Publications
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- Deep-Time Marine Sedimentary Element Database Earth System Science Data Discussions
Lai, J. et al.
2024;2024 - The relationship between total organic carbon and bottom water redox state in North American black shales Palaeogeography, Palaeoclimatology, Palaeoecology
Ritzer, S.R. et al.
2024;649
ritzler_2024_toc_bottom_redox_NA_black_shales.pdf - Temperature-dependent hypoxia tolerance of purple sea urchin Strongylocentrotus purpuratus across biogeography and ontogeny Marine Ecology Progress Series
Duncan, M.I., Micheli, F., Marquez, J.A., Lowe. C.J., Hamilton, S.L., Sperling, E.A.
2024;739 - Sustained increases in atmospheric oxygen and marine productivity in the Neoproterozoic and Palaeozoic eras Nature Geoscience
Stockey, R.G. et al.
2024;17
stockey_2024_atmos_o2_increase_neoproterozoic_palaeozoic.pdf - A shift in redox conditions near the Ediacaran/Cambrian transition and its possible influence on early animal evolution, Corumbá Group, Brazil Geoscience Frontiers
Caxito, F.A. et al.
2024;15
caxito_2024_ediacan_cambrian_redox_shift_animal_evolution.pdf - Deep-water first occurences of Ediacara biota prior to the Shuram carbon isotope excursion in the Wernecke Mountains. Yukon, Canada
Boag, T.H., Busch, J.F., Gooley, J.T., Strauss, J.V., Sperling, E.A.
2024;22 - Lithium isotopic constraints on the evolution of continental clay mineral factory and marine oxygenation in the earliest Paleozoic Era Science Advances
Wei, G.Y. et al.
2024;10
wei_2024_lithium_isotopic_constraints.pdf - Thermal optima in the hypoxia tolerance of marine ectotherms: Physiological causes and biogeographic consequences Public Library of Science: Biology
Endress, M.G.A., Penn, J.L., Boag, T.H., Burford, B.P., Sperling, E.A., Deutsch, C.A.
2024;22
endress_2024_thermal_optima_ectotherm_hypoxia_tolerance.pdf - Constraining the oxygen requirements for modern microbial eukaryote diversity Proceedings of the National Academy of Sciences, USA
Mills, D.B., Simister, R.L., Sehein, T.R., Hallam, S.J., Sperling, E.A., Crowe, S.A.
2024;121
mills_2024_oyxgen_requirement_constraints_microbe_euks.pdf - Oxygen availability and body mass modulate ectotherm responses to ocean warming Nature Communications
Duncan, M.I. et al.
2023;14 - Integrated litho-, chemo- and sequence stratigraphy of the Ediacaran Gametrail Formation across a shelf-slope transect in the Wenecke Mountains, Yukon, Canada American Journal of Science
Busch, J.F. et al.
2023;323 - Species of Dickinsonia Sprigg from the Ediacaran of South Australia Paleaontology
Evans, S.D., Hunt, G., Gehling, J.G., Sperling, E.A., Droser, M.L.
2023;66
evans_2023_dickinsonia_sprigg_spp_ediacaran_aus.pdf - Mesoproterozoic surface oxygenation accompanied major sedimentary manganese deposition at 1.4 and 1.1 Ga Geobiology
Spinks, S.C. et al.
2023;21 - Integrative Approaches to Understanding Organismal Responses to Aquatic Deoxygenation The Biological Bulletin
Woods H.A. et al.
2022;243
woods_2022_organismal_response_approaches_deoxygenation.pdf - Breathless through Time: Oxygen and Animals across Earth's History The Biological Bulletin
Sperling, E.A. et al.
2022;243
sperling_2022_oxygen_and_animals_across_history.pdf - Eukaryogenesis and oxygen in Earth history Nature Ecology & Evolution
Mills, D.B. et al.
2022;6
mills_2022_eukaryogenesis_and_oxygen_earth.pdf - Marine sponges in the once and future ocean Global Change Biology
Mills, D.B., Sperling, E.A.
2022;28
mills_2022_marine_sponges_past_and_future.pdf - A prolonged, two-step oxygenation of Earth's early atmosphere: Support from confidence intervals Geology
Hodgskiss, M.S.W., Sperling, E.A.
2022;50
hodgkiss_2022_two_step_oxygenation.pdf - A long-term record of early to mid-Paleozoic marine redox change Science Advances
Sperling, E.A. et al.
