The Curiosity Rover started this year with some remarkable images of small tube-like structures on Mars. The Mahli (Mars Hand Lens Imager) camera acquired the images on Sol 1922 and 1923 (January 01 and 02 2018). The structures are only 1 to 5 mm long and first spotted December 15 2017. To investigate further the rover later returned to the site.
The possibility of trace fossils were soon put on the table. The origin of these odd features is a question that may not be answered with the technology we have on Mars today. However, most experts is leaning towards a geological process, which is probably a safe bet.
I have made several 3D models from the Curiosity images lately, and gave this one a shot. And I am quite happy with the result.
I used 11 images acquired on Sol 1923 for the model with no pre-processing. The 11 images were loaded into a professional photogrammetry software to generate the point cloud. After that all images were used to generate the texture for the 3d model.