Enigmatic osteology in Miocene odontocete rostra suggests periostitis
Article first published online: 7 SEP 2009
© 2009 by the Society for Marine Mammalogy
Marine Mammal Science
Volume 26, Issue 2, pages 381–394, April 2010
How to Cite
Gerholdt, J. M. and Godfrey, S. J. (2010), Enigmatic osteology in Miocene odontocete rostra suggests periostitis. Marine Mammal Science, 26: 381–394. doi: 10.1111/j.1748-7692.2009.00342.x
- Issue published online: 15 APR 2010
- Article first published online: 7 SEP 2009
- Received: 1 April 2009Accepted: 9 June 2009
- Chesapeake Group;
- Hawthorn Group;
- Calvert Cliffs
Eight Miocene odontocete partial rostra (six specimens from the Chesapeake Group of Maryland, one from the Chesapeake Group of Virginia, and another from the Hawthorn Group of Florida) exhibit periostitis, of unknown etiology, characterized by proliferative bone growth. Periostitis is an inflammation of the periosteum secondary to a predisposing event such as a fracture or infection. Computed tomography reveals that the lesions are limited to the premaxillae and that they became progressively swollen and gnarled as evidenced by the onion-like layering within the deformity. The level of maturity and degree of organization of the periostitis indicates that it likely developed over a period of months or years in these individuals. Given this length of time, these pathologies seem not to have been life-threatening despite the gross size and shape of most of these periosteal reactions.
The fossils range in age from about 11 to 15 million yr and all eight rostra appear to be derived from the same, but as yet unnamed or unrecognized species of odontocete. The family from which these odontocetes derive remains unknown. Un-deformed rostra attributed to this species have not been identified, which opens the possibility that “abnormal” was the new normal for this species of odontocete.