An Istrian theropod tracksite destruction in 2012

In the photograph below is a small theropod trackway consisting of four footprints with seemingly rather long heel impression or drag mark (or both). The dinoturbated site is Lovrečica, Istria, Croatia, of the upper Cenomanian age (late Cretaceous). The best preserved footprint #3 shows some considerable damage (the displacement rims are broken off) left by the bulldozer which was working on nearby road construction. Some other tracks at the site were damaged to the even greater extent  and some track baring rocks are missing. The event raised a lot of dust in the daily newspapers in 2012, claiming that some of the tracks were stolen. In my opinion this is a clear case of irresponsibility and negligence towards the geological and natural heritage, by the local construction work investor and the contractor. The local community is to be blamed for not protecting its main natural history attraction. Unfortunately, the damage is irreversible, like usually in such occasions.
The footprints in the photo are about 23-28 cm long (give or take the "heel"). The animal was probably some 3 to 3,5 meters long. The prints marked with the question marks in the diagram are rather speculative.

Some of the sensationalist headlines  in the Croatian media, regarding the tracksite destruction:
Dinosaur tracks stolen with a bulldozer
Dinosaur tracks stolen in Istria using a bulldozer 

The paper where some of the Lovrecica tracks were described in 1998:
 Fabio M. DALLA VECCHIA: THEROPOD FOOTPRINTS IN THE CRETACEOUS ADRIATIC-DINARIC CARBONATE PLATFORM (ITALY AND CROATIA)

In the comparative drawing above are some of the footprints from the Lovrečica outcrop (the scale bar is 10 cm): the middle one is redrawn from Fabio's paper; the right one is from my photograph in this post.

 

Small sauropod footprints at the beach (2)

Here is one of the sauropod tracks on the limestone beach near the city of Pula. The length of the pes in the photograph is almost 80 cm, while the sauropod pes from the same age Solaris outcrop photo (see my previous post) is about 30 cm long. The largest sauropod footprints near Pula are about 120-130 cm long. It is interesting that in this track set the manus is a positive (cast) while the pes is concave.

Small sauropod footprints at the beach

Presented here in the photograph are the three small sauropod footprints, each one facing different direction. So they do not belong to the same trackway. The one in the middle is less preserved. This is from the Solaris late Albian Istrian site where Fabio Marco Dalla Vecchia described and named the ichnospecies: Titanosaurimanus nana*.
The best defined print in the photograph (on the right) is very similar in shape to the sauropod prints I have found near the city of Pula. Fabio concluded the fauna of Solaris compound consisted of dwarf dinosaurs. However, the tracks I have discovered near Pula (Pola) were significantly larger.

* 
New Dinosaur track sites in the Albian (Early Cretaceous) of the Istrian Peninsula (Croatia).
FORWARD. This contribution is the first of a series of papers which we wish to dedicate to the results of the detailed study of the Cretaceous paleoichnological sites cropping out in the Periadriatic Carbonate platforms and follows several prelimiary ic


Nominativo Autori    DALLA VECCHIA F.M., TARLAO A., TUNIS G., VENTURINI S.
Anno    2000
Titolo    New Dinosaur track sites in the Albian (Early Cretaceous) of the Istrian Peninsula (Croatia).
Rivista    MEM.SCI.GEOL.
Edizione    DIPARTIMENTO DI GEOLOGIA,PALEONTOLOGIA E GEOFISICA DELL'UNIV.DI PADOVA,2000.
Serie Volume    52/2:193-292
Illustrazioni    FIGG.75, TABB.10, 1 PL.
Parole chiave / Key words     PALEONTOLOGIA, CRETACICO, VERTEBRATA

