Australasian Science: Australia's authority on science since 1938

The Heart of a Good Fossil

By John Long

Palaeontologists have found their Holy Grail: the fossilied heart of a Cretacean fish.

The full text of this article can be purchased from Informit.

Most of us think of fossil vertebrate remains as being bones or teeth. In rare cases we can sometimes see skin impressions or the outline of feathers on fossil birds and dinosaurs, but these are among the top 1% for fossil preservation.

Such exquisite fossils come from deposits called konservat laggerstätten (meaning “place of storage”), which are the result of rapid burial and special chemical conditions involving low-oxygen environments. In special cases these deposits can preserve or mineralogically “ghost” a range of soft tissues, even complete internal organs, in the fossilised organism.

Scientists have long known about the famous Burgess Shale fossils in British Columbia, where soft-bodied worms and other invertebrate creatures were buried by rapid mud slides around 508 million years ago. However, well-preserved fishes from the 113–119 million-year-old Santana Formation of Brazil were among the first vertebrate fossils to show evidence of preserved soft tissues. These include parts of the glandular stomachs and bands of muscles, with the original tissue mostly replaced by chemical processes.

To find whole preserved internal organs in a fossil is the Holy Grail of palaeontology. Such discoveries contribute a wealth of new anatomical information that is essential for understanding evolutionary patterns.

Therefore the recent discovery of a...

The full text of this article can be purchased from Informit.