Certain phosphatic grains preserved in the rock record are interpreted as microfossils representing a diversity of microorganisms from bacteria to fossil embryos. In addition to bona fide primary biological features, phosphatic microfossils and fossil embryos commonly exhibit features that result from abiotic precipitation or diagenetic alteration. Distinguishing between abiotic and primary biological features can be difficult, and some features thought to represent biological tissue could instead be artifacts that are unrelated to the original morphology of a preserved organism. Here, we present experimentally generated, abiotically produced mineral precipitates that morphologically resemble biologically produced features, some of which may be observed in the rock record or noted in extant organisms, including embryos. These findings extend the diversity of biomorphic features known to result from abiotic precipitation.
Bibliographical noteFunding Information:
Portions of this work were supported by National Science Foundation grant #EAR-1057119 to JVB, and by funding from the University of Minnesota-Twin Cities Graduate Program and Department of Earth Sciences to CHC. SEM imaging and analysis were performed at LacCore, Department of Earth Sciences, University of Minnesota-Twin Cities, supported by NSF grant #NSF-IF-1462297. Additional SEM analysis was carried out in the Characterization Facility at the University of Minnesota, which receives partial support from NSF through the MRSEC program. The assistance of Beverly Flood, Elizabeth Ricci, Beverly Chiu, Erica Sheline, Peter Schroedl, Nick Seaton and manuscript reviewers and editors is gratefully acknowledged.