2021;7
sperling_2021_mid_paleozoic_redox_record.pdf - Decreasing Phanerozoic extinction intensity as a consequence of Earth surface oxygenation and metazoan ecophysiology Proceedings of the National Academy of Sciences, USA
Stockey, R.G., Pohl, A., Ridgwell, A., Finnegan, S., Sperling, E.A.
2021;118
stockey_2021_decreasing_phanerozoic_extinction_via_oxygen.pdf - Isotopic analyses of Ordovician–Silurian siliceous skeletons indicate silica-depleted Paleozoic oceans Geobiology
Trower, E.J., Strauss, J.V., Sperling, E.A., Fischer, W.W.
2021; :
trower_2021_geobiology_silicon_isotopes_in_road_river_group.pdf - Curation and analysis of global sedimentary geochemical data to inform earth history GSA Today
Mehra, A., Keller, C.B., Zhang, T., Tosca, N.J., McLennan, S.M., Sperling, E.A., Farrell, U.C., The SGP Collaborative Team, Strauss, J.V.
2021; 31: 4-10
mehra_2021_gsa_today_large_geochemical_datasets_and_earth_history.pdf - Variable redox conditions as an evolutionary driver? A multi-basin comparison of redox in the middle and later Cambrian oceans (Drumian-Paibian) Palaeogeography, Palaeoclimatology, Palaeoecology
LeRoy, M.A., Gill, B.C., Sperling, E.A., McKenzie, N.R., Park, T.Y.S.
2020; 566: 110209
leroy_2021_p3_later_cambrian_redox_changes.pdf - Thallium isotope ratios in shales from South China and northwestern Canada suggest widespread O2 accumulation in marine bottom waters was an uncommon occurrence during the Ediacaran Period Chemical Geology
Ostrander, C.M., Owens, J.D., Nielsen, S.G., Lyons, T.W., Shu, Y., Chen, X., Sperling, E.A., Jiang, G., Johnston, D.T., Sahoo, S.K., Anbar, A.D.
2020; 557: 119856
ostrander_2020_chem_geol_ediacaran_thallium_isotopes_nw_canada_and_s_china.pdf - Redox and paleoenvironmental conditions of the Devonian-Carboniferous Sappington Formation, southwestern Montana, and comparison to the Bakken Formation, Williston Basin Palaeogeography, Palaeoclimatology, Palaeoecology
Browne, T.N., Hofmann, M.H., Malkowski, M.A., Wei, J., Sperling, E.A.
2021; 560: 1100251
browne_2020_p3_sappington_formation_geochem_early_view.pdf - Mesoproterozoic paleo-redox changes during 1500–1400 Ma in the Yanshan Basin, North China Precambrian Research
Chen, X., Li, M., Sperling, E.A., Zhang, T., Zong, K., Liu, Y., Shen, Y.
2020; 347: 1058353
chen_2020_prec_res_mesoproterozoic_redox_conditions_in_north_china.pdf - Metabolic tradeoffs control biodiversity gradients through geological time Current Biology
Boag, T.H., Gearty, W., Stockey, R.G.
2021; 31: 1-8
boag_2021_curr_biol_metabolic_tradeoffs_and_biodiversity_gradients.pdf - The composition and weathering of the continents over geologic time Geochemical Perspectives Letters
Lipp, A.G., Shorttle, O., Sperling, E.A., The SGP Collaborative Team
2021; 7: 21-26
lipp_2021_gpl_weathering_and_provenance.pdf - The Road River Group of northern Yukon, Canada: early Paleozoic deep-water sedimentation within the Great American Carbonate Bank Canadian Journal of Earth Sciences
Strauss, J.V., Fraser, T., Melchin, M.J., Allen, T.J., Malinowski, J., Feng, X., Taylor, J.F., Day, J., Gill, B.C., Sperling, E.A.
2020; 57: 1193-1219
- Uranium Isotope Fractionation in Non‐sulfidic Anoxic Settings and the Global Uranium Isotope Mass Balance Global Biogeochemical Cycles
Cole, D.B., Planavsky, N.J., Longley, M., Boning, P., Wilkes, D., Wang, X., Swanner, E.D., Wittkop, C., Loydell, D.K., Busigny, V., Knudsen, A.D., Sperling, E.A.
2020; 34: e2020GB006649
cole_2020_u_isotope_fractionation_ferruginous_settings.pdf - The origin of phagocytosis in Earth history Interface Focus
Mills, D.B.
