2007 Dinosaur Dig In Frick, Switzerland

The 2007 dinosaur dig was conducted by an international team under the direction of Dr. Ben Pabst from the Aathal Dinosaur Museum. Apart from the Swiss, the team of about a dozen paleontologists included Dutch researchers from the National Museum of Natural History in Leiden, Netherlands (which financed the dig) as well as German colleagues from the Bonn University.

> Overview of the main site in the Frick Clay Pit.

The dig lasted from may through october and was very successful. That spring, by chance, an amateur paleontologist had discovered a new outcrop on a building site roughly one kilometre (three quarters of a mile) from the Frick Clay Pit. So the dig actually included two separate sites; the main site in the Frick Clay Pit which covered about 500 square metres (4500 square feet) and the building site which covered about 50 square metres (450 square feet).

The two outcrops yielded two specimen each; one very complete speciment from the building site (dubbed "Monica") and one very large animal of 7 to 8 metres (21 to 24 feet, dubbed "Thunder") from the main site. This latter find represents the largest skeleton found in Frick to date. Noteably, the 2007 dig also provided many articulated hands, a find that is rather rare and which is of some importance for the study of the anantomy of these dinosaurs. Ben Pabst remarked that we had actually found more (articulated) hands that year than in the 30 previous years combined.

> An articulated lower arm and hand of a plateosaur.

The excavation at the building site proved to be somewhat interesting; the strata on this site stand at an angle of approximately 70° and are thus going rapidly deeper below the foundation of what was to become a family home. As this was a building site, we only got a short time to unearth the fossils; at one point towards the end, the building site got flooded due to a summer thunderstorm. We had to organize for a water pump, a generator and some floodlights an had to finish the dig all through the night.

On both sites, the preservation of the bones proved to be excellent. The complete specimen from the building site is currently prepared and mounted and will be sent to Leiden this august, where it will be on display in the National Museum of Natural History. For some photos of the specimen, see this post.

> Fotos from the 2007 dinosaur dig in the triassic site of Frick, Switzerland. You can also watch the fotos as slideshow.

The 2007 dig made quite a splash in the international media which reported that the “largest dinosaur site of Europe“ with “hundreds“ or even “thousands“ of dinosaurs had been found. As usual however, the media misreported what had actually been said at a press conference and then one journal copied the story from another, further distorting it and so on.

What actually was said on the press conference was this: Based on 30 years of research in the main site, we can estimate that there is one skeleton to be found for every 100 square metres (roughly 1000 square feet). As there are now three known sites* in a 2.5 kilometre (1.5 mile) diametre around Frick, it can be speculated that the Frick area may have one of the largest accumulations of dinosaurs from this period in Europe. The problem though is that the concerning strata only crops out in few places in the area; so even if true, that doesn’t mean that hundreds of dinosaurs are going to be unearthed anytime soon (read: at all).

> Getting the bones out.

Anyway; we got quite a lot of press coverage, many visitors and we were even visited by a Dutch camera team. Also, Martijn, one of our Dutch colleagues made a blog from the dig (not unlike the one you are currently reading).

(* The third site was discovered about 10 years ago by myself and yielded some plateosaur remains too. However, there never was any excavation on that site).

What A Bone Can Tell

Due to their excellent preservation, the plateosaur finds from Frick, Switzerland have provided some interesting insight in the evolutionary biology of dinosaurs.

Until some twenty or thirty years ago, there was a general consensus that dinosaurs, a group descended from reptiles, were cold blooded just as present day reptiles are. This view changed drastically in the last couple of decades and it was stipulated that at least the farthest evolved dinosaurs could have been warm blooded.

> Were plateosaurs cold blooded? Copyright painting by Raúl Martín.

In the last ten years or so, the osteology (bone structure) of many dinosaurs has therefore been studied in order to find out more about the physiology of dinosaurs (dinosaur bones preserved well enough to display microscopic structures are still rather rare). The microscopic bone structure of cold blooded and warm blooded animals differs in that cold blooded animals have a lamellar bone structure mirroring the seasonally different growing rates due to changing ambient temperatures. Warm blooded animals on the other hand have a more uniform bone structure, mirroring steady growth rates throughout the year.

It turned out that dinosaurs have a bone structure that ressembles the one of present warm blooded animals such as birds or mammals rather than that of cold blooded reptiles. The interesting point is that judging from their bone structure, apparently even some of the oldest dinosaurs already displayed a warm blooded physiology.

In the last years, the new paradigm therefore was that dinosaurs probably descended from reptiles which (like the predescessors of mammals) had already evolved a warm blooded physiology.

A study by Dr. Martin Sander on the bone structure of the plateosaurs from Frick which was published in the december 2005 issue of “Science“ for the first time revealed apparently cold blooded bone structures in dinosaurs.

> Microscopic cross section through a plateosaur bone. Copyright photo: Dr. M. Sander.

So the Frick plateosaurs could proove that a warm blooded physiology was actually developed independently several times in evolution; in mammal-like reptiles and mammals but also in different groups of early dinosaurs. It seems that some of the earliest dinosaurs such as plateosaurus were rather cold blooded after all.

