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Dinosauria
 

Dinocephalosaurus waiting on the bottom, feeding at mid-levels and inhaling a throat bubble at the surface which can be passed to the lungs only after resuming the waiting/resting position.

If Not Vacuuming Fish, What Then?
Instead Dinocephalosaurus would have been a stealthy bottom-dweller with eyes able to look dorsally. When fish came within its strike-zone, the long neck could raise the toothy skull to snare one (Fig. 2). In this hypothesis, everything works like it looks like it should work, convergent with Plesiosaurus.

Bottom-Dwelling Respiration.
Respiration would have been a two-step process: raising the head to the surface to gather a bubble in the gular sac, then sinking the head to the bottom before passing the bubble horizontally back to the lungs. Otherwise, if the neck was vertical and underwater, the difference in water pressure would have prevented dorsal rib expansion and inhalation to move the air bubble down by expansion of the lungs, as smaller reptile, like turtles, practice.

A second specimen
attributed to Dinocephalosaurus (see below) was more recently described by Liu et al. 2017. A juvenile was inside, perhaps awaiting live birth or a trip to the beach for egg-laying. Distinct from the first specimen the fourth toe was longer, the cervicals were more slender and numerous and the tail was more robust.

 
Tritosauria
Tijubina
Huehuecuetzpalli
 
Tanystropheidae
Macrocnemus
Dinocephalosaurus
Amotosaurus
Langobardisaurus
Tanytrachelos
Tanystropheus
 
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Cosesaurus
Kyrgyzsaurus
Sharovipteryx
Longisquama
MPUM6009
other pterosaurs

 

 

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