Need help identifying

[Kevin Carter]

My friend recently began finding presumably Mammut bones in a ditch bank on the family's property here in northern Indiana. He also found this unidentified specimen at the same site. At first glance, it looked to me like one of the many horn corals I've found in southern Indiana, but that obviously didn't make sense given the context. The specimen measures 2-1/8" long by 1-1/4" in diameter. Any ideas? In case you're interested, I've also included a shot of some of the bone fragments found so far. Both bone fragments (which fit together) combined measure 14" long, 3" at its widest point (the joint), 2" at its thickest.

[Al Dente]

The smaller object is a horn coral. 

[Miocene_Mason]

The horn coral could be either washed in, brought in by glaciers, or just in the underlying rock with Pleistocene unconsolidated sediment above if it is indeed a mammoth, I'm not sure if it is though, @Harry Pristis might know better than I.

[ynot]

Welcome to TFF!

I do not see a horn coral here.

It looks like a partial iron concretion, but the pictures are too small to make out enough detail to be sure.

It would help if You could load larger pictures so We can see more detail. Especially of the two brown spots in the first closeup You already posted.

You can add more pictures in the reply section.

[Kevin Carter]

Thanks for your input. As I mentioned in the description, a horn coral was my first impression too. I've collected many horn corals through the years. Everything I have collected, however, has been calcitic. The mineral makeup of this specimen seems very different. Also, I've never seen the dimpled texture around the base before, even in horn coral specimens with deteriorated or missing wall structures. One other factor to consider: while it is possible this is glacial deposit (we certainly have our share of that around here), the area where this was found is ancient swamp. I've been scratching my head on this one. I'm not dismissing horn coral as a possibility, but I'm telling you, so far all that has been found at this site is dark soft earth and rib bones (three or four ribs so far). Other glacial material is conspicuously missing. A horn coral here seems out of context. And comparing this specimen in hand, side-by-side to other horn corals, this seems to be more flora than fauna.

I'll do my best to post better pictures. 

[Miocene_Mason]

5 minutes ago, Kevin Carter said:

Thanks for your input. As I mentioned in the description, a horn coral was my first impression too. I've collected many horn corals through the years. Everything I have collected, however, has been calcitic. The mineral makeup of this specimen seems very different. Also, I've never seen the dimpled texture around the base before, even in horn coral specimens with deteriorated or missing wall structures. One other factor to consider: while it is possible this is glacial deposit (we certainly have our share of that around here), the area where this was found is ancient swamp. I've been scratching my head on this one. I'm not dismissing horn coral as a possibility, but I'm telling you, so far all that has been found at this site is dark soft earth and rib bones (three or four ribs so far). Other glacial material is conspicuously missing. A horn coral here seems out of context. And comparing this specimen in hand, side-by-side to other horn corals, this seems to be more flora than fauna.

I'll do my best to post better pictures. 

Well if it is iron it wouldn't be an out of place concretion, bog iron is pretty common. I'm not sure it's not a horn coral yet wither, i see striations on the septa...

[Al Dente]

Here's a Heliophyllum that looks similar, also from Indiana.

[Kane]

It is possible that this is horn coral, but perhaps we need a fully lit image of the "core" to determine if there are septae present.

[Peat Burns]

Hard to be sure from the photos, but it could be a mineral encrusted conifer cone.  Spruce cones (both black spruce and white spruce) are nearly ubiquitous in northern Indiana mastodon sites (although the specimen in question is a bit big for either - I have on rare occasions encountered white pine cones which are much bigger).  I will say, however, that i've never seen a mineral encrusted cone.  Most look and feel more or less like recent ones (until they dry out and start to disintegrate).  I've only worked on one site where bog iron was present, a mammoth site in Shipshewana.  Could it be encrusted with iron deposits?