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some unsolicited thoughts on the worst dinosaur
ok first off YAY this is a really great paper that covers a lot of great points and officially makes several valid criticisms official. Kudos to the authors @Dave_Hone and @TomHoltzPaleo, really great and comprehensive work
I had to focus on the section on the tail, cause that interests me. Stoked that the authors have brought Schwarz-Wings et al., 2009 into the discussion! If there's any prior work that might reveal the aspects of Spinosaurs' tail, it's that. Yay Hone and Holtz!
Hone and Holtz also do a really great job of using this paper to refute the tail-propulsion interpretation. Long neural spines + weak/no zygapophyseal interactions = poor propulsionary organ. I gotta say Hone and Holtz is making me smile
A conclusion of Schwarz-Wings et al., 2009 may have been differently interpreted however: the high distal caudals that lack zygapophyseal overlap were suggested to represent an adaptation to steering - the distal tail becomes a rudder, as in modern crocodilians
Whether this applies to Spino requires biomechanical and muscular study of the caudal region. The epaxial caudal muscles of dyrosaurids didn't actually leave obvious scars - afaik this is attributed to intervertebral ligaments in S-W et al. Did spino have a more muscular tail?
Maybe Spino was using its tail as a rudder, like hyposaurines. A detailed study of the caudal muscles and stresses like Schwarz-Wings et al. is definitely needed. All in all though, a swimming pursuit predator seems unlikely. Great job Hone and Holtz! They absolutely killed it!!!
