Mittwoch, 17. Dezember 2008

Fieldwork Photo of the Week

Excursion group 2008 and Madygen badlands, close to the boundary between "Variegated Member" (T3) and "Upper Graycolored Member" (T4) of the Madygen Formation (subdivision of Dobruskina 1995).
The transitional zone includes sandstone horizons with large-scale x beds.

Dienstag, 9. Dezember 2008

Madygen: Recent contributions to symposia

12th International Palynological Congress, Bonn 2008:

Philippe Moisan, Hans Kerp, Sebastian Voigt, Benjamin Bomfleur: The fossil flora of the Madygen Formation from the Middle to Upper Triassic, Kyrgyzstan, Central Asia. Terra Nostra 2008/2: 194

Abstract. The Middle to Late Triassic Madygen Formation (Kyrgyzstan, Central Asia) is a unique fossil lagerstaette for Early Mesozoic insect remains and small reptiles with soft-tissue preservation. Plant fossils from these deposits from are known since the 1930s and constitute one of the richest and most diverse Triassic floras of Eurasia. However, they received very little attention to date and their studies have to date been based on macromorphological features only. We present the first record of epidermal features of this diverse Triassic flora based on recently recovered fossil plant material. Many of the Madygen plant fossils show a highly remarkable preservation. Due to its very fine grain-size, the embedding sediment has often formed a natural cast of the epidermal cell pattern. Such epidermal features allow detailed systematic descriptions as well as palaeoecological interpretations. This fossil flora is dominated by pteridosperms, ginkgophytes, and sphenophytes. In addition, algae, mosses, lycophytes and ferns occur and many are new for this fossil flora. The high abundance of fructifications is of particular interest. Another important aspect of the Madygen flora is that many gymnosperm leaves show evidence for plant-insect interactions (e.g. margin feeding, oviposition, mining traces). The supposed Middle to Late Triassic age of the flora coincides with one of the most important herbivore expansions in the fossil record. However, while this phenomenon has been recognised in the Middle and Upper Triassic of the USA, Western Europe, and South Africa, no data are available from coeval Central Asian sequences. The on-going study aims to provide a revised systematic description of the plants, including epidermal features to characterise the palaeoecosystem of the Madygen lagerstaette in more detail, and to contribute to a better understanding of the evolution of plant-animal interactions during the Early Mesozoic.

Ichnia, Cracow 2008:

Voigt, S., Buchwitz, M.: On the Mermia ichnofacies in a Triassic overfilled lake-basin of Southern Fergana (Kyrgyzstan, Central Asia). Ichnia 2008, Cracow (Poland), September 1- 5

