A Barasaurus besairiei fossil from Madagascar. Barasaurus was a procolophonoid parareptile which lived during the Late Permian and Early Triassic periods.
This is only a small, partial specimen consisting of some vertebrae and ribs (the ribs are mostly imprints), but given even partial skeletons sell for several hundred pounds, this is a super cheap specimen! Comes labelled and stored in an acrylic case with padding.
23mm (whole piece at longest length)
250 - 255 million years (Late Permian/Early Triassic)