Since photographing, we think we've identified the smaller item in the foreground, as a part broken from a fossilised heart urchin. The regular row of 'dots' is seen at the ends of the 'arms' of urchin fossils.
Could the larger item in the background be the outer part of an ammonite, as its shape is an arc, but the end facing the camera is strange, - having distinct 'lumps' as if thinner protusions have been broken off.
The big specimen is definitely an ammonite. The lumps you refer to reflect the shape of the septa (the dividing walls between chambers). Septa are often wavy or can be very intricately curved in 3D. In your specimen, some of the 'tops' of those undulations appear to have been broken off.
Not sure about your putative heart urchin; let's see if somebody else comments on that...
Location and other information about where you found it might help.