"Researchers with the National Oceanic and Atmospheric Administration believe they have identified a new species of whale in the Gulf of Mexico. The Rice's whale is a filter feeder that can grow to 42 feet. It's also critically endangered. There are believed to be fewer than 100 of them left.
It was only in the 1990s that scientists first determined that a small whale population was living in the northeastern Gulf of Mexico year-round. Marine biologists thought they were Bryde's (pronounced "broodus") whales, members of a species that lives in warm waters around the world.
Patricia Rosel, a research geneticist with NOAA Fisheries, says, "The first clue we had that there might be something unique, really more unique about them came from genetic data we collected in the mid-2000s, 15 years ago."
That genetic data suggested this was a new species. To confirm that, Rosel and her colleagues needed morphological data — information showing that the skulls of the whales in the Gulf were different from those of their close relatives. They finally got that in 2019 when a whale was stranded in southwest Florida."