Becaus its in the same Terrapene-carolina group its not called hybrids but intergrades, and very difficult
to see the distinction, i don't believe there are dominant characters with hybrides/or intergrades, each animal is uniek.
Its more a case of not seeing all characters a specie have in 1 turtle, and still very difficult, this makes it so important to not cross breed.
Its mutch easier to see difference from a hybride in stead of a intergrade.
Intergrades between T cc, T cm and T ct are never 100 % clear combination with T cb is sometimes more clear.
And don't forget hybrids and intergrades are both found in nature too
Some people believe T c major is a cross between ancient T putnami and T cb, T ct and Tcc but no evidence of this is found.
Although you can see colour variation in T c major depending on the area were the naturally occour.
I understand your using of intergrades terms... As the same meaning of subspecific hybrids !!!
But, you're right, using this term avoids any confusion...
Following your answer, some authors think that the actual terrapene carolina subspecies issued from two distinct lineages and , because of some evident reasons:
- differences of cranial distinctions.
- different mating behavior (T c major are more agressive and some are killers of other males ! T c triunguis are very tolerant...)
- different adaptations ( T c major are more aquatic, T c t and T c c are more terrestrial)
- not clear intergrading zones between T c major and T c triunguis, because of their different lifetyles...
So that, these authors argued the splitting of two distincts groups, or species:
- Terrapene major, with two subspecies: T m major & T m bauri...
- Terrapene carolina, with two subspecies: T c carolina and T c triunguis...
I don't have the papers at now about T c mexicana and T c yucatana status...
What would your opinion be about these author's reflexions?