Theraphosinae

Theraphosinae is the largest subfamily of New World tarantulas, containing roughly half of all known tarantula species and dozens of genera spread across North, Central and South America. These spiders are primarily ground-dwelling and are best known for their urticating hairs, a defensive feature that likely helped drive their evolutionary success.

The group’s taxonomic story starts in the early 1800s, when large South American species were described under the genus Theraphosa (now famous for giants like the Goliath birdeater). Theraphosa was established in the 19th century and later fixed as the type genus for the family Theraphosidae, anchoring the modern concept of “tarantulas.”

Throughout the late 19th and 20th centuries, collectors and arachnologists working across the Americas described a steady stream of new genera such as Aphonopelma, Brachypelma, Grammostola, Lasiodora, Pamphobeteus, Nhandu and many others. Early systematics relied almost entirely on external morphology—body shape, spines, and mating organs—so genera were often split or created based on a few visible traits. As a result, Theraphosinae accumulated many small or monotypic genera over time.

A major turning point came in the 1980s–1990s, when detailed cladistic work (especially by Pérez-Miles and collaborators) re-evaluated Theraphosinae using shared derived characters and produced the first robust, character-based framework for the subfamily. In the last decade, large molecular and phylogenomic studies have refined this picture, confirming Theraphosinae as a natural (monophyletic) group and revealing deeper relationships between its genera. Some well-known genera, including Brachypelma and Aphonopelma, have been shown to be non-monophyletic and have been split or re-defined accordingly.

Today, Theraphosinae is recognized as a diverse radiation of mostly terrestrial American tarantulas characterized by urticating setae, robust bodies, and a wide range of sizes and colors. The subfamily currently includes more than 60 valid genera—from iconic hobby staples to tiny range-restricted species—with new species and occasional new genera still being described as genetic tools reveal hidden diversity.