Can anyone help me identify this plant fossil visible on the surface of this rock? Research has not helped. I am just curious as to what the plant may be and which geological era it comes from. It would be great to find out!
The rock has been in my studio and unfortunately was splashed with ink and paint, so ignore the grey and yellow marks – the fossil appears in the pale grey markings. One of the leaves (?) bottom left is quite visible.
I brought the rock home as I was interested in the sea creature holes on the other side, and only later noticed the markings when I tried to remove the grey circles and the yellow stain.
The rock comes from Motunau beach north of Christchurch, and I attach some information from a really useful book for the uninitiated about the geology of the area which comes from the “Field Guide to NZ Geology” by Jocelyn Thornton.
Celia Wilson 
I do not know exactly what you have on your stone but I did see something very similar on Silurian rocks at Ferriters Cove in Ireland. (See https://natureinfocus.blog/2014/10/07/rocks-at-ferriters-cove-10/). I did wonder after writing the post whether the marks were in fact left by a seaweed drying on the stone surface, where the natural anti-bacterial properties of the algae had “dissolved” the underlying biofilm on the rock surface.
Ah, yes, that is what it probably is! I’ve had another response to an email query saying much the same thing. At least I can say what it is most likely to be. One ‘leaf’ nearby has a hard mineral edge, so I’m still not 100% sure. Thanks for your reply, Jessica.
Celia