What is killing my coneflowers?

Just noticed this a few days ago. Before that they were beautiful. Now they look like they have dried mud on the cones. I know it isn't mud but couldn't find any info from google that matched what I am seeing. Petals and other foliage looked ok at first but are shriveling now too. And new buds are getting it as soon as they open enough to expose the cone. I already cut them all for fear it will spread to other plants but do I need to dig them out completely? Beginning gardener so any help would be appreciated.

Here is another pic.

I do not know if this is what is after your cones but there is a tiny worm, don't know the name, that attacks the cones and eats them leaving a grey /black nasty mess. Look really close to see if you find one. They are hard to see. I would give them a spray of insecticidal soap right on the cones.

I cut all of them off because I have had huge fungus issues this year and was paranoid. I looked pretty close and didn't see any worms but when/if new ones grow this year I will have to take a better look. And spray with lots of neem oil. Thanks.

you may have an infestation of sunflower moth.
From the univ. of michigan:
Sunflower moth (Homoeosoma electellum) is one of the most damaging pests of sunflowers and echinacea. Univ. of Md. Extension officials report the larvae have been identified on echinacea. Female adults lay their eggs at the base of the florets. Early instars feed on pollen and florets. Later instars tunnel into the flower consuming tissue and seed. Larval feeding injury provides sites for fungal disease Rhizopus head rot which can lead to complete loss. Look for tangled mats of webbing on the flowers which are a sign of larval feeding.

cut a flower head in half and look for larvae.

Yep it is the sunflower moth. Thanks for the info. Oddly I have sunflowers right next to the echinacea that are untouched.

EEEEEGad another bug to look out for.