Wood Cells Fossilized into "Leopard Spots" on Mars.

Last edited on Sept. 15, 2025
Original figure: www.nature.com/articles/s41586-025-09413-0/figures/3
(Note: I used Zeke filter to enhance the colors. I enlarged the original photo by 800%.)

Original article: www.nature.com/articles/s41586-025-09413-0
Original caption: a, WATSON nighttime image of Cheyava Falls with both white-light LED groups on acquired on sol 1188 at a stand-off distance of 3.91 cm. Image resolution: 21.0 ± 0.4 µm per pixel. b, Colourized SHERLOC ACI image acquired on sols 1201–1202 outlined with a white box and overlain on the WATSON image from a. The ACI image is a focus merge of 13 ACI images acquired between stand-off distances of 4.035 cm and 4.335 cm and has an image resolution of about 10 µm per pixel. Three 1 × 1 mm SHERLOC spectral scans were acquired at the orange square location at stand-off distances of 4.01 cm, 4.035 cm and 4.06 cm. One 1 × 1 mm spectral scan was acquired at the blue square location at a stand-off distance of 4.035 cm. The black dotted rectangle shows the footprint of the PIXL scan acquired from this target. The magenta cross at the corner of the scan provides a reference point for comparison with c, which is the colourized SHERLOC ACI image from b. The image shows the authigenic nodule and reaction front features as well as the SHERLOC and PIXL scan locations. d, SHERLOC Raman spectra from representative targets in the Bright Angel unit with fits to an instrument –O-stretching overtone feature from the SHERLOC fused-silica optics (light grey, labelled ‘Bknd’) and the G-band signal at about 1,600 cm−1 associated with organic carbon in the targets Walhalla Glades (blue), Cheyava Falls (red) and Apollo Temple (green fit on grey spectrum). Malgosa Crest (yellow) shows no G-band signal above the instrument background. Scale bars, 5 mm. Credit: NASA/JPL-Caltech/MSSS.

In the subject figure, blue arrows point to rectangular/circular walls of fossilized (permineralized) wood cells in the transverse sections.
The arrowed cells are the "leopard spots"/"nodules" mentioned in the original Nature article.
The arrowed cells possess dark centers, which were originally the lumens of the wood cells.
The lumens are now filled with sediments.
The arrowed wood cells are 200 to 330 microns across.
According to the original Nature article, the "permineralized cell walls" likely contain vivianite and the "permineralized lumens" likely contain greigite.
Scale bars are all 5 mm.
Location of the place: see Figure 1 in the original article.

ChatGPT 5 advised me to state the following:
"The figure shows abundant nodules interpreted by the Perseverance team as Fe–P/Fe–S diagenetic features (‘leopard spots’). Here, we alternatively interpret many of these structures as fossilized wood-cell remains, based on their size, morphology, and repeating arrangement.”"

Added on Sept. 15: Wood cell remains co-exist with vivianite:
www.flickr.com/photos/fossil_lin/54786897350/in/dateposte...

Added on Sept. 15, 2025: ChatGPT 4o wrote two articles on the subject figure:
wretchfossil.blogspot.com/2025/09/leopard-spots-on-mars-a...
wretchfossil.blogspot.com/2025/09/evidence-for-fossilized...

Added on Sept. 14, 2025: More wood cell remains in Martian "leopard spots":
wretchfossil.blogspot.com/2025/09/wood-cell-like-microstr...

My albums: www.flickr.com/photos/fossil_lin/albums/
My articles: www.researchgate.net/profile/Liangtai-Lin/research
My website: wretchfossil.blogspot.com/

Taken on: September 11, 2025

Sets appears in: • Wood Cells from Mars

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