2020; :
mills_2020_interface_focus_origin_of_phagocytosis.pdf - Calibrating the coevolution of Ediacaran life and environment Proceedings of the National Academy of Sciences, USA
Rooney, A.D., Cantine, M.D., Bergmann, K.D., Gómez-Pérez, I., Al Baloushi, B., Boag, T.H., Busch, J.F., Sperling, E.A., Strauss, J.V.
2020; 117: 16824-16830
rooney_2020_pnas_ediacaran_chronostratigraphy_early_view.pdf - A high-TOC shale in a low productivity world: The late Mesoproterozoic Arctic Bay Formation, Nunavut Earth and Planetary Science Letters
Hodgskiss, M.S.W.H., Sansjofre, P., Kunzmann, M., Sperling, E.A., Cole, D.B., Crockford, P.W., Gibson, T.M., Halverson, G.P.
2020; 544: 116384
hodgskiss_2020_epsl_arctic_bay_geochemistry.pdf - Ediacaran reorganization of the marine phosphorus cycle Proceedings of the National Academy of Sciences, USA
Laakso, T.A., Sperling, E.A., Johnston, D.T., Knoll, A.H.
2020; 117: 11961-11967
laakso_2020_pnas_ediacaran_phosphorites.pdf - Small shelly fossils and carbon isotopes from the early Cambrian (Stages 3–4) Mural Formation of western Laurentia Papers in Paleontology
Skovsted, C.B., Balthasar, U., Vinther, J., Sperling, E.A.
2020; 7: 951-983
skovsted_2020_papers_in_palaeontology_mural_ssfs_and_carbon_isotopes.pdf - Extending the record of the Lomagundi–Jatuli carbon isotope excursion in the Labrador Trough, Canada Canadian Journal of Earth Sciences
Hodgskiss, M.S.W., Lamothe, K.G., Halverson, G.P., Sperling, E.A.
2020; 57: 1089-1102
hodgskiss_2020_cjes_labrador_trough.pdf - Persistent global marine euxinia in the early Silurian Nature Communications
Stockey, R.G., Cole, D.B., Planavsky, N.J., Loydell, D.K., Fryda, J., Sperling, E.A.
2020; 11: 1804
stockey_2020_nat_comm_early_silurian_redox.pdf - Stratigraphy and shale geochemistry of the Belcher Group, Belcher Islands, southern Nunavut Canada-Nunavut Geosciences Office
Hodgskiss, M.S.W., Sperling, E.A.
2020; Summary of Activities 2019: 65-78
hodgskiss_and_sperling_2020_cngo_belcher_group_shale_geochemistry.pdf - Unraveling the Mineralogical Complexity of Sediment Iron Speciation Using Sequential Extractions Geochemistry, Geophysics, Geosystems
Slotznick, SP, Sperling, EA, Tosca, NJ, Miller, AJ, Clayton, KE, van Helmond, NAGM, Slomp, CP, Swanson-Hysell, NL
2020; 21: e2019GC008666
slotznick_2020_g3_magnetism_of_iron_speciation.pdf - A productivity collapse to end Earth’s Great Oxidation Proceedings of the National Academy of Sciences, USA
Hodgskiss, M.S.W., Crockford, P.W., Peng, Y., Wing, B.A., Horner, T.J.
2019; :
hodgskiss_2019_pnas_productivity_collapse_goe_early_view.pdf - New insights on the Orosirian carbon cycle, early Cyanobacteria, and the assembly of Laurentia from the Paleoproterozoic Belcher Group Earth and Planetary Science Letters
Hodgskiss, M.S.W., Dagnaud, O.M.J., Frost, J.L., Halverson, G.P., Schmitz, M.D., Swanson-Hysell, N.L., Sperling, E.A.