Fluvio-lacustrine deposits of the Madygen Formation on the northern rim of the Turkestan Mountains in southwestern Kyrgyzstan are one of the few occurrences of Triassic continental strata in Central Asia. During the 1960s Russian palaeobiologists successfully explored the stratum typicum area of the Madygen Formation for macrofossils, unearthing a remarkably rich Early Mesozoic flora, thousands of insect remains, and unusual reptiles with soft-tissue preservation (Dobruskina, 1995). Considering the number, diversity and preservation of the finds, the locality represents a lagerstaette. Lacking investigations on the geological and palaeoecological background of the findings, however, its particular importance for the evolution of terrestrial ecosystems has not yet been revealed. Thus, a comprehensive approach on the Madygen ecosystem including a detailed facial analysis of the fossil-bearing strata is currently carried out.
The Madygen Formation is an up to 500 m thick series of predominantly siliciclastic rocks, which formed in an intermontane basin under humid to semi-humid climatic conditions. Sedimentary successions are composed of alluvial fan conglomerates, channel sandstones and overbank fines with intercalated coal seams of a highly-vegetated alluvial plain, as well as deltaic sandstones and laminated lacustrine mudstones of basin centre. Shallowing upward sequences and various other features, e.g. dense vegetation, wet soils, and the lack of desiccation cracks, typify the depositional environment of the Madygen Formation as an overfilled lake-basin sensu Bohacs et al. (2000).
Though they were never mentioned in earlier palaeontological reports, trace fossils of the Mermia ichnofacies belong to the most common phenomena of the Madygen fossil assemblage. Networks of tiny, irregularly branched burrows with high bedding-parallel extension are ubiquitous in the laminated mudstones of the lake deposits. Architecture and size of the burrows indicate deposit-feeding, worm-like trace makers such as the extant oligochaetes and aquatic insect larvae. The bioturbation maximum is recorded in mudstones of the transitional sublittoral to profundal lake zone which probably included a chemocline as in some modern stratified lakes. More shallow but clearly submerged parts of the lake were occupied by benthic ostracods and kazacharthra - triopsid-like branchiopods which are thought to be endemic to the Mesozoic of Central Asia (Chen et al., 1996). Body imprints of the kazacharthra occur spatially close to ribbon- and sickle-shaped trace fossils. We are attributing these traces to different types of kazachartran feeding activity: (1) grazing if the ground water layer is well aerated and (2) short-term mud-diving under oxygen-depleted conditions. All ichnia – the shallow penetrative traces and the presumable kazacharthran traces – were produced in the permanently subaquatic environment of a sizeable lake with a minimum length of 1.7 km. The restriction of trace types to a certain ground level relative to the chemocline may yield a basic approach for the subdivision of the Mermia ichnofacies.

German Paleontological Society Meeting, Erlangen 2008:

Voigt, S., Buchwitz, M., Fischer, J., Krause, D.: Longisquama's dorsal skin appendages: new finds from the type locality. Erlanger Geologische Abhandlungen, Sonderband 6: 117

Abstract. During the 1960s Russian palaeobiologists discovered two incomplete diapsid skeletons with skin impressions in lacustrine shales of the Triassic Madygen Formation, a continental sedimentary succession in southwest Kyrgyzstan, Central Asia. Described by A.G. Sharov in 1970 and 1971 the two finds became known for the uniqueness of the species they represent: While Sharovipteryx mirabilis was an early limb-supported reptilian glider with an exceptionally large uropatagium and probably an archosauromorph, Longisquama insignis, whose systematic position is still controversial, displays a series of elongate hockey-stick-shaped skin projections, rooting along the dorsal midline of the body. The appendages are structurally complex and some morphological features, e.g. the presence of a middle axis and the assumed branching, have motivated their comparison with avian feathers. Apart from four Longisquama paratype specimens with isolated skin appendages no further material belonging to one of the two diapsid species has ever been documented.
Here we report three new finds of the Longisquama appendages which have been recovered from the type locality in the northwestern Madygen outcrop area (Urochishche Dzhaylyau-Cho) during fieldwork in 2007: The single exemplar FG 596/V/1 has a length of 28.9 cm, exceeding all other known specimens by at least 100%. Comparable to the appendages of the holotype it comprises a narrow and relatively long proximal section with a tripartite appearance and a relatively short and wide distal section whose two corrugated longitudinal lobes are separated by a prominent middle axis. The apical end and the basal end are not preserved. FG 596/V/2 and FG 596/V/3 represent 3.6 and 3.7 cm long fragments of the distal section. In FG 596/V/1 and FG 596/V/3 the imprints on the left slab and right slab enclose a thin continuous sedimentary core, a feature which has been regarded as indicative for the overall membranous constitution of the appendages.
Especially the very long specimen FG 596/V/1 has some importance for the developmental and functional interpretation of Longisquama’s skin structures: Exceeding the proximal width of other dorsal appendages by only a small amount its length/ basal width ratio is conspicuously high (>50). This can be interpreted as a consequence of uniaxial growth with the constricted proximal and the extended distal section representing two distinct phases of a developmental cycle. Considering the shape and dimensions of FG 596/V/1 we find no easy explanation how the appendages could have formed a closed and stable airfoil, let alone one which produces enough lift to support gliding flight as assumed by the exponents of the hypothesis of a two-wing airborne Longisquama.

