An expansion of C 4 grasslands occurred between 6 and 8 million years ago in the Great Plains of North America, as evidenced by a marked shift to more 13 C-enriched carbon isotope compositions from large fossil mammal tooth enamel and paleosol carbonates. Prior to this expansion, habitats were comprised of exclusively C 3 vegetation. To explore this problem I present a compilation of bulk stabl...

This study provides a detailed magnetostratigraphic record of subsidence in the Linxia Basin, documenting a 27 Myr long sedimentary record from the northeastern edge of the Tibetan Plateau. Deposition in the Linxia Basin began at V29 Ma and continued nearly uninterruptedly until V1.7 Ma. Increasing rates of subsidence between 29 and 6 Ma in the Linxia Basin suggest deposition in the foredeep po...

East Asian summer monsoon (EASM) precipitation received by northern China over the past 800 thousand years (ky) is characterized by dominant 100-ky periodicity, mainly attributed to CO2 and Northern Hemisphere insolation-driven ice sheet forcing. We established an EASM record in the Late Miocene from lacustrine sediments in the Qaidam Basin, northern China, which appears to exhibit a dominant 1...

The geology of the Darien province of eastern Panama is presented through a new geologic map and detailed biostratigraphic and paleobathymetric analysis of its Upper Cretaceous to upper Miocene sediments. The sequence of events inferred from the stratigraphie record includes the collision of the Panama arc (the southwestern margin of the Caribbean plate) and South American continent. Three tect...

Hominoids, or taxa identified as hominoids, are known from much of Africa, Asia, and Europe since the Late Oligocene. The earliest taxa, fromAfrica, resemble extant hominoids but share with them mainly primitive characters. Middle and Late Miocene taxa are clearly hominoids, and by the end of the Middle Miocene most can be attributed to either the pongine (Pongo) or hominine (African ape and hu...

—A nearly complete fossil skull, including the rostrum, of blue marlin, Makaira nigricans Lacepède, 1802 (Perciformes: Xiphioidei: Istiophoridae), was collected from the Oso Member (latest Miocene) of the Capistrano Formation, Mission Viejo, Orange County, California. The specimen is compared with extant and fossil istiophorids, and 19 of its 20 morphological variables are within the range of v...

Significant down-core modal and compositional variations are described for granuleto cobble-sized clasts in the Early Pliocene to Middle/Late Miocene sedimentary cycles of the AND-1B drill core at the NW edge of the Ross Ice Shelf (McMurdo Sound). Long-term shifts in compositional patterns outline an evolving provenance which is interpreted as reflecting the combined effects and complex interac...

The genus Lespedeza (Fabaceae) consists of 40 species disjunctively distributed in East Asia and eastern North America. Phylogenetic relationships of all Lespedeza species and closely related genera were reconstructed using maximum parsimony, maximum likelihood, and Bayesian analyses of sequence data from five chloroplast (rpl16, rpl32-trnL, rps16-trnQ, trnL-F, and trnK/matK) and one nuclear (I...