biostratigraphy

Between the weird and wonderful rangeomorphs of the Ediacaran Period and the world-famous palaeocommunities of the Burgess Shale, the 'Early Cambrian' is host to a 'waste basket' of fossils untied by their small size and shelly construction.

These small shelly fossils (SSFs) aren't just a single group of animals, but represent several different invertebrate phyla. Further compounding the difficulty of their identification, each SSF, termed a 'sclerite', is part of a larger composite skeleton known as a 'sclerotome'. Whilst some complete sclerotomes have been preserved, many SSFs still represent multiple jigsaws thrown together and the pictures lost.

Piecing the SSFs back together and building a picture of the Earliest Cambrian is Dr Marissa Betts of the University of New England, Australia. Her work on the SSFs have provided a new framework for the regional stratigraphy of Australia and in this interview, we discuss why this was necessary, how she went about it and finally, what we know about the animals themselves.

Between the weird and wonderful rangeomorphs of the Ediacaran Period and the world-famous palaeocommunities of the Burgess Shale, the 'Early Cambrian' is host to a 'waste basket' of fossils untied by their small size and shelly construction.

These small shelly fossils (SSFs) aren't just a single group of animals, but represent several different invertebrate phyla. Further compounding the difficulty of their identification, each SSF, termed a 'sclerite', is part of a larger composite skeleton known as a 'sclerotome'. Whilst some complete sclerotomes have been preserved, many SSFs still represent multiple jigsaws thrown together and the pictures lost.

Piecing the SSFs back together and building a picture of the Earliest Cambrian is Dr Marissa Betts of the University of New England, Australia. Her work on the SSFs have provided a new framework for the regional stratigraphy of Australia and in this interview, we discuss why this was necessary, how she went about it and finally, what we know about the animals themselves.

Ostracods are tiny crustaceans (relatives of shrimps, crabs and water-fleas), distinguished by having a shell that is easily fossilised. As microfossils, by virtue of a long and rich fossil record, ostracods are extremely useful for determining the age of the sedimentary strata in which they are found, as well as providing clues to the nature of the environments and climates in which those deposits were formed. The first ostracods lived in shallow continental shelf seas during the early Ordovician period nearly 500 million years ago, later spreading and diversifying into deep oceanic as well as continental environments such as lakes and rivers.  Today, as living organisms, they are globally widespread and diverse, inhabiting almost every kind of aquatic environment from the abyssal depths of the oceans to freshwater ponds.