Friday, 18 April 2014

Tracks, tracks...everywhere

The tridactyl dinosaur footprints are omnipresent in the Cretaceous laminated sediments of Kamenjak. The problem is: they are not that easy to spot. Nor they are easy to define, because they are in a different state of preservation left on a varying substrate. Imagine a mud flat. The tide has just receded. The first dinosaurs to cross the mud will leave deep, often collapsing tracks. As the mud dries, the next tracks will be less and less visible. Dinosaurs step over the tracks left by the other dinosaurs (or themselves) earlier, making them deformed. The waves start to wash the shore. Some of the dried tracks will be erased, some will remain and get covered with the sand and mud. The trackways are often messy.
Here is an example of a dinoturbation with various types of tracks. I tried to interpret some of the tracks with the red outline. It seems that at least three kinds of theropods left their footprints. Of course, I couldn't see all the prints. It's hard to notice them and take photographs with a digital camera on a bright sunny day with almost white rocks reflecting light from all sides.

A close-up with somewhat different interpretation of the tracks in the middle of the outcrop (below).
The footprint is about 45 to 48 cm long. If my interpretation is correct, that transfers into a 6-7 meters long predatory dinosaur. You wouldn't want to meet such a beast! The other theropod was obviously much smaller.

A photograph of the Kamenjak's carbonate rocks below. These rocks are hiding hundreds if not thousands of Cretaceous tetrapod tracks for those with enough time, patience, determination and most important a good eye to discover and describe them.

A look back at the Porer islet with the lighthouse which is behind us now. We are walking towards the tip of the cape.

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