Theropods of Pula

 

Theropods were everywhere

From the Pula mega track site. Early Cretaceous (Late Albian)

I can see a left pes print of a big theropod. Note the middle toe (#3) curving slightly towards the right (the mid-line).

A question: Are these theropod or ornithopod tracks?

I am still not sure if these EK tracks from the mega track site are theropod or ornithopod tracks?

I am inclined towards the theropod ones. Judging from the shape and size of their footprints theropods were the most diverse dinosaurs at the site.



A reminder for my book:

Tracks, tracks again

A mid-Cretaceous layer from the Solaris outcrop, with mud cracks and a possible dinosaur track. The ripple marks on a lower layer. I was standing on the rock that was about 80 cm above the layer with the mud cracks.

A possible sauropod track with my interpretative outline (Albian near Pula)

 A probable sauropod track

A pebbly beach, Pula.

 Some parallel sauropod trackways near Pula.

 Recent dog tracks showing varieties in preservation.

 Lovrečica: a damaged theropod trackway. A buldozer went over them during some construction works.

 Lovrečica: a theropod track.

 Some unusual traces from a Pula beach.

 Sauropod tracks near Pula.

 Theropod tracks (Pula)

 Cliffs (Pula)

 Rudists (Pula)

 A beach in Pula

New tracks

Yesterday afternoon, I was walking along the outcrop near Pula, that I had visited only once before while searching for tracks. This time I had a bit more luck. I have found a couple of large theropod footprints in a straight line, but not as a complete sequence. The third, middle footprint was missing because it was covered with the rock layers. Although the state of preservation is rather poor, it seems both prints are from the left foot and the missing one is the right foot. The animal was walking fast with a rather long gait. The length of the footprint is about 45 cm.

 The last image above is my interpretative footprint outline.

 The outcrop has some interesting geological features. Gypsum crystals are quite abundant.

Here is another track site (probably sauropods) about a 100 meters further down the beach.

 Gypsum crystals are abundant and are glittering in the sun.

Many of the rocks are broken in a way as if they have been cut by a man. Which, of course, is not the case here.

I have found the new dinosaur tracks again.

It seems that almost every visit I make to the Pula beaches must end with my discovery of the new mid-Cretaceous, Pula ichnofauna tracks. It happened again in September 2014.
Here is one of the outcrops with my interpretation of the probable theropod tracks. The foot length is about 30 cm.

One of Pula's outcrops.

Pula and Brijuni

The view to the Porer lighthouse from the Verudela resort (Pula 9/2014)

 Tough roots making their way through the limestone.

 The recent sea gull trackway in cement from the Stoja camp (Pula)

The most photographed theropod footprint from the Pogledalo site of the Main Brijun island.

The next theropod footprint in a sequence (it comes after the one the photograph above) of the trackway from the Main Brijun island is the deeper one. The shallow one just bellow it in the photograph was made by another theropod of the same size (or the same one?) a bit later when the mud was a bit dryer. So, these are two parallel trackways. below in the left corner there is a poorly preserved impression of another theropod in the deep wet mud.

A probable small ornithopod (iguanodontoid?) track from the Main Brijun island (the Pogledalo Barremian site).

Traces of destruction at the Lovrecica track site

In this photograph the tracks of a medium-sized theropod from the Lovrecica Mid-Cretaceous track site are visible. The Istrian limestone (kirmenjak) is known for its toughness and durability. After all, many of the Istrian/Croatian and Italian towns used it extensively as building stone. Venice is the best known for its use.
Nevertheless, the damage left by the bulldozer driving over the outcrop is visible. It bruised the track's displacement rim (the white traces).
 The entire pieces of track bearing rock surface are missing now. The newspapers were sensationalistic in their reports claiming the tracks had been stolen. In my opinion it is a clear case of the negligence, ignorance and above all lack of protection implementation.

My interpretation is the red outline on the right. The bottom footprint is speculative.

A view at the sleepy Lovrecica, one early December morning in 2012.

The oak trees growing on the beach vis-à-vis Lovrecica.

Kamenjak ornithopod

There is an upper layer on the Grakalovac (Kamenjak #1) site, that has preserved tracks, too. I wonder why nobody has checked it out, yet. Just at a superficial glance I have spotted a nice, very small ornithopod footprint - in fact a natural cast, just about 12 cm long. I took a better look and there were a couple of poorly preserved tracks that formed a small trackway of apparently slowly walking dinosaur. See my photograph and interpretation outlines.

Whether this trackway was left by a juvenile or adult animal, nobody can tell. There are also some poorly preserved theropod tracks on that rock layer near by.

Grakalovac theropod tracks mystery (2)

Here is Fabio's (Dalla Vecchia et all, 2001) map of the Grakalovac (K1) site. In my opinion it is incomplete because the important (new?) tracks are omitted. The photograph below is turned upside down for coordinating the map's view point and the map's contents. "B" and "C" stand for the footprints and their track makers (see my diagram in the previous post). "S" stands for the undefined sauropod or/and ornithopod tracks.

