Apatite fission track thermochronometry data were collected from the Eastern Greater Caucasus orogen, Azerbaijan. Thermochronometry data constrain the history of exhumation and deformation of rocks within the orogen, which is an active accretionary prism. Thermochronometry data record the timing of cooling of a rock sample beneath a given closure temperature. Given an assumed or inferred geothermal gradient, thermochronometric ages can be used to infer exhumation rates and make interpretations about rates of deformation in orogens. The apatite fission track data presented here are analyzed in concert with apatite (U-Th)/He and zircon (U-Th)/He ages reported in Tye et al., in prep., to characterize the exhumation history of the Eastern Greater Caucasus.
Tye, A. R., Niemi, N. A., Safarov, R. T., Kadirov, F. A., & Babayev, G. R. (2021). Sedimentary response to a collision orogeny recorded in detrital zircon provenance of Greater Caucasus foreland basin sediments. Basin Research, 33(2), 933–967. https://doi.org/10.1111/bre.12499
Hind limbs can undergo dramatic changes in loading conditions during the transition from quadrupedal to bipedal locomotion. For example, the most early diverging bipedal jerboas (Rodentia: Dipodidae) are some of the smallest mammals in the world, with body masses that range 2-4 grams. The larger jerboa species exhibit developmental and evolutionary fusion of the central three metatarsals into a single cannon bone. We hypothesize that body size reduction and metatarsal fusion are mechanisms to maintain the safety factor of the hind limb bones despite the higher ground reaction forces associated with bipedal locomotion. Using finite element analysis to model collisions between the substrate and the metatarsals, we found that body size reduction was insufficient to reduce bone stress on unfused metatarsals, based on the scaled dynamics of larger jerboas, and that fused bones developed lower stresses than unfused bones when all metatarsals are scaled to the same size and loading conditions. Based on these results, we conclude that fusion reinforces larger jerboa metatarsals against high ground reaction forces. Because smaller jerboas with unfused metatarsals develop higher peak stresses in response to loading conditions scaled from larger jerboas, we hypothesize that smaller jerboas use alternative dynamics of bipedal locomotion that reduces the impact of collisions between the foot and substrate.
Villacis Nunez, Ray, Cooper, Moore (submitted). Body size reduction and metatarsal fusion were distinct mechanisms to resist bending as jerboas (Dipodidae) transitioned from quadrupedal to bipedal.
Reconstructed CT slices for a right cuboid of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81823), as a series of TIFF images. Raw projections are not included in this dataset.
Reconstructed CT slices for the partial cranium of the holotype specimen of Saadanius hijazensis in DICOM format. Data supporting the publication: New Oligocene primate from Saudi Arabia and the divergence of apes and Old World monkeys, https://doi.org/10.1038/nature09094
Raw projections are not included in this dataset.
Zalmout, I., Sanders, W., MacLatchy, L. et al. New Oligocene primate from Saudi Arabia and the divergence of apes and Old World monkeys. Nature 466, 360–364 (2010). https://doi.org/10.1038/nature09094, A cast of this specimen is held by the University of Michigan Museum of Paleontology (UMMP) under catalog number 14200., and 3D surface model viewable on UMORF site : https://umorf.ummp.lsa.umich.edu/wp/specimen-data/?Model_ID=1408
This dataset corresponds to 5,500 single-particle, dual-polarity mass spectra of biomass burning particles measured from a mobile laboratory during the 2017 prescribed burn at the University of Michigan Biological Station near Pellston, Michigan. Size-resolved chemical composition of individual particles, primarily ranging from 0.15 - 0.60 μm in vacuum aerodynamic diameter, was measured using an aerosol time-of-flight mass spectrometer (ATOFMS).
Reconstructed CT slices for a right navicular of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81831), as a series of TIFF images. Raw projections are not included in this dataset.
This scaled acceleration time series has been used in the graduate class, NA540, as an example of hydrodynamic impact. For a more detailed description of the tests, please see: Troesch, A.W. and Kang, C.-G., "Hydrodynamic Impact Loads on Three Dimensional Bodies," Proceedings of the 16th Symposium on Naval Hydrodynamics, Berkeley, July 1986, National Academy Press, Washington, D.C., 1987, pp. 537-558.
Troesch, A.W. and Kang, C.-G., "Hydrodynamic Impact Loads on Three Dimensional Bodies," Proceedings of the 16th Symposium on Naval Hydrodynamics, Berkeley, July 1986, National Academy Press, Washington, D.C., 1987, pp. 537-558. This item is not available online due to copyright restrictions, but the text can be searched using Hathi Trust: https://babel.hathitrust.org/cgi/pt?id=mdp.39015040312475
Journals sometimes focus the attention of the research community by having a special collection, sometimes an entire special issue, devoted to a single topic. A reasonable question to ask is whether the extra effort of organizing, promoting, and maintaining the special collection is worthwhile. The paper that this data set accompanies examines paper impact in the Journal of Geophysical Research Space Physics, separating the special collection papers from the non-special-collection submissions. The conclusion is that special collections are worth the extra work.
Liemohn, M. W., & Wooden, P. (2019). Editorial: Impact of special collections in JGR Space Physics. Journal of Geophysical Research Space Physics. https://doi.org/10.1002/essoar.10501036.2
Reconstructed CT slices for a right medial cuneiform (entocuneiform) of Cantius mckennai (University of Michigan Museum of Paleontology catalog number UMMP VP 81820), as a series of TIFF images. Raw projections are not included in this dataset.
Reconstructed CT slices for vertebrae of Phenacolemur (University of Michigan Museum of Paleontology catalog number UMMP VP 94723) as a series of TIFF images. Raw projections are not included in this dataset. The reconstructed slice data from the scan are offered here as a series of unsigned 16-bit integer TIFF images. The upper left corner of the first image (*_0000.tif) is the XYZ origin.