Sunday, July 25, 2010

Back to the field...

Hey, I almost abandoned nologic in most recent times. There are several reasons for this: First of all, in my spare time I mostly change diapers and try to keep my little heir cheerful. This is much fun and I really enjoy being a part of my own family. Next thing is that I devote any bit of time in my office to proceed with my PhD research project. There were some "distractions" recently, so I lost some time doing this and that. I participated in the IPC3 Meeting were I had permission to give a talk. This was really cool and now I know that I am not completely off the map with my research.

I will return to the field tomorrow. There is much to discover in the Western United States (mainly Utah, Idaho) in the Early Triassic. Concerning the weather, it's probably the worst time in the year to perform fieldwork but there is no other opportunity for me (baby). Anyway, I hope for good finds and new insights.

Beside other places I may go to this place:
This photo is supposed to show Hidden Pasture Canyon in southern Montana. The brown rocks on the left could be Lower Triassic. We'll see.


Sunday, May 16, 2010

Accretionary Wedge #25: Geo-Image

The current edition of the "Accretionary Wedge" is hosted by Highly Allochthonous. The motif this month is to gather geology-related images. Outcrops, sections, satellite images, minerals, fossils, seismic images, diagramms etc.

Here is mine: The Permian-Triassic transition epxosed at the Northface of the "Aferer Geisler" (Dolomites, Northern Italy).

The Bellerophon Formation (the brown/yellow succession in the lower part) represents late Permian (Changhsingian) shallow marine to marginal marine environments that yield insight into the pre-extinction world. The end-Permian mass extinction is suggested to have wiped out about 95% of all marine species, and thus is considered as the most severe biotic crisis that metazoan life encountered on our planet. The Werfen Formation (the grey to reddish slope in the middle part of the picture) extends from the latest Permian (latest Changhsingian) to the lower Triassic (Induan/Olenkian) and is one of the best studied succession of the end-Permian mass extinction and its aftermath. In this picture, the extinction level is exposed approximately where the trees end. The steep cliffs forming the top of this range are composed of reef carbonates for which the Dolomites are so noted.

The Dolomite region has been selected as a Unesco World Heritage site. Besides the breath-taking beauty of this landscape, the significance of this region for earth sciences has also been taken into account.

Saturday, May 15, 2010

50 Best blogs for Zoology students

Quite a while ago, it has been brought to me that my blog made it on a list featuring the best blogs for students of zoology. Please follow the link below. I am sure you'll find other blogs that are worth exploring....

50 Best blogs for Zoology students

I am not a very busy blogger, anyway, but I have to announce that my activities here are quite limited at the moment. There is a reason for that: It's male, 8 days old and is keeping me very busy besides doing my PhD. Haha. Nevertheless, there are a couple of posts in preparation that I will spill out as soon as I find some time to shape them a little bit.

best, r

Tuesday, April 6, 2010

Just in case you didn't know: Free digital Geological Maps (USGS)

May be this is just old news for you but possibly it is useful for someone out there. After browsing for basic geological maps of the United States, I discovered a page that solved all of my problems. Here at a page provided by the USGS, you can download geological maps of all states as shapefiles or kml-layer for Google Earth. It is very easy way to find localities for the next fieldtrip for instance.

The north-western area of the Utah Geology layer displayed in Google Earth

Monday, March 29, 2010

Chirotherium World Tour

A team of scientists from the TU Freiberg recently unearthed well-preserved tetrapod footprints from the Triassic of the High Atlas (Morocco). Surprisingly, this ichnofauna is dominated by the ichnogenus Chirotherium, wich is suggested to present an exclusive element of North-Pangean or Laurasian localities that are nowadays associated to Europe, China and North America. Although the scientists are aware that similar trackways were reported from western Gondwana (Argentina; Peabody, 1955), it was stated by several local newspapers that the imprints represent the first occurrences of such traces from Gondwana.

Fig. 1: Pes (the big one) and manus imprint of the ichnogenus
from the Triassic of Morocco (courtesy of Jan Fischer).

Extensive field work yielded several well-preserved imprints and trackways that can be assigned to the ichnospecies Chirotherium barthii (fig. 1), which is described from (watch out, confusing terms) upper Lower Triassic (Olenekian) to lower Middle Triassic (Anisian) rocks like the Moenkopi Formation of the western U.S. or the Buntsandstein of Central Europe (Klein & Haubold, 2007; and references therein).

