access to the collections of modern and fossil cetaceans under their care, M.D. Uhen for his tremendous contribution to the cetacean part of the Paleobiology Database (paleobiodb.org), T. Scheirer and S.J. Godfrey (CMM) for allowing us to modify the reconstruction of Xiphiacetus bossi prepared by the former, and Y. Tanaka, an anonymous reviewer, and the editors for their constructive comments. This research was supported by funding from the University of Pisa (PRA_2017_0032) to G.B., a grant from the Italian Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR) (PRIN Project, 2012YJSBMK EAR- 9317031) to G.B., and a National Geographic Society Committee for Research Exploration grant (GEFNE 177-16) to O.L.
Sources of information:
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