Buchwitz, M., Voigt S.: Dermal plates of a Triassic chroniosuchian with unique articulation mechanism. Erlanger Geologische Abhandlungen, Sonderband 6: 24

Montag, 8. Dezember 2008

Fieldwork Photo of the Week

Northern Alay Chain, Batken District, SW Kyrgyzstan.

Standing on massive Devonian limestones we are looking to the NNW. On the right you can see the greenish Madygen river oasis bearing a few farms and fruit plantations. On the left: the badlands represent the SW outcrop area of the Triassic Madygen Formation.

To the north and northwest reddish strata and ribs of Cretaceous conglomerate follow which overlie a narrow stripe of Jurassic. Than there is a succession of mostly Cenozoic rocks forming the core of a syncline.

In the distance you can see larger massifs of mostly Paleozoic schists, limestones and conglomerates. And then there is the greenish plain to the northwest marking another outcrop of fineclastic sediments.

This is Dzhaylyau-Cho ("good meadow"), the NW outcrop area of the Madygen Fm, including "Sharov Quarry" as the most famous locality for insects and tetrapods.

Can you see the artificial band-like wall to the west of the Madygen oasis - this is some relic from ancient times (built under Alexander the Great according to a myth).

Montag, 1. Dezember 2008

Fieldwork Photo of the Week

Two pix from the field camp:

The clubroom buildung, now fully erect and in use. In green: Our cook Ludmilla from Osh.

The penultimate act of packing and repacking one day before the end of the expedition.

Mittwoch, 26. November 2008

Constructivist geoscience and
what we can learn from the financial crisis

The analyses are done. Because you are supposed to do an 'integrated approach' you are working on 'integrating' your data and doing an interpretation that fits in with everything.

After a short or long search for patterns (as a geologist you are at least talented in pattern-spotting), you will find that no easy existing model fits with all data (or worse: every existing model fits with all data) which gives you the chance to chose the model you like best and alter it a bit. You are using an auxilliary hypothesis which explaines why this model, which is adequate in general, is not working properly for the data you are involving.

The best ist to raise a whole set of model assumptions which are not easy to be proven or disproven. Imagine it as a daughter company, to which you can export your credit risks in order to keep the bilance of your adapted existing model clean.

If there are some new data that appear to falsify your model you are employing your daughter company of auxilliary theses to explain why they are not at all problematic.

Given your business concept is good you even manage to invert contradicting data - under the light of your additional theses they actually support your model.

As you can handle it flexibly, you can of course add to or remove from the stock of your daughter company at free will. A good idea is to pay attention to fashions (if 'Milankovich cycles' or 'metamorphic core complexes' or 'climate change' are en vogue you may think about including them).

Successful model constructors manage to give their constructs the appearance of inner coherence (e.g. by means of categories, definitions and a quantitative bluff package) and sell them to others who 'succesfully' convert them to new areas and problems.

And then everything collapses - some new conflicting data pushes your model to the point of absurdity. Usually the new data fit in with a much more parsimonious alternative model. And no one will understand how you could have been so stupid to overlook that possibility in the first place...

Dienstag, 25. November 2008

Fieldwork Photo of the Weak

The Neverending Outcrop: Younger stratigraphic succession near Madygen, SW Kyrgyzstan.
The greyish-brownish Madygen Formation is overlayn uncomformably by varicoloured continental Jurassic strata which in turn are separated by an uncomformity from reddish deposits of the facially diverse Cretaceous including massive conglomeratic banks.

Paleogene: A yellowish marine succession containing mass occurrences of oysters and massive carbonates is followed by younger continental deposits of the Tertiary.

Note the roofs of premises belonging to the village of Madygen.

