Osteolepis
macrolepidotus
Class Sarcopterygi,
Infraclass Tetrapodomorpha, Superorder Osteolepidida, Order Osteolepiformes,
Family Osteolepidae
Geological
Time: Middle Devonian (385 Million Years Old)
Size (25.4
mm = 1 inch): Fossil fish is 151 mm in length (tip of nose to tip
of tail along backbone) on 145 mm by 120 mm matrix
Fossil Site:
Sandwick Fish Beds, Cruaday Quarry, Orkney, Scotland
 Description:
The Osteolepiform fish are thought to be the ancestors of the
Tetrapoda due to their paired lobed fins being homologous to
the limbs, and the choanae (posterior nostril). Osteolepis possessed
two rounded dorsal fins placed posteriorly, and a heterocercal
tail  with
a larger lower lobe. They have thick rhombic scales covered with
a cosmine layer (hence the shine). This ancient group of fish
are thought to have given rise to the Tetrapod bauplan. This
fish fossil example is preserved in dorsolateral aspect and shows
all the
classic the features with incredible detail. Note too the very
fine finnage that has been preserved. This one was professionally
prepared in the United
Kingdom and was collected in the 1980s. With the Cruaday Quarry
no longer in operation, and declared a Site of Special Scientific
Interest
there will
be little forthcoming in the future.
Also
see: Paleozoic
Fish Fossils |
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