Sunday, 15 December 2024

Prehistoric Mammal Discoveries 2024

Zalamdalestes
I have reached the end of another year and that means it's time for what has become a tradition on this blog over the last eight years: a look back at some of the discoveries about fossil mammals made in 2024 that didn't make into the regular posts. As usual, this will be a quick whistle-stop tour of mammalian palaeontology, hopefully focusing on some of the more interesting findings. Like any field of science, it has not been standing still.

Large Herbivores

Woolly mammoths (Mammuthus primigenius) are among the best-known of all prehistorical mammals to the general public and, aided by the fact that some lived recently enough to be preserved in permafrost, they are also amongst the best-studied. But there is still more to learn about the details of their lives and habits. A study published this year looked at the detailed isotopic composition of a fossil mammoth that had died about 12,000 BC in Alaska, showing that she was female, and had migrated over 1000 km (600 miles) during her lifetime, having originally been born in the Yukon. The area in which she died was popular with mammoths, but also with humans - she may have died peacefully, but the presence of people where mammoths congregated may not be a coincidence.

Sunday, 8 December 2024

Ancient Parrot-Beasts of Canada

Psittacotherium
Over 90% of living mammal species are placentals - that is, not marsupials or monotremes. The placentals can, using modern genetic data, be divided into four main groups, two of which originated in the Northern Hemisphere, and two in the southern. Naturally, when we look at unusual fossils for which we have no genetic data, it gets harder to figure out where in the family tree they might be placed. It's not always even obvious whether some of the early fossils are of placental mammals at all.

Such is the case with the taeniodonts. These were first identified as a distinct group of fossil mammals in 1876 by Edward Drinker Cope, so we've known about them for a long time. He placed them, based on perceived similarities to hedgehogs, as a suborder of the larger group then called the Insectivora. It eventually became clear that this wasn't valid, not least because "Insectivora" was one of the orders that had to be scrapped once we began to use genetic data to uncover deeper evolutionary relationships.