Freitag, 21. November 2008

Tectonics & Paleo (III):
The shearing of fossils and how to reverse it

Let's start in 2D: You have a flat fossil and regard only the deformation in the two dimensions of the fossil plane:

Easy, you may say. Fossils specimens like that are good strain indicators and it's not difficult to deduce the amounts of simple shear and flattening/lengthening necessary to transform the undeformed into the deformed specimens or vice versa:

There was a story, my tectonics prof told me from his study time when he was working for a famous German paleontologist: He was doing the retrodeformation of fossils using some kind of algorithm/ computing procedure - but only, until his sponsor found that he could reach the same effect by holding the fossil oblique over a photocopying machine (you can imagine what a disillusionment that was...).

In some cases, however, the problem is not as simple as in the example displayed above. Insect wings from Madygen and other localities often display a considerable amount of deformation but occur isolated and as palaeontological samples they have not been taken oriented (i.e. referenced to a system of external coordinate axes).

What was the original shape?

This question is crucial if you want to define and distinguish taxa (how many unnecessary species have been erected because the similarity of fossil specimens got lost in deformation?) but also searching for intraspecific variation, e.g. branching points that are highly variable in individuals of the same species.

My "bureau-mate" Olivier Bethoux, paleoentomologist, is currently doing his postdoc research working on that problem. I won't say much about his solution which involves morphometrics/ landmark analysis but keep you informed about results when they are published.

Montag, 17. November 2008

Fieldwork Photo of the Week

You can see the rise of our club room one day after the arrival in Madygen. Gas bottles, sample boxes, and limestone boulders are integral parts of the construction.

Borrowed this photo of a tent erection from this year's Madygen participant Daniel Rutte, who started an exchange semester in Golden, Colorado, shortly after the field trip and after becoming a Bachelor in Freiberg (but only 'of Science' unless I'm much mistaken).

Samstag, 15. November 2008

Triassic critters: Kazacharthrans

Kazacharthrans - or Katzen, as we call them (jokingly) in German - are an endemic group of small branchiopod crustaceans which were named after the former Soviet Republic of Kazakhstan, where the type locality is situated. All yet known occurrences are restricted to the Middle Triassic to Lower Jurassic of Central Asia (Kazakhstan, Mongolia, Turkmenistan, the northwestern Chinese Province Xinjiang, and Kyrgyzstan: the Madygen Formation).

The closest recent relatives of kazacharthrans and an anatomically quite similar group are the tadpole shrimps (Notostraca), including the 'living fossil' species Triops cancriformis, which has not changed since its earliest occurrence in the Triassic.

Kazacharthran head shield from Madygen; width: 1.2 cm.

The most complete body fossils from Madygen consist of a relatively large cephalothoracic shield (see pic) and a segmented tail with a small and spiny shield at the end (telson). Madygen finds show the head shield often considerably deformed. As the animals were subject to moulting, the abundancy of kazachthran body fossils is raised by the preservation of exuviae.

The riddle of kazachrathran radiation. Kazacharthrans are regarded as a Triassic offspring from the lineage of the otherwise conservative group of notostracans which have persisted since the Carboniferous without larger anatomical changes. As the Kazacharthra develop a relatively high diversity (14 genera, >20 species described) in a narrow spatial and temporal window, the crucial questions is, what their speciality (and fate) was.

Sebastian Voigt (who is in charge of the Madygen project here in Freiberg) is a paleoichnologist and also working on kazacharthran trace fossils and their ethological and ecological implications (see ref below), using the ichnia of recent triopsids for comparison (the reminiscence of a childhood dream to have those lovely trackmakers in your aquarium). Understanding the palaeoenvironment and fossil association of kazachathran body and trace fossils in the Madygen Fm will hopefully help to understand the peculiarity of "Katzen".


Chen P., K.G. McKennzie & Zhou, H.(1996): A further research into Late Triassic Kazacharthra from Xinjiang Uigur autonomous region, NW China. - Acta Palaeontologica Sinica 35(3): 272-301.

