Scarlet or Ruby Elfcup
These have never failed to appear in my wood each year. However, I have never come across them in December, so quite early this year probably as a result of the warmer weather and relentless rain!
They always seem to favour fallen branches of either Hazel, or in this case Oak, and always growing out of Moss.
Of the two species, Sarcoscypha austriaca is now thought to be the commoner of the two.
However under the microscope these lacked the coiled surface hairs so are Sarcoscypha coccinea - The Ruby Elfcup.