Possible Fossil Wood Residues in the Tissint Meteorite: A Morphological and Chemical Rebuttal

The Tissint meteorite has long been described as purely igneous, with its carbon content explained by abiotic synthesis alone. However, new high-resolution images reveal polygonal, cell-like features that closely resemble fossil wood cells. Combined with the discovery of abundant aromatic carbon species that match the thermal breakdown products of cellulose and lignin, this evidence suggests that fossil wood residues may be preserved in Tissint’s shocked interior.

Main Text

One of the key arguments against biological interpretations of the Tissint meteorite’s cell-like structures is the absence of direct chemical evidence for fossilized plant polymers such as cellulose, hemicellulose, or lignin. However, a closer look at the meteorite’s carbon chemistry suggests that this absence may not be definitive.

It is well established that cellulose and hemicellulose, both polysaccharides, and lignin, a complex phenolic polymer, break down under high-temperature conditions typical of volcanic or impact processes. When exposed to temperatures above 300–400 °C, these biopolymers decompose into small, stable organic compounds — including short-chain aliphatic hydrocarbons, simple oxygenated fragments, and aromatic units such as polycyclic aromatic hydrocarbons (PAHs) and phenolic derivatives.

The Science Advances study on Tissint reports an abundance of precisely these types of carbon species: diverse aromatic and aliphatic hydrocarbons embedded in olivine macrocrystals and melt veins; complex organomagnesium compounds formed where carbon interacted with magnesium silicates at high temperatures; and PAHs that match known products of lignin pyrolysis.

Although such compounds can certainly form abiogenically — through Fischer–Tropsch synthesis, magmatic degassing, or impact shock chemistry — they are also exactly the decomposition products expected from fossil wood subjected to partial melting and shock. Thus, their presence does not exclude the possibility that some portion of Tissint’s organic carbon originated from preexisting biogenic plant material, now reduced to simpler molecules that survived Mars’ low-temperature, low-oxygen environment.

Critically, the cell-like polygonal structures in the same zones where these organics are concentrated strengthen the link between morphological evidence and possible degraded chemical residues. If these shapes truly represent fossil wood cells, then it is logical that the only remaining chemical signature would be small, heat-resistant aromatic clusters — not intact biopolymers that would have vaporized under magmatic or impact temperatures.

To resolve this question, future analyses should focus on targeted searches for diagnostic lignin-derived marker compounds (e.g., syringyl, guaiacyl units), detailed isotopic signatures, and nano-scale mapping of organic inclusions within the “cell-like” zones. Until then, the presence of abundant aromatic carbon in close association with organized cell-like morphologies remains an intriguing line of evidence that warrants serious consideration — and careful, unbiased testing.

Conclusion

These overlooked clues may help rewrite what we know about life on Mars.