Schemm-Gregory M.,Senckenberg Forschungsinstitut und Naturmuseum
Palaontologische Zeitschrift | Year: 2010
Leonispirifer, a new delthyridoid brachiopod genus characterized by capillate micro-ornamentation with marginal microspines, very few ribs, and a brachidium consisting of spirals that have a small diameter and are oriented in the posterior direction, is identified from the Emsian La Vid Group in its type section in the Cantabrian Mountains in northern Spain. Its type species Leonispirifer leonensis is described and its phylogenetic origin from Filispirifer is discussed. For the first time, 3D reconstructions of Filispirifer and Leonispirifer are prepared that show the different spiralia orientations, lateral versus posterior, of these two genera. An attempt is made to reconstruct the life habits of Leonispirifer, paying special attention to its lophophore-based filter-feeding system. Leonispirifer was hitherto known from the Emsian La Pedrosa Formation of the La Vid Group in northern Spain, and probably from the Siegenian Assa Formation ("Rich 1") in Morocco. According to Early Devonian paleobiogeography, both regions belonged to the northern shelf of Gondwana. © 2010 Springer-Verlag.
Herrmann M.,Senckenberg Forschungsinstitut und Naturmuseum
Palaeobiodiversity and Palaeoenvironments | Year: 2010
The fine laminated black pelites of fossil Lake Enspel (Upper Oligocene, Westerwald, W-Germany) have been analysed using palynological methods. With the help of lacustrine organic walled algae it was possible to reconstruct some aspects of the ecology of the palaeolake. Two organic walled primary producers have been recognized (Botryococcus and the freshwater dinoflagellate Cleistosphaeridium lacustre). During holomictic periods of the lake, freshwater dinoflagellates and Botryococcus coexisted. In more meromictic phases, however, Botryococcus and Cleistosphaeridium lacustre act as competitors. During times of oligotrophic and acidic water conditions with less or nearly no nutrient input into the lake, Botryococcus was prevailing. In times with more eutrophic and alkaline water chemistry caused by increasing nutrient input into the palaeolake, Cleistosphaeridium lacustre was predominant. Subordinate algal cysts of Zygnemataceae together with pollen of shore plants (Typha, Sparganium) indicate areas of shallow water or even a swampy shoreland of unknown size around Lake Enspel during some time periods. © 2009 Senckenberg, Gesellschaft für Naturforschung and Springer.
Manegold A.,Senckenberg Forschungsinstitut und Naturmuseum
Ibis | Year: 2013
Two new parrot species (Psittaciformes) are described from the early Pliocene Varswater Formation at Langebaanweg, South Africa, an area where no parrots currently are found. A coracoid, humeri, ulnae, carpometacarpi, tibiotarsi and tarsometatarsi of at least four individuals are assigned to a new species of lovebird Agapornis. Additional tarsometatarsi of at least five individuals including a nestling are referred to a new genus and species of Psittacinae, a taxon endemic to Africa comprising the extant genera Poicephalus and Psittacus. Both species form the as yet earliest geological record of parrots in Africa and document the early diversification of the taxa Agapornis and Psittacinae. Evidence for parrots in general, and a putative graminivorous species of lovebird in particular, indicates that woodlands as well as grasslands were present at Langebaanweg during the early Pliocene, which is consistent with current hypotheses on the palaeoenvironment at and around this site. © 2012 British Ornithologists' Union.
Dlussky G.M.,Moscow State University |
Wedmann S.,Senckenberg Forschungsinstitut und Naturmuseum
Journal of Systematic Palaeontology | Year: 2012
Ants are a very successful group among insects, but the course of evolution of their biodiversity is still unclear. This study sheds light on ant diversification during the Eocene. Analysis of the ant taphocoenosis of the fossil site Grube Messel, Germany (47 Ma) yielded three poneromorph subfamilies and 22 new species in six genera, four of which are new: Pseudectatomma gen. nov., Cephalopone gen. nov., Cyrtopone gen. nov. and Messelepone gen. nov. Only one extant genus, Pachycondyla, is present in the taphocoenosis from Messel. The high diversity of poneromorph ants from Messel is very striking in comparison with middle to late Eocene European ambers. A significantly lower proportion of species in ambers can be assigned to poneromorph ants, and fewer poneromorph species are known from European ambers than from Messel. A possible gradual decline of the diversity of poneromorphs from the Eocene to the Miocene seems to be detectable worldwide. These insights are discussed in the context of the morphology and ecology of Poneromorpha and Formicomorpha. The proportion of ant castes in amber seems to indicate that already during the Eocene poneromorphs inhabited preferably litter and soil, whereas formicomorphs preferred the arboreal realm. The 'ponerine paradox' of having only a primitive social organization, yet being an old phylogenetic line with global distribution, is discussed with emphasis on palaeontological data but still remains unsolved. The evolutionary history of Myrmicinae is discussed. With the newly available palaeontological data, the timing and the dynamics of dominance by different subgroups of ants can be traced more precisely than before. Copyright © 2012 The Natural History Museum.
Brosing A.,Senckenberg Forschungsinstitut und Naturmuseum
Journal of Natural History | Year: 2014
Periodic moulting is vital for the growth of crustaceans. The process is characterized by a complete replacement of the mineralized exoskeleton, including eyestalks, legs, the pleon as well as the foregut and hindgut. In the present study a series of freshly moulted brachyuran exuviae [Maja crispata Risso, 1827; Cancer pagurus Linnaeus, 1758 and Pseudosesarma moeschi (De Man, 1888)] were investigated concerning the remaining calcified foregut structures. All investigated exuviae show part or complete degradation of the lateral expanded ossicles of the gastric mill (e.g. ossicles II, V and IX). Most of the ossicles of the pyloric filter are unaffected by the degradation processes. Reduction of the calcium content and the increasing flexibility of the foregut ossicles enable the passage of the bigger "old" foregut through the smaller oesophagus of the newly formed foregut. The gastric teeth of the examined exuviae are not influenced by the moulting process. © 2013 © 2013 Taylor & Francis.