Facial duplication: Case, review, and embryogenesis

The craniofacial anatomy of an infant with facial duplication is described. There were four eyes, two noses, two maxillae, and one mandible. Anterior to the single pituitary the brain was duplicated and there was bilateral arhinencephaly. Portions of the brain were extruded into a large frontal encephalocele. Cases of symmetrical facial duplication reported in the literature range from two complete faces on a single head (diprosopus) to simple nasal duplication. The variety of patterns of duplication suggests that the doubling of facial components arises in several different ways: Forking of the notochord, duplication of the prosencephalon, duplication of the olfactory placodes, and duplication of maxillary and/or mandibular growth centers around the margins of the stomatodeal plate. Among reported cases, the female:male ratio is 2:1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38153/1/1420250205_ftp.pd

ROM mapping of ligamentous constraints on avian hip mobility: implications for extinct ornithodirans

Studies of soft tissue effects on joint mobility in extant animals can help to constrain hypotheses about joint mobility in extinct animals. However, joint mobility must be considered in three dimensions simultaneously, and applications of mobility data to extinct taxa require both a phylogenetically informed reconstruction of articular morphology and justifications for why specific structures' effects on mobility are inferred to be similar. We manipulated cadaveric hip joints of common quail and recorded biplanar fluoroscopic videos to measure a 'ligamentous' range of motion (ROM), which was then compared to an 'osteological' ROM on a ROM map. Nearly 95% of the joint poses predicted to be possible at the hip based on osteological manipulation were rendered impossible by ligamentous constraints. Because the hip joint capsule reliably includes a ventral ligamentous thickening in extant diapsids, the hip abduction of extinct ornithodirans with an offset femoral head and thin articular cartilage was probably similarly constrained by ligaments as that of birds. Consequently, in the absence of extraordinary evidence to the contrary, our analysis casts doubt on the 'batlike' hip pose traditionally inferred for pterosaurs and basal maniraptorans, and underscores that reconstructions of joint mobility based on manipulations of bones alone can be misleading