Trilobite and sea star fossils
Trilobites are a group of arthropods that were one of the most abundant types of animals in the oceans between about 540 and 350 million years ago, after which they declined and finally became extinct about 250 million years ago. They are important fossils for dating rocks, interpreting the environments in which the rocks were deposited, and in helping to determine the relative positions of the ancient continents.
Trilobites are also popular with fossil collectors because of their great age and their complex and fascinating form. This specimen, of Early Devonian age (approximately 400 million years old), is from Morocco, where many exceptionally well-preserved trilobites have been found. It belongs to the relatively rare genus Kolihapeltis, characterised by long, backwardly curving spines arising from above the eyes and the back of the head.
The fossil sea star, belonging to the species Eoactis stachi, was found in 1980 near the corner of Russell and La Trobe streets during excavations for the Melbourne Underground Rail Loop.
Numerous other fossil sea stars and other types of echinoderms, such as ophiuroids (brittle stars), crinoids (sea lilies), and extinct groups such as cystoids, edrioasteroids, blastoids, ophiocistioids and the bizarre carpoids, occur in large numbers at certain localities in siltstones and sandstones of Late Silurian and Early Devonian age (400 million to 420 million years ago) in central Victoria. They represent one of the most diverse and scientifically important records of these fossils from rocks of this age.