Why do fish have vertical tail fins and whales have horizontal ones? - BBC Science Focus Magazine

News - World Cetacean Alliance

Why do aquatic mammals like dolphins and whales have horizontally oriented tail fins while fish have vertically oriented ones? - Quora

Ask Dr. Universe: Evolution gave marine mammals horizontal tails

Why do whale and dolphin tails go up and down? - Whale & Dolphin Conservation USA

the History of Ichthyosaurs Discovery

All Fish Have Vertical Tails While All Whales Have Horizontal Tails. Why?

the History of Ichthyosaurs Discovery

Biodiversity & Ecosystem Dynamics – Marine Education and Research Society

Fish BBC Science Focus Magazine

3sc, Author at Current Conservation

All Fish Have Vertical Tails While All Whales Have Horizontal Tails. Why?

science based - Is it more likely that merfolk would evolve with horizontal or vertical tails? - Worldbuilding Stack Exchange

Why do aquatic mammals like dolphins and whales have horizontally oriented tail fins while fish have vertically oriented ones? - Quora

Why orcas are more 'caring' than 'killer' whales - BBC Science Focus Magazine

zoology - Why is there a difference in the rotation of the tail fin in fish compared to marine mammals? - Biology Stack Exchange