Ichnofossils, Cracks or Crystals? A Test for Biogenicity of Stick-Like Structures from Vera Rubin Ridge, Mars

Baucon, Andrea; Carvalho, Carlos Neto de; Felletti, Fabrizio; Cabella, Roberto

doi:10.3390/geosciences10020039

Cited by 8 publications

(5 citation statements)

References 59 publications

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“…Numerous cocoon-eggs photographed on Sol 1032 are also embedded in substrate that appears to consist entirely of a coral-microbialite-like mass of coiled and worm-like forms (Figures 3,8,11,13,28,(30)(31)(32) whereas smooth and segmented tubular specimens have been photographed in this and other Gale Crater locations on Sols 130, 132, 302, 551, 553, 808, 809, 868, 906, 1280, 1921, as reported here and in other reports [1][2][3][4][5]; including specimens that appear to have multiple appendages and resemble insecta (Arthropoda) [6][7] whereas others are similar to ovoid-shaped lichenizedfungi topped with a single hole and which may be sporing. Moreover, some of the specimens resemble dead or fossilized puffballs with stems attached.…”

Section: Research Articlementioning

confidence: 72%

“…In other previous reports elongated tubular specimens photographed in Gale Crater have been interpreted as ichnofossils of burrowing worms [1,[3][4][5]. This interpretation was subsequently rejected by a NASA-controlled journal [21] which also failed to review or acknowledge the comparative statistical and quantitative morphological evidence that favors a biological interpretation [3][4][5]22].…”

Section: Discussionmentioning

confidence: 99%

“…(7) Given these limiting parameters, periodic catastrophic conditions, lack of evidence that vertebrates evolved, it is possible that current and past life on Mars might be limited to bacteria, algae, fungus, lichens and other simple eukaryotes, including metazoan invertebrates as previously reported [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] and as exemplified by the putative worms and insecta presented in this and other reports.…”

Section: Research Articlementioning

confidence: 99%

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Cocoons, Fungi, Nematodes, Rhizoids, Annelids, Eggs, Arthropoda in Gale Crater, Mars?

Joseph¹,

Wickramasinghe²,

Armstrong³

et al. 2023

Appl Cell Biol

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White and dark gray oblong-ovoid cocoon-egg-like forms (“cocoon-eggs”), less than a mm in diameter, many with a single hole in one end, and some with unidentifiable specimens protruding from (exiting or entering) these holes, were photographed on mudstone in Gale Crater, Mars, on Sol 1302. If biological some of these cocoon-eggs may be frozen, fossilized or have already “hatched” or undergone metamorphosis. Specimens resembling segmented and tubular worms and rhizoids and those with multiple appendages (Arthropoda) were also photographed on these and other substrates on Mars, including on Sols 130, 132, 302, 551, 553, 808, 809, 868, 906, 1280, 1921, in Gale Crater. Many Sol 1302 “cocoon-eggs” are embedded in substrate that appears to consist entirely of a coral-stromatolite-like mass of worm- and larvae-like forms; and similar worm and segmented larvae forms appear in the interior of three semi-transparent ovoid structures. Embedded in the soil surrounding these “cocoon-eggs” are numerous concave patches reminiscent of dried “egg-yolk,” cocoon remnants or fungus, and that may represent the final stage of “cocoon” collapse and disintegration; or they are fungal in origin. Some of the segmented and tubular worm-like forms may include rhizoids and tubular fungi. Ovoids with open apertures may be evidence of fungal sporing. The possibility that fungus and diverse species and their “cocoons” share the same substrate is supported by what appears to be cyanobacteria, worms, insecta (arthropoda), and stalks topped by ovoids or ovoid-shaped microbialite-like sediment. Fungi, lichens, cyanobacteria, stromatolites and arthropoda have been previously reported in other areas of Gale Crater, whereas fungal “puffballs” and specimens attached to rocks with stalks and topped with mushroom-like caps have been observed in Meridiani Planum. The possibility these specimens are abiogenic cannot be ruled out. The evidence, in our view, arguably supports the hypotheses that various organisms colonized Mars in the ancient or recent past.

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Section: Research Articlementioning

confidence: 72%

Section: Discussionmentioning

confidence: 99%

Section: Research Articlementioning

confidence: 99%

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Cocoons, Fungi, Nematodes, Rhizoids, Annelids, Eggs, Arthropoda in Gale Crater, Mars?

Joseph¹,

Wickramasinghe²,

Armstrong³

et al. 2023

Appl Cell Biol

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“…But the morphological analogy with terrestrial fossil traces of life-substrate interactions is impressive [41]. Some studies even highlight occurrence, on Martian sediments, of widespread structures like the famous microspherules discovered by the Rovers Spirit and Opportunity, often organized into some higher-order settings (Figure 22).…”

Section: Curiosity and Sam Resultsmentioning

confidence: 99%

New Insights into the Search for Life on Mars

Guaita¹

2021

Solar System Planets and Exoplanets

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The discovery by the Lander Phoenix (summer 2008) that the Mars polar soil is rich of perchloric acid salts (Na, Mg, Ca perchlorate) strongly could change the interpretation of the Martian experiment of 14CO2 release (LR, Labeled release experiment), performed in 70’s by both Viking Landers. The LR experiment gave substantially positive results but, at that time, possibility of Martian bacteria was ruled out because the CGMS instruments on board of both Vikings didn’t detect any trace of complex organic molecules. But Martian organics exist and were found in fair quantities by Curiosity, landed inside the Gale crater on 2012. So it is likely that Viking CGMS, working at about 500°C, could not see any organic substances (natural or bacterial) because, at that temperature, perchlorates decompose, releasing Oxygen that destroyed organics BEFORE their detection. In any case, the discovery of keragenic compounds by Curiosity, could also be indication of a presence of archea bacteria in the distant past of Mars, when the atmosphere of the Red Planet was wetter and denser than now.

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“…The Lobodiscus holotype ( Figure 2 ) can be interpreted as a macroorganismal fossil based on standard biogenicity criteria, including shape, degree of morphological differentiation, biologically plausible size range, and topological correspondence to well-established biogenic counterparts. 48 , 49 The degree of morphological differentiation of Lobodiscus , which shows at least two orders of bifurcating surface ridges, regularly spaced branches, and a potential apical pit in addition to well-defined lobes, contrasts with that of simpler radially symmetric sedimentary concretions erroneously interpreted as macrofossils. 50 Lobate discs with undulate outer edges may occur in pyrite concretions forming in fluid mixtures with different viscosities, 51 but the preservation of the specimen as siltstone is at odds with the physical and mineralogical demands of this process.…”

Section: Discussionmentioning

confidence: 99%