In the mosaic photograph below are the tracks and the pace lengths of Grakalovac theropods arranged by size, growing from left to right. In this case, it seems the smaller the theropod, the relatively longer pace.

The next mosaic photograph are the closeups of some individual prints. "D" is mostly in-filled outline of the track. The track marked with "D" is outside the map area. "S" is apparently an oval shaped manus-pes set  of a very small sauropod. The pes has the drag marks behind it.

Although at the first sight the image in the first row below appears to be medium-sized, it is in fact just a partial print, missing a good deal of the heel. This prints is also outside the Fabio's map. In the right is the enlarged and superimposed red outline of the "C" print. It is revealing the true shape and size of this print (about 36-38 cm long).
The bottom row is the "D" print again with the interpretation on the right.

More to come in one of the posts to come: Are the peculiar tracks on Grakalovac, hadrosaur baby tracks or the prints left by a very small ornithopod ?

Grakalovac theropod tracks mystery (1)

 Kamenjak theropod lineup

When comparing my finds, photographs and measurements from Kamenjak 1 and 3 (I had discovered two more tracksites on Kamenjak, so I have named the sites K1, K2 and K3), with the data and conclusions from Fabio's (Dalla Vecchia et all, 2001) paper Dinosaur track sites in the upper Cenomanian (Late Cretaceous) of istrian peninsula (Croatia), describing the tracks from Grakalovac promontory (Kamenjak 1 or K1) something just doesn't add up. Many new questions and speculations appear. Here are some of my thoughts regarding this problem:
1. The theropod morphotype with a relatively very long  middle toe (#3) is reminiscent of an ancient theropod trait going all the way from the late Triassic and early Jurassic (Anchisauripus, Grallator, Brontozoum). Given that in general theropod feet are rather conservative and that they have not changed much over the 100 million year span, this can be plausible. I have already concluded that the tracks on Grakalovac were probably left by a ceratosaur or a compsognathid.
2. Dalla Vecchia has noticed and featured in his paper two size classes of theropod tracks on Grakalovac (K1), both being the same or very similar morphotype.  It seems that Fabio and his colleagues either didn't notice the other tracks, or more likely that the erosion has uncovered these new tracks during the past 14 years. I have noticed several new tracks, some of which were quite unusual. Among them are the ones that look like belonging to a baby hadrosaur.
3. It is a consensus that Istria and some other parts of ADCP was by the Cenomanian (Late Cretaceous) large island with the dwarf insular dinosaurs inhabiting it. That's where my large-foot theropods from K1 and especially K2 don't quite fit in. Or do they?
In the diagram below is the Kamenjak theropods lineup. The little brown silhouette is the Chinese "large compsognathid", with the foot about 11-12,5 cm long (A); marked with (B) is the small Grakalovac (K1) theropod from Fabio's paper and my photographs with a foot 16,5-17 cm long; (C) is the larger specimen from the paper (K1) and (D) is the largest track maker from K1 with the foot 38-40 cm long. The yellow silhouette (E) is the giant with the similar foot shape from the K3 track site, I had discovered last year. Its foot was around 65-67 cm long. 

3. So what is strange with this "insular" ichnocenosis is the obvious presence of very large theropods. I could settle with the 5-meters long one as one of a plausible size (D), but my discovery of the footprints which translate into a 8-10 meters huge beast (E) made me wonder: Am I seeing things? Are my interpretations wrong? Maybe the tracks were deformed? Maybe these were over sized under tracks? So far the evidence speaks in favour of true tracks.
4. Diminishing size or regression in growth of once large insular herbivores in order to compensate for the reduced food sources and maintain the viable population is a well documented biological scenario. So far, the evidence (tracks of herbivorous dinosaurs in Cenomanian rocks of Istria) speaks in favour of the pygmy island dwellers.Those were the small sauropods and small ornithopods.
How do the large theropods fit in here? Maybe they were oriented towards the sea based food? Fish eating dinosaurs? Like the spinosaurids. In any case, I do speculate that the small sauropods had to have some form of defence against the fierce giant predators. Maybe they were heavily armoured like the ankylosaurs? It is even possible that we still didn't find the tracks of the larger Cenomanian Istrian herbivorous dinosaurs.
One thing is certain: We will continue researching and learning new things about dinosaurs and their fantastic, mysterious world.

Back to Grakalovac (3)

It is a bit strange but the small theropod track morphotype fits the really ancient theropod foot bones. The one by the late Triassic Coelophysis. I speculate that these footprints were maybe left by a ceratosaurid or possibly by a compsognathid. The "large compsognathid from the early Cretaceous Yixian formation of China"  Huaxiagnathus is almost big enough to be a suspect. It's foot is only about 25% shorter than this Grakalovac (Kamenjak 1) diminutive theropod footprint. The proportions of the toes are quite similar. So our mini theropod might have been some close relative of this Chinese predatory dinosaur.

The articulated Huaxiagnathus feet in profile, from the paper.

Marvelous looking flat exposed rocks on the Grakalovac promontory. The view from a higher track baring outcrop. Some of these feature ripple marks and some of them still hide other tracks and traces.