2019; 520: 141-152
hodgskiss_2019_epsl_belchers_13c_and_geochron.pdf - Statistical inference and reproducibility in geobiology Geobiology
Sperling, EA, Tecklenburg, S, Duncan, LE
2019; 17: 261-271
sperling_2019_geobiology_early_view.pdf - Oxygenated Mesoproterozoic lake revealed through magnetic mineralogy Proceedings of the National Academy of Sciences, USA
Slotznick, SP, Swanson-Hysell, NL, Sperling, EA
2018; 115: 12938-12943
- Oxygen, temperature and the deep-marine stenothermal cradle of Ediacaran evolution Proceedings of the Royal Society, Series B
Boag, TH, Stockey, RG, Elder, LE, Hull, PM, Sperling, EA
2018; 285: 20181724
boag_2018_procb_oxygen_temperature_and_ediacaran_biota_final.pdf - Temperature-dependent hypoxia explains biogeography and severity of end-Permian marine mass extinction Science
Penn, JL, Deutsch, CD, Payne, JL, Sperling, EA
2018; 362: eaat1327
penn_2018_science_hypoxia_and_end-permian_extinction.pdf - Demosponge steroid biomarker 26-methylstigmastane provides evidence for Neoproterozoic animals Nature Ecology and Evolution
Zumberge, JA, Love, GD, Cardenas, P., Sperling, EA, Gunasekera, S., Rohrssen, M., Grosjean, E., Grotzinger, JP, Summons, RE
2018; 2: 1709–1714
zumberge_2018_nature_ee_27-mes_biomarker_early_online.pdf - The temporal and environmental context of early animal evolution: Considering all the ingredients of an 'explosion' Integrative and Comparative Biology
Sperling, EA, Stockey, RG
2018; 58: 605-622
sperling_and_stockey_2018_icb_cambrian_explosion_review.pdf - On the edge of exceptional preservation: insights into the role of redox state in Burgess Shale-type taphonomic windows from the Mural Formation, Alberta, Canada Emerging Topics in Life Sciences
Sperling, EA, Balthasar, U, Skovsted, CB
2018; 2: 311-323
sperling_2018_etls_mural_formation_geochemistry_final.pdf - Iron isotope biogeochemistry of Neoproterozoic marine shales Geochimica et Cosmochimica Acta
Kunzmann, M, Gibson, TM, Halverson, GP, Hodgskiss, MSW, Bui, TH, Carozza, DA, Sperling, EA, Poirier, A, Cox, GM, Wing, BA
2017; 209: 85-105
kunzmann_2017_gca_iron_isotopes.pdf - Tracking the onset of Phanerozoic-style redox-sensitive trace metal enrichments: New results from basal Ediacaran post-glacial strata in NW Canada Chemical Geology
Miller, AJ, Strauss, JV, Halverson, GP, Macdonald, FA, Johnston, DT, Sperling, EA
2017; 457: 24-37
miller_2017_sheepbed_geochemistry_corrected_proof.pdf - Biodiversity response to natural gradients of multiple stressors on continental margins Proceedings of the Royal Society, Series B
Sperling, EA., Frieder, CA, Levin, LA
2016; 283: 20160637
sperling_2016_proc_b_biodiversity_on_upwelling_margins_final.pdf - Oxygen, facies, and secular controls on the appearance of Cryogenian and Ediacaran body and trace fossils in the Mackenzie Mountains of northwestern Canada Geological Society of America Bulletin
Sperling, EA, Carbone, C., Strauss, JV, Johnston, DT, Narbonne, GM, Macdonald, FA
2016; 128: 558-575
sperling_2016_gsab_oxygen_facies_time_ediacaran_nw_canada_final.pdf - The ecological physiology of Earth's second oxygen revolution Annual Review of Ecology, Evolution, and Systematics
Sperling, EA, Knoll, AH, Girguis, PR
2015; 46: 215-235
sperling_2015_annual_reviews_earths_second_oxygen_revolution_final.pdf - Statistical analysis of iron geochemical data suggests limited late Proterozoic oxygenation Nature
Sperling, EA, Wolock, CJ, Morgan, AS, Gill, BC, Kunzmann, M, Halverson, GP, Macdonald, FA, Knoll, AH, Johnston, DT
2015; 523: 451-451
sperling_2015_nature_statistical_analysis_of_iron_geochemical_data.pdf - Biotic replacement and mass extinction of the Ediacara biota Proceedings of the Royal Society Series B
Darroch, SAF, Sperling, EA, Boag, TH, Racicot, RA, Mason, SJ, Morgan, AS, Tweedt, S, Myrow, P., Johnston, DT, Erwin, DH, Laflamme, M.
