That does look like an interesting find, unusual for the Tees though. Did it look like it belonged there? I’ll have to check at work tomorrow, but it looks like it might be a juvenile erithacus, or part of at least. How big is the rock?
Found this on the banks of the upper Tees yesterday while out walking with my sons. The rock appears to be sedimentary and the ‘fossil’ is around 4″ in length. We often find small fossils up this way but this one is far bigger and as there is no other bone structures visible, I couldn’t make out what it may have been other than maybe vertebrae?