Prenatal Growth and Development in the Angolan Free-tailed Bat, Mops condylurus (Chiroptera: Molossidae)

Abstract

We present data on prenatal growth, development, and skeletal ossification for the Angolan free-tailed bat (Mops condylurus), a species distributed throughout sub-Saharan Africa. Specimens were measured for crown‐rump length (CRL), greatest length of the skull (GLS), forearm length, mass, and wing area. We cleared and differentially stained specimens for cartilage and bone to quantify pattern of skeletogenesis. Significant regressions for general growth trajectories were generated by plotting CRL and fetal mass against GLS. We quantified growth of the forearm, which showed a positive relationship with growth of the skull. Curiously, wing area was highly positively related to fetal mass, suggesting an ecomorphological relationship of wing loading and flight ability being established early in development in this species. Patterns of ossification in this species were more similar to those of phyllostomid and pteropodid bats than they were to vespertilionid bats, to which M. condylurus is apparently more closely related. In this paper, we provide the 1st published account of prenatal growth, development, and skeletal ossification for the Angolan free-tailed bat, Mops condylurus (Chiroptera: Molossidae). Understanding developmental patterns provides key insights into the evolution of form and function as well as the origins of key evolutionary innovations (Jablonka and Lamb 1998). Indeed, heterochronic shifts in developmental timing are in large part responsible for the evolutionary diversity of the vertebrate limb (Smith 2003).