A new species of Apterodon (Mammalia, Creodonta) from the Upper Eocene Qasr el-Sagha Formation of Egypt

The mandible of a medium-sized carnivore discovered by a recent Yale paleontological expedition to the Fayum Province of Egypt represents a new species of the creodont Apterodon. The type and only specimen of this new species, Apterodon saghensis, comes from the Upper Eocene Qasr el-Sagha Formation and thus represents the earliest terrestrial carnivore yet described from the African continent. Unfortunately the specimen contributes little to our understanding of the origin and relationships of Apterodon

Structure and Thermodynamic Stability of the OsC and OsC2 Molecules by Theoretical Calculations and by Knudsen Cell Mass Spectrometry

Knudsen cell mass spectrometric equilibrium measurements together with theoretical computations have been employed to gain structural and thermodynamic information of the OsC and OsC[sub 2] molecules. Several levels of theory have been applied to determine the structures, molecular parameters, and physico-chemical properties of OsC(g) and OsC[sub 2](g), and their singly charged ions. Complete active space self-consistent field (CASSCF) calculations were performed on the apparent [sup 3]Σ[sup -] ground state and first [sup 3]Δ excited state of OsC. From the analyzed gaseous equilibria and the thermal functions calculated from the computed molecular parameters, the following atomization enthalpies, Δ[sub a]H[sub 0][sup o](OsC,g) and Δ[sub a]H[sub 0][sup o](OsC[sub 2],g), and enthalpies of formation, Δ[sub f]H[sub 298.15][sup o](OsC,g) and Δ[sub f]H[sub 298.15][sup o](OsC[sub 2],g), in kJ mol-1, have been obtained: OsC, 605.6±14.0 and 895.4±14.0; OsC[sub 2], 1154.6±18.0 and 1059.5±18.0. The results have been compared with those for the other platinum metal carbides and oxides

Systematics, Phylogeny, and Evolution of Early Eocene Adapidae (Mammalia, Primates) in North America

245-279http://deepblue.lib.umich.edu/bitstream/2027.42/48489/2/ID339.pd

Quenched growth of nanostructured lead thin films on insulating substrates

Lead island films were obtained via vacuum vapor deposition on glass and ceramic substrates at 80 K. Electrical conductance was measured during vapor condensation and further annealing of the film up to room temperature. The resistance behavior during film formation and atomic force microscopy of annealed films were used as information sources about their structure. A model for the quenched growth, based on ballistic aggregation theory, was proposed. The nanostructure, responsible for chemiresistive properties of thin lead films and the mechanism of sensor response are discussed.Comment: 2 figures; accepted to Thin Solid Film

Reevaluating Traditional International Service-Learning during a Global Pandemic

Engineers in Action (EIA) Bridge Program provides engineering students with international service-learning opportunities through design-build footbridge projects. The conventional project model relies on an implementation trip as a primary learning activity. Prior to the pandemiccaused cancellations of all implementation trips in 2020, EIA resources were already being allocated to increase on-campus learning activities in an effort to improve the inclusivity of the program to students without the financial means to travel and forego paid internships. Online courses were developed using Open edX (https://eiaeducation.org) and the focus of students was shifted from preparing themselves to implement the bridge projects in person, to aiding local staff and communities to implement the projects without EIA students onsite. All student chapters remained actively engaged in their projects through the adapted project preparations and online courses. The successful adaptation of a service-learning project to an online format suggests that students still highly value these educational experiences. In the future, servicelearningprojects should consider offering online formats to engage more engineering studentsacross a wider range of institutions.</p

Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology

The best European locality for complete Eocene mammal skeletons is Grube Messel, near Darmstadt, Germany. Although the site was surrounded by a para-tropical rain forest in the Eocene, primates are remarkably rare there, and only eight fragmentary specimens were known until now. Messel has now yielded a full primate skeleton. The specimen has an unusual history: it was privately collected and sold in two parts, with only the lesser part previously known. The second part, which has just come to light, shows the skeleton to be the most complete primate known in the fossil record.We describe the morphology and investigate the paleobiology of the skeleton. The specimen is described as Darwinius masillae n.gen. n.sp. belonging to the Cercamoniinae. Because the skeleton is lightly crushed and bones cannot be handled individually, imaging studies are of particular importance. Skull radiography shows a host of teeth developing within the juvenile face. Investigation of growth and proportion suggest that the individual was a weaned and independent-feeding female that died in her first year of life, and might have attained a body weight of 650-900 g had she lived to adulthood. She was an agile, nail-bearing, generalized arboreal quadruped living above the floor of the Messel rain forest.Darwinius masillae represents the most complete fossil primate ever found, including both skeleton, soft body outline and contents of the digestive tract. Study of all these features allows a fairly complete reconstruction of life history, locomotion, and diet. Any future study of Eocene-Oligocene primates should benefit from information preserved in the Darwinius holotype. Of particular importance to phylogenetic studies, the absence of a toilet claw and a toothcomb demonstrates that Darwinius masillae is not simply a fossil lemur, but part of a larger group of primates, Adapoidea, representative of the early haplorhine diversification

Chorlakkia hassani, A New Middle Eocene Dichobunid (Mammalia, Artiodactyla) from the Kuldana Formation of Kohat (Pakistan)

117-124http://deepblue.lib.umich.edu/bitstream/2027.42/48496/2/ID347.pd

New Protocetid Whale from the Middle Eocene of Pakistan: Birth on Land, Precocial Development, and Sexual Dimorphism

BACKGROUND: Protocetidae are middle Eocene (49-37 Ma) archaeocete predators ancestral to later whales. They are found in marine sedimentary rocks, but retain four legs and were not yet fully aquatic. Protocetids have been interpreted as amphibious, feeding in the sea but returning to land to rest. METHODOLOGY/PRINCIPAL FINDINGS: Two adult skeletons of a new 2.6 meter long protocetid, Maiacetus inuus, are described from the early middle Eocene Habib Rahi Formation of Pakistan. M. inuus differs from contemporary archaic whales in having a fused mandibular symphysis, distinctive astragalus bones in the ankle, and a less hind-limb dominated postcranial skeleton. One adult skeleton is female and bears the skull and partial skeleton of a single large near-term fetus. The fetal skeleton is positioned for head-first delivery, which typifies land mammals but not extant whales, evidence that birth took place on land. The fetal skeleton has permanent first molars well mineralized, which indicates precocial development at birth. Precocial development, with attendant size and mobility, were as critical for survival of a neonate at the land-sea interface in the Eocene as they are today. The second adult skeleton is the most complete known for a protocetid. The vertebral column, preserved in articulation, has 7 cervicals, 13 thoracics, 6 lumbars, 4 sacrals, and 21 caudals. All four limbs are preserved with hands and feet. This adult is 12% larger in linear dimensions than the female skeleton, on average, has canine teeth that are 20% larger, and is interpreted as male. Moderate sexual dimorphism indicates limited male-male competition during breeding, which in turn suggests little aggregation of food or shelter in the environment inhabited by protocetids. CONCLUSIONS/SIGNIFICANCE: Discovery of a near-term fetus positioned for head-first delivery provides important evidence that early protocetid whales gave birth on land. This is consistent with skeletal morphology enabling Maiacetus to support its weight on land and corroborates previous ideas that protocetids were amphibious. Specimens this complete are virtual 'Rosetta stones' providing insight into functional capabilities and life history of extinct animals that cannot be gained any other way

New assessment of Pondaungia and Amphipithecus (Primates) from the late middle Eocene of Myanmar, with a comment on 'Amphipithecidae'

337-372http://deepblue.lib.umich.edu/bitstream/2027.42/48663/2/ID530.pd