As noted above, at least the ichnogenus seems to occur in Argentina as well but the new data from Morocco now strongly support the hypothesis of Peabody (1955) that Chirotherium is a track with a global distribution and its archosaurian producer inhabited the northern and southern hemisphere (see a reconstruction of the palaeoenvironment in fig. 2).

All specimens are currently under investigation by Hendrik Klein, Sebastian Voigt and Jörg Schneider of the TU Freiberg and I expect some interesting papers to be published in near future. For instance, the age of these findings will play an important role in unravelling the evolutionary history of archosaurs.

Fig. 2: A reconstruction of the palaeoenvironment based on the
geological context and sedimentary analysis of the track bearing interval.
Drawn by F. Spindler (taken from Sächsische Zeitung, march 20/21, 2010).


Peabody, F.E., 1955: Occurrence of Chirotherium in South America: Geological Society of America Bulletin, v. 66, p. 239-240.

Klein, H., Haubold, H., 2007: Archosaur footprints - potential for biochronolgy of Triassic contintal sequences. In Lucas, S.G., Spielmann, J.A., (eds): The Global Triassic. New Mexico Museum of Natural History and Science Bulletin 41.

Friday, February 26, 2010

Nothing new under the sun...III


again I am busy and there is simply no time to fudge more or less significant contributions for nologic. I have several papers in preparation and one is ready for submission. I registered for IPC3, which will be held in London this year. The abstract is already submitted and I hope I can give a talk there.

I added a link somwhere above where you can find short summaries and related publications of projects where I am (or have been) involved. I will keep this updated whenever something changes. If you are interested in some of my insignificant contributions such as abstracts and articles (definitely to come) drop me a line and I will see how I can help you.

Friday, January 8, 2010

Traces First #3: The tetrapod terrestrialisation

This post actually just represents one of those reviews that swamp the internet right now. However, it just fits so perfectly my Traces First-label that I simply can't refuse to put this one on nologic.

Recently, Niedźwiedzki and co-workers (2010) discovered vertebrate trackways in the early Middle Devonian of Poland. These traces, which represent imprints of walking tetrapods, demonstrate that backboned animals walked the earth approximately 20 Million Years earlier than has been previoulsy inferred from body fossils like Tiktaalik and Panderichthys for instance. Tiktaalik from the late Devonian of the Canadian arctic is suggested to represent a sarcopterygian fish, which is closely related to early land-based tetrapods like no other (primary) aquatic animal of the fossil record (Daeschler et al. 2006)

The recent finding from Poland is remarkable for two reasons:

(1) The morphology of the imprints suggests that they were produced by real limbs. If a creature would use stump-like fins as seen in Tiktaalik for extra-aquatic locomotion, the trace fossil would appear more like drag way, not a track way (haha). The traces from Poland show discrete imprints with no drag marks or something. The implication of this feature is that free moving limbs must have evolved much earlier.

(2) The traces were found in a completely unexpected environment. The terrestrialisation of vertrebrates has always been suggested to have happend somewhere in swamp-like landscapes or along river channels. The sedimentary rocks of the trace fossil bearing level are interpreted as strata deposited on a tidal flat. This offers two possibilties: Either first vertrebrates emerged from the marine (which to my knowledge has not been considered so far) or they came from somewhere else. Togehter with point (1), the latter opportunity pushes the terrestrialisation even further back in time.

With the contribution of Niedźwiedzki et al. (2010), another macro-evolutionary step is well predated by means of traces fossils.

As neat video from nature is available on youtube:


Niedźwiedzki, G., Szrek, P., Narkiewicz, K., Narkiewicz, M., Ahlberg, P.E., 2010: Tetrapod trackways from the early Middle Devonian period of Poland , nature, v. 463, p. 43-48 , doi:10.1038/nature08623.

Daeschler, E.B., Shubin, N.H., Jenkins, F.A.Jr, 2006: A Devonian tetrapod-like fish and the evolution of the tetrapod body plan, Nature, v. 440, p. 757-763, doi: 10.1038/nature04639.