Preliminary results on Madygen kazacharthrans can be found in the abstract volume of the 2007 fall meeting of the German Palaeontological Society (pdf, 33MB):
Voigt, S.(2007): Kazachartran body and trace fossils from shallow lake deposits of the Madygen Formation (Middle to Upper Triassic, Kyrgyzstan, Central Asia). In: O. Elicki & J.W. Schneider (eds): Fossile Ökosysteme. - Wissenschaftliche Mitteilungen 36, Institut für Geologie, TU Freiberg, p. 160

Samstag, 8. November 2008

Fieldwork Photo of the Week

July or August 2007 at "Sharov Quarry": Toilo, who is living in Madygen, is talking to me while I am dripping some fixation solution on a fish or plant fossil.

That pile of weathered shale debris we are sitting on is the product of Sharov's group in the 1960s and of our work. The photo is taken from the position of the outcrop wall.

The Sharov locality is the place where all hiherto described Madygen tetrapods, most insects and fishes, and some of the best plant fossils have been found.

Tectonics & Paleontology (II): Sclerochronology

Some five years ago I had one of my first presentation-preparing seminars and the list of available topics included 'sclerochronology', supervised by the tectonophysics prof. Searching the literature I found that the term referred to the study of the accretionary growth of mineralized organismic hard parts - a bit like the tree-ring chronology transferred to animal skeletons ('interesting', so I thought and chose 'sclerochronology' for my seminar talk).

There were many papers on mollusc life strategies and environmental change during the younger Cenozoic, mostly analyzing some long-living clams. Not many studies involved 'sclerochronology' as an actual dating method, often researchers were looking for either ontogenetic signals or climatic signals, often involving distinct taxa, localities, and stratigraphic levels for comparison.

Among the animal groups considered were brachiopods, bivalves, corals, belemnites, fish (otoliths) but also higher vertebrates: Enamel and accretionary growing bone can yield sclerochronological data - the method is also called 'skeletochronology' when applied on vertebrate hard parts.

And the link to tectonics? If you consider the cross section of a shell as representing a time series of fast and slow growth phases and phases of arrested growth, how exactly can you expect a tectonic signal to show up? I asked my tectonophysics prof what story he wanted me to tell and it was this:

A reference book on Quaternary dating methods (Lettis et al. 2000) also includes a chapter on sclerochronology in recent to subrecent corals inhabiting a shallow tropical tectonically active shelf. If the shelf area is part of a block which is elevated over another block by thrust faulting (as under compression along a convergent tectonic plate margin), this tectonic movement - which is not continuous but (mostly) discrete with larger earthquakes releasing most of the stress - can have consequences for the coral growth:

During an earthquake (along a thrust fault) the uppermost part of a colony is lifted over the water level, dies, and stops growing, while deeper-lying sections stay intact and continue their growth. If you count the annual growth bands and locate the points of growth arrestment after an earthqake you can derive the timing of earthquakes and also the amount of vertical displacement for each event. These data are sufficient for deriving the earthquake characteristic of the responsible fault - a classical aim of paleoseismology.

You could argue that all that has nothing to do with deep time processes and you are right: While the paleobiological and paleoclimatological approaches employing sclerochronology are not strictly limited in time, sclerochronological dating is restricted to the youngest few thousand years of the Holocene.

Some refs: Sclerochronology

... & Tectonics:
Buddemeier, R.W. & F.W. Taylor (2000): Sclerochronology. In: Lettis, W.R., J.S. Noller & J.M. Sowers (eds): Quarternary Geochronology: Methods and Applications. - Washington, AGU, pages 25- 40.

... in vertebrates
MacFadden, B.J. (2004)(ed): Incremental Growth in Vertebrate Skeletal Tissues: Paleobiological and Paleoenvironmental Implications. In: Palaeogeography, Palaeoclimatology, Palaeoecology 206(3-4).

