engleski

New discovered dinosaur tracksite in the Late Albian of Istria.

Deposits of the mid-Cretaceous period of Istrian peninsula bear the most abundant record of the dinosaur presence on the Adriatic-Dinaridic carbonate platform. There are many sites with the dinosaur footprints which were found in the sediments that crop out along the shore within the mid-Cretaceous sediments of the so-called West Istrian anticline. The most numerous localities are situated near the town of Pula and Novigrad. The new site was discovered near the city of Novigrad, at the Mareda locality. Regarding the geological map of the area (PLENIČAR et al., 1965) the age of the trackbearing sediment is Late Albian. The outcrop is situated at the sea shore and during the high tide it is partially covered with the sea water. The trackbearing layer is quite eroded due to the seawater abrasion. The Upper Albian carbonate succession at Mareda locality is similar to other Upper Albian localities in Istria. It is characterized by thin bedded limestones deposited in peritidal and foreshore environments with several shallowing-upward sequences. A dozen of rather shallow footprints have been recognized on the site. The discovered footprints are tridactyl, mesaxonic, longer than wide, with slender digits (Fig.). Their state of preservation is far from ideal regarding constant exposure to the seawater. The average length of the footprints is 25 cm and their width 16 cm. On all of the footprints the middle digit is the largest one while the outer two are of similar dimensions and diverging from the print axis. The digits are widest in their middle part and become narrower proximodistally. Sharply curved claw marks are visible on some of the digits. Around some footprints there is a clearly pronounced expulsion rim which resulted from the placing of the foot in the wet mud. We interpret the footprints as true tracks rather than undertracks although they are relatively shallow when compared to its average size. There are no clearly recognizable trackways at the outcrop although there are some series of eroded prints which could hint at such possibility. On the basis of the claw marks or pointed distal end of digital prints, relatively slender digit impressions and generally longer than wide prints, we conclude that these footprints belongs to a medium-sized bipedal theropod dinosaurs. The Late Albian dinosaur ichnocoenosis from Istria is constituted of mainly theropod but also sauropod and ornithopod footprints found at different localities (MEZGA, 2010). When compared to the other Late Albian theropod footprints in Istria the footprints from Mareda locality most closely resemble to the footprints found in the nearby Solaris (DALLA VECCHIA et al., 2000) and Ploče tracksites (MEZGA & BAJRAKTAREVIĆ, 2004) due to its similarity in dimensions and morphology.

Dinosaur Footprints, Theropods, Late Albian, Istria

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