26-1 TRACE FOSSILS FROM MARS (NASA CURIOSITY ROVER IMAGERY): EVIDENCE OF PAST MACROSCOPIC LIFE ON ANOTHER PLANET

Session: Interdisciplinary Paleontology: New approaches to solving complex paleontological problems (Posters)

Poster Booth No.: 29

Presenting Author:

Stephen Hasiotis

Authors:

Hasiotis, Stephen T.¹, Bown, Thomas M.², Nichols, Kimberly A.³, Brake, Sandra S.⁴, Magnin, Benjamin Patrick⁵, Johnson, Gary D⁶

(1) Geology, University of Kansas, Lawrence, KS, USA, (2) Anthropology and Geography, Colorado State University, Fort Collins, CO, USA, (3) Anthropology and Geography, Colorado State University, Fort Collins, CO, USA, (4) Earth and Environmental Systems, Indiana State University, Terre Haute, IN, USA, (5) French Geological Survey (BRGM), Orleans, Centre-Val de Loire, France, (6) Earth Sciences, Dartmouth College, Hanover, NH, USA,

Abstract:

The search for extant and past life on Mars has increased at a feverish pace in the last half-century since the inconclusive results from experiments conducted by two Viking landers in 1976. Recently, NASA announced discovery of potential biosignatures of microbial life from probable lakebed deposits in Jezero Crater by Perseverance Rover. Here, we document numerous examples of macroscopic, three-dimensional (3D) structures in probable fluvio-lacustrine deposits of Gale Crater captured in imagery by Mars Curiosity Rover. If encountered in rock outcrops on Earth, these structures would unquestionably be considered trace fossils (i.e., ichnofossils), much like those produced by unicellular and multicellular organisms on Earth.

            Trace fossils are biogenic structures (e.g., burrows, nests, trackways, root patterns, biolaminates) that document behavior of past life. They are produced by organisms’ interactions with sediment, rock, or other organisms that are preserved in the geologic record. Whereas an organism can leave only a partial or complete body fossil, it can produce numerous traces that can be identified and defined by their 3D morphology. In contrast, the life activity of microorganisms is commonly identified and defined by chemical signatures. Trace fossils are proxies for past life, serving as ‘hidden’ biodiversity because the organism itself is not preserved. Macroscopic traces, therefore, should be sought in planetary imagery by astrobiologists because they are visual verifications of past life that do not require chemical analyses of samples returned to Earth to assess their validity as evidence of past life.

            Earthlike Martian traces include cm-scale, isolated, interpenetrating, vertical to inclined to horizontally oriented, commonly tubular to crescent-shaped structures; mm- to cm-scale rectilinear and dendritic forms; cm-scale matlike, crinkled features; and cm-scale circular redoximorphic features. Several different morphologies are observed in this study; some are abundant and most are preferentially cemented with respect to the country rock, weathered out in bas-relief by wind deflation. The Martian traces are compared with trace fossil morphotypes in upper Eocene–lower Oligocene deposits of the Fayum Depression in Egypt (where eolian weathering also dominates) and Plio–Quaternary lacustrine deposits in Kenya.

            These structures appear to be the first definitive evidence of extraterrestrial life, past or present. Future work should target Earthlike Martian trace fossils for biomolecular analyses that would further corroborate evidence for the existence of past life on Mars.

Geological Society of America Abstracts with Program. Vol. 58, No. 4, 2026

doi: 10.1130/abs/2026RM-14216

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