... in marine animals
Schöne, B.R. & D. Surge (2005)(eds): Looking back over Skeletal Diaries - High-resolution Environmental Reconstructions from Accretionary Hardparts of Aquatic Organisms. In: Palaeogeography, Palaeoclimatology, Palaeoecology 228(1-2).

Sonntag, 2. November 2008

Tectonics and Paleontology (I): Series Intro

In Germany paleontologists often have graduated in geoscience study programs. At some universities, such as my Freibergian alma mater, paleontology is mostly taught as a branch of geology dealing with fossils for the purpose of solving geoscientific problems: Fossils provide information about the age of sedimentary rocks (biostratigraphy) or their maturity (see for example: conodont alteration index) or formation conditions (biofacial analysis) or are relevant for paleogeographic reconstructions (paleobiogeography) or for paleoclimatic inference. As a matter of fact fossils are useful and paleontology is not the end in itself, no art pour l'art...

...and so forth. Perhaps some of you heard a similar story.

There are some advantages, though, when you are coming from the geological side: You know your rocks and minerals alright. You have learned how to draw maps and what geoinformation is and all those analytical methods for rock samples and how to get a picture of an ancient biotope from sedimentological criteria and how to find the most fossiliferous places and strata.

In my M.Sc. studies of geology/paleontology I was supposed to chose 3 out of 13 electives, including petrology, tectonics/geodynamics, geology of mineral deposits, geochemistry, sedimentology, pedology, hydrogeology, geotechnics, paleontology, mathematical geology/ geoinformatics and mineralogy. I did a bit of everything with the exception of hydrogeology and focussed on all that non-applied basic research stuff, including paleontology and tectonics.

And when the project in Kyrgyzstan started somewhat later than expected I did - not only for reasons of timing - my master thesis on fissures and normal faults in the Ethiopian rift (see here). Over the years I found more and more links between tectonics and paleontology including rather subtle ones. Some posts will help me to keep them in mind.

Mittwoch, 29. Oktober 2008

Wing types, Sharovipteryx, Longi

In his review on wing evolution Dietrich Schaller (1985) distinguished wing types according to function, type of wing attachment, and type of airfoil support.

Accordingly there are 'limb wings' and wings not involving limbs. The latter ones can be jointless, such as the pleural wings of Draco and kuehneosaurids, or single-jointed, such as the chitinous wings of insect flapping fliers.

What about the "enigmatic" Madygen beasts?

was an early limb-wing glider. Depending on the interpretation of wing topology it is reconstructed either with the fore- and hindlimbs connected by a wing membrane - representing the type of a 'skelobrachial glider' (sensu Schaller) - or with separate brachial (arm) wings and skelosal (leg) wings.

The latter case is discussed in particular by Dyke et al. (2006): Their modelling of the aerodynamic properties of different Sharovipteryx wing configurations demonstrates that a double delta wing morphology would have been the most advantageous for gliding (using certain input conditions based on model assumptions derived from the study of the morphology of the only fossil specimen).

Longisquama as a two-wing glider is not classified as easily. It would possess multi-segment and muli-jointed gliding wings which would constitute airfoils without further structures for support. Schaller did not consider such a configuration. Or else, it would have jointless wings comparable to the membranous muscle-supported flank wings of the gliding gecko Ptychozoon - but with the difference of being segmented, attached to the back and several times as long (minor drawbacks?).


Schaller, D. (1985): Wing Evolution. In: Hecht, M.K., J.H. Ostrom, G. Viohl & P. Wellnhofer: The beginnings of birds. - Eichstätt (Freunde des Juramuseums), pp. 333- 348.

Dyke, G.J., R.L. Nudds & J.M.V. Rayner (2006): Flight of
Sharovipteryx mirabilis: the world's first delta-winged glider. - Journal of Evolutionary Biology 19(4): 1040-1043.

Sonntag, 26. Oktober 2008

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).

