Header

UZH-Logo

Maintenance Infos

A dolphin fossil ear bone from the northern Neotropics–insights into habitat transitions in iniid evolution


Aguirre-Fernández, Gabriel; Mennecart, Bastien; Sánchez-Villagra, Marcelo R; Sánchez, Rodolfo; Costeur, Loïc (2017). A dolphin fossil ear bone from the northern Neotropics–insights into habitat transitions in iniid evolution. Journal of Vertebrate Paleontology:e1315817.

Abstract

An iniid fossil (Cetacea, Odontoceti) is reported based on a periotic found in the Codore Formation (late Miocene to middle Pliocene) of northwestern Venezuela. The marine sediments where the Codore dolphin was collected have yielded another cetacean and a diverse elasmobranch fauna. Cladistic analysis indicates a close relationship between the Codore dolphin and the extant Amazon River dolphin (Inia geoffrensis); key characteristics include a large cochlear portion that is dorsoventrally compressed and the extremely small size of the posterior process. High-resolution micro-computed tomography scans were used for the description and analysis of the bony labyrinth endocast. Geometric morphometric analysis of the bony labyrinth endocast places the Codore dolphin as intermediate between the La Plata dolphin (Pontoporia blainvillei) and Inia geoffrensis (principal component 1), but distinctive from both extant species (principal component 2).Comparisons of the depositional environment with cladistically informed reconstructions and inferences based on cochlear and vestibular anatomy suggest that the Codore dolphin had the flexibility to enter marine, brackish, and fluvial environments as some extant cetaceans do today (e.g., Pontoporia blainvillei).

Abstract

An iniid fossil (Cetacea, Odontoceti) is reported based on a periotic found in the Codore Formation (late Miocene to middle Pliocene) of northwestern Venezuela. The marine sediments where the Codore dolphin was collected have yielded another cetacean and a diverse elasmobranch fauna. Cladistic analysis indicates a close relationship between the Codore dolphin and the extant Amazon River dolphin (Inia geoffrensis); key characteristics include a large cochlear portion that is dorsoventrally compressed and the extremely small size of the posterior process. High-resolution micro-computed tomography scans were used for the description and analysis of the bony labyrinth endocast. Geometric morphometric analysis of the bony labyrinth endocast places the Codore dolphin as intermediate between the La Plata dolphin (Pontoporia blainvillei) and Inia geoffrensis (principal component 1), but distinctive from both extant species (principal component 2).Comparisons of the depositional environment with cladistically informed reconstructions and inferences based on cochlear and vestibular anatomy suggest that the Codore dolphin had the flexibility to enter marine, brackish, and fluvial environments as some extant cetaceans do today (e.g., Pontoporia blainvillei).

Statistics

Altmetrics

Downloads

2 downloads since deposited on 20 Jun 2017
2 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Paleontological Institute and Museum
Dewey Decimal Classification:560 Fossils & prehistoric life
Language:English
Date:2017
Deposited On:20 Jun 2017 14:31
Last Modified:20 Jun 2017 14:32
Publisher:Taylor & Francis
ISSN:0272-4634
Publisher DOI:https://doi.org/10.1080/02724634.2017.1315817

Download

Preview Icon on Download
Filetype: PDF - Registered users only
Size: 4MB
View at publisher

TrendTerms

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.
You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.

Author Collaborations