Riassunto / Abstract    FORWARD. This contribution is the first of a series of papers which we wish to dedicate to the results of the detailed study of the Cretaceous paleoichnological sites cropping out in the Periadriatic Carbonate platforms and follows several prelimiary ichnological descriptions (e.g. Dalla Vecchia, 1994; 1996; 1997a,b, 1998b; Dalla Vecchia and Tarlao, 1995). Despite that the presence of dinosaur footprints in the Istrian sector of the Adriatic-Dinaric carbonate platform was known since 1925 (Bachofen-Echt, 1925a,b), until very recent years nobody fully understood the great significance of this presence under the paleobiological, paleoecological and paleogeographical point of view. Dinosaur footprints reveal also the potential that these fossil traces may have for aiding sedimentological and modern stratigraphic analysis, such as the cyclostratigraphy. Multidisciplinary study of the sediments and traces yeld fundamental information about the palaeoenvironmental conditions of the different sites. In many cases recognition of subaerial episodes may be possible only because dinosaur prints were found. The number of sites with dinosaur evidence in the Cretaceous Periadriatic Carbonate platforms increased dramatically during the last years, particularly in the northern sector of the Adriatic-Dinaric carbonate platform (Fig. 1). The names of the sites are given in Croatian and Italian (the latter in Italics) in order to indicate both the actual names and those to be found in italian literature and topography of the region. Footprints have been found in the upper Hauterivian, upper Barremian, upper Albian and upper Cenomanian of Istrian peninsula, where also late Hauterivian-early Barremian bones were discovered (Boscarolli et al., 1993; Dalla Vecchia, 1998a). The Istrian levels containing bones are located in a large depression filled with marginal and open lacustrine carbonates (Dini et al., 1998). Dinosaur footprints are present also in the upper Hauterivian of the Cansiglio Plateau of NE Italy (Dalla Vecchia and Venturini, 1995; Dalla Vecchia, 1999) and in the Senonian of Murge, S Italy. Important discoveries of complete dinosaur skeletons and scattered bones and teeth have been done in the lower Albian of Pietraroja (S Italy) (Dal Sasso and Signore, 1998), and in the upper Santonian and Campanian/Maastrichtian of Karst, NE Italy and Slovenia. This paper concerns track sites of late Albian age found in two localities of western coast of Istria, respectively Solaris camp site, near Cervera/Cervar, Tar municipality (NW Istria) and Puntisella /Puntizela, near Fasana/Fazana (SW Istria). The paleoichnological field work in the Solaris camp site was possible thanks to a grant of the late The Dinosaur Society, which permitted to collect a lot of data and, in particular, to execute a detailed map of the site and the casting of several footprints. For this reason, the present contribution is particularly "conspicuous" and had to be divided into two parts. The first concerns the aspects most related to sedimentology and stratigraphy (authored by Giorgio Tunis and Sandro Venturini), the second (by Fabio M. Dalla Vecchia and Alceo Tarlao) is dedicated mainly to paleoichnology and paleobiological-paleogeographical aspects.

My old Nanotyrannus drawing

I don't know when exactly did I make these drawings of Late Cretaceous tyrannosaurid Nanotyrannus lancensis (Bakker, Currie & Williams, 1988), but it was probably sometime in the late 80's or early 90's of the previous century. I think that I used the photographs of the fossil published in Discovery magazine as reference. According to my knowledge at the time, I drew theropods with lizard-like lips.

 

A tough call

Here is another example of how difficult it is to try to interpret a flawed track. Again, it is probably a theropod from the Main Brijun, Pogledalo promontory. If true, the length of the (right pes) print is about 65 cm. The main problem is that many tracks consist of both positive and negative; the concave and convex (in filling) impression. The prominent part (either positive or negative) of the footprint is usually in the distal toes area. Or there's where the deepest part of the impression is situated, if the mud is deep. But quite often it can be a combination: some toe prints have in filling while some don't.  Than there is the displacement rim problem. It can also be negative or positive. The problem of mud collapse, etc...

An excellent paper (pdf file is free to download) on the subject of track identification:

Intra-Trackway Morphological Variations Due to Substrate Consistency: The El Frontal Dinosaur Tracksite (Lower Cretaceous, Spain)

 

Dinosaurs were messy ... (3)

Here is an example how hard it can be to correctly identify the tracks. I have photographed a small fraction of the Barremian (cca 125 mya) dinoturbation at the Pogledalo promontory of the Main Brijun island in Istria (Croatia).
Outlined with the red line are all the visible theropod footprints. A very large single foot impression is only partly visible under the covering sediment. Applying Dalla Vecchia's ideal footprint model of the theropod from that site (the green silhouette) I managed deriving the track size of that particular theropod. It was bout 65 cm long. The beast itself was at least 10-11 meters long. The size of an adult  Altispinax. Other footprints are from considerably smaller individuals. The prints were distorted due to the mud collapse. There are at least 8 theropod footprints in this photo. Probably more.

The largest theropod trackway in the world?

That Summer of 2011, I couldn't believe my own eyes. After finding some really huge single theropod footprints near Pula, measuring about a meter in length, I managed discovering even larger theropod tracks there. What's more, they were in a sequence: 5 large footprints in a row with regular spacing in between and the adequate pace angulation! There were a few of the prints of the same size and shape outside the trackway as well. Alas, all poorly preserved. Some large iguanodontoid footprints were near, too.
Here is a couple of photographs showing the trackway. I have posted two views for better understanding: from the starting point and from the finishing point. Footprints # 2 and #3 were collapsed in deep mud, while #5 is obviously an overtrack. No 4 is relatively best preserved.
Now hold your breath: the size of the footprint is some 115-125 cm in length, dwarfing any other similar find in the whole world! The footprints were rather broad, but they differ from the ornitischian ones by the relatively slender toes.

There is no way we can identify the exact track maker. However, it might have been one from the stock of the largest predatory dinosaurs of the mid-Cretaceous: a carcharodontosaurid or a spinosaurid. Anyhow, the theropod that left these enormous footprints must have been at least 18 meters long. Below is my restoration of the possible Pula environment with some of the possible track makers.

My article on the finds of giant theropod tracks in Pula was published in 2010 in "Vecernji list" (a major Croatian newspaper)  and in "Zivljenje in tehnika" (a major Slovenian popular science magazine) - "Po stopinjah dinozavrov v Istri" 3/62. I have yet to write the paper.

Notice: The fact that this post is dated April the 1st is just a coincidence. The photographs and the data are genuine and serious and have nothing to do with "April the fools' day".