Pterosaurs most likely did not have feathers (feathers appear to be a dinosaurian invention). However, many do appear to have had a body covering of some sort, usually filamentous in nature, and more akin to fur than feathers (and technically referred to as ‘pycnofibers’). See, for example, here.
“Pyncofibers.” I like that. Not quite as catchy as “thagomizers” but it will do.
This is a thagomiser to all who weren’t sure.
By the way, it’s now the official term for the spikes on the end of the tail of a stegosaurus. Just another way Gary Larson’s name will live on forever through science.
Classification by descent isn’t the only meaningful kind of classification. Another kind is evolutionary grade, of which reptiles is the most common example.
It would be nice to have a word for dinosaurs that excludes birds, though I’m not sure it would quite qualify as an evolutionary grade. Unfortunately, we don’t (yet), so for now, we’ll just have to hobble along with the annoying ambiguity; when someone says “dinosaur” we have to wonder, if it’s not clear from context, whether they mean the clade (including birds) or the grade (excluding birds). When used informally, it’s not even clear whether it includes pterosaurs, etc.
Ideally, we’d just pick a nice new word for the clade that includes all dinosaurs, and continue to use the common term “dinosaur” to mean those extinct things. Unfortunately, we already christened Dinosauria, so that ship has sailed.
Words have different meanings to different people. Many words that are used both technically and commonly have rather different shades of meaning depending on the context. I think it is quite reasonable to say that “birds are not dinosaurs” and “birds are dinosaurs” depending on which meaning of the word you are using.
That’s just how living languages are. Words evolve, just like dinosaurs into birds.
I asked a paleontologist why were birds included with dinosaurs. Yes, they are evolutionary offspring, but there are differences. Only a small minority of dinosaurs evolved into true birds, and birds have evolutionary features not found in what most of us would consider dinosaurs. Amphibians evolved from fish, and we don’t call them land fish.
He told me that paleontologists are little kids at heart. They like playing in the dirt and running around outside. The idea that the dinosaurs they played with and loved as kids were still around was just too much to resist. We all dreamed of what the world would be like if we could have a pet dinosaur, and now we can.
Aron Ra has an interesting YouTube video on the subject, titled Pterosaurs are Terrible Lizards.
One factor is that birds arose among dinosaurs much more recently than mammals and dinosaurs arose among amniotes.
That line of reasoning could be used for literally every animal, extant or extinct. All taxa, pretty much by definition, have evolutionary features their ancestors did not possess.
Right, yet still, for most, the taxa make sense. For example, reptiles, fish, and mammals are all vertebrates. There isn’t a taxonomic category that includes all three but means “fish” to most of us. I suspect that the main reasons for this are simply historic accidents and good guesses on the part of folks like Linnaeus.
I bet there are plenty of cases where the common names cause the same kind of confusion that we have with birds and dinosaurs. There certainly are plenty of cases where we have two words for groups that aren’t really distinct, scientifically. (Turtles vs. tortoises, frogs vs. toads – both distinctions meaning different things in the UK versus the US, and neither mapping well to significant taxonomic distinctions.)
I followed this whole discussion for 12 freeking years (not really, just today) and then you go and do this to me…
What very recent fossil discovery?
And why did it throw a great deal of confusion into the relationship between sharks and bony fish?
Curious minds want to know!
Whenever someone wants to go out for “fish” for dinner, I say “I’m not in the mood for ‘fish’, can we go get some mammal?”
I suspect he’s referring to Ozarcus mapesae, an early shark that demonstrates that a) modern sharks are far more evolved than previously thought (i.e., they are not the “living fossils” they have often been said to be), and b) the jaw structure of living sharks is probably more derived than that of early bony fishes (Osteichthyes) - previously, it was believed that the gill structures of sharks represented the ancestral condition for most jawed vertebrates. This find might shake up where sharks (Chondrichthyes) fall in with jawed vertebrates (Gnathostomata), relative to the bony fishes.
All the more reason, really, why we should not be guided by the vernacular definitions for various groups. Taxa are redefined when new evolutionary information becomes available. That’s necessary to make sure that scientists, at least, are all on the same page when referring to a given group. If the redefinition makes sense, it catches on, and becomes standard. If it doesn’t make sense, then the redefinition is largely ignored.
Such redefinitions as are considered valid, then, filter, albeit more gradually, into the general populace. Schoolchildren today, for example, have far less resistance to birds being considered dinosaurs than many folks who were taught the more traditional (and increasingly outdated) Linnaean taxonomy, with Reptilia and Aves in separate Classes.
Thank you Mr. Finch. Fascinating topic…some of it over my head, but enlightening nonetheless. Although it didn’t happen, I wanted to be a paleontologist as a kid, and this just tickled the kid in me, thanks.
Thanks John