The reproductive tract is a key structure in vertebrate anatomy, and its development and differentiation has been studied in detail in bony model organisms like mice and zebrafish. In mammals and birds, reproductive development begins with an undifferentiated gonad and two sets of ducts, the Wolffian ducts and the Müllerian ducts. In males, the Wolffian duct goes on to form the male reproductive tract while the Müllerian duct degenerates; in females, the opposite happens. In bony fishes, like the zebrafish, a completely new duct forms to carry sperm or egg out of the body. However, reproductive tract development in non-bony vertebrate groups remains unclear and we know little about its development and the timing of male and female differentiation. Cartilaginous fishes, including sharks, skates, and rays, are useful for studying the evolution of development because they diverged from bony vertebrates over 400 million years ago, and their developmental patterns can give insight into the diversity of vertebrate reproductive structures. To compare reproductive tract development in cartilaginous fishes with other vertebrates, we studied the little skate (Leucoraja erinacea). Skates are oviparous (egg-laying) and are easy to obtain at different developmental stages. We investigated the reproductive tract by performing histological sectioning and Masson’s trichrome staining from the first emergence of the gonad to hatching. We compared males and females and, identified reproductive structures including the indifferent gonads, differentiated ovaries and testes, oviducts, cloaca, ductus deferens, and urogenital sinus. We found that in the skate, reproductive tract development is more similar to mammals and birds than to bony fishes like zebrafish, suggesting that this dual duct system is ancestral for jawed vertebrates. Our results can give evolutionary insight into how this fundamental anatomical structure diverged across vertebrates.