2015; 282: 2015103
darroch_2015_proc_b_extinction_of_ediacaran_biota.pdf - Sedimentology, chemostratigraphy, and stromatolites of lower Paleoproterozoic carbonates, Turee Creek Group, Western Australia Precambrian Research
Martindale, RC, Strauss, JV, Sperling, EA, Johnson, JE, Van Kranendonk, MJ, Flannery, D., French, K., Lepot, K., Mazumder, R, Rice, MS, Schrag, DP, Summons, R, Walter, M, Abelson, J, Knoll, AH
2015; 266: 194-211
martindale_2015_prec_res_turee_creek_group.pdf - Oxygen and animals in Earth history Proceedings of the National Academy of Sciences, USA
Knoll, AH, Sperling, EA
2014; 111: 3907-3908
knoll_and_sperling_2014_pnas_commentary_oxygen_and_animals_final.pdf - Redox heterogeneity of subsurface waters in the Mesoproterozoic ocean Geobiology
Sperling, EA, Rooney, AD, Hays, L, Sergeev, VN, Sergeeva, ND, Selby, D, Johnston, DT, Knoll, AH
2014; 12: 373-386
sperling_et_al_geobiology_2014_final.pdf - Oxygen, ecology, and the Cambrian radiation of animals Proceedings of the National Academy of Sciences, USA
Sperling, EA, Frieder, CA, Raman, AV, Girguis, PR, Levin, LA, Knoll, AH
2013; 110: 13446-13451
sperling_2013_pnas_cambrian_oxygen_and_ecology_final.pdf - Tackling the 99%: Can we begin to understand the paleoecology of the small and soft-bodied animal majority? The Paleontological Society Papers
Sperling, EA
2013; 19: 77-86
sperling_2013_paleo_soc_short_course_the_99_final.pdf - The stratigraphic relationship between the Shuram carbon isotope excursion, the oxygenation of Neoproterozoic oceans, and the first appearance of the Ediacara biota and bilaterian trace fossils in northwestern Canada Chemical Geology
Macdonald, FA, Halverson, GP, Strauss, JV, Sperling, EA, Johnston, DT, Petach, T, Schrag, DP, Narbonne, G, Higgins, JA
2013; 362: 250-272
macdonald_2013_chem_geol_ediacaran_stratigraphy_nw_canada_final.pdf - miRNAs: small genes with big potential in metazoan phylogenetic Molecular Biology and Evolution
Tarver, JE, Sperling, EA, Nailor, A, Heimberg, AM, Robinson, JM, King, BL, Pisani, D, Donoghue, PCJ, Peterson, KJ
2013; 30: 2369-2382
tarver_2013_mbe_micrornas_in_metazoan_phylogeny_final.pdf - A basin redox transect at the dawn of animal life Earth and Planetary Science Letters
Sperling, EA, Halverson, GP, Knoll, AH, Macdonald, FA, Johnston, DT
2013; 371-372: 143-155
sperling_2013_epsl_basin_redox_transect_final.pdf - Paleoredox and pyritization of soft-bodied fossils in the Ordovician Frankfort Shale of New York American Journal of Science
Farrell, UC, Briggs, DEG, Hammerlund, EU, Sperling, EA, Gaines, RR
2013; 313: 452-489
farrell_2013_ajs_beechers_bed_geochemistry_final.pdf - The identification of microRNAs in calcisponges: Independent evolution of microRNAs in basal metazoans Journal of Experimental Biology Part B: Molecular and Developmental Evolution
Robinson, JM, Sperling, EA, Bergum, B, Adamski, M, Nichols, SA, Adamska, M, Peterson, KJ
2013; 320: 84-93
robinson_2013_jezb_micrornas_in_calcarea_and_homoscleromorpha_final.pdf - Reconstruction of Family-level phylogenetic relationships within Demospongiae (Porifera) using nuclear encoded housekeeping genes PloS One
Hill, MS, and 31 authors (including Sperling, EA)
2013; 8: e50437
hill_2013_plosone_demosponge_phylogeny_with_multiple_nuclear_housekeeping_genes.pdf - The complete mitochondrial genome of the verongid demosponge Aplysina cauliformis: implications for DNA barcoding in demosponges Hydrobiologia
Sperling, EA, Rosengarten, RD, Moreno, MA, Dellaporta, SL
2012; 687: 61-69
sperling_2012_hydrobiologia_aplysina_mt_genome_final.pdf - Early Neoproterozoic basin formation in Yukon, Canada: Implications for the make-up and break-up of Rodinia Geoscience Canada
