Current Research of the Ulm Team

b) Dala peilertae Müller, 1983. Work on this species had started with Jens Høeg from Copenhagen way back in 2001 during Dieter's first and only sabbatical so far.
The biggest problem remains that there is no head available! The species is currently under re-study including more SEM work. We have, particularly, to make more measurements after we discovered variability of several features: setal pattern on the endites of the of thoracopods, fringe pattern of abdominal segments, and occurrence of sensilla on tergites. The species seems to represent another entomostracan taxon, possibly the sister taxon to all other Maxillopoda.

We will try to do more on these two animals, because both have an impact on the understanding of the ground pattern of Eucrustacean/ Entomostraca. Dala, moreover, has an impact on the stem lineage of the Maxillopoda. Since these in-group eucrustacean taxa are heavily questioned and "not supported by molecular data", we aim at providing good new data as soon as possible. This shall, hopefully, help supporting the monophyly of Entomostraca as the sister taxon to Malacostraca, further – in addition to the LC Yicaris dianensis from China, another one "of such kind" in our hands now.

c) We also hope to continue our work on Yicaris dianensis together with Xiguang Zhang in due course. The material contains several successful stages so we are looking forward to investigate the ontogeny in detail.

d) The most appealing new taxon is the study of a tiny larva from the same locality as Yicaris, but from a slightly younger horizon. It is an early metanauplius of an unknown but clearly entomostracan eucrustacean species, which has a more modern-fashioned look than Yicaris. Exceptional ar its posterior head shied spine and a spine externding perpendicularly from the hypostome in front of the labrum. Its larval status can be derived from its fairly immature maxillula and the initial maxilla, which is represented by only a spine.

The descriptive paper on this new form, which will receive the name Wujicaris klausmuellerae will be published shortly in Current Biology – more here very soon.

Studies of larval sequences

Joachim Haug joined the Ulm team in late fall 2005 together with his wife Carolin as a collaborator in a project embedded in the DFG Priority Programme "Deep Metazoan Phylogeny". After successful application to a new DFG grant and a likewise successful disputation, Joachim is continuing his work in Ulm as a postdoc. He is currently studying more stem crustaceans and their ontogenies but also larvae of Rhynie Chert and Solnhofen limestones, of extant crustaceans, and larval series in the Burgess-Shale material. In a wider sense Joachim aims at combining these data available from 'Orsten' larvae with the ontogenies in Arthropoda in general. He also looks for heterochronic events during evolution of Crustacea and Arthropoda, apparently one of the driving forces to modify morphologies.

1. During this study he has, for example, found a possibility to discriminate the one-eyed twins Goticaris longispinosa (left) and Cambropachycope clarksoni, often known oly from isolated eyes (paper on these published summer 2009). He also learnt to use the 3D reconstruction software BLENDER, which turned out to be an excellent tool in our studies (see here). Our comparisons also benefitted from models Joachim produced from other 'Orsten' and also from extant animals, such as of the predatory water flea Bythotrephes (e.g. longimanus) (left).

2. When studying Oelandocaris oelandica, on e of the "stem crustaceans", Joachim discovered that in Henningsmoenicaris scutula the "Proximal Endite" (PE), which in Oelandocaris was developed only on the 3rd appendage (mandible of labrophoran crustaceans), does not appear in the first instar, but much later. If this is an ontogenetic feature of Crustacea sensu lato, it may provide us with a further tool to discriminate between the different early stem taxa. It also gives a further proof that the PE is new to Crustacea and that Eucrustacea neither had such a PE, nor a coxa, which is a modification of this endite! The paper on Henningsmoenicaris has been accepted by TRSE and is in press now.

a) More than two papers on compound eyes of stem crustaceans are currently being prepared in collaboration with Brigitte Schoenemann, Bonn. More here soon.

b) Upper Cambrian/Lower Ordovician pentastomid parasites

c) Middle Cambrian tardigrade

This long-lasting project is a co-operation with Reinhardt Kristensen, Copenhagen, Denmark. Poor you, but we hopefully finish this paper before you are entirely rotten!

4. Other research activities – To the Top

a) Running projects with partners

• A project on phosphatocopines from Poland with preserved soft parts is a collaboration with Ewa Olempska, Poland. This work is still under way, but first results will be shown in due course here.
• Another manuscript on phosphatocopines but from China prepared by Andreas Maas in collaboration with Prof. Dong from Nanjing is in press now.
• New Comley material is expected to be explored due to new excavations by Mark Williams and David Siveter
• A book about the 'Orsten' is planned together with Euan Clarkson, UK, possibly also Andreas Braun – but this project is still in the very far distance.

b) Other projects

2) Research dealing with material from the Devonian Rhynie Chert and the Upper Jurassic Solnhofen limestones is done mainly by Carolin and Joachim. Some papers are already published, more are in press and submitted. More material is still under study.