The closest kinfolk of modern-day sharks, hybodontiform sharks, first appeared through the newest Devonian, roughly 361 million years in the past.
These went extinct along with dinosaurs on the finish of the Cretaceous interval, an period estimated to have ended roughly 66 million years in the past.
They’d two dorsal fins, every supported by a outstanding fin backbone and the sharks’ measurement ranged from mere centimetres to roughly 10ft (3m) in size.
This consequently makes Asteracanthus one of many largest representatives of each its species and period.
For perspective, fashionable sharks, which have been already various through the Jurassic, solely grew to 7ft (2m) in size in very uncommon situations.