.Michael Samuel

and 2 more

Background; We here present a first intraspecific eco-variant post natal attempt at evaluation of skull signaling in the small African pangolin (Boreoeutheria) family, sub-family phatagininae emphasizing evolutionary trend in ontogeny. Forty; digitally processed skulls and foramen magnum outlines of this species from different geo-locations were assessed for asymmetry, foramen magnum shape variations and modularity hypotheses on skull areas using geometric and Elliptical Fourier analyses methods. Results; Regression of log transformed centroid size and asymmetric components suggested significant expression of asymmetry through ontogeny (p˂0.03) with size accounting for 81.34% of asymmetric shape changes. Multivariate analysis of regression confirmed directional but low (p˂0.5) fluctuating asymmetry (F1539=3.4045, F882= 3.2665, for dorsal and ventral views respectively). Intraspecific ontogenetic allometric trajectories followed rostro-caudal and caudo-lateral directions; intercepts for shape/size predictions were parallel. Mahalanobis distances between centroids (2.42) of specimens were significant (p˂ 0.01). Variance-covariance matrix in ontogeny lies between 0.0017 and 0.56 suggestive of shape overlaps and variations. Foramen magnum outline descriptors by incremental harmonics explained morphologic details; the first 4 effective principal components defined 96.98% of shape properties, while (3.02%) constituted finer details. 74.1% accuracy decline after size factor elimination. Modulation PCA: of Covariance Matrix and Asymmetry component was 88.38% and 7.48% (PC1 and 2) variance % predicted 10.08%. Conclusions; The study confirmed directional ‘handedness’ and fluctuating asymmetries among skull samples studied, an attenuated ability to maintain paired symmetric bilaterality irrespective of geo-location. Foramen magnum shape assumed priority over size in ontogeny with profound asymmetry (from the 5th harmonic); an indication of precocity and early presumptive form for arboreal adaptation this observation in conjunction with modularity inference suggested instability and global weakness of cranial integration processes and modules. These findings will be of value for species conservation and may be vital in pangolin evolutionary systematics.