Donald E. Savage

Anthropoid Origins in Asia? New Discovery of Amphipithecus from the Eocene of Burma

A new fossil of the primate Amphipithecus mogaungensis Colbert from the late Eocene of Burma shows that this species has a mandibular and molar morphology very similar to Oligocene and post-Oligocene higher primates. It has an exceptionally deep jaw. Its brachybunodont first and second molars have smooth enamel but lack hypoconulids. The shape of its second molar is nearly square—an advanced higher primate feature. Amphipithecus mogaungensis and related taxon Pondaungia cotteri Pilgrim are the earliest known higher primates. They suggest that Southeast Asia was an early theater of higher primate diversification.

Critique of certain Eocene Primate taxa

Abstract All Paleogene primates are plagued by uncertaintiesconcerning their classification and phyletic relationships. Purgatorius is taken as an example of a primitive primate and on this basis two genera, Donrussellia and Teilhardina are analyzed. Donrussellia is relegated to subgeneric status within Teilhardina and the included species are considered possibly to have been near the ancestry of the omomyid-adapid complex. The North American species Teilhardina americana is the most primitive omonyid presently known from that continent.

Comments on mammalian paleontologicstratigraphy and geochronology; Eocene stages and mammal ages of Europe and North America

Abstract 1. In terrains and intervals such as the nonmarine paleogene in Europe where fossil-mammal samples are found mostly in isolated pockets or lenses lacking stratigraphic contiguity with other samples of fossils, relative or ordinal dating by stage-of-evolution or phyletic position or niveau repere of the paleospecies (i. e., the phyletically controlled index taxon or association of taxa) remains the best technique for applying paleontology to chronostratigraphy and geochronology. 2. In terrains and intervals such as many Tertiary basins of nonmarine sedimentation in North America where the stratigraphic relationships between fossil-mammal samples can be analyzed (i. e., measured and oriented spatially) with necessary precision, the chronozone, based on joint occurrence (overlapping stratigraphic ranges) of selected paleospecies, makes the most useful and most refined unit for geochronologic correlation. 3. All paleontological techniques for dating are basically empirical and should be reviewed and revised constantly. There is a limit to paleontological resolution in chronostratigraphy and geochronology. 4. The Sparnacian Substage is a valid and useful chronostratigraphic unit and should be perpetuated, despite the fact that it is difficult to correlate with marine stratigraphic sections.

Villafranchian Age and its Radiometric Dating, II: ABSTRACT

The Villafranchian, though identified by non-marine phenomena, was one of the most precisely typified of the commonly used European Cenozoic Stages-Ages. Pareto (1865) gave exact geographic location and characteristic rocks of his stratotype for Villafranchian and listed the fossils that were known (three proboscidean species). Villafranchian has been applied throughout Eurasia and Africa on the basis of a characteristic array of species of mammals. These species were obtained first from sites in Italy and France that were believed to be the same age as Paretos Villafranchian. Validity and utility of the Villafranchian, as recognized through most of the Eastern Hemisphere, are not vitiated because some of its characterizing mammalian assemblages are younger than the type or because its lower boundary may not coincide with the currently accepted lower boundary of the Quaternary. Large mammals now known from the stratotype, together with small mammals, mollusks, and plants End_Page 479------------------------------ recently collected, will provide a more secure paleontologic basis for correlation with type-Villafranchian ecology. Although no materials suitable for radiometric dating of type Villafranchian has been found, volcanic rocks associated with the correlative Etouaires fauna near Issoire, France, have yielded a K/Ar date of 3.4 m.y. The nearby younger Villafranchian fauna of Roca Neyra is 2.5 m.y. In beds from a zone between these two faunas is the fossil flora of Boissac, of perimediterranean type dominated by deciduous trees and containing bamboo. The oldest geological indications of cold climate that have been dated in the Auvergne of France are at Coupet (solifluction), 1.9 m.y., and Vazeills (crioturbated earth), 1.8 m.y. Coupet also has a fauna, thought by Bout to be mid-Villafranchian. The oldest glacial deposit dated from the Northern Hemisphere (Sierra Nevada) is 2.7 m.y., whereas the oldest evidence of Pleistocene cold climate in the Southern Hemisphere (New Zealand) is slightly older than 2.5 m.y. End_of_Article - Last_Page 480------------