I have been researching the question. Todays standard for the American dominique has a rose combs. Some flocks carry the allele for strait (tall single) comb at a low frequency. The single comb is recessive so in flocks where allele is rare, birds within same flock that homozygous and thus exhibit the trait are even more rare.
Some folks do not distinguish between American dominiques and barred plymouth rocks, the latter has a straight comb, even though the two breeds differ noticeably for several other characters.
One of the hatcheries I acquired dominique chicks from had about 10% strait combs and a characteristic of feather development that makes me think they have a considerable amount of barred plymouth rock. What you are looking at may be of similar origin.
Honestly, I think it's just someone who thinks Barred Rocks and Dominiques are the same thing.
Single combs usually mean a Barred Rock, Rose Combs mean a Dominique. And if you're NOT looking at hatchery stock birds, there's a huge bodily difference too, but with hatchery stock - The comb is the only difference, sadly.
I raise heirloom dominiques...they are all offspring from my grandpa's flock from back in the 1940's. I also raise and show Bantam doms
Phenominal breed, one of many old American breeds who have "stood the test of time". I've never had a single comb bird come from my flock, so everyone is correct assuming barred rock...they look very similar.
The question was is there more than one Dominique and to yes there is more than one Dominique BUT the American Dominique comes only Rose Comb..
There is a Dom or Dominique pattern that you can find on some breeds of game fowl and the Dom pattern on game fowl has been around longer then the American Dominique and Barred Rock Breed.
At least four more breeds have the dom / cuckoo / hawk color pattern. American barred holland, California grey, cuckoo marans and the Scottish grey that was around at and likely before the establishment of the American dominique. Latter like dom colored gamefowl is one of possible progenitors of the American dominique. The Europeans also have a derivative of our American dominique that to me appears to have infusion of one of the heavier Asian game breeds. Rose comb is most obvious difference setting present day American dominique apart but there are other characters as well.