Submitted 9 hours ago by xkcdbot@lemmy.world [bot] to xkcd@lemmy.world
https://imgs.xkcd.com/comics/dinosaurs_and_non_dinosaurs.png
xkcd #3204: Dinosaurs And Non-Dinosaurs
Title text:
Staplers are actually in Pseudosuchia, making them more closely related to crocodiles than to dinosaurs.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: xkcd.com/3204/
Who else is in the lower right corner? 🙋♂️
I also am a stapler
TIL dimetrodon is not a dinosaur, based on a silhouette in a cartoon.
I haven't really thought about dimetrodons since I was a kid.
The name (dimetrodon ≈ two teeth sizes) is also a clue, as teeth specialization is very much a synapsid (i.e., mammal and proto-mammal) thing.
They are actually closer related to mammals than to any modern reptile
And almost all of these are fishes.
I’m a bit thick. Not certain if this is a joke that went over my head or not.
Im still in a rabbit hole trying to understand why some aren’t dinosaurs.
If you take the tree of life showing the evolutionary branch, you won’t be able to pick off a branch that includes all of the things you would think of as “fish” but excludes all of the things you think of as “not fish”.
The reason for that is that all land animals with a four limb body plan, including reptiles, mammals, and birds dinosaurs evolved from a family of fish called tetrapods. But there are still tetrapods in the ocean that you would think of as “fish”, and I don’t mean whales.
Hank Green has a much more entertaining and complete discussion at youtu.be/-C3lR3pczjo
Basically all life on Earth that’s not some bacteria or fungi originally developed in the oceans, and only later adapted to life on land. If you go back far enough, the common ancestor of anything that walks, crawls, or flies ultimately originally swam.
Non-biologist here. Is this a taxonomy thing? So, if it’s under /animalia/chordata/reptilia/dinosauria/, it’s in that dino box, right?
What about penguins then? According to Wikipedia, they’re under /animalia/chordata/aves/etc. I don’t see …/reptilia/dinosauria/ anywhere in that classification. Likewise, seagulls are under /animalia/chordata/aves/… etc. so nowhere near dinosauria. What am I missing here?
What am I missing here?
That untangling evolutionary history is really messy :D It’s not part of Kingdom/Phylum/Class/etc classification, but biologists also use clades to understand evolutionary history. Birds and theropod dinosaurs belong to the clade Theropoda, and to the clade Saurischia which includes some more dinosaurs, and they all belong to the Dinosauria clade which includes all dinosaurs.
The division (as interpreted by evolutionary biologists) between birds and the rest of Saurischia is smaller than the division between Saurischia and the rest of Dinosauria. So, if everything in Dinosauria is a dinosaur, so are birds.
Ok, so what’s the deal with this clade thing? Why don’t we use that for classifying birds?
Then again, maximizing the number of inconsistent exceptions seem to be a running theme in biology, so I guess it’s on brand…
The title text is a further joke about taxonomy, predicated on the assumption that staplers are biological organisms (which they are not)[citation needed]
If penguins are still dinosaurs, then earth is still solely inhabited by single cell organisms and we’re clearly not.
wdym “still” dinosaurs? you can’t evolve out of a clade
I’ve never heard of a clade for single cell organisms, though there are some that only contain single cell organisms
I’d put the stapler in the “seem like/are not” section. Raaaarrrrr
Seems like dinosaur, isn't: https://i.ebayimg.com/images/g/TGwAAOSw9mFWHRS~/s-l400.jpg
GraniteM@lemmy.world 8 hours ago
Fuck that, I’ve been in close proximity to ostriches and emus and they one hundred percent seem like dinosaurs.
Image
TwodogsFighting@lemdro.id 8 hours ago
Cassowaries are even worse.
GraniteM@lemmy.world 7 hours ago
The cassowary was the only thing in the zoo that Steve Irwin seemed a little bit scared of. There’s an episode where the cassowary got loose and he immediately stopped joking around and told all the keepers to go get the shields to corral it back into its pen. I wouldn’t dream of fucking around with a cassowary.