Samstag, 18. Oktober 2008


Unpacking of the 2008 finds in a rather relaxed "subbotnik".
This year's fieldwork season turned out to be a good one for plants and for Philippe Moisan Tapia, palaeobotanist and graduate student at the University of Münster - he is doing his dissertation on the Madygen flora.

Mittwoch, 15. Oktober 2008

Triassic critters: Titanopterans

Among the most remarkable fossil insects from Madygen are the titanopterans which can reach wing spans of 50 cm. The Titanoptera form a subgroup of the Neoptera and were usually regarded as having an order rank when the Linnean taxonomic system is applied.

Recently, there was a revision done by Olivier Béthoux, who is currently working as a Humboldt research fellow at the geological institute of my alma mater (actually he is my "bureau mate"):

Béthoux (2007): Cladotypic taxonomy applied: Titanopterans are Orthopterans. - Arthropod Systematics & Phylogeny 65(2): 135- 156.

Recent orthopterans include grasshoppers and crickets. Olivier Béthoux shows on the basis of wing venation topology that members of a Permian "family" of Orthoptera - the Tcholmanvissiidae - are the closest relatives of the Triassic group Titanoptera. Such a relationship was also proposed by Madygen researcher A. G. Sharov as early as 1968 but later doubted by others.

The 'Titanopterida' are newly defined as a subgroup of the 'Tcholmantitanopterida' which are in turn a subgroup of Tcholmanvissiidae:

"Species that evolved from the (segments of) metapopulation lineage in which the character state ‘in forewing, CuPaα• + CuPaβ and CuPb having the same point of origin’, as exhibited by giganteus Tillyard, 1916 and vulgaris Sharov, 1968, has been acquired." (see page 145)

The cryptic formulas refer to higher order branches of the posterior Cubitus (CuP), a main wing veine.

Olivier's paper is interesting for another reason: As announced in the title he uses the relationship of titanopterans as an example for applying his concept of cladotypic taxonomy which on its own may be worth a post here (after I got the point). One part of his idea may be frightening for some biologists - as in the definition above there is no longer a need for binary nomenclature.

Fieldwork Photo of the Week

Blue-collar workers: undergrads Daniel & Juliane plus me.

Montag, 13. Oktober 2008

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.

Madygen: never heard? - for sure you did

hear about Longisquama and Sharovipteryx, the notorious "engimatic small diapsids" that are discussed every other year for their phylogenetic relevance and/or functional morphology.

Both come from a thin slice of lake sediments within the Triassic Madygen Formation, a several hundred meter thick succession of continental sedimentary rocks.

For the first time distinguished by KOCHNEV (1934) in an unpublished report and named after the village Madygen, the fossiliferous sediments came into the focus of Soviet palaeobiologists from Moscow, who carried out several excavations during the 1960s.

Madygen became a classic locality and primary source for Early Mesozoic insects. Moreover the group discovered macrofloral remains, molluscs, crustaceans, fish, an urodelan, a cynodont and two small skeletons of diapsid reptiles. The latter were described by the great Russian palaeoentomologist ALEXANDER G. SHAROV between 1966 and 1971.

Several approaches focussed on the sedimentology and stratigraphy of the Madygen Fm - a geological mapping and analysis of the flora by DOBRUSKINA (e.g. 1995) delivered a Ladinian- Carnian age.

During the last three years, palaeontological fieldwork in Madygen intensified again when the far-off realm of SW Kygrgyzstan was again headed for by a Moscovian group of palaeontologists and by a German research group.

Some refs (see also linked WP articles of Longisquama & Sharovipteryx):

Sharov, A.G. (1966): [Unique discoveries of reptiles from Mesozoic beds of Central Asia.] - Bjulleten Moskovskogo Obscestva Ispytatelej Prirody, Otdel geologiceskij, 61 (2): 145- 146 (Moscow).

Dobruskina, I.A. (1995): Keuper (Triassic) Triassic Flora from Middle Asia (Madygen, Southern Fergana). - New Mexico Museum of Natural History and Science Bulletin 5: 1-49


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!"