The females of most species are brightly colored with six prominent spines on their broad, hardened, shell-like abdomens.

[10] Gasteracantha has a complex taxonomic history, and many questions of species limits and distribution and generic interrelationships remain unanswered.

Furthermore, challenges include the variability within individual Gasteracantha species (e.g., color polymorphism and variable length and shape of spines), a lack of male specimens and descriptions for many species, missing or damaged type specimens, and ambiguous initial descriptions in 18th- and 19th-century scientific literature.

[11] The 69 species currently recognized by World Spider Catalog include dozens of synonyms and subspecies, many based on literature well over 100 years old.

[1] A 2019 study examining three mitochondrial and two nuclear genes found that Gasteracantha is paraphyletic with respect to Macracantha, Actinacantha, and Thelacantha.