Feeds

Wedding tackle started out as PROTO-SHARKS' LEGS, boffins say

Cut me off at the knees and call me a tripod

New hybrid storage solutions

Researchers from Australia and the UK have taken a look back over the fossil records of placoderms - an early type of armoured fish - and come up with a startling suggestion: some of the earliest male genital organs known to palaeontology started out as a kind of “legs”.

Well, not quite legs, since placoderms were aquatic: rather, what the researchers have concluded in their study was that their organs, referred to as “claspers” because of the creatures' reproductive habits, started out as paired appendages rather than (as in sharks), modified single fins.

Placoderms were predators – the world's first megapredators, two of the researchers (Flinders' John Long and Curtin's Kate Trinajstic) explain at The Conversation, here. They existed for 70 million years, becoming extinct 360 million years ago, and the largest reached the size of a modern great white shark.

They're also the earliest creatures known to have evolved copulation (instead of spawning into the water), which adds spice to the interest science shows in them.

It's the detail of that copulation that the researchers, from Curtin University, the Western Australian Museum, Monash and Flinders Universities, the Australian Synchrotron, and the Natural History Museum in London have drilled into.

What they've found challenges the long-held assumption that male sex organs' evolution broadly mirrored that of the shark, in which a fin evolved to become the clasper that impregnated the female.

Placoderm mating

Placoderms' probable mating style. Image: John Long, Flinders University

“Unlike the claspers of modern sharks and rays that are a part of the paired pelvic fins, the claspers and female basal plates in placoderms were not at all connected to that fin,” Long and Trinajstic write. “Instead they developed as an extra pair of limbs further down the body.”

Further: “The claspers in placoderms can now be regarded as a serial homologue or gradual development of the other paired appendages - an extra pair of legs, so to speak.” ®

Secure remote control for conventional and virtual desktops

More from The Register

next story
Boffins say they've got Lithium batteries the wrong way around
Surprises at the nano-scale mean our ideas about how they charge could be all wrong
Thought that last dinosaur was BIG? This one's bloody ENORMOUS
Weighed several adult elephants, contend boffins
Europe prepares to INVADE comet: Rosetta landing site chosen
No word yet on whether backup site is labelled 'K'
City hidden beneath England's Stonehenge had HUMAN ABATTOIR. And a pub
Boozed-up ancients drank beer before tearing corpses apart
'Duck face' selfie in SPAAAACE: Rosetta's snap with bird comet
Probe prepares to make first landing on fast-moving rock
Archaeologists and robots on hunt for more Antikythera pieces
How much of the world's oldest computer can they find?
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
Top 5 reasons to deploy VMware with Tegile
Data demand and the rise of virtualization is challenging IT teams to deliver storage performance, scalability and capacity that can keep up, while maximizing efficiency.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.