Possible Macro-Fossil fragments?

When i "scanned" the HiRISE data from yesterdays releases, I stumbled across an interesting structure in a gully of a crater slope. With an article, I read recently, in mind about the possibilities of detecting fossil signatures on Mars i added the following crop image to my collection:

This crop from the HiRISE data of a Mars southern highlands crater shows something appearing like macro fossil fragments - scattered about 50 m across. Maybe this features got washed free by liquids when the gully been carved. The area visible is about 120 m across. The fragments show some similarity in appearance and are aligned as expected for larger fossils on earth (if well preserved). I also seen a single fragment perfectly just like this fragments in the Ritchey Crater HiRISE data

quotation of the related article

"Along with caves, Boston said some top-notch nooks and crannies on Earth to look for fossils are in things with vertical relief that slices down through layers, like canyon walls, fault escarpments, and river/stream outflow channels. For Mars and other crater-rich environments, obviously crater walls where things are excavated down to some deeper strata are first-rate sites.

"The best thing about these places is that large -- as in macroscopic -- buried fossilized material is usually weathering out of the outcrops. One can see them laying about and follow the fragments to the source," Boston said. "

If considering large macro fossils(thus former large life forms)on Mars slightly possible, may the above image be an example of Bostons assumptions or just a normal geological feature in Mars gullies and ridges?
What else should macro fossils look like from the viewpoint of HIRISE, if there actualy are some visible in exposed spots?

HiRISE coverage this article refers to:
Gullies on Pole-Facing Slope and Arcuate Ridges on Crater Floor

Here is another suggestion from me:
I recently realised a strange similarity of earth columnar stromatolites like this:

and repeative patterns found on Mawrth Vallis surfaces like this example:

..especialy the upper part of the zoom inset.

I realy would like to see rovers taking in-situ images and samples of this kind of surface - maybe we will find a nice (martian) surprise here

Sources tell Spaceflight Now that the more detailed data on magnetite crystals and carbonate discs now available largely counter a wide range of opposing theories as to why the finding should not be supported as biological in origin.

Now, 13 years after the Martian meteorite life story emerged, the science team finally feels vindicated. Their data shows the meteorite is no smoking gun but is full of evidence that supports the existence of life on the surface of Mars, or in subsurface water pools, early in the planet's history.

The new data are expected to be addressed publicly within days by NASA Headquarters in Washington, where they could become part of the political debate on future NASA mission directions.

and from same page:

Although led by a Johnson Space Center team, the additional evidence for Martian life in the Allen Hills meteorite has been an open topic for the last several weeks in astrobiology division halls at the NASA Ames Research Center near San Francisco and at the Jet Propulsion Laboratory, Pasadena. It's hot news.

The new work centers on so-called magnetic bacteria that on Earth, and apparently Mars as well, leave distinctively-shaped remnants in the rock. In addition the features test with a high chemical purity more like a biological feature than geological.

These are just like the magnetite-related life forms found in the meteorite believed to represent Martian life forms, says Dr. Dennis Bazylinski, who peer reviewed the new findings. He also studies such Earth life forms in his laboratory at the University of Nevada at Las Vegas.

Joe in Texas