The genus Ctenosaura, commonly known as the Spiny-tailed or Black Iguanas, is comprised of 17 distinct species which are divided into three subgenera. Ctenosaura palearis, along with C. melanosterna, C. bakeri, and C. oedirhina, belongs to the subgenus Loganiosaura. These four species occur along the Caribbean versant of Honduras and Guatemala and on the Honduran Bay Islands. Along with a number of morphological characters, what these species share in common is their status as Critically Endangered on the Red List of the IUCN.
C. palearis, C. bakeri, C. melanosterna, and C. oedirhina are all medium sized Spiny-tailed Iguanas attaining a maximum total length of 80 cm. Of these species, C. bakeri, C. melanosterna and C. palearis have a well-developed pendulous dewlap, while C. oedirhina has a transverse gular fold. C. bakeri, C. melanosterna and C. palearis also have long spade-shaped dorsal spines, which are often held flat against the body, giving them a somewhat rakish appearance. All four species differ from other ctenosaurs in several skull characters, which reinforces the view that this group is monophyletic, i.e. descended from a single common ancestor.