New Fossils Redefining a Dinosaur

[Troodon]

A new Science News article talks about how new fossils are changing our views of what makes up a dinosaur.  Interesting reading.

 

https://www.sciencenews.org/article/new-fossils-are-redefining-what-makes-dinosaur

 

 

[Tidgy's Dad]

Yes, very interesting, we still have so much to learn. 

Th skull depression, though, could still be said to be a feature only of dinosaurs and their stem group? So anything post Triassic with this feature must still be dinosaurian, surely. (as far as we know thus far). 

[Troodon]

3 minutes ago, Tidgy's Dad said:

Yes, very interesting, we still have so much to learn. 

Th skull depression, though, could still be said to be a feature only of dinosaurs and their stem group? So anything post Triassic with this feature must still be dinosaurian, surely. (as far as we know thus far). 

With discovery comes a new understanding of how little we indeed do know about theses creatures.  The way I read the article the hole in the hip socket is the only feature diagnostic to Dinosauria.  All the others are not certain.

[Tidgy's Dad]

2 hours ago, Troodon said:

With discovery comes a new understanding of how little we indeed do know about theses creatures.  The way I read the article the hole in the hip socket is the only feature diagnostic to Dinosauria.  All the others are not certain.

Hmmm, so birds have this as well, one supposes, that must be what makes them dinosaurs. 

Yet some dinosaurs don't have an opening all the way though eg. ankylosaurs , but a hollow on each side? https://books.google.co.ma/books?id=M00_DwAAQBAJ&pg=PA18&lpg=PA18&dq=ankylosaurus+hip+joint&source=bl&ots=KjPDasiaAd&sig=PYydw7Upbz7FaQDdfEY9ROmf7ts&hl=en&sa=X&ved=0ahUKEwj8hKyJ7rnZAhWGWCwKHQY7D5UQ6AEIbzAK#v=onepage&q=ankylosaurus hip joint&f=false

 

[Troodon]

35 minutes ago, Tidgy's Dad said:

Hmmm, so birds have this as well, one supposes, that must be what makes them dinosaurs. 

Yet some dinosaurs don't have an opening all the way though eg. ankylosaurs , but a hollow on each side? https://books.google.co.ma/books?id=M00_DwAAQBAJ&pg=PA18&lpg=PA18&dq=ankylosaurus+hip+joint&source=bl&ots=KjPDasiaAd&sig=PYydw7Upbz7FaQDdfEY9ROmf7ts&hl=en&sa=X&ved=0ahUKEwj8hKyJ7rnZAhWGWCwKHQY7D5UQ6AEIbzAK#v=onepage&q=ankylosaurus hip joint&f=false

 

No idea on the birds or Anky.  I dont profess to be very knowledgeable on hips.

[Miocene_Mason]

4 hours ago, Troodon said:

I dont profess to be very knowledgeable on hips.

Somebody call in the paleohipologists!

very informative, thanks for posting!

[BobWill]

Thanks for posting this story. I had heard about it but not seen it yet. This all makes perfect sense given the slow and subtle way changes occur in different groups. As more characters are compared and more and earlier dinosaurs are available to examine this may get even more blurry. This also makes the old "where are the missing links" question sillier than ever. Now it takes hundreds of different species to see major distinctions. It's how evolution works. I was surprised to see an important feature didn't even make the "long" list. How many fenestra (holes) are in the skull was considered important just a few years ago when I took an online course on dinos.

 

[Troodon]

11 hours ago, BobWill said:

. I was surprised to see an important feature didn't even make the "long" list. How many fenestra (holes) are in the skull was considered important just a few years ago when I took an online course on dinos.

 

Good point but you're correct and its the course from the Tyrrell.  Don't have an answer.