Alassa

Geological time

Miocene

Age: 13.6–11.6 million years ago
Period: Middle Miocene (Serravallian)
Formation: Pakhna Formation
Depositional environment: Deep marine slope basin (bathyal)
Fossil types: Fish (e.g. pipefish, cutlassfish), echinoids (heart urchins), cephalopods (Argonauta, Aturia), planktonic foraminifera, pteropods, nannofossils, occasional plant fragments
Paleoecology highlights: Soft seafloor with burrowing echinoids, abundant plankton, occasional anoxic events, nearby vegetated landmass shedding organic debris

During the Middle Miocene, the area around modern-day Alassa was submerged beneath a quiet, deep sea. Far from any shoreline, the seafloor lay hundreds of meters below the surface, covered in soft, pale mud made from the steady rain of microscopic plankton shells. The water above was calm and dimly lit, fading into a rich, dark blue. Life here was sparse but specialized; heart-shaped sea urchins slowly moved through the sediment in search of food, while the remains of drifting plankton and deep-sea fish settled gently onto the seabed. Occasionally, leaves from nearby forests on the rising Troodos landmass would drift down to the depths, hinting at green hills beyond the horizon. This was a peaceful, still environment; remote, nutrient-rich, and largely untouched by waves or sunlight.

Map

Tree of Life

Alassa

Actinopterygii

Aves

Bivalvia

Chordata

Coleoidea

†Heterobrissus montesi

Ostreida

Plantae

Unclassified

Venus