‍Orsten Research – Ulm Team

‍This page will list relevant Orsten research activities of the Ulm Team, Germany.

‍1. Crustacea currently under study

‍1.1. Eucrustacea

‍Dala peilertae Müller, 1983.

‍Work on this species had started way back in 2001 during Dieter's first and only sabbatical so far. The biggest problem remains that there seemed to be 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 ofsensilla on tergites. And we have found at least four specimens with remains of the head region – though very badly preserved. We can confirm that the species represents 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 Eucrustacea / 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 (published in 2007).

‍2. "Stem Arthropods" (derivatives of the stem lineage of Euarthropoda or early members of Arthropoda s. l.)

‍This long-lasting project is a co-operation with Reinhardt Kristensen, Copenhagen, Denmark. Poor you, but we hopefully finish this paper on you before you are entirely rotten! Chances have increased indeed, because Dieter and Andreas have sent a new version to their collaborators.......

‍3. Other research activities

‍Odds and ends (isolated arthropod legs, strange arthropod fragments, non-arthropods, incl. sponges, putative echinoderm larvae, and cyanobacteria) from the Swedish, Siberian and Australian 'Orsten'-type lagerstaetten

‍The large material of the Swedish 'Orsten' contains numerous specimen of unclear affinities to known forms, isolated limbs surely belonging to animals not described yet, but completely uncertain. They shall be documented step by step to demonstrate the variation in the material, plasticity of life forms and the species abundance in the 'Orsten' meiofaunas. At present we estimate that the upper Middle Cambrian to Furongian 'Orsten' of Sweden comprised more than 60 different species, the finds altogether outranging the 80, so that 'Orsten' occurrences, although "just representing a window into the meiofauna", will have a species record as high as the other Cambrian lagerstätten.

‍At least part of this was investigated by Christopher Castellanifor his dissertation. First papers were prepared, e.g. about sponges or cyanobacterians, but he disappeared and the chances that the masses will be finished are but low.