The Lantern Vol. 46, No. 1, December 1979

• Visions in Chains • The Bean • Who Can We Watch Tonite? • Night Glider • The Hurricane • Crisp New Paper • Compassion • Loneliness • 301 • Ode to Man • Unsteady Hands • The Beachcomber • The Pounce • Graveyard Shift • Houston Refineries • Haiku • The End of the Game • A Rose • Ode to a Ziffle • To Carson McCullers • In the May Month • Ghostly Chanting • Travel Excerpts • Face in the Crowd • Waiting in an Airport • A Taste of Winter\u27s Embracehttps://digitalcommons.ursinus.edu/lantern/1115/thumbnail.jp

Hard-Object Feeding in Sooty Mangabeys (Cercocebus atys) and Interpretation of Early Hominin Feeding Ecology

Morphology of the dentofacial complex of early hominins has figured prominently in the inference of their dietary adaptations. Recent theoretical analysis of craniofacial morphology of Australopithecus africanus proposes that skull form in this taxon represents adaptation to feeding on large, hard objects. A modern analog for this specific dietary specialization is provided by the West African sooty mangabey, Cercocebus atys. This species habitually feeds on the large, exceptionally hard nuts of Sacoglottis gabonensis, stereotypically crushing the seed casings using their premolars and molars. This type of behavior has been inferred for A. africanus based on mathematical stress analysis and aspects of dental wear and morphology. While postcanine megadontia, premolar enlargement and thick molar enamel characterize both A. africanus and C. atys, these features are not universally associated with durophagy among living anthropoids. Occlusal microwear analysis reveals complex microwear textures in C. atys unlike those observed in A. africanus, but more closely resembling textures observed in Paranthropus robustus. Since sooty mangabeys process hard objects in a manner similar to that proposed for A. africanus, yet do so without the craniofacial buttressing characteristic of this hominin, it follows that derived features of the australopith skull are sufficient but not necessary for the consumption of large, hard objects. The adaptive significance of australopith craniofacial morphology may instead be related to the toughness, rather than the hardness, of ingested foods

Genetic Diversity and Population History of a Critically Endangered Primate, the Northern Muriqui (Brachyteles hypoxanthus)

Social, ecological, and historical processes affect the genetic structure of primate populations, and therefore have key implications for the conservation of endangered species. The northern muriqui (Brachyteles hypoxanthus) is a critically endangered New World monkey and a flagship species for the conservation of the Atlantic Forest hotspot. Yet, like other neotropical primates, little is known about its population history and the genetic structure of remnant populations. We analyzed the mitochondrial DNA control region of 152 northern muriquis, or 17.6% of the 864 northern muriquis from 8 of the 12 known extant populations and found no evidence of phylogeographic partitions or past population shrinkage/expansion. Bayesian and classic analyses show that this finding may be attributed to the joint contribution of female-biased dispersal, demographic stability, and a relatively large historic population size. Past population stability is consistent with a central Atlantic Forest Pleistocene refuge. In addition, the best scenario supported by an Approximate Bayesian Computation analysis, significant fixation indices (ΦST = 0.49, ΦCT = 0.24), and population-specific haplotypes, coupled with the extirpation of intermediate populations, are indicative of a recent geographic structuring of genetic diversity during the Holocene. Genetic diversity is higher in populations living in larger areas (>2,000 hectares), but it is remarkably low in the species overall (θ = 0.018). Three populations occurring in protected reserves and one fragmented population inhabiting private lands harbor 22 out of 23 haplotypes, most of which are population-exclusive, and therefore represent patchy repositories of the species' genetic diversity. We suggest that these populations be treated as discrete units for conservation management purposes

Morphometric and technological analysis of Acheulean large cutting tools from Porzuna (Ciudad Real, Spain) and questions of African affinities

The Acheulean of central Spain is well known from a handful of sites. Rarely, however, are these assemblages subject to systematic technological and morphological analyses. Numerous years of surface collection within the Porzuna area (Ciudad Real) has yielded a substantial collection of Lower-Middle Palaeolithic lithic material (with over 8000 stone tools), now housed at the Museo Provincial of Ciudad Real. It has been suggested that the LCT technology of the Spanish Acheulean may have been directly influenced by ESA African technological traditions; however, others have suggested a European origin for the technology. Here we present a techno-typological and 3D morphometric analysis of the LCT's collected at Porzuna. We compare the Porzuna artefacts to other known local assemblages from Ciudad Real as well as Acheulean LCT's from north, east and South Africa, to investigate potential technological and morphological affinities. Results of our analysis show that despite sharing technological similarities, such as the use of large flakes as blanks, significant morphological differences exist between the African and Iberian LCTs

Is the deciduous/permanent molar enamel thickness ratio a taxon-specific indicator in extant and extinct hominids?

In Primates, enamel thickness variation stems from an evolutionary interplay between functional/adaptive constraints (ecology) and the strict control mechanisms of the morphogenetic program. Most studies on primate enamel thickness have primarily considered the permanent teeth, while the extent of covariation in tooth enamel thickness distribution between deciduous and permanent counterparts remains poorly investigated. In this test study on nine extant and fossil hominids we investigated the degree of covariation in enamel proportions between 25 pairs of mandibular dm2 and M1 by a so-called “lateral enamel thickness diphyodontic index”. The results did not provide an unambiguous picture, but rather suggest complex patterns likely resulting from the influence of many interactive factors. Future research should test the congruence of the “diphyodontic signal” between the anterior and the postcanine dentition, as well as between enamel and the enamel-dentine junction topography