Two Hollow Bones

[bthemoose]

I found a couple of interesting fossil bones yesterday along the Calvert Cliffs (Miocene exposure) in Maryland. Any ideas to what these belonged?

 

#1 - My guess is this one is a bird bone. It's smooth (inside and out) and hollow all the way through to the closed end. If this is from a bird, do you know what type of bone it is (anatomically)? And any thoughts on what type of bird it might be from? I realize that isolated and broken bones can't usually be identified too specifically, but this seems fairly large, so I'm wondering if there might be good candidates for type of bird.

 

 

#2 - This spike-shaped/pointy bone is also at least partially hollow inside, though the walls of the bone are thicker/more robust than the one above. I'm not sure if the central cavity goes all the way through. I've only been able to confirm that it's a few centimeters deep, just past the longitudinal holes/borings on the outside of the bone; however, I think the cavity may extend further but is filled in with matrix (I don't have the tools handy at the moment to clean more of this out). Speaking of those holes on the outside, they're irregular/asymmetrical, and I'm guessing they're post-mortem invertebrate borings.

 

As can be seen in the two photos on the bottom left there are two grooves on opposite sides that run the length of the bone--one of these is more distinct than the other, though the one on the other side might just be more worn. I haven't a clue what this one is, and would love to hear your thoughts!

 

[MrBones]

The first one looks like some kind of bovid tibia, I'd wait for other members to specify 

[bthemoose]

10 minutes ago, MrBones said:

The first one looks like some kind of bovid tibia, I'd wait for other members to specify 

Thanks, so perhaps not a bird then.

[MrBones]

2 minutes ago, bthemoose said:

Thanks, so perhaps not a bird then.

Yes, I used to think all hollow bones belonged to birds....but that was not the case. Most long bones are hollow.

[Fossildude19]

Pointed one looks like a rostrum. Bill fish? Dolphin? 

[LordTrilobite]

Those holes in the second bone kinda look like possible boring holes made by invertebrates.

[bthemoose]

9 hours ago, Fossildude19 said:

Pointed one looks like a rostrum. Bill fish? Dolphin? 

Thanks—are there things I should look for to try to narrow down to one or the other?

 

7 hours ago, LordTrilobite said:

Those holes in the second bone kinda look like possible boring holes made by invertebrates.

That’s what I think too. They seem too irregular to be tooth holes.

[Plax]

scale wrong for bovid tibia I'd think