1Center for Functional Anatomy and Evolution, Johns Hopkins University, 2School of Physical Therapy, Slippery Rock University, 3Department of Anthropology, University of Florida
March 26, 2015 , Archview Ballroom
This study investigates development of the nasal turbinals in Lemur catta from the fetal to adult stages. The great number of turbinals in strepsirrhines is assumed to correlate with a strong olfactory sense, but recent work indicates some morphological variations exist among lemurs and lorises. The developmental basis and functional implications of this variation have not been explored.
Using CT scans and histology of five different Lemur catta at different ages, we were able to observe the order in which the turbinals develop. Six large “endoturbinals” are present: four ethmoturbinals, one nasoturbinal, and one maxilloturbinal. Four smaller turbinals are found in the frontal recess. Histology of neonates reveals that most elements are present at birth, except that only three turbinals are present in the frontal recess. The sequence of ossification starts in utero with the nasoturbinal, maxilloturbinal, and the first ethmoturbinal. Posterior to these turbinals, ethmoturbinals II though IV, as well as the frontoturbinals, are ossifying by about one month postnatally. Through these observations, we are able to demonstrate that the nasal turbinals in Lemur catta develop from anterior to posterior. Furthermore, since the majority of the ethmoturbinals and the frontoturbinals ossify later in infancy, it can be surmised that they are expanding in size postnatally via cartilaginous growth. These observations imply that some olfactory surfaces are less extensive in newborns and instead expand gradually as the posterior ethmoturbinals grow. Accordingly, olfactory reliance may increase postnatally as surface area expands.
Supported by NSF # BCS-1231350; NSF # BCS-1231717; and NSF # BCS-0959438