Brian W Zimmer

• Appalachian State University

Bipedal trackways discovered in 1978 at Laetoli site G, Tanzania and dated to 3.66 million years ago are widely accepted as the oldest unequivocal evidence of obligate bipedalism in the human lineage 1–3 . Another trackway discovered two years earlier at nearby site A was partially excavated and attributed to a hominin, but curious affinities with...

The Placerias/Downs’ Quarry complex in eastern Arizona, USA, is the most diverse Upper Triassic vertebrate locality known. We report a new short-faced archosauriform, Syntomiprosopus sucherorum gen. et sp. nov., represented by four incomplete mandibles, that expands that diversity with a morphology unique among Late Triassic archosauriforms. The mo...

Fossil hominin footprints preserve data on a remarkably short time scale compared to most other fossil evidence, offering snapshots of organisms in their immediate ecological and behavioral contexts. Here, we report on our excavations and analyses of more than 400 Late Pleistocene human footprints from Engare Sero, Tanzania. The site represents the...

Complete version of this abstract online at: https://gsa.confex.com/gsa/2019AM/webprogram/Paper339845.html The Placerias/Downs quarry (PDQ) complex in east-central Arizona is the most diverse Late Triassic nonmarine vertebrate locality in the world, yielding dozens of taxa since the first excavations in the 1930s. The PDQ is low in the Chinle and...

Hominin footprint sites are excellent sources of data that provide insights into early human physiology, anatomy, and social structures. They are also potential tourist attractions that are often situated in relatively under-developed parts of the world. Unfortunately, many footprint sites are also located in high energy environments and/or are pre...

We report on the radioisotopic age, formation, and preservation of a late Pleistocene human footprint site in northern Tanzania on the southern shore of Lake Natron near the village of Engare Sero. Over 400 human footprints, as well as tracks of zebra and bovid, are preserved in a series of volcaniclastic deposits. Based on field mapping along with...

The purpose of this field guide is to describe a three-day itinerary to examine examples of recent (late Pleistocene and Holocene) monogenetic volcanism in the eastern Trans-Mexican Volcanic Belt (TMVB; Figure 1) with particular emphasis on the phreatomagmatic structures (maar-type volcanoes). In this area, these include spectacular exposures of de...

The eastern Trans-Mexican Volcanic Belt is characterized by a diversity of volcanoes that are related to different processes and eruptive styles. The spectacular exposures of late Pleistocene and Holocene volcanism provide a unique opportunity to explore a variety of volcanic features and deposits that may be relevant for volcanic hazard assessment...

The eastern Trans-Mexican Volcanic Belt is characterized by a diversity of volcanoes that are related to different processes and eruptive styles. The spectacular exposures of late Pleistocene and Holocene volcanism provide a unique opportunity to explore a variety of volcanic features and deposits that may be relevant for volcanic hazard assessment...

Cerro Pinto is a Pleistocene rhyolite tuff ring-dome complex located in the eastern Trans-Mexican Volcanic Belt. The complex is composed of four tuff rings and four domes that were emplaced in three eruptive stages marked by changes in vent location and eruptive character. During Stage I, vent clearing produced a 1.5-km-diameter tuff ring that was...

The Lake Natron Homo sapiens footprint site is located in northern Tanzania along the East African Rift escarpment. The site is positioned south of Lake Natron within an ephemeral channel of the Engare Sero River. The hominid footprints are preserved in a tuff, which originated from one of the volcanic centers surrounding the site. Two large volcan...

Many studies in ecology, soil science, and global climate change require accurate estimates of soil organic C (SOC). When calibrated with direct SOC determinations, loss-on-ignition (LOI) has been proposed as a rapid, inexpensive, and accurate method for estimating SOC. We collected 0- to 15- and 15- to 50-cm mineral soil samples from 102 plots wit...

Cerro Pinto is a rhyolite dome complex located in the eastern Trans-Mexican Volcanic Belt. The complex is composed of four tuff rings and four domes that were emplaced in three distinct eruptive stages marked by changes in vent location and eruptive character. Each of these stages contained eruptive sequences that follow simple rhyolite-dome models...

Red Mountain volcano is a Pleistocene (ca. 740 ky) cinder cone north of Flagstaff, AZ, in the northern Mio- Recent San Francisco volcanic field. Red Mountain erupted onto Permian sedimentary rocks with low topographic relief, likely covered in some places by older flows. The cone evolved through several stages that erupted and emplaced cinder, lava...