We made this holoscape with pics we downloaded off Google images - spared no expense.
Penetrative copulation is the default setting for the Gnathostomata!
Paper = http://www.nature.com/nature/journal/vaop/ncurrent/full/nature13825.html
Summary = http://www.nature.com/news/fossils-rewrite-history-of-penetrative-sex-1.16173
(Note that on the simplified cladogram, the Chondrichthyes branch is mislabelled as Placodermi - and they've credited me as "David Choo")
About to head off for 2 weeks in the northern Simpson Desert in search of Early-Middle Devonian fish fossils. Will be out of contact until the 1st week of August.
We'll take what we can get, but my #1 goal is to find some pituriaspids.