This week I have a real mystery object for you to try your hand at identifying. It’s from the River Thames and it was found by a strandline archaeologist who shared it with Keith Dunmall (who is a Youth Engagement Manager at @WaterAidUK) during a planning meeting for @Thamestidefest.
Keith shared it on Twitter looking for an identification, and he kindly sent me some extra pics:
Do you have any idea what this might be?
No need for cryptic clues, I think this one may be tricky enough to be enough of a challenge as it is!
Have fun!
Zygoma 
Petrified lamprey head?
Or perhaps a breast bone, which might make more sense, but still not enough to satisfy.
Synsacrum it is, then.
It looks like a centreline structure bearing tooth sockets. Such as found in some fish. Like a vomer of glossohyal.. I don’t think I’ll have time to compare to known examples but it will be interesting to see what species it comes out as (from memory it doesn’t look like Salomon or Pike but it seems to be about the right size for those.)
Bone comb spine remains. No idea what bone it is though.
At first glance, I thought coral. Then I considered a jawbone – it looks alveolar, and has what looks like teeth sockets. But the flip side has me stymied – parts are broken off that look like that could be spines? I like Richard and Palfryman’s suggestions that it is from a sea creature, and (don’t laugh), but I thought of a baby Kronosaurus.
I like the suggestions below for a synsacrum, and there is a very interesting article about tailbones called “From dinosaur to bird”, with some images of pygostyles and caudal bones that look like the image above. Seabirds, in particular, have very long, straight pygostyles.
I think it’s the synsacrum of a bird, without the ilia fused – the foramina are for spinal nerves.
A-ha! Brilliant thought.
certainly looks porous like a bone, but my first thought (mostly from the 2nd picture) was the peduncle or central rib of a pinecone after all the scales are removed. can i 2nd DrewM’s guess?
How about a synsacrum with all the delicate parts broken off?
Another vote for synsacrum. I wouldn’t guess species from pictures alone, but if you can find butchery marks you can narrow it down a bit.
Pretty sure it’s a biro.
As Freyman states, it’s a synsacrum. The top image appears to be a left lateral view, and the curved surface one might construe as a lingual margin if a mandible is actually a ventral feature.