Roy both U. henkeli and U. sikorae have the 'frill' along the entire body. Depending on the health of the animal, and the activity time, humidity, etc. the dermal flap may or may not be more or less noticeable.
Here's a dermal flap on a U. sikorae, and in fact, I find that my U. sikorae have more pronounced dermal flaps most of the time than the U. henkeli ( which tends to tuck under more)

Andrew Gilpin