I love bats

and moles

Did you know that the smallest mammals are bats (by volume, apparently the Etruscan Shrew has the smallest mass on average (1.95g compared to the bat's average 2g), but who's weighing all these bats and shrews?) 

 

But not this guy

this is a paniki or kabog, known in the west as the giant golden-crowned flying fox

it's so large and furry

finally a bat big enough to hug

I would like to go to the Philippines to hug this guy

Also you must notice that it has large ears and eyes

and they look like very normal and mammalian. The nose is snout shaped like other mammals (dogs)

This guy does not echo locate. You know this because of its normal mammal face. They use their large eyes and ears to sense stuff and do not bounce sound waves

This is the smallest bat

It is also the smallest mammal 

How cute!! but i cannot hug this one (it might die)

WHat the heck??? so cute!!

This bat is also south east asian and it is called Khun Kitti Bat or Kitti's Hog-nosed Bat named after zoologist Kitti Thonglongya. 

They have a classic fucked up bat face that echolocators have

You can see that their nose/mouth area is looking kinda messy. These are leaf nosed bats that have that structure to make calls to echolocate. As such, they have small eyes compared to good eyesight bats.

So far it is believed that all bats come from the same common ancestor and different mammals did not convergently evolve to become flying mammals. This makes a lot of sense and evolving into a powered flight animal seems very unlikely.

No one knows what was the common ancestor to all the bats. They assume is some sort of flappy glidey mammal like a sugarglider but no fossil has been discovered here. It was like suddenly bats arrived and even the oldest fossils of bats look so much like current bats

It's possible that their ancestor lived in a particular geography that did not present good conditions for fossilisation, but as soon as flight was gained, the bats were able to leave and go literally anywhere and more bats in more places = more fossils

See, like this diagram hypothesises that their common ancestor is a non flying mammal, that branched off into phylogenies that gained flight at different times. I think this is probably not the case

I think it's probably more like this where 1 "species"* of bats gained flight and then went on to be the common ancestor of all bats

obviously it's not impossible but it would be pretty shocking that the same mammal went on to have separate lineages that independently evolved flight

i guess if the environmental pressures were the same?

But it's unlikely that we will ever know. The flappy glidey mammals probably did not fossilise well so we won't know what came before the bats

*species is a useful term but it is contextual.. it is not solidly defined (because biology is messy and unpredictable) as it has to be used in a case by case way. there are always exceptions