Project 420: M. A. O'Leary, B. A. Patel, M. N. Coleman. 2012. New data on the petrosal of Bothriogenys (Mammalia, Artiodactyla, Anthracotheriidae), and petrosal volume and density comparisons among aquatic and terrestrial artiodactyls and outgroups. Journal of Paleontology. 86 (1):44-50.
Abstract
We report the first detailed endocranial description of the petrosal bone of the ear region in two new specimens of the anthracotheriid artiodactylan Bothriogenys from the Early Oligocene of the Jebel Qatrani Formation, Fayum, Egypt. The new fossils have petrosals with a hyperinflated (pachyostotic) tegmen tympani (the roof over the middle ear), closely resembling the condition in certain cetancodontans such as hippopotamids and basal cetaceamorphans (fossil stem taxa to extant Cetacea). The morphology of the petrosal, particularly its relative size and density, has been considered an important indicator of the ability of a marine mammal to localize sound transmitted in water, yet petrosal size (pachyostosis) and density (osteosclerosis) have not previously been quantified independent of each other. We examine the new fossils in the context of a preliminary CT-based study of petrosal density (extant taxa only) and petrosal volume (extant and extinct taxa) in a sample of artiodactylans and outgroups. In our extant comparative sample, the petrosals of cetaceans are both dense and voluminous as has been previously stated. We find, however, that the tegmen tympani is relatively voluminous (pachyostotic) without being particularly dense (osteosclerotic) in Hippopotamus amphibius, an extant taxon that has been documented to show some aquatic hearing behaviors, albeit less derived ones than those seen in cetaceans. A voluminous tegmen tympani, which is present in ï‚…Bothriogenys, may have specific implications for behavior that are distinct from increases in petrosal density.Read the article »
Project DOI: 10.7934/P420, http://dx.doi.org/10.7934/P420
This project contains |
---|
Download Project SDD File |
Currently Viewing:
MorphoBank Project 420
MorphoBank Project 420
- Creation Date:
14 October 2010 - Publication Date:
03 January 2012 - Media downloads: 1
This research
supported by
Authors' Institutions
- American Museum of Natural History (AMNH)
- Midwestern University
- Stony Brook University
Members
member name | taxa | specimens | media |
Maureen O'Leary Project Administrator | 1 | 2 | 1570 |
Mark Coleman Full membership | 0 | 0 | 0 |
Biren Patel Full membership | 0 | 0 | 0 |
Project has no matrices defined.
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 386 | |
Project downloads | 383 | |
Media downloads | 1 | M54045 (1 download); |
Document downloads | 2 | MicroCT information (1 download); Supplementary Cranial Description (1 download); |