Madygen bryophytes and lycopsids

Moisan, P., S. Voigt, J. W. Schneider & H. Kerp. 2012. New fossil bryophytes from the Triassic Madygen Lagerstätte (SW Kyrgyzstan). Review of Palaeobotany and Palynology 187:29–37. [Abstract]

Recent paper on liverworts and leafy mosses from the Madygen Formation. Adds some new aspects about the Madygen flora which is known for its diversity of seed ferns, lycopsids, horsetails, and cycadophytes whereas (unambiguous) fossils of non-vascular plants, some of them occurring densely packed in shallow lacustrine sediments (and possibly represent submerged plants of the lake margin), have been described for the first time by Moisan and colleagues.

Moisan, P. & S. Voigt. 2013, in press. Lycopsids from the Madygen Lagerstätte (Middle to Late Triassic, Kyrgyzstan, Central Asia). Review of Palaeobotany and Palynology. [Abstract]

Revision of the Madygen lycopsids and of the problematic "Longisquama-appendage-like" foliage Mesenteriophyllum based on materials excavated between 2006 and 2009 whose macromorphological and microscopic epidermal features were studied. Originally described by Sixtel (1961) as a new genus of gymnosperms, Mesenteriophyllum-like plants are now found to belong to different higher lycopsid taxa (Pleuromeiales, Isoetales).

The Longisquama paper in press got some media coverage

Science writer Jeff Hecht wrote an article discussing results of our study:

Jeff Hecht: Reptile grew feather-like structures before dinosaurs. New Scientist, issue 2857, 23 March 2012.

Was a bit afraid of this, because often a finely nuanced statement is cited incorrectly or even turned into the opposite when the message of a paper is adapted for a non-specialist audience. Looks okay, though.

New papers on Kyrgyzsaurus, Madygenerpeton, and Longisquama

Alifanov, V. R. and E. N. Kurochkin. 2011..Kyrgyzsaurus bukhanchenkoi gen. et sp. nov., a new reptile from the Triassic of southwestern Kyrgyzstan. Paleontological Journal 45(6):639-647.
[DOI: 10.1134/S0031030111060025] [link]

Description of a reptile fossil with skin preservation discovered in 2006. Comes form the same locality as Sharovipteryx and Longisquama. The authors interpret the specimen as a member of drepanosaurs, a Late Triassic group of archosauromorphs. This paper represents one of the last contributions of the Russian palaeornithologist Evgenii N. Kurochkin who passed away recently.

Buchwitz, M., C. Foth, I. Kogan, and S. Voigt. 2012 in press. On the use of osteoderm features in a phylogenetic approach on the internal relationships of the Chroniosuchia (Tetrapoda: Reptiliomorpha). Palaeontology. [DOI: 10.1111/j.1475-4983.2012.01137.x] [link]

Includes a graphic reconstruction of Madygenerpeton (drawing by Frederik Spindler).

Buchwitz, M. and S. Voigt. 2012 in press. The dorsal appendages of the Triassic reptile Longisquama insignis: reconsideration of a controversial integument type. Paläontologische Zeitschrift.
[DOI: 10.1007/s12542-012-0135-3] [Link]

More thorough description/ graphic documentation compared to Voigt et al.(2009) and considers some aspects of diapsid skin evolution.

Madygen freshwater sharks made the JVP front page

Fischer, J., S. Voigt, J. W. Schneider, M. Buchwitz & S. Voigt (2011): A selachian freshwater fauna from the Triassic of Kyrgyzstan and its implication for Mesozoic shark nurseries. Journal of Vertebrate Paleontology 31: 937- 953. [Abstract]

Aha: Egg capsules and microvertebrate fossils can be a worthwile study object after all. (Event though Jan Fischer, my fellow grad student at the Geological Institute in Freiberg, had an interview with a critical local newsreporter who doubted that anybody could ever be interested in something like that.)

Jan and colleagues describe chondrichthyan egg capsule fossils from the Madygen Formation and refer them to Palaeoxyris, a capsule type usually assigned to hybodont sharks, and Fayolia, probably produced by xenacanth sharks. These fossils are accompagnied by nearby finds teeth of hybodont shark teeth - most of them are tiny and probably belonged to juveniles of the newly erected species Lonchidion ferganensis.

Oxygen isotope analysis of the teeth and their comparison to hybodont teeth from other localities yields a clear freshwater signal for the Madygen samples, indicating that the shark offspring indeed inhabited a freshwater habitat.

Facial analysis of the sedimentary succession of the Madygen Formation demonstrates the presence of wide-spread shallow and vegetated shore areas during the Middle Triassic which could have functioned as a shark nursery, i.e. a separate and ecologically distinct habitat for juveniles which was not invaded by adult sharks of the same species.