On a related note it is interesting that the importance of these bones was only discovered recently. When the bone structure of the Frick plateosaurs was first fotographed some ten years ago (at the time I also took some photos from the bones I found at “my“ site), it was not surprising to see an apparently cold blooded structure in these ancient dinosaurs. At the time the bone structures of dinosaurs was largely unknown and many questions on bone structures had yet to be answered in present animals. So then, we were rather disappointed in what we saw. Only after some ten years of studying bone structures and discovering that any other preserved dinosaur bones (including triassic forms) looked warm blooded did we actually understand that our original find was interesting after all...

2006 Theropod Find In Frick, Switzerland

In 2006, for the first time in Frick, Switzerland, the remains of a small theropod were unearthed. Apart from the missing hind legs and skull, the find is relatively complete and well preserved. The find was excavated and prepared by Dr. Ben Papst. The complete specimen would measure approximately 2.5 metres (8 feet).

> Reconstruction of a Liliensternus liliensterni, one of the members of the coelophysoid theropods.

The 2006 specimen is currently in the Paleontological Institute and Museum of the University of Zurich for further investigation. The scientific determination is pending. It surely belongs into the group of coelophysoid theropods; thus it could be a Coelophysis, a Liliensternus, an other known species or even a new species from that group. The specimen is later to be on display in the Frick Dinosaur Museum.

> Fotos from the 2006 coelophysoid find. Note the small 4th finger of the specimen. You can also watch the fotos as slideshow here.

This find is relatively important since it is one of only 4 or 5 finds of it's kind in Europe and the only one from Switzerland. One important feature of the 2006 find is that it has three fully formed fingers and one smaller one. It could thus mark a missing link in the evolution of theropods who reduced their fingers from 5 to 3 early in their lineage.

Learn more about the Frick, Switzerland site here

History Of The Frick, Switzerland Site

In the town of Frick, which is situated in the Jura Mountains of northwestern Switzerland, a clay pit has been exploited for the production of brick since the early 1900s. The sediments the factory exploits are from the Late Triassic and Early Jurassic, and span about 27 million years, from 217-190 million years (get stratigraphic timetable here). In 1961, the factory lab chief found what later turned out to be the first dinosaur bones.

> Zoomable satellite map of the Frick clay pit. View Larger Map

The bones were from strata deposited in the Norian Stage of the Late Triassic, about 205 to 210 million years ago. More bones turned up in the following years and in 1976 and 1977, first excavations began. It became obvious that the excavated dinosaur bones belonged to Plateosaurus engelhardti, a prosauropod of about 6-10 metres (18-30 feet).

> Plateosaurs. Copyright painting by Raúl Martín.

In 1979 and 1984/1985, more excavations were organized. The latter excavation yielded an almost complete skeleton which is now on display in it's finding position in the Frick Dinosaur Museum (website in German only).

> Almost complete Plateosaur specimen unearthed in 1985 on display in the Frick Dinosaur Museum. See more photos from the Frick Dinosaur Museum in this post.

Further excavations took place in 1988, 1995, 2006 and 2007. The different successive excavations yielded about a dozen more or less (in)complete plateosaur skeletons, as well as a number of theropod theeth.

> Foto from the 2007 dig. See more photos from this dig here.

The 2006 dig for the first time revealed a theropod find which is currently studied at the University of Zurich (read more about the 2006 theropod find here). The skeleton is a small, yet to be determined coelophysoid (Coelophysis, Liliensternus,...?).

> The 2006 coelophysoid theropod remains. Copyright photo: Dr. Ben Pabst.

Associated finds include small scattered remains such as lung fish teeth, crocodile dermal denticles, as well as remians from fish and even freshwater sharks. The sedimentologic and taphonomic study revealed that the region was once a broad, arid coastal mud flat which was episodically affected by mud flows from flash floods in nearby wadis (see late triassic paleogeography in this post). The excavated Plateosaurs most certainly got stuck in mud traps.

> Plateosaurs stuck in a mud trap. Copyright painting by Raúl Martín.

This is evidenced by the fact that most Plateosaur finds are embedded in the same position; lying on their belly, with their spread out hind legs below the body. Also, many finds only consist of the lower half of the body. Aparently, small predators were eating away the upper body of many of the trapped Plateosaurs. Accordingly, many shattered bones from the upper bodies as well as predator theet have been found all around.

> Note the height differences in the 1985 specimen's body parts, pointing to a deposition in a mud trap.

Considered all the finds, Frick is one of the most important Plateosaur finding sites in the world and (unlike the German Trossingen) the only major European site that currently delivers fossils.

> Section of the Frick clay pit by Dr. H. Furrer. Measurments are in metres, time is indicated in million years.

Other interesting findings include the fact that the bones have been preserved in the form of the iron phosphate mineral vivianite. Vivianite has also been found in many archeologic sites where bodies have been deposited in dysoxic conditions and it is known to form within few years. The preservation of the bones is indeed exceptional and even microscopic bone structures have been preserved. The bones have also been found to be enriched in rare earth elements.

Pictures

This is Lindy's flickr photo stream.

> Photos from the preparated hind legs of plateosaurus "Monica", found 2007 on the building site in Frick Switzerland. You can also watch the photos as slideshow. Copyright photos: Dr. Ben Pabst.

> Photos from the 2007 dinosaur dig in the triassic site of Frick, Switzerland. You can also watch the photos as slideshow.

> Photos from the 2006 coelophysoid find. Note the small 4th finger of the specimen. You can also watch the photos as slideshow.

> Photos from the Frick, Switzerland dinosaur museum. You can also watch the photos as slideshow.