Over the course of evolution, the digestive tract across diverse species has evolved to adapt to different habitats and diets. Leucoraja erinacea, or the little skate, distinguishes itself from other vertebrates by its spiral-shaped intestine. The spiral develops by an inner fold that elongates and rotates into a right-hand helix. This ancestral shape, unique to all basal fishes, increases the absorptive surface area while fitting into the tight abdominal spaces of skates, sharks, and rays. Previous work from our lab showed that the spiral is initiated by an asymmetric growth into the lumen. To determine the mechanism of initiation, I addressed how cell shape, polarity, and proliferation play a role in initiating spiral formation by breaking organ symmetry. Here we show that there is an increase in cell proliferation on the left side of the mesenchyme prior to the break in symmetry. Once the spiral fold has begun to form, significant differences in cell shape and organization appear between the left and right mesenchyme. During this time, the epithelial endoderm becomes polarized. This leads to the question: how do cellular mechanisms, such as cell signaling, determine these highly conserved behaviors of the cells? Our results further demonstrate that Nodal cell signaling is necessary for initiating asymmetry, indicating that cell changes are predetermined prior to break in symmetry. The spiral intestine not only helps us uncover the evolutionary origins of our long, coiled intestine but it also provides us an opportunity to better understand the fundamentals of how organs gain their shapes.