#ornithoscelida

[opabinia--regalis]

ok here's some dinosaur yappery, why i think ornithoscelida is the most parsimonious explanation for numerous aspects of early dinosaur evolution:

phylogeny from crown aves up to the base of archosauria (as i mentioned i no longer regard this placement of lagerpetidae as accurate but that's a minor detail):

[dinofloof]

Huh, come to think of it, I wonder if Ornithoscelida ever gained any steam…

…

Nope, doesn’t look like it! ¯\_(ツ)_/¯

[a-dinosaur-a-day]

it's been a while, how's the validity of Ornithoscelida faring?

Pretty much dead in the water, the study that showed it was pretty bad it turns out

[paleonativeart]

Day 8: Scutellosaurus lawleri

A Navajo woman saw a small armored dinosaur right a side of her. Why give a nice taste of #nativember along with #Dinovember for the same month.

[ask-palaeoblr]

As how legit is the Ornithoscelida theory regarded these days? What are the pros and cons?

[drawingwithdinosaurs]

What do you think of the reclassification of theropods and ornithopods into ornithoscelida? I think that it kinda makes sense but its still pretty weird.

This has been sitting in my inbox for ages because I’m lazy and forgetful, oops.

My initial reaction the day Ornithoscelida dropped boiled down to a giddy “NO WAY, WHAT?!?!” (albeit with more expletives). It was a pretty bold and exciting claim to make if it could be backed up, and while sceptical I was quite willing to embrace it. To me, it made enough sense on principle and neatly tied together a few things, like how theropod-like things like heterodontosaurids were. But when the hype died down and the study was dissected more, it turned out the phylogenetic data used that found Ornithoscelida was flawed, and rebuttal studies specifically testing early dinosaur relationships were published that still favoured Saurischia and Ornithischia over Ornithoscelida (just), and there’s an upcoming response using a fixed version of their data that doesn’t sound like it bodes well for Ornithoscelida. I found Ornithoscelida compelling when it was first published but I have to admit that today I’m more swayed that Saurischia and Ornithischia are correct after all.

Something I do appreciate Ornithoscelida for doing, though, is tearing down the rigid Saurischia/Ornithischia dichotomy that’s been emphasised in dinosaur education ever since they were brought back together in the 70s. The split between them had been treated as an important division amongst dinosaurs, but when you get down to it all the early dinosaurs are so similar to each other that there would be nothing particularly significant about it. The individual originations of theropods, sauropodomorphs and ornithischians would all have more merit than the split into Saurischia and Ornithischia by itself. The fact that studies have found that Ornithoscelida and even Phytodinosauria are only slightly less favourable than Saurischia is also pretty important in highlighting just how uncertain early dinosaur relationships are. Ornithoscelida may not be rewriting the books, but it has an important contribution to the sections on dinosaur evolution.

(I’m also really quite fond of the name too, especially since it’s resurrected from a long forgotten bit of dinosaur taxonomy, gotta love that. In hindsight though, I kind of wish it could have been brought back for the clade of silesaurids + dinosaurs. Like, Ornithoscelida was originally named for dinosaurs + the supposedly “dinosaur-like” Compsognatha, it fits so well thematically!)

[astrodraws]

Inktober may be long past, but I still have my list! CARNOTAURUS SASTREI, the meat-eating bull. So mean.

[mcblackneck]

Some Mongolian fauna consisting of “Tarbosaurus bataar” and “Tsaagan mangas”. My Opus magnum when it comes to photoshop and I must admit that I’m really satisfied with the result!