A toothless whale with no baleen

[Halichoeres]

Check out Maiabalaena, a stem-mysticete from the Oligocene of Oregon. This is clearly related to the baleen whales, having lost its teeth, but shows no evidence of baleen yet either. Pretty great transitional fossil. It would have been a good suction feeder but not as efficient as its later relatives once they had evolved baleen. The fossil was discovered decades ago, but only recently properly prepared and scanned to be sure it couldn't have carried baleen.




a reconstruction by Alex Boersma

Paper (open access): https://www.cell.com/current-biology/fulltext/S0960-9822(18)31414-3

And a write-up at phys.org: https://phys.org/news/2018-11-whales-lost-teeth-evolving-hair-like.html