IMAGES available: http://www.eurekalert.org/pub_jrnls/sci/public_releases/dino.html
A new study in the 3 August issue of the journal Science suggests that the external fleshy nostril of dinosaur noses may have been perched far forward, in a "rostral" position, rather than towards the back of their bony nose opening.
In fact, the rostral nostril appears to be the norm for reptiles, birds, and mammals, making it one of the few rules of anatomical construction among animals, says study author Lawrence M. Witmer of Ohio University.
The finding could have implications for how dinosaurs breathed, smelled, and regulated their body temperature and water loss, perhaps providing clues to how they adapted to different environments.
As a human, the rostral nostril might not seem like a big deal: our own bony nostril is relatively small, leaving little doubt about where the fleshy nostril could be placed. Among dinosaurs such as the long-necked sauropods, duck-billed dinosaurs, and horn-crowned dinosaurs such as Triceratops , however, the bony nostril opening can be more than two feet long, stretching half the length of the skull. So where within such a huge bony nostril was the dinosaur's smaller fleshy nostril located?
Traditionally, the fleshy nostril has been placed at the back of the bony nostril opening in dinosaurs, but this positioning may have more to do with history than biology, according to Witmer.
Early paleontologists thought that the big sauropods were amphibious, and may have used an upward-facing nostril placed dorsally, or at the back of the bony opening, as a snorkel as the
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Contact: Ginger Pinholster
gpinhols@aaas.org
202-326-6421
American Association for the Advancement of Science
2-Aug-2001