Oxford Ragwort on Sand Dunes

When I saw these flowers I could not think what they were. Even now I am not absolutely certain. They looked familiar but not quite right. Poring over different sources of identification, I believe they are Oxford Ragwort (Senecio squalidus) rather than Common Ragwort (Senecio jacobaea) based on the sprawling growth habit instead of upright stems, and the shape of the leaves which are pinnate with a pointed end lobe compared with the common sort that has a rounded end lobe. If this is correct, I don’t understand how the plant is growing on a sand dune in Swansea Bay. The species is more characteristic of disturbed ground and often appears along railway tracks, verges, and waste ground.

If it isn’t the species I have suggested, perhaps someone would like to correct me?