Subnasoalveolar anatomy and hominoid phylogeny: Evidence from comparative ontogeny
Anthropology; Evolutionary Biology; evolution; allometry; great apes; miocene; form; sexual dimorphism; extant; fossil hominids; Homo; late; african apes; facial kyphosis; character phylogeny; chimp; hylobatids; ontogenetic; orangutans; skull material; subnasal development
The present analysis evaluated extant hominoid subnasal morphological variation from an ontogenetic perspective, documenting both qualitative and allometric details of subnasal maturation in Hylobates, great apes and modern humans. With respect to intraspecific variation, results of log-linear modeling procedures indicate that qualitative features of the subnasal region shown previously to discriminate extant taxa (Ward and Kimbel, 1983; McCollum et al., 1993) do not vary appreciably with either age or sex. In terms of quantitative variation, aside from observed changes in the position of the anterior attachment of the nasal septal cartilage relative to the lateral margins of the nasal cavity, the morphology of the subnasal region does not vary appreciably with age. Furthermore, it was found that sexual dimorphism in subnasal form is present only in Pongo and Gorilla and is the result of sexual bimaturism rather than sexual variation in canine size. In considering interspecific variation in subnasal form, there is a propensity among hominoid taxa for the nasal cavity floor to be free of substantial topographic relief. The smoothly continuous nasal floor topography identified in the majority of hominoid taxa appears to be produced by extensive resorption of the anterior nasal cavity floor that accompanies an upward rotation of the anterior maxilla during craniofacial ontogeny. Comparisons of ontogenetic allometric trajectories indicate that relatively little of the variation in hominoid subnasal form can easily be attributed to variation in body/cranial size. Instead, variation in craniofacial orientation, vascular anatomy and incisor size and inclination were identified as potential mediators of hominoid subnasoalveolar anatomy. Although results of this analysis confirm that many details of the orangutan subnasal morphology are derived for this taxon, there is little conclusive evidence to support recent reports that the morphology displayed by Gorilla is primitive for great apes (Begun, 1992, 1994). (C) 1997 Wiley-Liss, Inc.
McCollum M A; Ward S C
American Journal of Physical Anthropology
1997
1997-03
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1002/(sici)1096-8644(199703)102:3%3C377::aid-ajpa7%3E3.0.co;2-s" target="_blank" rel="noreferrer noopener">10.1002/(sici)1096-8644(199703)102:3%3C377::aid-ajpa7%3E3.0.co;2-s</a>
New specimens of Elphidotarsius russelli (Mammalia, ?Primates, Carpolestidae) and a revision of plesiadapoid relationships
alberta; evolution; late; ordered characters; outgroups; paleocene; Paleontology; parsimony; plesiadapiformes; primatomorpha; pronothodectes-gaoi fox; systematic position
Significant new material of the plesiadapiform Elphidotarsius russelli is described from Montana and Alberta. Previously the most poorly documented carpolestid, this species is now known from numerous isolated teeth and many jaw fragments. New material from the Crazy Mountains Basin, Montana substantially extends its known geographic range and shows that E. russelli is the most derived species of Elphidotarsius, with many features that foreshadow characteristics of Carpodaptes; consequently, emending the diagnosis of Elphidotarsius has been necessary. A phylogenetic analysis based on 73 characters scored for all species of Elphidotarsius. Pronothodectes, and Saxonella, as well as Purgatorius unio, Purgatorius janisae, Pandemonium dis, Chronolestes simul, and Carpodaptes hazelae, indicates that Elphidotarsius is a paraphyletic stem taxon at the base of Carpolestidae. Numerous crossing synapo-morphies among these taxa show that a single anagenetic lineage can no longer represent the evolution of early carpolestids. This analysis also clarifies basal plesiadapoid relationships. Carpolestidae is the sister taxon to Plesiadapidae, and Saxonellidae is sister group to the carpolestid/plesiadapid clade. Contrary to previous hypotheses, Chronolestes and Pandemonium are found to lie outside of a clade including the other members of Carpolestidae, Saxonellidae, and Plesiadapidae, implying that they are basal plesiadapoids that diverged before the evolution of the common ancestor to the three main plesiadapoid families.
Silcox M T; Krause D W; Maas M C; Fox R C
Journal of Vertebrate Paleontology
2001
2001-03
Journal Article
<a href="http://doi.org/10.1671/0272-4634(2001)021%5B0132:nsoerm%5D2.0.co;2" target="_blank" rel="noreferrer noopener">10.1671/0272-4634(2001)021%5B0132:nsoerm%5D2.0.co;2</a>