Showing posts with label Hadrosauropodus. Show all posts
Showing posts with label Hadrosauropodus. Show all posts

Tuesday, 27 May 2014

A poorly preserved ornithopod track


Here is another example of a "questionable" dinosaur track from Pula. According to my scale I would grade it as a poorly preserved track (***). It is not easy to spot on these weathered rocks, although it is a convex, or relief track. The natural cast. It is slightly darker colour and there are more similar prints there. In its overall shape it does remind of an ornithopod, iguanodontoid footprint of the Hadrosauropodus type, but due to the state of its preservation it may still be a theropod.
See the b/w outline of Hadrosauropodus langstoni  - Lockley et al. (2003) track at the bottom.
My interpretation is the red outline over the print in the second image.




Some of the Cretaceous hadrosaur tracks are well described in a paper. HADROSAUR FOOTPRINTS FROM THE UPPER CRETACEOUS FRUITLAND FORMATION, SAN JUAN BASIN, NEW MEXICO, AND THE ICHNOTAXONOMY OF LARGE ORNITHOPOD FOOTPRINTS SPENCER G. LUCAS1, ROBERT M. SULLIVAN2, STEVEN E. JASINSKI2 AND TRACY L. FORD

"A reconsideration of the ichnotaxonomy of large ornithopod footprints suggests that only two
ichnogenera may be valid: Caririchnium (= Hadrosauropodus) and Amblydactylus (= Iguanodontipus)."


Monday, 3 February 2014

Why is larger track harder to spot?



It is hard to believe, but people are more likely to notice the small dinosaur tracks, than the large ones. Even many professional paleontologists fall into that group. Although, it is rather ironic. Don't you think? I mean, many dinosaurs were known for their giant size. After all they were the largest terrestrial animals that ever lived. 
A few years ago, at first doubtful of my own eyes, I managed finding very large dinosaur tracks on the Istrian beach which is very busy with tourists in the Summer months.The age is Early Cretaceous, Late Albian. Before some 100 million years ago.





In the photo is a giant iguanodontoid footprint (right foot) measuring about 85-90 cm in length. This was my first find of a gigantic ornithopod track. I have never expected that I will find a couple of even much larger iguanodontoid foot impressions, in the same area, just a year later. The red outline is my interpretation of the main shape. There are several less preserved prints of the same animal around this impression. 

These are footprints from other countries for comparison:


Note the resemblance with Caririchnium sp. from the Uhangri formation (image from the Research Report on the Haenam Dinosaur Tracksite, Korea, 1998)...

...or with this footprint of Hadrosauropodus nangxiogensis (from Xing et al. 2009).

It seems, the Istrian iguanodontoid footprints show both features of an hadrosaurian track and the iguanodontian one.