New paper on cycadophytes from Madygen

Moisan, P., S. Voigt, C. Pott, M. Buchwitz, J. Schneider, and H. Kerp. in press. Cycadalean and bennettitalean foliage from the Triassic Madygen Lagerstätte (SW Kyrgyzstan, Central Asia). Review of Palaeobotany and Palynology. [DOI:10.1016/j.revpalbo.2010.11.008]

Philippe Moisan who is doing his Ph.D. in Münster (with paleobotanist Hans Kerp as his supervisor) studies the flora of the Triassic Madygen Fm. In his first paper on that issue he introduces cycadophyte finds collected between 2005 and 2009.

Many of the studied the specimen come from the same succession and locality as Madygenerpeton (there is also a small sketch of the sedimentary profile, see Fig. 2).

One thing I learned from this study was that so-called "xeromorphic features", i.e. plant features that are usually the consequence of an adaptation to aridity, cannot only occur in xerophytes, i.e. in plants adapted to dry environments, but (for other reasons) in hygrophytic and halophytic plants as well.

Indications for aridity, such as desiccation crack horizons or or seasonally drying-out ponds and rivers or wide-spread red bed sediments are lacking in Madygen. Thus, according to Philippe's interpretation, "xeromorphism" in Madygen plants probably served other purposes than the xeromorphism of xerophytes (e.g. "self-cleaning of the leaf surface, regulation of excessive radiation and leaf temperature, mechanical defense against phytophagous insects").

Three recent papers on chroniosuchians

Buchwitz M, Voigt S. 2010. Peculiar carapace structure of a Triassic chroniosuchian implies evolutionary shift in trunk flexibility. Journal of Vertebrate Paleontology 30: 1697-1708. [Link]

Schoch RR, Voigt S, Buchwitz M. 2010. A chroniosuchid from the Triassic of Kyrgyzstan and analysis of chroniosuchian relationships. Zoological Journal of the Linnaean Society 160: 515-530. [Link]

Klembara J, Clack J, Čerňanský A. 2010. The anatomy of palate of Chroniosaurus dongusensis (Chroniosuchia, Chroniosuchidae) from the Upper Permian of Russia. Palaeontology 53: 1147-1153. [Link]

The redescription of the Chroniosaurus dongusensis palate by Klembara and colleagues adds further data to the morphological dataset provided by Clack and Klembara (2009) in their revision of C. dongusensis on the basis of a new specimen (which is the most complete of any yet known chroniosuchian). According to the updated phylogenetic analysis from the 2010 paper Chroniosaurus as the only included chroniosuchian taxon formed the sister group of embolomeres.

Schoch and colleagues (me included) describe Madygenerpeton pustulatus, a new species of chroniosuchians from the Middle to Late Triassic of Central Asia with a highly derived skull morphology and a carapace that was chroniosuchid-like in many aspects. The find shows that one lineage of chroniosuchids survived the Permian-Triassic boundary (by 20 or so million years).

The authors discuss characteristics uniting chroniosuchians with "higher reptiliomorphs" and unlike the approach of Klembara and colleagues their cladistic analysis, which includes five chroniosuchian taxa, results in a position of chroniosuchians somewhat closer to amniotes than to embolomeres. Chroniosaurus comes out as the closest relative of Madygenerpeton (both share the characteristic ornamentation of the skull and osteoderms besides other features).

Buchwitz & Voigt consider the functionality of chroniosuchian carapaces, comparing them to archosaur osteoderm systems. They argue that chroniosuchian carapaces basically served terrestrial locomotion but that the higher lateral flexibility of the Madygenerpeton osteoderm system was linked to a secondary increase in undulation swimming capability.

Reference:
Clack JA, Klembara J. 2009. An articulated specimen of Chroniosaurus dongusensis, and the morphology and relationships of the chroniosuchids. Special Papers in Palaeontology 81: 15-42. [Link]

Palges Meeting October 2010 in Munich

The 80 th Annual Meeting of the German Paleontological Society took place from the 6th through the 8th October 2010 within the halls of the Bavarian State Collection for Geology and Paleontology in Munich.

Of particular interest for me was the session on Early Mesozoic vertebrates chaired by the Rauhut couple and Richard Butler as it united many interesting characters, such as Silvio Renesto, Martin Ezcurra, Rainer Schoch, and Daniela Schwarz-Wings and covered a variety of Triassic vertebrates including archosaurs, temnospondyls, and bony fish.

With 5 talks and 6 posters our small Freibergian working group had quite a number of contributions this year (my prof Jörg Schneider was talking about Paleozoic cockroaches from China, Olaf Elicki about Cambrian trace fossils from Africa and the Middle East, Frederik Spindler about the evolution of haptodonts and other early synapsids, Jan Fischer about oxygen isotope signals in Permian and Triassic freshwater shark teeth and I had a talk on osteoderm histology and the Chroniosuchia). My colleagues Ilja Kogan and Jan Fischer won the 1st poster prize with their poster entitled "The Madygen lake deposits: A unique multi-taxa kindergarten for Triassic fisches" - which is quite an achievement as normally the winner comes from the host institute of the Palges Meeting.

The image on the right shows me in front of a poster entitled "Paleontology in the German Wikipedia" [pdf].

