tutor: Mike Horne FGS

for the Centre for Life Long Learning

University of Hull

Most of the fossils we find are of invertebrate animals living in an aquatic environment. Here are some scientific jargon words we can use to describe their mode of life.

Benthic (or Benthonic) - living in or on the bottom.
Boring - benthic organisms that bore into a solid surface.
Burrowing - benthic organisms that burrow into soft sediment.
Epifaunal / Epibionts - benthic organisms living on the surface of the sediment or rock.
Flotsum - floating on the surface of the water.
Flying - living above the seas/land.
Infaunal / Endobionts - benthic organisms living in the sediment or rock.
Nektobenthos - swimming near and resting on bottom surface.
Nektonic - swimming in the water column.
Pelagic - living in the water column.
Planktonic (or Planktic) - floating or drifting (not swimming) in the water column.
Sessile - benthic organisms that do not move around.
Water-column - imaginary "column" of water between the surface and sediment on the bottom.
Vagrant - benthic organisms that move around.

Deposit feeders - feed on the sediment - may be swallowers (eat sediment as a whole) or collectors (pick bits of food out of the sediment).
Grazers - feed off the sediment/bottom surface.
Parasites - often attached to and feeding off another organism, without killing it.
Predators - actively hunt their food.
Scavengers - feed off dead animals, food left by others, what ever is available.
Suspension feeders - feed off particle suspended in the water.

Supratidal - above High Tide
Littoral - between High and Low Tides
Sub-littoral - below Low Tide
Continental shelf - shallow seas around continental margins - up to 200 m deep.
Neritic realm - the water on the continental shelf
Photic zone - water lit by sunlight, up to 200 m deep.
Bathyal - The Continental slope from the shelf down to the abyssal plane
Oceanic Realm - water over 200 m deep
Aphotic - water that receives no sunlight, over 200 m deep.
Abyssal plain - the bottom of the Oceans - 4 to 5 000 m deep.
Hadal - deeps and trenches over 5 000 m deep.

Planktonic - light weight; some species thickening in part of shell to float deeper in the water column; may have been attached to something floating.

Nektonic - streamlined; some form of defence; sharp teeth for attack.

Epifaunal - rooted; flattened on one side; thickening of shell to protect from predators and high energy environment; spines for defence; large surface area to stop sinking in soft sediment.

Infaunal - streamlining for burrowing; blindness; reduction in shell thickness and defence; ornament may be smooth for burrowing or perhaps rough for boring.

copyright Mike Horne - 2019

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