Many organisms that live today have barely changed their body shape in millions of years and look extremely similar to their ancestors. With the help of Sussex Wildlife Trust we have compared some of our Sussex chalk fossils, which are around 100 million years old, with modern animals that live in UK seas today.
Fossil Sea Urchin, Stereocidaris sceptrifera
Like many modern types living on the seabed, these sea urchins had spines as protection against hungry fish. This fossil is lacking it’s spines but you can still see where they would have been held.
Fossil of Stereocidaris sceptrifera, an ancient species of sea-urchin (or Echinoid). Photo by Bob Foreman
Common sea urchin, Echinus esculentus
Also known as the edible sea urchin. A large, round sea-urchin up to 15cm across with short, strong spines. Usually brick-orange in colour, with white bumps which the orange spines are attached to. Lives amongst seaweed and rocks, where it grazes on algae and small shellfish
Found on rocky shores, particularly around the north and west.
An edible species, eaten particularly in Spain and Portugal.
Fossil fish, Ctenothrissa radians sp.
Fossil fish, Ctenothrissa radians sp., this is a rare complete example of this beautiful scaly fish which was found by Charles Potter in the late 19th Century.
Black seabream, Spondyliosoma cantharus
The black sea bream, also known as a Porgy, is an omnivorous fish, eating seaweeds and small invertebrates.
Black sea bream breed in the Kingmere Marine Conservation Zone in Sussex between April and May. The males excavate a small shallow in the seabed, moving the gravel or sand around the edge to create a sort of crater into which the female lays her eggs. The male then protects the eggs until they hatch. He will fan them with his tail to keep them clear of sand or debris and wards off hungry predators, including smaller bream, wrasse and even whelks!
How to identify:
A large silvery fish, with an oval shape. Shaded bands running along the length of the upper flanks. It has a long single dorsal and anal fin and a small mouth. The tail is large and forked displaying a black band on it, most obviously noticeable on juveniles.
Juveniles usually have numerous broken yellow stripes running along the body. Spawning males are nearly completely black in colour, except for vertical white bars.
Found off south west Britain the Irish Sea and the English Channel.
All black sea breams are born female! They change to males when they reach 30cm. All fish over 40cm are male.
Lobster, Palaeastacus dixoni
This rare fossil lobster was found in the Lower Chalk, Clayton, East Sussex and is from the Upper Cretaceous era. It has been preserved in wonderful detail. First drawings of this fossil appeared in scientific journals in 1850. Collected by Henry Willet.
Common Lobster, Homarus gammarus
A large crustacean, that grows up to 1 metre long, although more typically to about 50cm in lenght. Lobsters are a deep purplish-blue colour, with red antennae. They live in crevices and caves amongst rocks from the low tide mark and deeper. Their first pair of legs have massive grabbing pincers.
How to identify:
Unmistakeable: other species of lobster are smaller and not the same colour
Found all round our coasts.
Lobsters are nocturnal, hiding during the day in their caves.