Prehistoric Mammal Discoveries 2025

Computer reconstruction of the skeleton of the Miocene
 right whale Megabalaena, published this year

As another year draws to a close, it's time to take another dash through the mammalian palaeontological findings of the last twelve months. As always, this will be a rapid survey of some discoveries that I find particularly interesting without any detailed discussion, but hopefully covering as wide a range of prehistoric mammals as I can.

Large Herbivores

Land mammals don't come much larger than mammoths, and such animals, and their mastodon relatives, have shaped the world around them through their mere presence and the food they chose to eat. A study on southern mammoths (Mammuthus meridionalis) uncovered at a million-year-old site in northern Spain showed that the climate at the time was already Mediterranean, a warm gap within the Ice Ages, causing them to feed more on grasslands than trees. While hyenas had fed on some of the carcasses, they were not alone, as the evidence also shows clear signs of butchering with stone tools.

Age of Mammals: The Eocene (Pt 1)

When Scottish geologist Charles Lyell first created the system of epochs we now use for dividing the Age of Mammals, he designated four of them. This was in 1833, so he did not know the true age of the Earth, let alone the timespans of the epochs he was naming - he was basing them purely on geological strata and the types of fossil seashells found within them. We now know, however, thanks to the wonders of radiometric dating techniques, that the oldest of the four epochs he defined spanned over half of the Age of Mammals, longer than the other three put together.

Two epochs have been carved out at either end since, so the Eocene is not quite as long now as it was when Lyell named it. However, it remains the longest of the seven epochs since the extinction of the non-avian dinosaurs, still occupying a third of that entire stretch. As currently defined, it runs from 56 to 34 million years ago. Compared with the entire age of the Earth, that's not very much, but from the point of view of most mammalian palaeontology, that's unusually long.