Panderichthys

Life image of Panderichthys rhombolepsis

• Latvia

Panderichthys is about 380 million year old fossil fish genus from the Upper Devonian, which is also known as primitive coelacanth. So far, the only known Panderichthys rhombolepsis Art is named after the German Baltic Panderichthys paleontologist Christian Heinrich Pander, who described numerous spätpaläozoische fish.

Anatomical details

Fins

Panderichthys is interpreted as a transitional form between fish and primitive land vertebrates ( Tetrapoda ), since the bones of his front flippers were already largely converted to limbs, the posterior pelvic fins, however, were still largely fish-like. The change in the bones of the forelimbs and its anchoring to the hull was also concluded that the muscles of the animal 's body already at least could be supported temporarily. This transition from fins to legs is one of the most important changes that have vertebrates enables the shore.

The movement of the animal on the ground was described by a researcher at Uppsala University as " snaking ", wherein the animal is likely to have used its forelimbs to hold onto the ground.

In custody, in Tallinn, almost completely preserved specimen (archive number GIT 434-1 ) were studied in 2008 with the help of a computer tomograph (CT ) Details of the fins. It turned out that previous studies had been in error, as the result of extensive bone structures in the fins had been described. This one had the time concluded that the bones of the fingers and toes only later - had developed and were not already created in the skeleton of the fish - in the terrestrial vertebrates. In the CT images now created distinguished themselves in the fins of Panderichthys contrast significantly from numerous bones, which were interpreted as a precursor of the products resulting from them finger and Zehknochen.

Spiracles

The remarkable thing about this fossil are also the two strongly enlarged spiracles (breathing holes) in the gills. The group of researchers from Uppsala interpreted these openings in Nature than those openings, which later the ear canals of land vertebrates developed, especially the middle ear. Also the formation of the bone at the top of Panderichthys have on their studies, on both characteristics of fish and of land vertebrates. When primeval Panderichthys the spiracles would, however, still clearly served the receiving water and were therefore possibly expanded in the course of evolution of the species, because the animal often dormant lay on the ground. This primarily of underwater breathing serving the bony canal was possibly used during the further course of evolution of these vertebrates later for air breathing and later closed with a skin, from which emerged the eardrum.

These findings occurred at a copy of the Latvian Museum of Natural History in Riga and make according to the authors, further evidence is that even the most complex organs such as the ear canal have emerged through the process of evolution from simple precursor lesions. The trade journal "Nature" pointed this change in a comment so as to: "Our ears once breathed. " ( German: " Our ears have once breathed. " )