After 1972, biologists had almost four decades to get used to the idea that birds had this amazing miraculous lung thingy that was unique in the animal kingdom. Then in 2010, Colleen Farmer and Kent Sanders of the University of Utah blew our collective minds by demonstrating that alligators have unidirectional flow-through lungs, too. That means that far from being a birds-only thing, unidirectional flow-through lung ventilation was probably primitive for Archosauria, and was therefore the default state for non-avian dinosaurs, pterosaurs, the other ornithodirans and the hordes of croc-line archosaurs.

The birdy-ness of crocodilian lungs was further cemented earlier this year when Schachner et al. described the lung morphology and airflow patterns in Nile crocs, which have lungs that are if anything even more birdlike than those of gators. I got to review that paper and blogged about it here.

Now…well, you read the headline. Monitor lizards have unidirectional airflow through their lungs, too. This falls at about the halfway point between "whatisthisIdonteven"–I mean, dude, unidirectional airflow in friggin’ lizards!–and “yeah, that makes a weird sort of sense”. Because to sum up a lot of science unscientifically, monitors just kick a little more ass than other squamates. They have crazy high aerobic capacities for animals that aren’t birds or mammals, they’re ecologically versatile and geographically widespread, they get waaay bigger than any other extant lizards (Komodo dragons) and until recently got even bigger than that (Megalania). Is it going too far to link the success of varanids with their totally pimpin’ flow-through lungs? Maybe, maybe not. But it seems like fertile ground for further study.