Ethel the Aardvark goes Quantity Surveying

photograph by Tim's Australian Nature Pics

just cleansing my energy<3

No thoughts just Sit In Tube

But then around 30 million years ago — halfway through the Age of Mammals, give or take — something happened. The nautiloids started disappearing. Fewer species, less diversity. Bit by bit they shrank back into their current small range. What happened halfway through the Age of Mammals? Well, here’s one clue: the nautiloids’ long retreat showed a pattern. It wasn’t everywhere and all at once. They disappeared first in the northern arctic regions; then in the Antarctic; then in temperate zones; finally across most of the tropics except that one small patch. This pattern suggested a culprit: a warm-blooded predator that evolved in the Arctic and then spread around the world. But… the armored cephalopod design had been around forever. They’d been living with predators for half a billion years. Sharks. Primitive armored fish. Not-so-primitive modern fish. In the age of dinosaurs, they had to deal with ichthyosaurs, plesiosaurs, and mosasaurs. Back in the Paleozoic, they were hunted by eight-foot-long giant sea scorpions. Way back in the Cambrian, they had to live with the anomalocariids. In the early Age of Mammals, there were primitive whales and sea-going crocodiles. The armored cephalopod design took them all in stride and kept going. So what happened?

obsessed with this photo. the face of a slurper

I recall some book recounting how mammals turned their face inside-out during our evolution in the latest Paleozoic -- reptiles and bird mostly have their head and jaw muscle inside their skulls, mammals mostly have them outside. This also allows us to have complex facial expressions, which are vital for mammalian communication, and only exist because of milk.