Welcome to the blog of the Mesozoic vertebrates research group of the Bayerische Staatssammlung für Paläontologie und Geologie

Friday 6 July 2012

Bellubrunnus and what we do and don't know about Jurassic pterosaurs

Pterosaurs - the flying reptiles - were an important component of Mesozoic terrestrial ecosystems, yet their fossil record is strongly biased towards some exceptional localities. One of them are the Late Jurassic limestones of southern Germany. These rocks have not only yielded the first pterosaur to be described scientifically - Pterodactylus, first described by Collini in 1784, and still kept in our collections here in Munich -but, together with the famous Santana beds of Brazil and the Yixian Formation of China, they have yielded one of the most diverse pterosaur faunas in the world.

However, if you thought that we already know everything about the Late Jurassic pterosaurs from southern Germany, think again - David Hone of the University College London and his coauthors (among them once again the master of UV photography, Helmut Tischlinger) have just published a new species of long-tailed pterosaur from the laminated limestones at Brunn, eastern Bavaria. They called the new taxon, which is based on a wonderfully preserved specimen that technically belongs to our collections, though it is currently housed in Solnhofen, Bellubrunnus - the beauty from Brunn. And Bellubrunnus is not the only new pterosaur from the Late Jurassic limestones of southern Germany: Just recently, two of the authors of the new paper - Eberhard "Dino" Frey and Helmut Tischlinger - together with Christian Meyer from the Museum in Basel described the oldest azhdarchid pterosaur (the group that the giant Cretaceous forms belong to), Aurorazhdarcho, from the Solnhofen limestones, and several other new pterosaurs have recently been found.

Skeleton of Bellubrunnus. Length c. 14 cm.
Why, you may ask, is that so? Well, apart from the obvious - that pterosaur diversity was greater than hitherto recognized - this is due to a pecularity of the geological setting that is little known outside Germany: What is often lumped together as "Solnhofen limestones" actually represent several geological units that span the time from the "middle" Kimmeridgian (c. 152.5 million years ago) to the Early Tithonian (c. 148 million years ago). They thus span several million years, but so far, mainly the Solnhofen Formation has yielded abundant fossil material, including most known pterosaur specimens and the iconic Archaeopteryx. However, this is mainly due to the fact that this is the only unit that has systematically been explored in the past 200 years, since the Solnhofen slabs were the best for lithography and are also used as building materials. Nevertheless, the underlying Rögling and Thorleite formations (and their equivalents) and the overlying Mörnsheim Formation are also very fossiliferous, at least in parts. These units are now being explored more systematically, and, apart from taxa shared between the different units, we also see a lot of new species coming out. The locality that Bellubrunnus comes from, the quarry at Brunn, is thus quite a bit older than the "classical" Solnhofen limestones, and only the systematic excavations by Martin Röper of the Bürgermeister Müller Museum in Solnhofen (another one of the authors on the paper) are starting to reveal the ecosystem of that time. Likewise, a new systematic excavation in the Mörnsheim Formation at the Schaudiberg close to Mörnsheim has already resulted in the recovery of several new taxa, and in a quarry close to Wattendorf worked in by Matthias Mäuser of the Naturkundemuesum Bamberg and Winfried Werner of the BSPG the so far oldest fauna from the Late Jurassic limestones is currently being exhumed. We can thus expect many more new discoveries.

Geological profile through the Upper Jurassic of southern Germany, with placement of several localities indicated. Slightly modified from Fürsich et al. (2007; Palaeogeogr., Palaeoclim., Palaeoecol. 243: 92-117 )
The Upper Jurassic limestone formations of southern Germany thus represent an almost unique opportunity to study the changes in a Jurassic ecosystem over a geologically short period of time. That some taxa are common to all of the different units, whereas others, such as the pterosaurs, seem to show marked differences between the faunas might indicate different evolutionary dynamics in different groups. However, it will also not be easy to tell evolutionary changes in these groups from possible effects of environmental changes between the different units. Thus, everything is known about the Late Jurassic pterosaurs of southern Germany? Far from that, the work has just begun...


Hone, D. W. E., Tischlinger, H., Frey, E. & Röper, M. 2012. A new non-pterodactyloid pterosaur from the Late Jurassic of southern Germany. PLoS One 7(7): e39312. doi:10.1371/journal.pone.0039312

3 comments:

  1. Hi Oli,

    thanks for the ice words on our paper. Certainly I hope and expect there'll be more to come from Brunn.

    Dave

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  2. Phantastic paper! I took a photograph of the holotype when it was in the exhibition of the Naturkundemuseum Ostbayern, but I am very happy to see that the authors submitted it to a PLoS journal, so we can use the abundant material for the Wikipedia article. I remember a lot of other specimens from Brunn in that exhibition which was then undescribed, for example the Rhynchocepalia spp. nov. (BSP XVIII – VFKO – A 10 and BSP XVIII – VFKO – A 8). Do you know if they're described yet?

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  3. No, these specimens are not described yet. At least one seems to represent a new taxon, though both might. Last year, I took Marc Jones to see these specimens, and I hope we can do something on them together at some stage.

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