>> An incomplete cranium. That’s it? How do they know it was reptilian? <<
It’s not. It’s mammalian. Mammals and their branch of the amniote* tree have one hole on each side of their jaw, allowing jaw muscles to slip through the hole, creating the ability to move the jaw side to side, thus allowing mammals to chew food much better.
Not sure why they call it “reptile-like,” since they seem to suggest it was hairy and suckled its young.
*amniotes include mammals, birds and what you probably learned to call reptiles. Although now, the reptiles on the mammalian side, which are all extinct, are called “synapsids,” referring to this jaw structure.
I totally agree. Based on the evidence around 2014, I thought this debate was over. The new findings in this article show nothing new to prove 'reptilian'. They just seem to still be calling them reptilian-mammals.
In fact, I actually found one of those old articles with a pretty solid reply that it is mammal: “For decades, scientists have been debating whether the extinct group, called Haramiyida, belongs within or outside of Mammalia,” said co-author Jin Meng, a curator in the Museum’s Division of Paleontology. “Previously, everything we knew about these animals was based on fragmented jaws and isolated teeth. But the new specimens we discovered are extremely well preserved. And based on these fossils, we now have a good idea of what these animals really looked like, which confirms that they are, indeed, mammals.”
https://sciworthy.com/early-mammals-diverged-from-reptiles-much-earlier-than-thought-in-the-late-triassic/