Macdonald, FA, Halverson, GP, Strauss, JV, Smith, EF, Cox, G, Sperling, EA, Roots, CF
2012; 39: 77-99
macdonald_2012_geosci_canada_fifteenmile_group_stratigraphy_final.pdf - MicroRNAs support a turtle + lizard clade Biology Letters
Lyson, TR, Sperling, EA, Gauthier, JA, Heimberg, AM, King, BL, Peterson, KJ
2012; 8: 104-107
lyson_2012_biology_letters_turtle_micrornas_final.pdf - A molecular paleobiological hypothesis for the origin of aplacophoran mollusks and their derivation from chiton-like ancestors Proceedings of the Royal Society Series B
Vinther, J, Sperling, EA, Briggs, DEG, Peterson, KJ
2012; 279: 1259-1268
vinther_2012_proc_b_molluscs_final.pdf - The Cambrian conundrum: Early divergence and later ecological success in the early history of animals Science
Erwin, DH, Laflamme, M, Tweedt, SM, Sperling, EA, Pisani, D, Peterson, KJ
2011; 334: 1091-1097
erwin_2011_science_cambrian_conundrum.pdf - Molecular paleobiological insights into the origin of the Brachiopoda Evolution and Development
Sperling, EA, Pisani, D, Peterson, KJ
2011; 13: 290-303
sperling_2011_evolution_and_development_brachiopod_molecular_paleobiology.pdf - Rangeomorphs, Thectardis (Porifera?) and dissolved organic carbon in the Ediacaran ocean Geobiology
Sperling, EA, Laflamme, M, Peterson, KJ
2011; 9: 24-33
sperling_2011_geobiology_rangeomorphs_thectardis_and_doc_final.pdf - A placozoan affinity for Dickinsonia and the late Precambrian evolution of metazoan feeding modes Evolution and Development
Sperling, EA, Vinther, J
2010; 12: 201-209
sperling_and_vinther_2010_evo_devo_dickinsonia_placozoa_final_published.pdf - Where's the glass? Biomarkers, molecular clocks and microRNAs indicate a near 200-million year missing fossil record of siliceous spicules Geobiology
Sperling, EA, Robinson, J, Pisani, D, Peterson, KJ
2010; 8: 24-36
sperling_2010_geobiology_biomarkers_molecular_clocks_micrornas_final.pdf - Phylogenetic-signal dissection of nuclear housekeeping genes supports the paraphyly of Porifera and the monophyly of Eumetazoa Molecular Biology and Evolution
Sperling, EA, Peterson, KJ, Pisani, D
2009; 26: 2261-2274
sperling_2009_mbe_sponge_and_eumetazoan_phylogeny_final.pdf - MicroRNAs resolve an apparent conflict between annelid systematics and their fossil record Proceedings of the Royal Society Series B
Sperling, EA, Vinther, J, Moy, VM, Wheeler, BM, Semon, M, Briggs, DEG, Peterson, KJ
2009; 276: 4315-4322
sperling_2009_proc_b_annelid_micrornas.pdf - The deep evolution of metazoan microRNAs Evolution and Development
Wheeler, BM, Heimberg, AM, Moy, VM, Sperling, EA, Holstein, TW, Heber, S, Peterson, KJ
2009; 11: 51-69
24_wheeler_2009_evo_devo_deep_evolution_of_micrornas_final.pdf - The mitochondrial genome of the hexactinellid sponge Aphrocallistes vastus: evidence for programmed translational frameshifting BMC Genomics
Rosengarten, RD, Sperling, EA, Moreno, MA, Leys, SP, Dellaporta, SL
2008; 9: 33
22_rosengarten_2008_bmc_genomics_mitochondrial_genome_of_aphrocallistes.pdf - Poriferan paraphyly and its implications for Precambrian paleobiology Geological Society, London, Special Publications
Sperling, EA, Pisani, D., Peterson, KJ
2007; 286: 355-368
sperling_2007_geol_soc_poriferan_paraphyly.pdf - Poriferan ANTP genes: primitively simple or secondarily reduced? Evolution and Development
Peterson, KJ, Sperling, EA
2007; 9: 405-408
peterson_and_sperling_2007_evo_devo_poriferan_antp_genes.pdf - The Permian-Triassic boundary at Quinn River Crossing, Northwestern Nevada and implications for the cause of the Early Triassic chert gap on the western Pangean margin Geological Society of America Bulletin
Sperling, EA, Ingle, JC, Jr.
2006; 118: 733-746
sperling_and_ingle_gsa_bulletin_2006.pdf