Even though there are many private collectors and paleontology enthusisasts in Germany, Austria, and Switzerland you won't find much about "regional paleontology" in the German Wikipedia which was the reason for my colleagues and me to introduce some aspects of Wikipedian (Pop-)Sciencewriting.

The poster praised the advantages Wikipedia can have if it is reasonably incorporated in public outreach campaigns and we commented critically on the dinosaur focus which increases the already biased public image of what paleontology is about.

Madygenerpeton pustulatus: first description finally out

Schoch, R. R., S. Voigt, and M. Buchwitz. 2010. A chroniosuchid from the Triassic of Kyrgyzstan and analysis of chroniosuchian relationships. Zoological Journal of the Linnean Society 160(3): 515-530. [Abstract]

Madygen trace fossil paper

Voigt, S. and D. Hoppe. 2010. Mass Occurrence of Penetrative Trace Fossils in Triassic Lake Deposits (Kyrgyzstan, Central Asia). Ichnos 17:1-11. [Link]

Besides the exquisite soft body preservation of insects and tetrapods within some parts of the lacustrine succession, the Triassic Madygen lake shows a rich inventary of invertebrate trace fossils, studied by my colleague from Freiberg Sebastian Voigt.

The interesting point about these ichnofossil assemblages is that they demonstrate a certain differentiation of the lake ground in better and less well aerated zones, displaying different degrees of bioturbation and abundances of indicative ichnotaxa.

You can imagine that fresh water lake grounds only became inhabited stepwise after the conquest of land by animals, so these trace fossil assemblages mark a certain evolutionary level of lake ecosystems, otherwise rarely documented in detail from the Middle to Late Triassic.

Questionnaire for Geobloggers(incl. Paleobloggers)

http://geoblogs.stratigraphy.net/survey/

The organisator is my former study colleage Lutz Geißler (now M.Sc. in geology), who is at the German forefront of publicising geoscience - with his web portals geoberg.de, geonetzwerk.org, and with his postcard/ poster/ online campaign "Wir sind überall." ("We are everythere!" - referring to the role geoscience plays in daily life/ for the satisfaction of basic needs).

Reptile from the Petrified Forest of Chemnitz

In Early Permian volcaniclastic deposits of Chemnitz (Saxony, Germany) the partial skeleton of 30-cm-long basal reptile including a complete autopodium, further parts of the limbs, the vertebral column, thorax, and a fragmentary skull have been discovered last week by excavators from the Natural History Museum of Chemnitz.

This is the first tetrapod fossil from these deposits which are otherwise famous for their in situ silified tree stems ("Petrified Forest of Chemnitz").

World's Largest Mineral Collection

The opening week of Terra Mineralia is over, setting the signal for the new permament exhibition whithin the walls of the recently restored city castle of Freiberg, Saxony (the most beloved place of my studies besides Madygen).

The exhibition features spectacular pieces from the private collection which Erika Pohl donated to the TU Bergakademie Freiberg. Together with the quite large mineral stock of the Bergakademie's Mineralogical Institute the new gains make the Freibergian collection the largest in the world (...not bad for a town of 40-odd-thousand inhabitants).

The opening celebrations were also the chance for us geoscience students and scientists to communicate what we are doing to the general public and to people from other university departments - so we organized the

GeoDays 2008. Within the premises of Terra Mineralia we had a geo-photo competition, a poster exhibition, and a small program of lectures and presentations on 3D modelling, sand, soil, moon rocks, saxonian vertebrate fossils etc.

Among other GeoDays volunteers I was also involved in the children's program: For some hours between Thursday and Saturday I was responsible for the "raw material" station in a point-collecting game:

The children had to connect objects of daily use with the minerals which served as raw materials - an idea realized by Alexandra Käßner, another PhD student of the geological institute (nice one, Alex!)

.... though it is not easy to keep countenance when you have two kindergarten groups - ten kids each - standing around you, keen on solving the quest in order to get a point. (The price? - I think some small colourful polished piece of mineral).

Go here for some GeoTage impressions (including me in the first pic).

Longisquama paper in press

Link to online first version:

Voigt, S. Buchwitz, M., Fischer, J., Krause, D. & Georgi, R.(2008): Feather-like development of Triassic diapsid skin appendages. - Naturwissenschaften

The paper introduces some new finds (appendage fragments found in 2007) and a specific interpretation which aspects of development can be inferred from the morphology of the complex appendage fossil.

Preamble

REMEMBERING the golden age of rising rationality when Haeckel convinced the unknowing masses with a multimedia show of colourful posters and bottles of (manipulated) embryos

WITH THE AIM of promoting the study of a worthwhile fossil site and its countless treasures

CRAVING for salvation in the heavenly realm of barrier-free communication

WITH THE CONFIDENCE that sharing our nerdy views can be therapeutical for us and alien beings alike

UNAWARE of the blogospherical disturbances and paracademic noise lying before us and

SALUTING to the free spirits of earth and life science

we, Michael of Freiberg, have started this palaeo/geo blog. "Hello world!"