In a shallow river arm, a pair of Acanthostega release eggs into the murky water, where they will develop protected by the maze of plant debris. In the background, some Groenlandaspis swim around.
This scene takes place in Greenland during the Late Devonian, around 365 million years ago.
The Devonian was a time of big changes, as terrestrial plants began to form huge forests, fish reached a diversity level never seen before and the tetrapods (a group including all amphibians, reptiles, birds and mammals) were taking their first steps on land.
Acanthostega was around 0.6 meter in length and inhabited freshwater ecosystems in Greenland, which at this time was positioned just south of the equator.
Its morphology led researchers to conclude that it had a fully aquatic lifestyle, in contrast to the famous tetrapod Ichthyostega, which probably was able to walk on land.
Groenlandaspis was a placoderm, a group of armoured fish from the Silurian and Devonian.
While some other members of the placoderms reached enormous sizes, the species Groenlandaspis mirabilis from Greenland was only 7.5 cm long.
by 'Paleo Pete' Peter Nickolaus
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