Teranota and its implications on anomalodesmatan phylogeny
Bedded carbonaceous siltstones from the Buechel Subformation of the Bergisch-Gladbach–Paffrath Syncline, Germany, of Middle Devonian (Middle Givetian) age have yielded a remarkable sample of extremely elongated, articulated bivalves preserved in life orientation. The specimens are associated with a single left valve embedded horizontally in the bedding plane and further isolated but articulated shells. Combining the information given by the specimens and the palaeobiological interpretations allows the reconstruction of the complete morphology and probable life habits. The very distinct morphological features led to the erection of a new taxon, Teranota ebbighauseni Rogalla & Amler, 2000, provoking discussion on habitats, life habits and evolutionary trends in anomalodesmatan bivalves. A combination of characters typical of the orthonotids and the modiomorphids, as well as the preserved life position at an angle of some 60–70° relative to the bedding plane, suggests that these specimens were part of a minor branch off the main evolutionary lineages within the Anomalodesmata. It is proposed that these animals represent a convergent line of endobenthic bivalves distantly related to true siphonate forms.
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The Evolutionary Biology of the Bivalvia
Bivalves are key components of Recent marine and freshwater ecosystems and have been so for most of the Phanerozoic. Their rich and long fossil record, combined with their abundance and diversity in modern seas, has made bivalves the ideal subject of palaeobiological and evolutionary studies. Despite this, however, topics such as the early evolution of the class, relationships between various taxa and the life habits of some key extinct forms have remained remarkably unclear.
In the last few years there has been enormous expansion in the range of techniques available to both palaeontologists and zoologists and key discoveries of new faunas which shed new light on the evolutionary biology of this important class.
This volume integrates palaeontological and zoological approaches and sheds new light on the course of bivalve evolution. This series of 32 original papers tackles key issues including: up to date molecular phylogenies of major groups; new hard and soft tissue morphological cladistic analyses; reassessments of the early Palaeozoic radiation; important new observations on form and functional morphology; analyses of biogeography and biodiversity; novel (palaeo)ecological studies