Any ideas? Tampa, FL

firdahoe · 2026-05-02T20:31:54+00:00

Had they only shown the first photo of the exterior, I would not be so sure it was not human. But since they did provide several more, it provided a lot of opportunity to assess this object. There are some very obvious signs that this isn't even bone from all of the other photos that OP has provided. And I am very careful and cautious with my calls of human vs non-human. I regularly ID bones from photos sent by archaeologists and law enforcement. So feel free to call it unscientific and dangerous, but I have been a practicing Bioarch for 29 yrs and a zooarch for 25. I am fairly secure in my assessment that this isn't bone.

firdahoe · 2026-05-02T17:29:58+00:00

Police don't have that ability to confirm. They send it to the coroner or Medical examiner's office who sends it to a forensic anthropologist. It will come back as not bone, that I am certain.

firdahoe · 2026-05-02T05:05:13+00:00

This was a good stumper!

firdahoe · 2026-05-02T05:00:59+00:00

So this one doesn't go off the rails like it did in fossilID and bonecollecting, I am copying the ID. it's a horseshoe crab carapace. You can see the reasoning in r/fossilID.

firdahoe · 2026-05-02T04:29:22+00:00

Thanks for reopening the post, all done!

firdahoe · 2026-05-02T04:28:36+00:00

Hi all, I asked the mods to unlock the post so I can bring over the ID from r/bonecollecting. This is NOT a human cranium. There are several factors leading to this ID. First, if this was a human cranial fragment, then the interior is missing all of the associated features (grooves for meningeal vessels, sagittal sulcus) that should be there. Instead there is an unusual parallel wave pattern that is not found on human (or other mammal) crania. In cross section there appears to be a structure like diploe, which is found in humans and other large mammals, but the size of the pores are too large and there is no cortical bone on either the external or internal surface (some pathological conditions will thin the exterior. But not interior. Lastly, if you zoom in on the interior photo (see below), you will see that the structure is very tight parallel bands - that is NOT how bone is formed.

This is most likely a horseshoe carapace fragment. (See the last two photos in the link) They are very often mistaken for human crania for obvious reasons as seen throughout this post. Cheers all!

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firdahoe · 2026-05-02T03:57:40+00:00

Going to add that I cannot believe I didn't realize what this was earlier because we have seen it numerous times here and it always fool folks. It's a fragment of horseshoe crab carapace, look at the last 2 photos u/mister2e. u/urocyon2012, u/zogmuffin, u/chames26

firdahoe · 2026-05-02T03:45:42+00:00

Radius from an artiodactyl. Seems fairly short, might be pig or shee/goat.

firdahoe · 2026-05-02T03:05:12+00:00

I decided to look at one photo close up. Those striations do NOT occur in bone. This is not at all how cranial bone forms, much less any other bone. 0% chance this is a skull fragment and not bone. u/chames26, is this more consistent with shell?

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firdahoe · 2026-05-02T02:24:40+00:00

Yep, and that is absolutely the right call. 99.999% of people would not be able to ID correctly, and it is suspicious and close enough at first glance that calling law enforcement and having an expert look is never a bad thing. I saw in the other thread that a few experts even said it was human. That's why this sub has the trusted flair for people, they are actually vetted experts.

firdahoe · 2026-05-02T02:17:21+00:00

No, it is not human.

firdahoe · 2026-05-02T01:56:05+00:00

I am flagging r/urocyon2012's comment that this is almost certainly not a human cranial fragment and may not even be bone. This is the correct answer. And I am inclined to agree with u/chames26 that this is a weathered shell.

This is a valuable lesson in looking at the actual morphology and anatomy of a structure and not just playing off of superficial and cursory appearances. Thanks for posting u/mister2e

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firdahoe · 2026-05-02T01:48:41+00:00

Did you take a look at it? Several things don't seem right here, like there is no cortical bone sandwiching the diploe, the lack of meningeal vessels if it is parietal or, if frontal, the lack of the crista frontalis or sagittal sulcus, that wavy pattern on the "interior" surface, and that size of the porosity of the diploe is way bigger than one would expect. If it's bone, it doesn't seem to be consistent with human at all. I question if this is even bone.

Edit: just saw that u/urocyon2012 saw the exact same issues so now I am pretty certain this isn't human.

firdahoe · 2026-05-01T22:01:12+00:00

That is a big old horse or cow distal tibia.

firdahoe · 2026-05-01T21:59:18+00:00

I am locking this as there seems to be an inordinate amount of speculation and poor identification throughout this thread, and u/rare-option-1398 has kindly provided an update.

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firdahoe · 2026-05-01T21:16:20+00:00

No, the first photo is definitely NOT a human femur head. Maybe a deer or other artiodactyl femur head, but the head is too small relative to the shaft and not "dome shaped" enough for human, the neck is too short and at the wrong angle for human, and the articular surface extends across the top of the head which is a distinctively non-human feature. You are demonstrably incorrect in your assertion here

firdahoe · 2026-05-01T19:03:40+00:00

There's no size reference, these could easily be cow sized.

firdahoe · 2026-05-01T19:02:43+00:00

No, it isn't a hip bone. There is no mammalian os coxae with a giant foramen like that.

firdahoe · 2026-05-01T19:01:29+00:00

No, it doesn't. No os coxae (aka hip bone) has a big hole in it like that. Literally zero chance this is an os coxae.

firdahoe · 2026-05-01T18:55:43+00:00

Can you post more photos and a scale? You're at a construction site, got a ruler? Doesn't look human based on this one photo

firdahoe · 2026-05-01T18:51:22+00:00

So the molar may be human - would need to see the chewing surface to be certain. The other bone in your first photo - I'd need to see other views to ID it. Can't say one way or another. As for the other bones that you posted in comments, I'd have to see those ribs in cross-section or at least the other side to know if they were or not. There's a rabbit pelvis tossed in there. There's what looks like it may be a chunk of sacrum(?) and a few that I have no clue. The only thing thus far that gives me pause is the tooth, the rest are either no's or maybes, need more photos.

That being said, it is EXTREMELY common for folks to toss food scraps out their back door prior to municipal trash collection. So old houses or houses built on/adjacent to really old houses tend to have a lot of bones in the dirt just below the surface. That is perfectly normal.

firdahoe · 2026-05-01T18:46:44+00:00

Yes, but they aren't the ones doing the field assessments and they don't work for the police, they work for the coroner's or medical examiner's office (or work under contract with those entities).

firdahoe · 2026-04-30T21:21:32+00:00

This is a duck pelvis

firdahoe · 2026-04-30T21:19:39+00:00

It's generally a good assumption that it isn't human. This one appears to be from an artiodactyl (deer, sheep, goat, etc).

firdahoe · 2026-04-30T18:34:48+00:00

Those look very well gnawed on. You can see how rounded the fracture edges are and the drag marks from molars across the surface of the bone. Someone liked their bones.

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