Mosasaur Vertebrae ID

[FOSSIL FARMER]

I'm hoping someone out there might be able to ID these vertebrae for me. I'm fairly certain they're mosasaur of some type, but I'm not very familiar with this vertebrate stuff. I'm thinking the other bone is part of a paddle.  I found these in the Pierre shale of South Dakota on private property with permission.

 

[M Harvey]

Definitely mosasaur vertebrae.  Species ID is above my pay grade.  The second photo looks like a partial mosasaur scapula.

[FOSSIL FARMER]

Definitely above my pay grade as well. The other bone was somewhat stuck to one of the verts by shale when I found them. I should've gotten better end photos of it, but it is complete on both ends.Thanks for the confirmation.

[hemipristis]

Yup, mosasaur. Nice ones, too

[Praefectus]

Nice pieces. Definitely mosasaur bits, but I'm not sure they are identifiable. 

[FOSSIL FARMER]

Thanks, I wasn't sure if certain types had identifying spinal characteristics. I mostly find ammonites, crabs, and lobsters, so this mosasaur stuff is all new to me.

5 hours ago, Praefectus said:

Nice pieces. Definitely mosasaur bits, but I'm not sure they are identifiable. 

 

[pachy-pleuro-whatnot-odon]

Based on the overall lengths of the vertebrae and the size of the parapophyses these are lumbar vertebrae.

 

(source)

 

Species is more difficult to identify, however, since mosasaur vertebrae are generally rather undiagnostic in that sense. The only thing you can basically tell is whether a vertebra can be attributed to a plioplatecarpine mosasaur or a non-plioplatecarpine by whether the vertebral face a wider rather than round. See below photograph from the Museum voor Natuurwetenschappen in Brussels:

 

A = Plioplatecarpus houzeaui; B = Mosasaurus lemonnieri; C = Mosasaurus hoffmannii

 

When it comes to the non-vertebral bit of bone you've got, this isn't a paddle bone. It's far too wide and flat for that. More likely, it's a bit of a pelvic or pectoral element, and may, therefore, indeed belong to a scapula, as had been suggested.

[FOSSIL FARMER]

1 hour ago, pachy-pleuro-whatnot-odon said:

Based on the overall lengths of the vertebrae and the size of the parapophyses these are lumbar vertebrae.

 

(source)

 

Species is more difficult to identify, however, since mosasaur vertebrae are generally rather undiagnostic in that sense. The only thing you can basically tell is whether a vertebra can be attributed to a plioplatecarpine mosasaur or a non-plioplatecarpine by whether the vertebral face a wider rather than round. See below photograph from the Museum voor Natuurwetenschappen in Brussels:

 

A = Plioplatecarpus houzeaui; B = Mosasaurus lemonnieri; C = Mosasaurus hoffmannii

 

When it comes to the non-vertebral bit of bone you've got, this isn't a paddle bone. It's far too wide and flat for that. More likely, it's a bit of a pelvic or pectoral element, and may, therefore, indeed belong to a scapula, as had been suggested.

Thanks for all the good info. I'm hoping to go back and find some more of this critter, so I might be back with more questions for all of you knowledgeable folks.