Fossil of the Month
Fossil des Monats
Fossile du mois
April 2020: Cetacean vertebrae. Beaumaris Sandstone, Beaumaris. Collected and curated by Bayside Earth Sciences Society in 2019.
Once upon a time, some six million years ago, a small whale, probably much the same size as a large dolphin, was swimming in Balcombe Bay. For some unknown reason, it died. Perhaps it was diseased, for if it had been attacked by a larger predator, the bones we see in this image would probably not be aligned as they are.
After death, the whale’s body sank to the seafloor, where it was covered in sediment before scavengers had an opportunity to tear the carcase apart. What looks like a series of alternating vertebra and vertebral discs is actually part of a vertebral column of a young whale. Each vertebra in this example is made up of a larger primary vertebral body (about 50 mm long), with a thinner, ossified epiphysis at each end (each about 9 mm thick). If the whale had lived to become an adult, these three portions would have joined together, generally obscuring the suture between the components. This slab of rock, from the Beaumaris Sandstone at Beaumaris, contains the four partially ossified whale vertebrae.