More on Pula ankylosaurs

I have discovered the second site containing ankylosaur tracks (dinoturbation) near Pula about a year after the first one, which is about a kilometre away. It is interesting, but this time I thought I was looking at the single theropod footprint. Yet, it didn't seem right. It didn't look like a typical theropod footprint. Nearby was the second impression, only convex (infilling). The pace angle was too wide for a theropod. I have also noticed there were in fact 5 toe impressions. The print was obviously left by a quadrupedal animal: a large ankylosaur. Later, I have discovered more foot impressions of the same animal, or the animal of the same size.

The red outline of the best preserved impressions in the ankylosaur trackway.

Another foot impression ( right hind foot - pes) of the large Sauropelta-like dinosaur on the same outcrop. This one is not part of the trackway above (red outline is my interpretation).

Click to enlarge.

The new ankylosaur tracks discovery

When I took this photograph back in 2009 it didn't tell me much. It just looked like it might have been some unidentified dinosaur trackway. Or not. My first suspect was a sauropod, of course. This morning I was browsing through my files looking for some photographs for the text I intended publishing and something caught my eye in this image. Some of the "footprints" actually looked like if they had toes. The toes were arranged pretty much in the order like in the ankylosaur feet (Sauropelta-like): I quickly added up the simple math and it dawned to me that this little dinoturbation is in fact the part of the large ankylosaur dinoturbation for which I thought had ended a few meters away.
In my red outline you can see my interpretation of some of the tracks. Yes, these ankylosaurs were gregarious and they congregated in three size-classes. There were also some medium-sized (maybe dromaeosaur-like) and some huge theropods around.

LM = left manus; LP = left pes; RP = right pes (click image to enlarge)

Giant ankylosaurs

  Here are the pes footprints of the two giant ankylosaurs (not to scale) with my interpretations on the right:

Pula Albian (mid-Cretaceous) ankylosaur right pes lenght: 85-95 cm (A, B) - I am standing on it's toe #5 of it's four pes toes;

Tumbler Ridge (Canada) late Cretaceous anky has a scale of 10 cm for size comparison (about 44 cm total pes length) (E, F) Photo credit: Rich McCrea. 

 I know it sounds unbelievable, but the Pula ankylosaur, as derived from the size of the largest pes footprints (there are at least 6 of the foot impressions at the Pula site) must have measured some 14-16 meters in length (!)  In a way it wasn't that surprising to me, since all of the super mega fauna members from Pula site were world record holders. Check out my title banner: these are the ultra dinosaurs from Pula in scale (!) They were gregarious, as it seems from the fossil record. Maybe comprising of small family groups. A pair or more adult dinosaurs guarding and taking care of their offspring.
It is interesting that some members of  Thyreophora - a subgroup of the ornithischian dinosaurs
which include well-known suborders Ankylosauria and Stegosauria, had diverse number of toes.
While some of the ankylosaur ichnogenera had three, the others had four toes on their hind feet.
Thus it is possible to miss identify the thyreophoran three-toed pes tracks for iguanodontoid ones and vice versa, especially if the front feet impressions are missing or are poorly preserved. Despite of the enormous record size of the Pula, Istrian tracks it is less likely that these were artifacts.

The Tumbler Ridge site

Ankylosaur tracks

 From 2010-2012 I have also discovered a few ankylosaur tracks near Pula. There were even possible baby ankylosaur prints. However, the most impressive are the giant pes footprints measuring some 75 cm in length. In the pictures below are a couple of nicely preserved ones, left by somewhat smaller individuals. However they were still large by any standards. Compare the tips of my shoes for size. The ankylosaur was probably similar to Polacanthus or Sauropelta. The upper images apparently represent the right pes, while the lower ones feature the left pes.

Compare to some of the footprints from Tumbler Ridge. See the Anky trackway
More tracks.

Nodosaur and possibly Rhabdodon finds in Quarry Stranice near Slovenske Konjice (repost from BDW 2005)

   

Mesozoic Mosaic pg #5

Illustration: Sauropelta - by Beri (graphite), Copyright © 2004-2005 Berislav Krzic

 

Mesozoic Mosaic pg #5
Photograph of Struthiosaurus austriacus (Bunzel 1870) fossil on display in Natural History Museum in Vienna Site: Muthmannsdorf near Wiener Neustadt, Austria Struthiosaurus might look like a cross between Edmontonia and Sauropelta, says Kenneth Carpenter, Ph.D. Struthiosaurus References s: (update 2014) Sympatry of two ankylosaurs (Hungarosaurus and cf. Struthiosaurus) in the Santonian of Hungary
Nodosaur and possibly Rhabdodon finds in Quarry Stranice near Slovenske Konjice   In the sediments of Quarry Stranice (kamnoloma Stranice) near SlovenskeKonjice (Campanian; gosauski razvoj) in north-east Slovenia, fossils of single and colonial corals were found. In addition to the corals, bivalves, fragments of sponges, snail shells, ostracodes, briozoa, algae and foraminifera were also found. On the west side of the site, near Lipa, fragments of fish teeth, a crocodylian tooth and the long bones of dinosaurs were discovered. These fossils were first found in 1999 by Franc Pajtler, and researched by Dr. Irena Debeljak. Dr. Debeljak (ZRC SAZU) thought the bones possibly belonged to a medium-sized quadrupedal plant-eating nodosaur, which was a member of the family Ankylosauria. This is the second discovery of dinosaurs in Slovenia. The first one, near Kozina, was in an area that was separated from Quarry Stranice in the Upper Cretaceous by the sea, precluding a comparison of the fauna from the two sites. The fossils of dinosaurs, crocodylians, turtles and freshwater fish indicate a rich vertebrate fauna at that time. The nearest site to Stranice with nodosaur remains is in the vicinity of Vienna (Muthmannsdorf -Wienerneustadt, Avstria). The locality of Quarry Stranice (kamnoloma Stranice) near Slovenske Konjice thus becomes an important palaeontological find. The fossils are on display in the Natural History Museum in Ljubljana: http://www2.pms-lj.si/oddelki/paleontologija/stranice.html English translation: Berislav Krzic Edited by: Brian Franczak Note (Feb/2014): as to my knowledge, up to this day, no further research has been conducted regarding the Quarry Stranice fossil finds.   .