<
https://theconversation.com/sharks-now-roam-the-open-ocean-but-for-200-million-years-they-only-lived-near-the-sea-floor-264265>
"When you picture a shark, you probably think of a large, powerful predator
cruising the open ocean.
Species such as the great white shark, tiger shark and bull shark dominate
popular media, with stories of rare and isolated cases of attacks on humans
(such as the tragic death of surfer Mercury Psillakis last Saturday on Sydney’s
northern beaches) instilling a widespread fear of sharks in the public, and
influencing government policy. For example, the expanding use of shark nets and
other “control equipment” across Australia.
While these three species are certainly charismatic predators, they represent
less than 0.6% of living sharks. The more than 500 species of living sharks
exhibit an astounding diversity of shapes and sizes, from giant 20-metre-long
whale sharks to phone-sized bioluminescent lanternsharks, flattened angel
sharks, hammerheads, sawsharks, goblin sharks and wobbegongs.
But how did sharks become so diverse? A new study I led investigated the
evolution of body shape in sharks from their ancient ancestors more than 400
million years ago, all the way to the present day."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
