'It seems that size really does matter': Males of 4 never-before-seen tarantula species have record-long genitalia [View all]

https://www.livescience.com/animals/spiders/it-seems-that-size-really-does-matter-males-of-4-never-before-seen-tarantula-species-have-record-long-genitalia

The males of four newfound tarantula species have extremely long genitalia so that they can keep their distance from aggressive females during mating, researchers say.

Scientists have had to create an entirely new spider genus after four new tarantula species were found to have such long genitalia that they couldn't fit into any pre-existing category.

Male tarantulas' genitals are typically 1.5 to two times the length of their head and thorax put together. But the newfound spiders' palps — specialized appendages to transfer sperm during mating — are four times as long as their upper bodies and almost half as long as their longest legs, according to a new study.

These tarantulas occur in the Arabian Peninsula and the Horn of Africa, and are typically found in burrows and rock crevices.