Unusual Mutations: Animals With Extra Limbs
Polymelia is the growth of one or more limbs beyond a species’ normal set. In animals it arises mainly three ways: a parasite that scrambles limb-bud signaling, as Ribeiroia ondatrae does in frogs; incomplete conjoined twinning in mammals; and atypical regeneration after injury, as in branch-armed octopuses. Published: June 5, 2026. Last reviewed: June 5, […]
The Deep-Sea Unknown Off Japan: An Animalia Incertae Sedis Filmed at Depth
By Dr. Wren Ashby · Published May 13, 2026 · Updated May 13, 2026 In April 2026, a paper in Biodiversity Data Journal described a small, pale, bilaterally symmetrical organism that had been filmed gliding above the floor of the Ryukyu Trench at roughly 9,130 meters [1]. The authors, working with the Minderoo-UWA Deep-Sea Research […]
The Curious Case of Two-Headed Snakes
By Dr. Wren Ashby · Published May 7, 2026 · Updated May 13, 2026 The Curious Case of Two-Headed Snakes A two-headed snake is the most photogenic answer to a quiet embryological question: what happens when a single embryo begins to twin and then changes its mind. The condition is called bicephaly, or more precisely […]